Short-term cardiorespiratory adaptation to high altitude in children compared with adults.

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Kriemler, S; Radtke, T; Bürgi, F; Lambrecht, J; Zehnder, M; Brunner-La Rocca, H P

2016-02-01

As short-term cardiorespiratory adaptation to high altitude (HA) exposure has not yet been studied in children, we assessed acute mountain sickness (AMS), hypoxic ventilatory response (HVR) at rest and maximal exercise capacity (CPET) at low altitude (LA) and HA in pre-pubertal children and their fathers. Twenty father-child pairs (11 ± 1 years and 44 ± 4 years) were tested at LA (450 m) and HA (3450 m) at days 1, 2, and 3 after fast ascent (HA1/2/3). HVR was measured at rest and CPET was performed on a cycle ergometer. AMS severity was mild to moderate with no differences between generations. HVR was higher in children than adults at LA and increased at HA similarly in both groups. Peak oxygen uptake (VO2 peak) relative to body weight was similar in children and adults at LA and decreased significantly by 20% in both groups at HA; maximal heart rate did not change at HA in children while it decreased by 16% in adults (P < 0.001). Changes in HVR and VO2 peak from LA to HA were correlated among the biological child-father pairs. In conclusion, cardiorespiratory adaptation to altitude seems to be at least partly hereditary. Even though children and their fathers lose similar fractions of aerobic capacity going to high altitude, the mechanisms might be different. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Physical fitness differences of students with different cardiorespiratory endurance levels

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Stojanović Darko

2016-01-01

Full Text Available In order to determine physical fitness differences in students with different cardiorespiratory endurance levels, a study was conducted on a sample of students of the Faculty of Sport and Physical Education at the University of Nis. The sample was divided into two subsamples, where the first subsample comprised 27 female students and the other 35 male students. Physical fitness was assessed using eight tests from the Eurofit battery of tests: the single-leg balance test - for the assessment of general balance, plate tapping - for the assessment of speed of movement, sit-and-reach - for the assessment of flexibility, the standing broad jump - for the assessment of explosive strength, the handgrip test - for the assessment of static strength, sit-ups - for the assessment of repetitive trunk strength, the bent arm hang - for the assessment of muscular endurance and the 10x5 meter shuttle run - for the assessment of the speed/agility. Cardiorespiratory endurance was estimated with the aid of 20 m endurance shuttle-run test. Based on the level of cardiorespiratory endurance, the participants in each subsample, were divided into three groups using a cluster analysis: high (VKRI, average (PKRI and low level (NKRI. The physical fitness differences of students with different cardiorespiratory endurance levels were calculated using the one-way analysis of variance. The results showed that there were no differences in physical fitness of students with different cardiorespiratory endurance levels. Based on the results it can be concluded that the level of cardiorespiratory endurance does not affect the components of physical fitness among students of both sexes.

Cardiorespiratory Fitness and Blood Pressure: A Longitudinal Analysis.

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Agostinis-Sobrinho, César; Ruiz, Jonatan R; Moreira, Carla; Abreu, Sandra; Lopes, Luís; Oliveira-Santos, José; Mota, Jorge; Santos, Rute

2018-01-01

To examine the association between cardiorespiratory fitness and cardiovascular indices 2 years later, and to determine whether changes in cardiorespiratory fitness are associated with cardiovascular indices at a 2-year follow-up in adolescents. The sample comprised 734 adolescents (349 girls) aged 12-18 years followed for 3 years from the LabMed Physical Activity Study. Cardiorespiratory fitness was assessed by the 20-meter shuttle run test. Height, weight, waist circumference, and resting blood pressure (BP) were measured according to standard procedures. Regression analyses showed a significant inverse association between cardiorespiratory fitness at baseline and systolic BP (B = -0.126; P = .047) and rate pressure product (B = -29.94; P = .016), at follow-up after adjustments for age, sex, height, pubertal stage, socioeconomic status, and waist circumference. Significant differences were found between cardiorespiratory fitness groups (fit vs unfit) at baseline and systolic BP and rate pressure product at follow-up (P fitness changes and systolic BP (P = .024) and rate pressure product (P = .014), after adjustment for age, sex, height, pubertal status, socioeconomic status, and waist circumference. Changes in cardiorespiratory fitness during adolescence were associated with cardiovascular indices over a 2-year period. Adolescents with persistently low levels of cardiorespiratory fitness exhibited the highest levels of systolic BP and rate pressure product. Copyright © 2017 Elsevier Inc. All rights reserved.

A 24-h assessment of physical activity and cardio-respiratory fitness among female hospital cleaners

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Larsen, Mette Korshøj; Krustrup, Peter; Jespersen, Tobias

2013-01-01

measured. The methods were feasible for the objective 24-h sampling of physical activity and cardio-respiratory fitness among cleaners. Measurements showed that the cleaners walked 20,198 ± 4,627 steps per day. During working hours, the average cardio-respiratory load was 25 ± 6% of heart rate reserve (HRR......). The cleaners had a low estimated cardio-respiratory fitness (34 mlO2/kg/min), a high BMI (50%, >25 kg/m(2)) and blood pressure (50%, >120/>80 mmHg). The high amount of steps, the relatively high cardiovascular load at work and low cardio-respiratory fitness illustrate the need for further investigation...... of the relationship between physical activity at work and in leisure, and cardiovascular health in this population. Practitioner Summary: This study evaluated the feasibility of methods for objective 24-h sampling of physical activity among cleaners; the methods used were found to be feasible. The cleaners had a high...

Effects of preoperative carprofen on cardio-respiratory, hormonal and metabolic stress response in calves during umbilical surgery under isoflurane inhalation anaesthesia.

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Schulze, I; Poos, E M; Meyer, H; List, A K; Kaestner, S B R; Rehage, J

2016-10-01

The aim of this study was to examine the effects of preoperative carprofen on the cardiorespiratory, hormonal and metabolic stress response during umbilical surgery under isoflurane anaesthesia combined with local anaesthesia, in calves. A randomised, blinded experimental study was conducted in 24 calves. Carprofen (n = 12; 1.4 mg/kg) or physiological saline solution (controls; n = 12) was administered 1 h prior to surgery. Anaesthesia was induced with xylazine (0.1 mg/kg, IM) and, after the onset of sedation (i.e. after 5-8 min), ketamine was administered (2 mg/kg, IV). Anaesthesia was then maintained with isoflurane (ISO) in oxygen to effect and completed by infiltration of the incision line with 20 mL of 2% procaine. Cardiorespiratory, endocrine and metabolic parameters were examined before, during and after surgery at short intervals. In both groups, anaesthesia appeared adequate for the surgical intervention. Heart rate, stroke index and arterial blood pressure were significantly elevated after the onset of surgery. Oxygen partial pressure and oxygen delivery increased, while the oxygen extraction ratio decreased intraoperatively, ensuring sufficient oxygen supply. In the control group, the mean surge in serum cortisol concentrations tended to be higher (P = 0.089) and systemic vascular resistance (SVR) was significantly greater (P carprofen group during surgery. In conclusion, the anaesthetic protocol used in this study induced reliable analgesia in both groups. The lower serum cortisol levels and SVR may indicate a reduced surgical stress response in calves undergoing umbilical surgery under ISO anaesthesia after administering carprofen preoperatively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Information transfer and information modification to identify the structure of cardiovascular and cardiorespiratory networks.

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Faes, Luca; Nollo, Giandomenico; Krohova, Jana; Czippelova, Barbora; Turianikova, Zuzana; Javorka, Michal

2017-07-01

To fully elucidate the complex physiological mechanisms underlying the short-term autonomic regulation of heart period (H), systolic and diastolic arterial pressure (S, D) and respiratory (R) variability, the joint dynamics of these variables need to be explored using multivariate time series analysis. This study proposes the utilization of information-theoretic measures to measure causal interactions between nodes of the cardiovascular/cardiorespiratory network and to assess the nature (synergistic or redundant) of these directed interactions. Indexes of information transfer and information modification are extracted from the H, S, D and R series measured from healthy subjects in a resting state and during postural stress. Computations are performed in the framework of multivariate linear regression, using bootstrap techniques to assess on a single-subject basis the statistical significance of each measure and of its transitions across conditions. We find patterns of information transfer and modification which are related to specific cardiovascular and cardiorespiratory mechanisms in resting conditions and to their modification induced by the orthostatic stress.

Cardio-respiratory response of young adult Indian male subjects to stress: Effects of progressive muscle relaxation

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Arunima Chaudhuri

2014-01-01

Full Text Available Background: Stress and anxiety have become an integral part of our lives. Of late, this has resulted in the increase in incidence of hypertension and coronary heart disease. Objectives: To assess the effect of progressive muscle relaxation (PMR on young adult males and its role in the modulation of cardio-respiratory response on exposure to stress. Materials and Methods: This prospective cross-sectional study was conducted in a tertiary care referral hospital. Undergraduate male students under stress were chosen for the study. Fasting blood samples were drawn to analyze sugar and lipid profile, followed by anthropometric measurements and ECG. In the resting condition, blood pressure, pulse rate, and spirometric parameters; forced vital capacities (FVC, and forced expiratory volume in 1 sec (FEV 1 % were measured. Then, they were made to exercise with bicycle ergometer and post exercise, the vital parameters were recorded. All subjects were given a training of Jacobson′s Progressive Muscular Relaxation and asked to practice this technique for 3 months. All parameters were re-evaluated. Results: Significant decreases in resting heart rate, systolic blood pressure and diastolic blood pressure, total cholesterol, triglyceride, and low density lipoprotein (LDL cholesterol levels of subjects were seen after PMR training. Exercise-induced rise in heart rate and blood pressure were also significantly less in subjects following PMR training. Conclusion: Progressive muscle relaxation helps in modulation of heart rate, blood pressure, and lipid profile in healthy normal adult male individuals.

INFLUENCE OF PHYSICAL TRAINING ON CARDIORESPIRATORY ENDURANCE IN PREADOLESCENT AGE

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Marjan Marinkovic

2009-01-01

Full Text Available Cardiorespiratory or aerobic endurance is the ability of the whole body to sustain physical activity for an extended period of time, involving relatively large groups of muscles. The attitudes on the possible impact of training on cardiorespiratory endurance in preadolescents are contradictory. Our study enrolled 195 boys aged 11 to 12 years. Experimental group (n=92 consisted of the children who had been involved with planned and programmed water polo training for at least two years. Control group (n=103 consisted of schoolchildren who only had had regular physical education in schools. Our investigation protocol included standardized anthropometric measurements and tests, performed respecting the appropriate protocols. Statistical analysis of the results demonstrated that there were no significant differences in age and relative values of oxygen consumption (VO2peak. Body height and mass, as well as the skinfold thickness, were significantly higher in experimental group subjects. The values of absolute VO2peak, FVC and FEV1.0 were also significantly higher in the examinees involved with water polo training. These findings stress the importance of a systematic training process even in this early period of growth and development in order for the trainees to acquire important functional advantages. We believe that a properly planned and programmed physical training can significantly contribute to the development of cardiorespiratory endurance even as early as preadolescent age.

Hormonal, metabolic, and cardiorespiratory responses of young and adult athletes to a single session of high-intensity cycle exercise.

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Engel, Florian; Härtel, Sascha; Wagner, Matthias Oliver; Strahler, Jana; Bös, Klaus; Sperlich, Billy

2014-11-01

This study aimed to determine the effects of a single high-intensity interval training (HIIT) session on salivary cortisol (SC) levels, physiological responses, and performance in trained boys and men. Twenty-three boys (11.5 ± 0.8 years) and 25 men (29.7 ± 4.6 years) performed HIIT (4 consecutive Wingate Anaerobic Tests). SC in boys and men increased after HIIT from 5.55 ± 3.3 nmol/l to 15.13 ± 9.7 nmol/l (+173%) and from 7.07 ± 4.7 nmol/l to 19.19 ± 12.7 nmol/l (+171%), respectively (p HIIT, mean heart rates in boys were higher (p HIIT in young athletes is associated with a higher activation of the hormonal stress axis than other types of exercise regimes as described in the literature. This study is the first to show a pronounced SC increase to HIIT in trained boys accompanied by elevated levels of blood lactate concentrations and heart rate suggesting a high cardio-respiratory, metabolic, and hormonal response to HIIT in 11-year-old boys.

Comparison of cardiorespiratory responses between Surya Namaskar and bicycle exercise at similar energy expenditure level.

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Sinha, Biswajit; Sinha, Tulika Dasgupta; Pathak, Anjana; Tomer, O S

2013-01-01

Surya Namaskar (SN), a popular traditional Indian yogic practice called "Sun Salutations", includes practice of twelve physical postures involving alternate backward bending and forward bending postures. The practice of twelve postures in succession makes one round of its practice. Many people practise it as part of their daily physical fitness regimen. No study is available to compare cardiorespiratory responses of SN with bicycle exercise (BE). 20 healthy Yoga instructors practicing various Yogic practices including SN since last 7-8 years participated in the study. They performed SN in the laboratory according to their customary daily practice routine. The subject also performed incremental load bicycle exercise test till exhaustion on their second visit for measuring their VO2 max. SN and BE were compared at three similar exercise intensity levels in terms of % of VO2 max. The exercise intensities were light (10-20% VO2 max), moderate (21-40% VO2 max) and high intensities (41-50% VO2 max). Heart rate at high work intensity was significantly higher in BE than SN (P < .001). Ventilation and carbon dioxide output were significantly higher in BE than SN at high exercise intensity (P < 0.001). Overall, cardiorespiratory stress is less in SN than BE at similar work intensities.

Neurochemical phenotypes of cardiorespiratory neurons.

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Pilowsky, Paul M

2008-12-10

Interactions between the cardiovascular and respiratory systems have been known for many years but the functional significance of the interactions is still widely debated. Here I discuss the possible role of metabotropic receptors in regulating cardiorespiratory neurons in the brainstem and spinal cord. It is clear that, although much has been discovered, cardiorespiratory regulation is certainly one area that still has a long way to go before its secrets are fully divulged and their function in controlling circulatory and respiratory function is revealed.

C-reactive protein, physical activity and cardiorespiratory fitness in Portuguese adolescents: a cross-sectional study.

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Agostinis Sobrinho, Cesar Aparecido; Moreira, Carla Marisa Maia; Mota, Jorge Augusto Pinto da Silva; Santos, Rute Marina Roberto

2015-09-01

The goal of this study was to investigate the association of physical activity (PA) and cardiorespiratory fitness with C-reactive protein (CRP) concentration in adolescents. The sample included 386 Portuguese adolescents (n = 207, female), age 12-18 years, assessed in the year 2012. The PA was assessed with the use of accelerometers, and the cardiorespiratory fitness was assessed by the Fitnessgram Pacer test. Blood samples were collected after a 10-hour fasting, and high-sensitivity PCR concentration was further assessed. Significant associations between CRP and cardiorespiratory fitness were found for females (r = -0.313; p genders. Therefore, CRP is apparently negatively associated with cardiorespiratory fitness, with differences between males and females; for females it seems less dependent than BMI.

Low level of objectively measured physical activity and cardiorespiratory fitness, and high prevalence of metabolic syndrome among Pakistani male immigrants in Oslo, Norway

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Eivind Andersen

2011-08-01

Full Text Available Background: The level of physical fitness in south Asian immigrants living in Norway is largely unknown, but the level of physical activity seems to be low, possibly in part explaining their high prevalence of diabetes and cardiovascular diseases. However, previous studies have used self-reported measures of physical activity, and it might be questioned whether the previous data reflect the true physical activity level.Aim: To describe objectively measured physical activity level, cardiorespiratory fitness and diabetes risk in a group of Pakistani immigrant men living in Oslo, Norway.Methods: One hundred and fifty Pakistani immigrant men in the age group 25-60 years were included. Physical activity level was assessed with an accelerometer. Cardiorespiratory fitness was measured until exhaustion on a treadmill, and diabetes risk was evaluated with an oral glucose tolerance test.Results: Mean age was 37.3 years (SD=7.7. Total physical activity level was 308 counts/min (SD=131, and peak oxygen uptake was 34.2 ml·kg-1·min-1 (SD=5.6. Fifty percent of the participants had the metabolic syndrome, and 76% were obese. Physical activity level and cardiorespiratory fitness level were lower, and prevalence of the metabolic syndrome higher in a subgroup of taxi drivers as compared with those inother occupations (P<0.05.Conclusions: Physical activity and cardiorespiratory fitness levels are low and diabetes risk high among Pakistani immigrant men living in Oslo, especially in taxi drivers

Cardiorespiratory Fitness and Motor Skills in Relation to Cognition and Academic Performance in Children – A Review

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Haapala, Eero A.

2013-01-01

Different elements of physical fitness in children have shown a declining trend during the past few decades. Cardiorespiratory fitness and motor skills have been associated with cognition, but the magnitude of this association remains unknown. The purpose of this review is to provide an overview of the relationship of cardiorespiratory fitness and motor skills with cognitive functions and academic performance in children up to 13 years of age. Cross-sectional studies suggest that children with higher cardiorespiratory fitness have more efficient cognitive processing at the neuroelectric level, as well as larger hippocampal and basal ganglia volumes, compared to children with lower cardiorespiratory fitness. Higher cardiorespiratory fitness has been associated with better inhibitory control in tasks requiring rigorous attention allocation. Better motor skills have been related to more efficient cognitive functions including inhibitory control and working memory. Higher cardiorespiratory fitness and better motor skills have also been associated with better academic performance. Furthermore, none of the studies on cardiorespiratory fitness have revealed independent associations with cognitive functions by controlling for motor skills. Studies concerning the relationship between motor skills and cognitive functions also did not consider cardiorespiratory fitness in the analyses. The results of this review suggest that high levels of cardiorespiratory fitness and motor skills may be beneficial for cognitive development and academic performance but the evidence relies mainly on cross-sectional studies. PMID:23717355

Lack of age-related increase in carotid artery wall viscosity in cardiorespiratory fit men

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Kawano, Hiroshi; Yamamoto, Kenta; Gando, Yuko; Tanimoto, Michiya; Murakami, Haruka; Ohmori, Yumi; Sanada, Kiyoshi; Tabata, Izumi; Higuchi, Mitsuru; Miyachi, Motohiko

2013-01-01

Objectives: Age-related arterial stiffening and reduction of arterial elasticity are attenuated in individuals with high levels of cardiorespiratory fitness. Viscosity is another mechanical characteristic of the arterial wall; however, the effects of age and cardiorespiratory fitness have not been determined. We examined the associations among age, cardiorespiratory fitness and carotid arterial wall viscosity. Methods: A total of 111 healthy men, aged 25–39 years (young) and 40–64 years (middle-aged), were divided into either cardiorespiratory fit or unfit groups on the basis of peak oxygen uptake. The common carotid artery was measured noninvasively by tonometry and automatic tracking of B-mode images to obtain instantaneous pressure and diameter hysteresis loops, and we calculated the effective compliance, isobaric compliance and viscosity index. Results: In the middle-aged men, the viscosity index was larger in the unfit group than in the fit group (2533 vs. 2018 mmHg·s/mm, respectively: P viscosity index was increased with advancing age, but these parameters were unaffected by cardiorespiratory fitness level. Conclusion: These results suggest that the wall viscosity in the central artery is increased with advancing age and that the age-associated increase in wall viscosity may be attenuated in cardiorespiratory fit men. PMID:24029868

Entropy Information of Cardiorespiratory Dynamics in Neonates during Sleep

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Maristella Lucchini

2017-05-01

Full Text Available Sleep is a central activity in human adults and characterizes most of the newborn infant life. During sleep, autonomic control acts to modulate heart rate variability (HRV and respiration. Mechanisms underlying cardiorespiratory interactions in different sleep states have been studied but are not yet fully understood. Signal processing approaches have focused on cardiorespiratory analysis to elucidate this co-regulation. This manuscript proposes to analyze heart rate (HR, respiratory variability and their interrelationship in newborn infants to characterize cardiorespiratory interactions in different sleep states (active vs. quiet. We are searching for indices that could detect regulation alteration or malfunction, potentially leading to infant distress. We have analyzed inter-beat (RR interval series and respiration in a population of 151 newborns, and followed up with 33 at 1 month of age. RR interval series were obtained by recognizing peaks of the QRS complex in the electrocardiogram (ECG, corresponding to the ventricles depolarization. Univariate time domain, frequency domain and entropy measures were applied. In addition, Transfer Entropy was considered as a bivariate approach able to quantify the bidirectional information flow from one signal (respiration to another (RR series. Results confirm the validity of the proposed approach. Overall, HRV is higher in active sleep, while high frequency (HF power characterizes more quiet sleep. Entropy analysis provides higher indices for SampEn and Quadratic Sample entropy (QSE in quiet sleep. Transfer Entropy values were higher in quiet sleep and point to a major influence of respiration on the RR series. At 1 month of age, time domain parameters show an increase in HR and a decrease in variability. No entropy differences were found across ages. The parameters employed in this study help to quantify the potential for infants to adapt their cardiorespiratory responses as they mature. Thus, they

Entropy Information of Cardiorespiratory Dynamics in Neonates during Sleep.

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Lucchini, Maristella; Pini, Nicolò; Fifer, William P; Burtchen, Nina; Signorini, Maria G

2017-05-01

Sleep is a central activity in human adults and characterizes most of the newborn infant life. During sleep, autonomic control acts to modulate heart rate variability (HRV) and respiration. Mechanisms underlying cardiorespiratory interactions in different sleep states have been studied but are not yet fully understood. Signal processing approaches have focused on cardiorespiratory analysis to elucidate this co-regulation. This manuscript proposes to analyze heart rate (HR), respiratory variability and their interrelationship in newborn infants to characterize cardiorespiratory interactions in different sleep states (active vs. quiet). We are searching for indices that could detect regulation alteration or malfunction, potentially leading to infant distress. We have analyzed inter-beat (RR) interval series and respiration in a population of 151 newborns, and followed up with 33 at 1 month of age. RR interval series were obtained by recognizing peaks of the QRS complex in the electrocardiogram (ECG), corresponding to the ventricles depolarization. Univariate time domain, frequency domain and entropy measures were applied. In addition, Transfer Entropy was considered as a bivariate approach able to quantify the bidirectional information flow from one signal (respiration) to another (RR series). Results confirm the validity of the proposed approach. Overall, HRV is higher in active sleep, while high frequency (HF) power characterizes more quiet sleep. Entropy analysis provides higher indices for SampEn and Quadratic Sample entropy (QSE) in quiet sleep. Transfer Entropy values were higher in quiet sleep and point to a major influence of respiration on the RR series. At 1 month of age, time domain parameters show an increase in HR and a decrease in variability. No entropy differences were found across ages. The parameters employed in this study help to quantify the potential for infants to adapt their cardiorespiratory responses as they mature. Thus, they could be useful

The Inverse Relationship between Cardiorespiratory Fitness and Intima-Media Thickness with Prehypertensive Middle-Aged Women.

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Kim, Dokyung; Park, Wonhah

2017-12-01

Individuals with prehypertension have a greater risk of developing hypertension and cardiovascular disease than those with normal blood pressure. Good cardiorespiratory fitness has been associated with a reduced risk for cardiovascular diseases, but whether it is related to slower progression of early atherosclerosis is unclear. We evaluated 442 women, aged 40-60 years, with resting systolic blood pressure 120-139 mmHg and diastolic blood pressure 80-89 mmHg, defined as prehypertension in cross-sectional study. Blood glucose, blood lipids and carotid intima-media thickness (CIMT) were measured at rest. Cardiorespiratory fitness (VO 2 peak) was measured by respiratory gas exchange during a treadmill exercise test. Participants were divided into three cardiorespiratory fitness levels: low, moderate, and high. The prevalence of subclinical carotid atherosclerosis was defined as a mean carotid intima-media thickness greater than the 75 th percentile. After adjustment for various confounders, a high cardiorespiratory fitness level was associated with significantly lower SBP, DBP and CIMT compared with low and moderate fitness (p fitness were each associated with significantly lower odds ratios for carotid atherosclerosis 0.74 (95% CI 0.45-0.92) and 0.70 (95% CI 0.46-0.95), respectively, compared with low fitness. Our results indicate that good cardiorespiratory fitness is associated with a slower progression of early atherosclerosis in middle-aged women. These findings are important, because they emphasize that middle-aged women can be evaluated for cardiorespiratory fitness to estimate their future risk for atherosclerotic vascular diseases.

The Obesity Paradox and Cardiorespiratory Fitness

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Paul A. McAuley

2012-01-01

Full Text Available Cardiorespiratory fitness as an explanation for the obesity paradox warrants further examination. We evaluated independent and joint associations of cardiorespiratory fitness and adiposity with all-cause mortality in 811 middle-aged (age, 53.3±7.2 years male never smokers without documented cardiopulmonary disease or diabetes from the Veterans Exercise Testing Study (VETS. Cardiorespiratory fitness was quantified in metabolic equivalents (METs using final treadmill speed and grade achieved on a maximal exercise test. Subjects were grouped for analysis by METs: unfit (lowest third and fit (upper two-thirds; and by body mass index (kg/m2: nonobese (18.5−29.9 and obese (≥30.0. Associations of baseline fitness and adiposity measures with all-cause mortality were determined by Cox proportional hazards analysis adjusted for age, ethnicity, hypertension, hypercholesterolemia, family history of coronary artery disease, and cardiovascular medication use. In multivariate analysis, mortality risk for obese/fit men did not differ significantly from the nonobese/fit reference group. However, compared to the reference group, nonobese and obese unfit men were 2.2 (=0.01 and 1.9 (=0.03 times more likely to die, respectively. Cardiorespiratory fitness altered the obesity paradox such that mortality risk was lower for both obese and nonobese men who were fit.

PM2.5, oxidant defence and cardiorespiratory health: a review.

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Weichenthal, Scott A; Godri-Pollitt, Krystal; Villeneuve, Paul J

2013-05-04

Airborne fine particle mass concentrations (PM2.5) are used for ambient air quality management worldwide based in part on known cardiorespiratory health effects. While oxidative stress is generally thought to be an important mechanism in determining these effects, relatively few studies have specifically examined how oxidant defence may impact susceptibility to particulate air pollution. Here we review studies that explore the impact of polymorphisms in anti-oxidant related genes or anti-oxidant supplementation on PM2.5-induced cardiorespiratory outcomes in an effort to summarize existing evidence related to oxidative stress defence and the health effects of PM2.5. Recent studies of PM-oxidative burden were also examined. In total, nine studies were identified and reviewed and existing evidence generally suggests that oxidant defence may modify the impact of PM2.5 exposure on various health outcomes, particularly heart rate variability (a measure of autonomic function) which was the most common outcome examined in the studies reviewed. Few studies examined interactions between PM2.5 and oxidant defence for respiratory outcomes, and in general studies focused primarily on acute health effects. Therefore, further evaluation of the potential modifying role of oxidant defence in PM2.5-induced health effects is required, particularly for chronic outcomes. Similarly, while an exposure metric that captures the ability of PM2.5 to cause oxidative stress may offer advantages over traditional mass concentration measurements, little epidemiological evidence is currently available to evaluate the potential benefits of such an approach. Therefore, further evaluation is required to determine how this metric may be incorporated in ambient air quality management.

Effects of long-term dharma-chan meditation on cardiorespiratory synchronization and heart rate variability behavior.

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Chang, Chih-Hao; Lo, Pei-Chen

2013-04-01

Remarkable changes in cardiorespiratory interactions are frequently experienced by Chan meditation practitioners following years of practice. This study compares the results of our study on cardiorespiratory interactions for novice (control group) and experienced (experimental group) Chan meditation practitioners. The effectual co-action between the cardiac and respiratory systems was evaluated by the degree of cardiorespiratory phase synchronization (CRPS). In addition, an adaptive-frequency-range (AFR) scheme to reliably quantify heart rate variability (HRV) was developed for assessing the regulation of sympathetic-parasympathetic activity and the efficiency of pulmonary gas exchange. The enhanced HRV method, named HRVAFR, can resolve the issue of overestimating HRV under the condition of slow respiration rates, which is frequently encountered in studies on Chan meditation practitioners. In the comparison of the three data sets collected from the two groups, our findings resulted in innovative hypotheses to interpret the extraordinary process of the rejuvenation of cardiorespiratory functions through long-term Dharma-Chan meditation practice. Particularly, advanced practitioners exhibit a continuously high degree of cardiorespiratory phase synchronization, even during rapid breathing. Based on our post-experimental interview with advanced practitioners, the activation of inner Chakra energy, during the course of Chan-detachment practice, frequently induces perceptible physiological-mental reformation, including an efficient mechanism for regulating cardiorespiratory interactions.

Cardio-respiratory capacity as an important biomarker of health

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Jaroslav Novák

2016-12-01

Full Text Available Background: Cardio-respiratory capacity is an important factor in human health. It's quality depends on many objective factors (such as age and gender, but it can be influenced also by others (physical activity, nutrition. Low level of cardio-respiratory capacity significantly correlates with numerous health failures. Objective: Evaluation of the cardio-respiratory capacity in athletes enables a prediction of performance. In a non-sporting population a critically low level of cardio-respiratory capacity could be a warning signal of a high risk of diseases. The Spiroergometric examination needs very sophisticated technical equipment including O2-CO2 analyzer. The aim of the study was to examine the possibility of how to replace direct measurement of oxygen consumption by the method. Methods: 2 777 protocols from the data base of examinations performed in the period of 1994 till 2015 were used. Cardio-respiratory capacity in all examinations was evaluated according to maximal oxygen uptake VO2max, physical working capacity W170 and maximal performance on the cyclo-ergometer. Step-vice increased workload on cyclo-ergometer based on procedure used in International Biological Program was applied to obtain the characteristics of cardio-respiratory capacity of each subject (2 015 men and 762 women. Results: Correlation coefficients r and regression equations of cardio-respiratory capacity characteristics (W170, W170/kg, VO2max, VO2max/kg, Wmax, Wmax/kg were calculated. The highest correlation was found between VO2max and Wmax and between VO2max/kg and Wmax/kg, both in men and women (r = .89 in men and r = .85 in women for VO2max and Wmax. The most important regression equations are: (men VO2max = 0.0095 . Wmax + 0.54 (l/min (r = .89, VO2max/kg = 8.3 . Wmax/kg + 13 (ml/min/kg (r = .83; (women VO2max = 0.0083 . Wmax + 0.67 (l/min (r = .85, VO2max/kg = 8.0 . max/kg + 13 (ml/min/kg (r = .83. Conclusions: It was proved that VO2max and VO2max/kg values

Cardiorespiratory fitness, fatness and incident diabetes

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Holtermann, Andreas; Gyntelberg, Finn; Bauman, Adrian

2017-01-01

Aims Increases in prevalence have led to a diabetes pandemic. Obesity and low cardiorespiratory fitness (CRF) are considered to be central mechanisms. We investigated if the effect of CRF on diabetes risk was equivalent across levels of fatness among healthy men. Methods In total 4988 middle-aged......: 0.76–1.23). Conclusion High CRF has a stronger protective effect on diabetes among obese than among normal weight men, supporting the recommendation of fitness-enhancing physical activity for preventing diabetes among the obese.......Aims Increases in prevalence have led to a diabetes pandemic. Obesity and low cardiorespiratory fitness (CRF) are considered to be central mechanisms. We investigated if the effect of CRF on diabetes risk was equivalent across levels of fatness among healthy men. Methods In total 4988 middle......-aged Caucasian employed men free of cardiovascular disease, diabetes and cancer were included from the Copenhagen Male Study starting in 1970–71. CRF was assessed using a sub-maximal bicycle ergometer test and body mass index (BMI) was measured by height and weight. Their interaction and stratified associations...

A review of cardiorespiratory fitness-related neuroplasticity in the aging brain

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Scott M Hayes

2013-07-01

Full Text Available The literature examining the relationship between cardiorespiratory fitness and the brain in older adults has increased rapidly, with 30 of 34 studies published since 2008. Here we review cross-sectional and exercise intervention studies in older adults examining the relationship between cardiorespiratory fitness and brain structure and function, typically assessed using Magnetic Resonance Imaging (MRI. Studies of patients with Alzheimer’s disease are discussed when available. The structural MRI studies revealed a consistent positive relationship between cardiorespiratory fitness and brain volume in cortical regions including anterior cingulate, lateral prefrontal, and lateral parietal cortex. Support for a positive relationship between cardiorespiratory fitness and medial temporal lobe volume was less consistent, although evident when a region-of-interest approach was implemented. In fMRI studies, cardiorespiratory fitness in older adults was associated with activation in similar regions as those identified in the structural studies, including anterior cingulate, lateral prefrontal, and lateral parietal cortex, despite heterogeneity among the functional tasks implemented. This comprehensive review highlights the overlap in brain regions showing a positive relationship with cardiorespiratory fitness in both structural and functional imaging modalities. The findings suggest that aerobic exercise and cardiorespiratory fitness contribute to healthy brain aging, although additional studies in Alzheimer’s disease are needed.

Cardiorespiratory fitness in 16 025 adults aged 18-91 years and associations with physical activity and sitting time

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Eriksen, L; Grønbaek, M; Helge, J W

2016-01-01

cardiorespiratory fitness than women, depending on age, and cardiorespiratory fitness decreased by 0.26 and 0.23 mL/min/kg per year in men and women, respectively. Cardiorespiratory fitness was higher among participants who reported a high level of physical activity in leisure time compared with participants who...... fitness was estimated in 16 025 individuals aged 18-91 years from validated cycle ergometer exercise tests. Level of leisure time physical activity (sedentary, light, moderate, and vigorous) and daily sitting time in hours was obtained from a self-administered questionnaire. Men had 20-33% higher......Our aim was to provide up-to-date cardiorespiratory fitness reference data for adults of all ages and to investigate associations between cardiores-piratory fitness and leisure time physical activity as well as sitting time. In the Danish Health Examination Survey 2007-2008, cardiorespiratory...

Arterial stiffness is associated to cardiorespiratory fitness and body mass index in young Swedish adults: The Lifestyle, Biomarkers, and Atherosclerosis study.

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Fernberg, Ulrika; Fernström, Maria; Hurtig-Wennlöf, Anita

2017-11-01

Background Early changes in the large muscular arteries are already associated with risk factors as hypertension and obesity in adolescence and young adulthood. The present study examines the association between arterial stiffness measurements, pulse wave velocity and augmentation index and lifestyle-related factors, body composition and cardiorespiratory fitness, in young, healthy, Swedish adults. Design This study used a population-based cross-sectional sample. Methods The 834 participants in the study were self-reported healthy, non-smoking, age 18-25 years. Augmentation index and pulse wave velocity were measured with applanation tonometry. Cardiorespiratory fitness was measured by ergometer bike test to estimate maximal oxygen uptake. Body mass index (kg/m 2 ) was calculated and categorised according to classification by the World Health Organisation. Results Young Swedish adults with obesity and low cardiorespiratory fitness have significantly higher pulse wave velocity and augmentation index than non-obese young adults with medium or high cardiorespiratory fitness. The observed U-shaped association between pulse wave velocity and body mass index categories in women indicates that it might be more beneficial to be normal weight than underweight when assessing the arterial stiffness with pulse wave velocity. The highest mean pulse wave velocity was found in overweight/obese individuals with low cardiorespiratory fitness. The lowest mean pulse wave velocity was found in normal weight individuals with high cardiorespiratory fitness. Cardiorespiratory fitness had a stronger effect than body mass index on arterial stiffness in multiple regression analyses. Conclusions The inverse association between cardiorespiratory fitness and arterial stiffness is observed already in young adults. The study result highlights the importance of high cardiorespiratory fitness, but also that underweight individuals may be a possible risk group that needs to be further studied.

Cardiorespiratory fitness and vision loss among young and middle-age U.S. adults.

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Loprinzi, Paul D; Zebardast, Nazlee; Ramulu, Pradeep Y

2015-01-01

To examine the association between vision loss and cardiorespiratory fitness among young and middle-age U.S. adults. The study had a cross-sectional design. The National Health and Nutrition Examination Survey 1999-2004 served as the study setting. Study subjects included 3135 adults ages 20 to 49 years. Cardiorespiratory fitness was assessed from cardiorespiratory extrapolation using heart rate response during submaximal treadmill testing, with inadequate cardiorespiratory fitness defined as below the 60th percentile for age and gender. Visual acuity was objectively assessed for each eye. Multivariable regression (linear and logistic) models were computed to examine the association between cardiorespiratory fitness and vision. Poorer cardiorespiratory fitness (β = -3.7 mL O2/kg per minute; 95% confidence interval: -5.3 to -2.2) was observed in subjects with visual impairment after adjusting for age, gender, race/ethnicity, and comorbid illness. Participants with vision impairment, as compared with those with normal sight, had 4.4-fold higher odds of having inadequate cardiorespiratory fitness (95% confidence interval: 1.04-18.97), whereas participants with uncorrected refractive error were not more likely to demonstrate poorer cardiorespiratory fitness. Adults with visual impairment, but not adults with uncorrected refractive error, demonstrate a significant reduction in cardiorespiratory fitness and are much more likely to have inadequate fitness compared with those with normal vision. Evaluation and implementation of strategies to increase cardiorespiratory fitness among those with vision impairment, in particular, are needed.

The Pilates method and cardiorespiratory adaptation to training.

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Tinoco-Fernández, Maria; Jiménez-Martín, Miguel; Sánchez-Caravaca, M Angeles; Fernández-Pérez, Antonio M; Ramírez-Rodrigo, Jesús; Villaverde-Gutiérrez, Carmen

2016-01-01

Although all authors report beneficial health changes following training based on the Pilates method, no explicit analysis has been performed of its cardiorespiratory effects. The objective of this study was to evaluate possible changes in cardiorespiratory parameters with the Pilates method. A total of 45 university students aged 18-35 years (77.8% female and 22.2% male), who did not routinely practice physical exercise or sports, volunteered for the study and signed informed consent. The Pilates training was conducted over 10 weeks, with three 1-hour sessions per week. Physiological cardiorespiratory responses were assessed using a MasterScreen CPX apparatus. After the 10-week training, statistically significant improvements were observed in mean heart rate (135.4-124.2 beats/min), respiratory exchange ratio (1.1-0.9) and oxygen equivalent (30.7-27.6) values, among other spirometric parameters, in submaximal aerobic testing. These findings indicate that practice of the Pilates method has a positive influence on cardiorespiratory parameters in healthy adults who do not routinely practice physical exercise activities.

Analyses of Heart Rate, Respiration and Cardiorespiratory Coupling in Patients with Schizophrenia

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Steffen Schulz

2015-01-01

Full Text Available Schizophrenia is a severe mental disorder associated with a significantly increased cardiovascular mortality rate. However, the underlying mechanisms leading to this cardiovascular disease (CVD are not fully known. Therefore, the objective of this study was to characterize the cardiorespiratory influence by investigating heart rate, respiration and the causal strength and direction of cardiorespiratory coupling (CRC, based mainly on entropy measures. We investigated 23 non-medicated patients with schizophrenia (SZ, comparing them to 23 age- and gender-matched healthy controls (CO. A significantly reduced complexity was found for the heart rate and a significantly increased complexity in respiration and CRC in SZ patients when compared to corresponding measurements from CO (p < 0.001. CRC analyses revealed a clear coupling, with a driver-responder relationship from respiration to heart rate in SZ patients. Moreover, a slight driver-responder relationship from heart rate to respiration could be recognized. These findings lead to the assumption that SZ should be considered to be a high-risk group for CVD. We hypothesize that the varying cardiorespiratory regulation contributes to the increased risk for cardiac mortality. Therefore, regular monitoring of the cardiorespiratory status of SZ is suggested to identify autonomic regulation impairment at an early stage—to develop timely and effective treatment and intervention strategies.

Self-reported cardiorespiratory fitness

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Holtermann, Andreas; Marott, Jacob Louis; Gyntelberg, Finn

2015-01-01

BACKGROUND: The predictive value and improved risk classification of self-reported cardiorespiratory fitness (SRCF), when added to traditional risk factors on cardiovascular disease (CVD) and longevity, are unknown. METHODS AND RESULTS: A total of 3843 males and 5093 females from the Copenhagen...

Heart rate variability biofeedback improves cardiorespiratory resting function during sleep.

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Sakakibara, Masahito; Hayano, Junichiro; Oikawa, Leo O; Katsamanis, Maria; Lehrer, Paul

2013-12-01

The present study was designed to examine the effect of heart rate variability (HRV) biofeedback on the cardiorespiratory resting function during sleep in daily life. Forty-five healthy young adults were randomly assigned to one of three groups: HRV biofeedback, Autogenic Training(AT), and no-treatment control. Participants in the HRV biofeedback were instructed to use a handheld HRV biofeedback device before their habitual bedtime, those in the AT were asked to listen to an audiotaped instruction before bedtime,and those in the control were asked to engage in their habitual activity before bedtime. Pulse wave signal during sleep at their own residences was measured continuously with a wrist watch-type transdermal photoelectric sensor for three time points. Baseline data were collected on the first night of measurements, followed by two successive nights for HRV biofeedback, AT, or control. Cardiorespiratory resting function was assessed quantitatively as the amplitude of high frequency(HF) component of pulse rate variability, a surrogate measure of respiratory sinus arrhythmia. HF component increased during sleep in the HRV biofeedback group,although it remained unchanged in the AT and control groups. These results suggest that HRV biofeedback before sleep may improve cardiorespiratory resting function during sleep.

Peak Cardiorespiratory Responses of Patients with Subacute Stroke During Land and Aquatic Treadmill Exercise.

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Lee, Yong Ki; Kim, Bo Ryun; Han, Eun Young

2017-05-01

The aim of this work was to investigate the cardiorespiratory responses of patients with subacute stroke to exercise stress tests with aquatic and land treadmills. Twenty-one consecutive patients who presented with first-ever subacute stroke in 2013-2015. All subjects underwent symptom-limited incremental exercise testing with aquatic and land treadmills. Land treadmill speed started at 1.5 km/h and increased 0.5 km/h every 1 to 2 minutes until maximal tolerable speed was achieved. Thereafter, the grade was elevated by 2% every 2 minutes. In the aquatic treadmill test, subjects were submerged to the xiphoid in 28°C water. Treadmill speed started at 1.5 km/h and was increased 0.5 km/h every 2 minutes thereafter. Cardiorespiratory responses were recorded with aquatic and land treadmills. Compared to land treadmill exercise, aquatic treadmill exercise achieved significantly better peak VO2 (22.0 vs 20.0; P = 0.02), peak metabolic equivalents (6.3 vs 5.8; P = 0.02), and peak rating of perceived exertion (17.6 vs 18.4, P = 0.01). Heart rate and VO2 correlated significantly during both tests (land treadmill: r = 0.96, P aquatic treadmill: r = 0.99, P Aquatic treadmill exercise elicited significantly better peak cardiorespiratory responses than land treadmill exercise and may be as effective for early intensive aerobic training in subacute stroke patients.

Screen time and passive school travel as independent predictors of cardiorespiratory fitness in youth.

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Sandercock, Gavin R H; Ogunleye, Ayodele A

2012-05-01

The most prevalent sedentary behaviours in children and adolescents are engagement with small screen media (screen-time) and passive travel (by motorised vehicle). The objective of this research was to assess the independence of these behaviours from one another and from physical activity as predictors of cardiorespiratory fitness in youth. We measured cardiorespiratory fitness in n=6819 10-16 year olds (53% male) who self-reported their physical activity (7-day recall) school travel and screen time habits. Travel was classified as active (walking, cycling) or passive; screen time as 4 h. The multivariate odds of being fit were higher in active travel (Boys: OR 1.32, 95% CI: 1.09-1.59; Girls: OR 1.46, 1.15-1.84) than in passive travel groups. Boys reporting low screen time were more likely to be fit than those reporting >4 h (OR 2.11, 95% CI: 1.68-2.63) as were girls (OR 1.66, 95% CI: 1.24-2.20). These odds remained significant after additionally controlling for physical activity. Passive travel and high screen time are independently associated with poor cardiorespiratory fitness in youth, and this relationship is independent of physical activity levels. A lifestyle involving high screen time and habitual passive school travel appears incompatible with healthful levels of cardiorespiratory fitness in youth. Copyright © 2012 Elsevier Inc. All rights reserved.

Energy cost and cardiorespiratory changes during the practice of Surya Namaskar.

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Sinha, B; Ray, U S; Pathak, A; Selvamurthy, W

2004-04-01

Surya Namaskar (SN), a group of Yogic exercise consists of a set of twelve postures which is practiced by some of the yoga practitioners. The present study was undertaken to observe critically the energy cost and different cardiorespiratory changes during the practice of SN. Twenty-one male volunteers from the Indian Army practiced selected Yogic exercises for six days in a week for three months duration. The Yogic practice schedule consisted of Hatha Yogic Asanas (28 min), Pranayama (10.5 min) and Meditation (5 min). In the Yogic practice schedule 1st they practiced Kapal Bhathi (breathing maneuvers) for 2 min then Yogamudra (yogic postural exercise) for 2 min, after that they took rest until oxygen consumption and heart rate (HR) came to resting value. Subsequently subjects performed SN for 3 min 40 seconds on an average. After three months of training at the beginning of the fourth month subjects performed entire Yogic practice schedule in the laboratory as they practiced during their training session and experiments were carried out. Their pulmonary ventilation, carbondioxide output, Oxygen consumption, HR and other cardiorespiratory parameters were measured during the actual practice of SN. Oxygen consumption was highest in the eighth posture (1.22+/-0.073 1 min(-1)) and lowest in the first posture (0.35+/-0.02 1 min(-1)). Total energy cost throughout the practice of SN was 13.91 kcal and at an average of 3.79 kcal/min. During its practice highest HR was 101+/-13.5 b.p.m. As an aerobic exercise SN seemed to be ideal as it involves both static stretching and slow dynamic component of exercise with optimal stress on the cardiorespiratory system.

[Cardiorespiratory capacity in children living at moderate altitude].

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Gómez-Campos, Rossana; Arruda, Miguel; Almonacid-Fierro, Alejandro; Holbold, Edílson; Amaral-Camargo, Cristiane; Gamero, Diego; Cossio-Bolanos, Marco A

2014-04-01

To determine the cardiorespiratory capacity of school children living at moderate altitude. 795 children (394 children and 401 girls) were selected from urban public schools in Arequipa, Peru at moderate altitude (2,320 m). Anthropometric variables (body mass, height, body fat percentage) and cardiorespiratory capacity were assessed using the Course Navette test, considering the following categories: deficient, poor, fair, good, very good and excellent. The results showed significant differences in all categories (poverweight (r=-0.20 to -0.22) and a moderate negative correlation with obesity (r=-0.39 to -0.42) were described for both genders. Low levels of cardiorespiratory capacity in boys and girls living at moderate altitude are observed, which is negatively correlated with excess body weight. The results suggest that 1 in 5 children are likely to suffer some type of cardiovascular event.

Adverse effect of outdoor air pollution on cardiorespiratory fitness in Chinese children

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Gao, Yang; Chan, Emily Y. Y.; Zhu, Yingjia; Wong, Tze Wai

2013-01-01

Little is known about the health impact of air pollution on children's cardiovascular health. A cross-sectional study was conducted and data was analysed in 2048 Chinese schoolchildren (aged 8-10 years) in three districts of Hong Kong to examine the association between exposure to outdoor air pollution and cardiorespiratory fitness. Annual means of ambient PM10, SO2, NO2 and O3 from 1996 to 2003 were used to estimate individual exposure of the subjects. Cardiorespiratory fitness was measured for maximal oxygen uptake (VO2max), predicted by the multistage fitness test (MFT). Height and weight were measured and other potential confounders were collected with questionnaires. Analysis of covariance was performed to estimate the impact of air pollution on complete speed in the MFT and predicted VO2max. The results showed that children in high-pollution district had significantly lower complete speed and predicted VO2max compared to those in low- and moderate-pollution districts. Complete speed and predicted VO2max was estimated to reduce 0.327 km h-1 and 1.53 ml kg-1 min-1 per 10 μg m-3 increase in PM10 annual mean respectively, with those in girls being greater than in boys. Being physically active could not significantly result in improved cardiorespiratory fitness in polluted districts. The adverse effect seems to be independent of short-term exposure to air pollution. We concluded that long-term exposure to higher outdoor air pollution levels was negatively associated with cardiorespiratory fitness in Chinese schoolchildren, especially for girls. PM10 is the most relevant pollutant of the adverse effect. Elevated cardiorespiratory fitness observed in physically activate children could be negated by increased amount of inhaled pollutants during exercise.

Associations of sedentary behaviour, physical activity, blood pressure and anthropometric measures with cardiorespiratory fitness in children with cerebral palsy.

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Jennifer M Ryan

Full Text Available Children with cerebral palsy (CP have poor cardiorespiratory fitness in comparison to their peers with typical development, which may be due to low levels of physical activity. Poor cardiorespiratory fitness may contribute to increased cardiometabolic risk.The aim of this study was to determine the association between sedentary behaviour, physical activity and cardiorespiratory fitness in children with CP. An objective was to determine the association between cardiorespiratory fitness, anthropometric measures and blood pressure in children with CP.This study included 55 ambulatory children with CP [mean (SD age 11.3 (0.2 yr, range 6-17 yr; Gross Motor Function Classification System (GMFCS levels I and II]. Anthropometric measures (BMI, waist circumference and waist-height ratio and blood pressure were taken. Cardiorespiratory fitness was measured using a 10 m shuttle run test. Children were classified as low, middle and high fitness according to level achieved on the test using reference curves. Physical activity was measured by accelerometry over 7 days. In addition to total activity, time in sedentary behaviour and light, moderate, vigorous, and sustained moderate-to-vigorous activity (≥10 min bouts were calculated.Multiple regression analyses revealed that vigorous activity (β = 0.339, p<0.01, sustained moderate-to-vigorous activity (β = 0.250, p<0.05 and total activity (β = 0.238, p<0.05 were associated with level achieved on the shuttle run test after adjustment for age, sex and GMFCS level. Children with high fitness spent more time in vigorous activity than children with middle fitness (p<0.05. Shuttle run test level was negatively associated with BMI (r2 = -0.451, p<0.01, waist circumference (r2 = -0.560, p<0.001, waist-height ratio (r2 = -0.560, p<0.001 and systolic blood pressure (r2 = -0.306, p<0.05 after adjustment for age, sex and GMFCS level.Participation in physical activity, particularly at a vigorous intensity, is

[The effects of Cardiodoron on cardio-respiratory coordination--a literature review].

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Cysarz, D; Heckmann, C; Kümmell, H C

2002-10-01

In healthy subjects self-regulation of the organism establishes the order of rhythmical functions. This self-regulation is altered in patients suffering from idiopathic orthostatic syndrome resulting from disturbances of functional aspects only. Thus the cardio-respiratory coordination, which may serve as the representative of the order of rhythmical functions, is modified. In the case of idiopathic orthostatic syndrome the anthroposophic medicine offers the medicament Cardiodoron(r). Does it stimulate self-regulation in order to normalise the cardio-respiratory coordination? This claim is analysed by a systematic review of the literature. Only those publications were considered where the cardio-respiratory coordination was analysed in studies with patients or healthy subjects. The methods of the studies with patients and healthy subjects vary strongly. Nevertheless, a normalisation of the cardio-respiratory coordination could be found in studies with patients suffering from idiopathic orthostatic syndrome as well as in studies with healthy subjects. The studies show that the use of the medicament results in a normalisation of the cardiorespiratory coordination. By stimulating the self-regulation the medicament leads to an improvement of the order of rhythmical functions in the human organism. Copyright 2002 S. Karger GmbH, Freiburg

Cardiorespiratory fitness and nutritional status of schoolchildren: 30-year evolution

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Gerson Luis de M. Ferrari

2013-07-01

Conclusion: During a 30-year analysis with reviews every ten years from 1978/1980, there was a significant decrease in cardiorespiratory fitness in schoolchildren of both genders, which cannot be explained by the nutritional status. The decline in cardiorespiratory fitness was greater in individuals with normal weight than in overweight individuals.

Cardiorespiratory interactions in humans and animals: Rhythms for life.

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Elstad, Maja; O'Callaghan, Erin L; Smith, Alexander J; Ben-Tal, A; Ramchandra, Rohit

2018-03-09

The cardiorespiratory system exhibits oscillations from a range of sources. One of the most studied oscillations is heart rate variability, which is thought to be beneficial and can serve as an index of a healthy cardiovascular system. Heart rate variability is dampened in many diseases including depression, autoimmune diseases, hypertension and heart failure. Thus, understanding the interactions that lead to heart rate variability, and its physiological role, could help with prevention, diagnosis and treatment of cardiovascular diseases. In this review we consider three types of cardiorespiratory interactions; Respiratory Sinus Arrhythmia - variability in heart rate at the frequency of breathing, Cardioventilatory Coupling - synchronization between the heart beat and the onset of inspiration, and Respiratory Stroke Volume Synchronization - constant phase difference between the right and the left stroke volumes over one respiratory cycle. While the exact physiological role of these oscillations continues to be debated, the redundancies in the mechanisms responsible for its generation and its strong evolutionary conservation point to the importance of cardiorespiratory interactions. The putative mechanisms driving cardiorespiratory oscillations as well as the physiological significance of these oscillations will be reviewed. We suggest that cardiorespiratory interactions have the capacity to both dampen the variability in systemic blood flow as well as improve the efficiency of work done by the heart while maintaining physiological levels of arterial CO 2 . Given that reduction in variability is a prognostic indicator of disease, we argue that restoration of this variability via pharmaceutical or device-based approaches may be beneficial in prolonging life.

In 6- to 8-year-old children, hair cortisol is associated with body mass index and somatic complaints, but not with stress, health-related quality of life, blood pressure, retinal vessel diameters, and cardiorespiratory fitness.

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Gerber, Markus; Endes, Katharina; Brand, Serge; Herrmann, Christian; Colledge, Flora; Donath, Lars; Faude, Oliver; Pühse, Uwe; Hanssen, Henner; Zahner, Lukas

2017-02-01

Hair cortisol measurement has become an increasingly accepted approach in endocrinology and biopsychology. However, while in adult research hair cortisol has been proposed as a relevant biomarker for chronic stress (and its adverse consequences), studies with children are scarce. Therefore, the goal of the present exploratory study was to examine the associations between hair cortisol concentrations (HCCs), stress, and a series of health-related outcomes in a sample of Swiss first grade schoolchildren. The sample consisted of 318 children (53% girls, M age =7.26, SD=0.35). Hair strands were taken near the scalp from a posterior vertex position, and HCCs were tested for the first 3-cm hair segment. Parents provided information about their children's age, gender, parental education, children's stress (recent critical life events, daily hassles), health-related quality of life, and psychosomatic complaints. Body composition, blood pressure, retinal vessel diameters, and cardiorespiratory fitness were measured with established methods. In multiple regression analyses, higher HCCs were weakly associated with increased BMI in girls (β=0.22, pstress, health-related quality of life, blood pressure, retinal vessel diameters, and cardiorespiratory fitness. Although small significant relationships were found between HCCs, BMI and somatic complaints, the findings of this exploratory study challenge the view that HCCs can be used as a reliable biomarker of recent critical life events, daily hassles, health-related quality of life, and cardiovascular health indicators in non-clinical young children. Copyright © 2016 Elsevier Ltd. All rights reserved.

Does synchronization reflect a true interaction in the cardiorespiratory system?

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Toledo, E; Akselrod, S; Pinhas, I; Aravot, D

2002-01-01

Cardiorespiratory synchronization, studied within the framework of phase synchronization, has recently raised interest as one of the interactions in the cardiorespiratory system. In this work, we present a quantitative approach to the analysis of this nonlinear phenomenon. Our primary aim is to determine whether synchronization between HR and respiration rate is a real phenomenon or a random one. First, we developed an algorithm, which detects epochs of synchronization automatically and objectively. The algorithm was applied to recordings of respiration and HR obtained from 13 normal subjects and 13 heart transplant patients. Surrogate data sets were constructed from the original recordings, specifically lacking the coupling between HR and respiration. The statistical properties of synchronization in the two data sets and in their surrogates were compared. Synchronization was observed in all groups: in normal subjects, in the heart transplant patients and in the surrogates. Interestingly, synchronization was less abundant in normal subjects than in the transplant patients, indicating that the unique physiological condition of the latter promote cardiorespiratory synchronization. The duration of synchronization epochs was significantly shorter in the surrogate data of both data sets, suggesting that at least some of the synchronization epochs are real. In view of those results, cardiorespiratory synchronization, although not a major feature of cardiorespiratory interaction, seems to be a real phenomenon rather than an artifact.

Muscular and Cardiorespiratory Fitness in Homeschool versus Public School Children.

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Kabiri, Laura S; Mitchell, Katy; Brewer, Wayne; Ortiz, Alexis

2017-08-01

The growth and unregulated structure of homeschooling creates an unknown population in regard to muscular and cardiorespiratory fitness. The purpose of this research was to compare muscular and cardiorespiratory fitness between elementary school aged homeschool and public school children. Homeschool children ages 8-11 years old (n = 75) completed the curl-up, 90° push-up, and Progressive Aerobic Capacity Endurance Run (PACER) portions of the FitnessGram to assess abdominal and upper body strength and endurance as well as cardiorespiratory fitness. Comparisons to public school children (n = 75) were made using t tests and chi-square tests. Homeschool children showed significantly lower abdominal (t(148) = -11.441, p fitness by total PACER laps (t(108) = 0.879, p = .381) or estimated VO 2max (t(70) = 1.187, p = .239; χ 2 (1) = 1.444, p = .486). Homeschool children showed significantly lower levels of both abdominal and upper body muscular fitness compared with their age and gender matched public school peers but no difference in cardiorespiratory fitness.

Resilience as a mediator between cardiorespiratory fitness and mental health-related quality of life: A cross-sectional study.

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Pozuelo-Carrascosa, Diana P; Martínez-Vizcaíno, Vicente; Sánchez-López, Mairena; Bartolomé-Gutiérrez, Raquel; Rodríguez-Martín, Beatriz; Notario-Pacheco, Blanca

2017-09-01

In this cross-sectional study, we analyzed the relationship between resilience, cardiorespiratory fitness, and mental health-related quality of life, and examined whether resilience acts as a mediator between the latter two. The study included 770 university students, aged 18-30 years, from Cuenca, Spain. Anthropometric, sociodemographic, cardiorespiratory fitness (20 m shuttle run test), biochemical parameters, resilience, and mental health-related quality of life measurements were analyzed. The results showed that mental health-related quality-of-life values were significantly higher in students who had good cardiorespiratory fitness and a high level of resilience. Moreover, resilience acted as a partial mediator between cardiorespiratory fitness and mental health-related quality of life at 33.79%. Therefore, in young adults, resilience mediates the relationship between cardiorespiratory fitness and mental health-related quality of life. These findings should be taken into account by nurses and other public health professionals, because in addition to the development of physical activity interventions to improve mental health-related quality of life, it is necessary to implement measures that increase resilience to achieve mental wellness. © 2017 John Wiley & Sons Australia, Ltd.

A preseason cardiorespiratory profile of dancers in nine professional ballet and modern companies.

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Bronner, Shaw; Ojofeitimi, Sheyi; Lora, Jennifer Bailey; Southwick, Heather; Kulak, Michelina Cassella; Gamboa, Jennifer; Rooney, Megan; Gilman, Greg; Gibbs, Richard

2014-01-01

While studies have investigated the physical demands of dance in terms of cardiorespiratory fitness, there are no recent comparisons of cardiorespiratory response to exercise among professional dancers of different genres. Our purpose was to: 1. develop a cardiorespiratory profile of professional dancers; 2. investigate differences in peak and recovery heart rate (HR) between professional modern and ballet dancers using an accelerated 3-minute step test; 3. demonstrate the relationship between cardiorespiratory variables; and 4. investigate the effects of company and work variables on the dancers' cardiorespiratory profiles. We hypothesized greater cardiorespiratory fitness in modern dancers than in ballet dancers, due to the nature of their repertory. Furthermore, we hypothesized that company profiles would reflect differences in work variables. Two hundred and eleven dancers (mean age 24.6 ± 4.7) from nine companies (two modern and seven ballet) performed a 3-minute step test. Demographics, height, mass, blood pressure (BP), smoking history, and resting peak and recovery HR were recorded. Body mass index (BMI) and fitness category were calculated. Independent t-tests were used to compare differences in demographics and cardiorespiratory variables due to genre, MANOVA were conducted to compare differences due to company, and correlations were calculated to determine the relationships between cardiorespiratory variables (p < 0.05). Modern dancers demonstrated higher mass and BMI, lower BP, lower resting HR and HR recovery, and a higher percentage were categorized as "fit" compared to ballet dancers (p < 0.03). There were differences between companies in age, experience, BMI, BP, resting, peak, and recovery HR, and fitness category (p < 0.001). The differences in cardiorespiratory fitness levels that may be related to rigor of repertory, rehearsal and performance seasons, or off-season exercise training are discussed. Results support the need for comprehensive

Cardiorespiratory interactions during periodic breathing in awake chronic heart failure patients.

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Pinna, G D; Maestri, R; Mortara, A; La Rovere, M T

2000-03-01

We applied spectral techniques to the analysis of cardiorespiratory signals [instantaneous lung volume (ILV), instantaneous tidal volume (ITV), arterial O(2) saturation (Sa(O(2))) at the ear, heart rate (HR), systolic (SAP), and diastolic (DAP) arterial pressure] during nonapneic periodic breathing (PB) in 29 awake chronic heart failure (CHF) patients and estimated the timing relationships between respiratory and slow cardiovascular (cardiorespiratory interactions during PB and 2) to test the hypothesis of a central vasomotor origin of PB. All cardiovascular signals were characterized by a dominant (>/=84% of total power) oscillation at the frequency of PB (mean +/- SE: 0.022 +/- 0.0008 Hz), highly coherent (>/=0.89), and delayed with respect to ITV (ITV-HR, 2.4 +/- 0.72 s; ITV-SAP, 6.7 +/- 0.65 s; ITV-DAP, 3.2 +/- 0.61 s; P cardiorespiratory rhythm led by the ventilatory oscillation and suggest that 1) the cyclic increase in inspiratory drive and cardiopulmonary reflexes and 2) mechanical effects of PB-induced changes in intrathoracic pressure are the more likely sources of the HR and blood pressure oscillations, respectively. The timing relationship between ITV and blood pressure signals excludes the possibility that PB represents the effect of a central vasomotor rhythm.

Relationship between Body Mass Index, Cardiorespiratory and Musculoskeletal Fitness among South African Adolescent Girls.

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Bonney, Emmanuel; Ferguson, Gillian; Smits-Engelsman, Bouwien

2018-05-28

Background : Cardiorespiratory and musculoskeletal fitness are important health indicators that support optimal physical functioning. Understanding the relationship between body mass index and these health markers may contribute to the development of evidence-based interventions to address obesity-related complications. The relationship between body mass index, cardiorespiratory and musculoskeletal fitness has not been well explored, particularly in female adolescents. The aim of this study was to investigate the association between body mass index, cardiorespiratory and musculoskeletal fitness among South African adolescent girls in low-income communities. Methods : This cross-sectional study included 151 adolescent girls, aged 13⁻16 years. Cardiorespiratory fitness was measured using the 20 m shuttle run test and musculoskeletal fitness was assessed using a variety of field-based tests. Height and weight were measured with standardised procedures and body mass index (BMI) was derived by the formula [BMI = weight (kg)/height (m)²]. Participants were categorised into three BMI groups using the International Obesity Task Force age- and gender-specific cut-off points. Pearson correlations were used to determine the association between body mass index, cardiorespiratory fitness and measures of musculoskeletal fitness at p ≤ 0.05. Results : Overweight and obese girls were found to have lower cardiorespiratory fitness, decreased lower extremity muscular strength, greater grip strength, and more hypermobile joints compared to normal-weight peers. BMI was negatively associated with cardiorespiratory fitness and lower extremity muscular strength. Conclusions : The findings indicate that increased body mass correlates with decreased cardiorespiratory and musculoskeletal fitness. Interventions should be developed to target these important components of physical fitness in this demographic group.

Epigenetic regulation of hypoxic sensing disrupts cardiorespiratory homeostasis.

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Nanduri, Jayasri; Makarenko, Vladislav; Reddy, Vaddi Damodara; Yuan, Guoxiang; Pawar, Anita; Wang, Ning; Khan, Shakil A; Zhang, Xin; Kinsman, Brian; Peng, Ying-Jie; Kumar, Ganesh K; Fox, Aaron P; Godley, Lucy A; Semenza, Gregg L; Prabhakar, Nanduri R

2012-02-14

Recurrent apnea with intermittent hypoxia is a major clinical problem in preterm infants. Recent studies, although limited, showed that adults who were born preterm exhibit increased incidence of sleep-disordered breathing and hypertension, suggesting that apnea of prematurity predisposes to autonomic dysfunction in adulthood. Here, we demonstrate that adult rats that were exposed to intermittent hypoxia as neonates exhibit exaggerated responses to hypoxia by the carotid body and adrenal chromaffin cells, which regulate cardio-respiratory function, resulting in irregular breathing with apneas and hypertension. The enhanced hypoxic sensitivity was associated with elevated oxidative stress, decreased expression of genes encoding antioxidant enzymes, and increased expression of pro-oxidant enzymes. Decreased expression of the Sod2 gene, which encodes the antioxidant enzyme superoxide dismutase 2, was associated with DNA hypermethylation of a single CpG dinucleotide close to the transcription start site. Treating neonatal rats with decitabine, an inhibitor of DNA methylation, during intermittent hypoxia exposure prevented oxidative stress, enhanced hypoxic sensitivity, and autonomic dysfunction. These findings implicate a hitherto uncharacterized role for DNA methylation in mediating neonatal programming of hypoxic sensitivity and the ensuing autonomic dysfunction in adulthood.

Relationship between Body Mass Index, Cardiorespiratory and Musculoskeletal Fitness among South African Adolescent Girls

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Emmanuel Bonney

2018-05-01

Full Text Available Background: Cardiorespiratory and musculoskeletal fitness are important health indicators that support optimal physical functioning. Understanding the relationship between body mass index and these health markers may contribute to the development of evidence-based interventions to address obesity-related complications. The relationship between body mass index, cardiorespiratory and musculoskeletal fitness has not been well explored, particularly in female adolescents. The aim of this study was to investigate the association between body mass index, cardiorespiratory and musculoskeletal fitness among South African adolescent girls in low-income communities. Methods: This cross-sectional study included 151 adolescent girls, aged 13–16 years. Cardiorespiratory fitness was measured using the 20 m shuttle run test and musculoskeletal fitness was assessed using a variety of field-based tests. Height and weight were measured with standardised procedures and body mass index (BMI was derived by the formula [BMI = weight (kg/height (m2]. Participants were categorised into three BMI groups using the International Obesity Task Force age- and gender-specific cut-off points. Pearson correlations were used to determine the association between body mass index, cardiorespiratory fitness and measures of musculoskeletal fitness at p ≤ 0.05. Results: Overweight and obese girls were found to have lower cardiorespiratory fitness, decreased lower extremity muscular strength, greater grip strength, and more hypermobile joints compared to normal-weight peers. BMI was negatively associated with cardiorespiratory fitness and lower extremity muscular strength. Conclusions: The findings indicate that increased body mass correlates with decreased cardiorespiratory and musculoskeletal fitness. Interventions should be developed to target these important components of physical fitness in this demographic group.

Cardiorespiratory Coupling: Common Rhythms in Cardiac, Sympathetic, and Respiratory Activities

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Dick, Thomas E.; Hsieh, Yee-Hsee; Dhingra, Rishi R.; Baekey, David M.; Galán, Roberto F.; Wehrwein, Erica; Morris, Kendall F.

2014-01-01

Cardiorespiratory coupling is an encompassing term describing more than the well-recognized influences of respiration on heart rate and blood pressure. Our data indicate that cardiorespiratory coupling reflects a reciprocal interaction between autonomic and respiratory control systems, and the cardiovascular system modulates the ventilatory pattern as well. For example, cardioventilatory coupling refers to the influence of heart beats and arterial pulse pressure on respiration and is the tendency for the next inspiration to start at a preferred latency after the last heart beat in expiration. Multiple complementary, well-described mechanisms mediate respiration’s influence on cardiovascular function, whereas mechanisms mediating the cardiovascular system’s influence on respiration may only be through the baroreceptors but are just being identified. Our review will describe a differential effect of conditioning rats with either chronic intermittent or sustained hypoxia on sympathetic nerve activity but also on ventilatory pattern variability. Both intermittent and sustained hypoxia increase sympathetic nerve activity after 2 weeks but affect sympatho-respiratory coupling differentially. Intermittent hypoxia enhances sympatho-respiratory coupling, which is associated with low variability in the ventilatory pattern. In contrast, after constant hypobaric hypoxia, 1-to-1 coupling between bursts of sympathetic and phrenic nerve activity is replaced by 2-to-3 coupling. This change in coupling pattern is associated with increased variability of the ventilatory pattern. After baro-denervating hypobaric hypoxic-conditioned rats, splanchnic sympathetic nerve activity becomes tonic (distinct bursts are absent) with decreases during phrenic nerve bursts and ventilatory pattern becomes regular. Thus, conditioning rats to either intermittent or sustained hypoxia accentuates the reciprocal nature of cardiorespiratory coupling. Finally, identifying a compelling physiologic

Independent associations of physical activity and cardiorespiratory fitness with metabolic risk factors in children: the European youth heart study

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Ekelund, U; Anderssen, S A; Froberg, K

2007-01-01

AIMS/HYPOTHESIS: High levels of cardiorespiratory fitness (CRF) and physical activity (PA) are associated with a favourable metabolic risk profile. However, there has been no thorough exploration of the independent contributions of cardiorespiratory fitness and subcomponents of activity (total PA...... the association between activity and clustered risk is independent of adiposity. Our results suggest that fitness and activity affect metabolic risk through different pathways....

Evolution of cardiorespiratory interactions with age.

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Iatsenko, D; Bernjak, A; Stankovski, T; Shiogai, Y; Owen-Lynch, P J; Clarkson, P B M; McClintock, P V E; Stefanovska, A

2013-08-28

We describe an analysis of cardiac and respiratory time series recorded from 189 subjects of both genders aged 16-90. By application of the synchrosqueezed wavelet transform, we extract the respiratory and cardiac frequencies and phases with better time resolution than is possible with the marked events procedure. By treating the heart and respiration as coupled oscillators, we then apply a method based on Bayesian inference to find the underlying coupling parameters and their time dependence, deriving from them measures such as synchronization, coupling directionality and the relative contributions of different mechanisms. We report a detailed analysis of the reconstructed cardiorespiratory coupling function, its time evolution and age dependence. We show that the direct and indirect respiratory modulations of the heart rate both decrease with age, and that the cardiorespiratory coupling becomes less stable and more time-variable.

Cardiorespiratory fitness and age-related arterial stiffness in women with systemic lupus erythematosus.

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Montalbán-Méndez, Cristina; Soriano-Maldonado, Alberto; Vargas-Hitos, José A; Sáez-Urán, Luis M; Rosales-Castillo, Antonio; Morillas-de-Laguno, Pablo; Gavilán-Carrera, Blanca; Jiménez-Alonso, Juan

2018-03-01

The aim of this study was twofold: (i) to examine the association of cardiorespiratory fitness with arterial stiffness in women with systemic lupus erythematosus; (ii) to assess the potential interaction of cardiorespiratory fitness with age on arterial stiffness in this population. A total of 49 women with systemic lupus erythematosus (mean age 41.3 [standard deviation 13.8] years) and clinical stability during the previous 6 months were included in the study. Arterial stiffness was assessed through pulse wave velocity (Mobil-O-Graph® 24 hours pulse wave velocity monitor). Cardiorespiratory fitness was estimated with the Siconolfi step test and the 6-minute walk test. Cardiorespiratory fitness was inversely associated with pulse wave velocity in crude analyses (P fitness × age interaction effect on pulse wave velocity, regardless of the test used to estimate cardiorespiratory fitness (P fitness was associated with a lower increase in pulse wave velocity per each year increase in age. The results of this study suggest that cardiorespiratory fitness might attenuate the age-related arterial stiffening in women with systemic lupus erythematosus and might thus contribute to the primary prevention of cardiovascular disease in this population. As the cross-sectional design precludes establishing causal relationships, future clinical trials should confirm or contrast these findings. © 2018 Stichting European Society for Clinical Investigation Journal Foundation.

Effects of Beetroot Juice Supplementation on Cardiorespiratory Endurance in Athletes. A Systematic Review

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Raúl Domínguez

2017-01-01

Full Text Available Athletes use nutritional supplementation to enhance the effects of training and achieve improvements in their athletic performance. Beetroot juice increases levels of nitric oxide (NO, which serves multiple functions related to increased blood flow, gas exchange, mitochondrial biogenesis and efficiency, and strengthening of muscle contraction. These biomarker improvements indicate that supplementation with beetroot juice could have ergogenic effects on cardiorespiratory endurance that would benefit athletic performance. The aim of this literature review was to determine the effects of beetroot juice supplementation and the combination of beetroot juice with other supplements on cardiorespiratory endurance in athletes. A keyword search of DialNet, MedLine, PubMed, Scopus and Web of Science databases covered publications from 2010 to 2016. After excluding reviews/meta-analyses, animal studies, inaccessible full-text, and studies that did not supplement with beetroot juice and adequately assess cardiorespiratory endurance, 23 articles were selected for analysis. The available results suggest that supplementation with beetroot juice can improve cardiorespiratory endurance in athletes by increasing efficiency, which improves performance at various distances, increases time to exhaustion at submaximal intensities, and may improve the cardiorespiratory performance at anaerobic threshold intensities and maximum oxygen uptake (VO2max. Although the literature shows contradictory data, the findings of other studies lead us to hypothesize that supplementing with beetroot juice could mitigate the ergolytic effects of hypoxia on cardiorespiratory endurance in athletes. It cannot be stated that the combination of beetroot juice with other supplements has a positive or negative effect on cardiorespiratory endurance, but it is possible that the effects of supplementation with beetroot juice can be undermined by interaction with other supplements such as caffeine.

Cardiorespiratory interactions: the relationship between mechanical ventilation and hemodynamics.

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Cheifetz, Ira M

2014-12-01

The overall goal of the cardiorespiratory system is to provide the organs and tissues of the body with an adequate supply of oxygen in relation to oxygen consumption. An understanding of the complex physiologic interactions between the respiratory and cardiac systems is essential to optimal patient management. Alterations in intrathoracic pressure are transmitted to the heart and lungs and can dramatically alter cardiovascular performance, with significant differences existing between the physiologic response of the right and left ventricles to changes in intrathoracic pressure. In terms of cardiorespiratory interactions, the clinician should titrate the mean airway pressure to optimize the balance between mean lung volume (ie, arterial oxygenation) and ventricular function (ie, global cardiac output), minimize pulmonary vascular resistance, and routinely monitor cardiorespiratory parameters closely. Oxygen delivery to all organs and tissues of the body should be optimized, but not necessarily maximized. The heart and lungs are, obviously, connected anatomically but also physiologically in a complex relationship. Copyright © 2014 by Daedalus Enterprises.

Physical Activity, Body Mass Index, and Cardiorespiratory Fitness among School Children in Taiwan: A Cross-Sectional Study

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Pei-Lin Hsieh

2014-07-01

Full Text Available There is evidence that cardiorespiratory fitness and physical activity significantly reduce cardiovascular risks in adults. A better understanding of the association between cardiorespiratory fitness, physical activity, and childhood obesity is vital in assessing the benefits of interventions to prevent obesity. This study was to examine the relationship between physical activity, body mass index, and cardiorespiratory fitness levels in Taiwanese children. A cross-sectional study was designed. Study participants consisted of 2419 school children (1230 males and 1189 females aged 12 years old living in a southern Taiwan county with one the highest countrywide rates of childhood obesity. The weight status of the participants was defined as underweight, normal, overweight, or obese according to specific criteria. Cardiorespiratory fitness was then assessed by an 800-m run. Participants were queried on their physical activity habits via a questionnaire survey. The overall prevalence of overweight/obesity was 29.6%. Normal, underweight and overweight boys and girls had an increased odds ratio of being categorized with higher cardiorespiratory fitness than obese one for both gender. A significantly higher level of cardiorespiratory fitness was found in children who engaged in regular physical activity than in children who engaged only in irregular physical activity. Obese children are more likely to lack cardiorespiratory fitness. Physically active children have significantly better cardiorespiratory fitness levels than inactive children. This study supports the conclusion that BMI and physical activity are significantly correlated with cardiorespiratory fitness levels. Findings may provide educational professionals with information to assist their developing effective health promotion programs to healthy weight and improving cardiorespiratory fitness for children.

Cardiorespiratory fitness and nutritional status of schoolchildren: 30-year evolution.

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Moraes Ferrari, Gerson Luis de; Bracco, Mario Maia; Matsudo, Victor K Rodrigues; Fisberg, Mauro

2013-01-01

To compare the changes in cardiorespiratory fitness in evaluations performed every ten years since 1978/1980, according to the nutritional status and gender of students in the city of Ilhabela, Brazil. The study is part of the Mixed Longitudinal Project on Growth, Development and Physical Fitness of Ilhabela. The study included 1,291 students of both genders, aged 10 to 11 years old. The study periods were: 1978/1980, 1988/1990, 1998/2000, and 2008/2010. The variables analyzed were: body weight, height, and cardiorespiratory fitness (VO2max - L.min-1 and mL.kg-1.min-1) performed using a submaximal progressive protocol on a cycle ergometer. Individuals were classified as normal weight and overweight according to curves proposed by the World Health Organization of body mass index for age and gender. Analysis of variance (ANOVA) with three factors followed by the Bonferroni method were used to compare the periods. The number of normal weight individuals (61%) was higher than that of overweight. There was a significant decrease in cardiorespiratory fitness in both genders. Among the schoolchildren with normal weight, there was a decrease of 22% in males and 26% in females. In overweight schoolchildren, males showed a decrease of 12.7% and females, of 18%. During a 30-year analysis with reviews every ten years from 1978/1980, there was a significant decrease in cardiorespiratory fitness in schoolchildren of both genders, which cannot be explained by the nutritional status. The decline in cardiorespiratory fitness was greater in individuals with normal weight than in overweight individuals. Copyright © 2013 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Cardiorespiratory performance and physical activity in normal weight and overweight Finnish adolescents from 2003 to 2010.

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Palomäki, Sanna; Heikinaro-Johansson, Pilvikki; Huotari, Pertti

2015-01-01

We investigated changes in cardiorespiratory performance, BMI and leisure-time physical activity among Finnish adolescents from 2003 to 2010. In addition, we compared cardiorespiratory performance levels between normal weight and overweight adolescents, grouped according to their physical activity. Participants were a national representative samples of 15-16-year-old adolescents in their final (ninth) year of comprehensive school in 2003 (n = 2258) and in 2010 (n = 1301). They performed an endurance shuttle run test and reported their height and weight and leisure time physical activity on a questionnaire. Results showed no significant secular changes in cardiorespiratory performance from 2003 to 2010. The mean BMI increased in boys. Leisure-time physical activity increased among normal weight girls. Adolescents of normal weight had better cardiorespiratory performance than those classified as overweight at both assessment points. BMI-adjusted physical activity was a significant determinant for cardiorespiratory performance among overweight adolescents, and very active overweight adolescents had similar cardiorespiratory performance levels as moderately active adolescents of normal weight. The results of the present study support the idea that the physical activity has the great importance for the cardiorespiratory performance in adolescents. Overweight adolescents, in particular, benefit from higher levels of physical activity.

Screen time, cardiorespiratory fitness and adiposity among school-age children from Monteria, Colombia.

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Arango, Carlos M; Parra, Diana C; Gómez, Luis F; Lema, Lucía; Lobelo, Felipe; Ekelund, Ulf

2014-09-01

To explore the association between electronic media exposure (television viewing time, personal computer/video game use, total screen time), and waist circumference and body mass index, and study whether this association is independent of cardiorespiratory fitness, in a representative sample of adolescents from Montería, Colombia. Cross-sectional study analyzing data from 546 students aged 11-18 years, from fourteen randomly selected schools. Z-scores for WC and BMI were calculated. The physical activity module of the Global School Health Survey 2007 was used to determine EME, and the shuttle run test was used to assess CRF. Linear regression models adjusted by age, school location, physical activity level, type of institution (public or private), consumption of sweetened beverages, fast food, and fried food were used. Among boys, independently of cardiorespiratory fitness, high television viewing time (≥ 2 h/day) (β=+0.22; p3h/day) was positively associated with waist circumference (β=+0.34; pnegatively associated with body mass index. These findings support the evidence on the negative impact of excessive electronic media exposure and low cardiorespiratory fitness, and highlight the need for interventions and prevention strategies. Copyright © 2013 Sports Medicine Australia. All rights reserved.

Cardiorespiratory fitness and muscle strength in pancreatic cancer patients.

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Clauss, Dorothea; Tjaden, Christine; Hackert, Thilo; Schneider, Lutz; Ulrich, Cornelia M; Wiskemann, Joachim; Steindorf, Karen

2017-09-01

Cancer patients frequently experience reduced physical fitness due to the disease itself as well as treatment-related side effects. However, studies on physical fitness in pancreatic cancer patients are missing. Therefore, we assessed cardiorespiratory fitness and muscle strength of pancreatic cancer patients. We included 65 pancreatic cancer patients, mostly after surgical resection. Cardiorespiratory fitness was assessed using cardiopulmonary exercise testing (CPET) and 6-min walk test (6MWT). Hand-held dynamometry was used to evaluate isometric muscle strength. Physical fitness values were compared to reference values of a healthy population. Associations between sociodemographic and clinical variables with patients' physical fitness were analyzed using multiple regression models. Cardiorespiratory fitness (VO 2 peak, 20.5 ± 6.9 ml/min/kg) was significantly lower (-24%) compared to healthy reference values. In the 6MWT pancreatic cancer patients nearly reached predicted values (555 vs. 562 m). Maximal voluntary isometric contraction (MVIC) of the upper (-4.3%) and lower extremities (-13.8%) were significantly lower compared to reference values. Overall differences were larger in men than those in women. Participating in regular exercise in the year before diagnosis was associated with greater VO 2 peak (p fitness with regard to both cardiorespiratory function and isometric muscle strength, already in the early treatment phase (median 95 days after surgical resection). Our findings underline the need to investigate exercise training in pancreatic cancer patients to counteract the loss of physical fitness.

Exploring the utility of cardiorespiratory fitness as a population health surveillance indicator for children and youth: An international analysis of results from the 20-m shuttle run test.

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Lang, Justin J

2018-02-01

Emerging evidence has demonstrated the strong link between cardiorespiratory fitness and multiple aspects of health (i.e., physiological, physical, psychosocial, cognitive), independent of physical activity, among school-aged children and youth. Cardiorespiratory fitness is a trait that does not vary substantially from day-to-day, and provides an indication of recent physical activity levels, making it an important possible indicator of population health. Thus, the objective of this dissertation was to investigate the utility of cardiorespiratory fitness, measured using the 20-m shuttle run test, as a broad, holistic health indicator for population health surveillance among children and youth. To achieve this objective we completed 7 manuscripts, all prepared for submission to peer-reviewed, scientific journals: (1) Systematic review of the relationship between 20-m shuttle run performance and health indicators among children and youth. (2) Review of criterion-referenced standards for cardiorespiratory fitness: what percentage of 1 142 026 international children and youth are apparently healthy? (3) Cardiorespiratory fitness is associated with physical literacy in a large sample of Canadian children aged 8 to 12 years. (4) International variability in 20-m shuttle run performance in children and youth: Who are the fittest from a 50-country comparison? A systematic review with pooling of aggregate results. (5) Making a case for cardiorespiratory fitness surveillance among children and youth. (6) International normative 20-m shuttle run values from 1 142 026 children and youth representing 50 countries. (7) Temporal trends in the cardiorespiratory fitness of children and adolescents representing 19 high-income and upper middle-income countries between 1981 and 2014. Combined, this dissertation provides support for the importance of cardiorespiratory fitness for health surveillance among school-aged children and youth. Results from the international analysis

Tracking of BMI, fatness and cardiorespiratory fitness from adolescence to middle adulthood: the Zagreb Growth and Development Longitudinal Study.

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Sorić, Maroje; Jembrek Gostović, Mirjana; Gostović, Mladen; Hočevar, Marija; Mišigoj-Duraković, Marjeta

2014-01-01

Effective intervention strategies aiming to improve cardiorespiratory fitness and to decrease body fatness are needed. However, long-term stability of these traits is not well understood. To assess long-term tracking of cardiorespiratory fitness and body fatness from late adolescence to middle adulthood. The sample consisted of 50 participants (31 boys) from the Zagreb Growth and Development Longitudinal Study who were followed up in adulthood (median age = 43). Fatness was evaluated through BMI and skin-folds, while cardiorespiratory fitness was assessed using a cardiopulmonary exercise test. Inter-age partial correlation coefficients were calculated to evaluate tracking. Body mass index and skin-folds showed moderate tracking from age 15 years to middle adulthood (partial r = 0.55, p < 0.001 and partial r = 0.52, p < 0.001, respectively), while tracking of subcutaneous fat distribution was somewhat lower (partial r = 0.38, p < 0.01). At the same time, the observed tracking of peak oxygen uptake was low-to-moderate (partial r = 0.30, p = 0.03), while ventilatory aerobic and anaerobic thresholds did not show significant tracking. The results of this study indicate that preventive efforts aiming to increase cardiorespiratory fitness should include all adolescents, irrespective of their cardiorespiratory fitness status. Conversely, strategies aiming at obesity prevention should focus on high-risk groups of adolescents.

Cardiorespiratory fitness and death from cancer

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Jensen, Magnus Thorsten; Holtermann, Andreas; Bay, Hans

2017-01-01

OBJECTIVES: Poor cardiorespiratory fitness (CRF) is associated with death from cancer. If follow-up time is short, this association may be confounded by subclinical disease already present at the time of CRF assessment. This study investigates the association between CRF and death from cancer...

Long-term exposure to gaseous air pollutants and cardio-respiratory mortality in Brisbane, Australia

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Xiao Yu Wang

2009-05-01

Full Text Available This study examines the association of long-term exposure to gaseous air pollution with cardio-respiratory mortality in Brisbane, Australia, in the period 1996-2004. The pollutant concentrations were estimated using geographical information system (GIS techniques at the statistical local area (SLA level. The generalized estimating equations model was used to investigate the impact of nitrogen dioxide (NO2, ozone (O3 and sulphur dioxide (SO2 on mortality due to cardio-respiratory disease after adjusting for a range of potential confounders. An increase of 4.7% (95% confidence interval = 0.7-8.9% in cardio-respiratory mortality for 1 part per billion (ppb increment in annual average concentration of SO2 was estimated. However, there was no significant association between long-term exposures to NO2 or O3 and death due to cardio-respiratory disease. The results indicate that the annual average concentration of SO2 is associated with cardio-respiratory mortality at the SLA level and this association appears to vary with the geographical area.

PPARγ2 C1431T genotype increases metabolic syndrome risk in young men with low cardiorespiratory fitness.

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Sanada, Kiyoshi; Iemitsu, Motoyuki; Murakami, Haruka; Tabata, Izumi; Yamamoto, Kenta; Gando, Yuko; Suzuki, Katsuhiko; Higuchi, Mitsuru; Miyachi, Motohiko

2011-02-11

The peroxisome proliferator-activated receptor gamma 2 (PPARγ2) genotypes are related to obesity and the metabolic syndrome (MetS). A low level of cardiorespiratory fitness is also a strong determining factor in the development of MetS. This cross-sectional study was performed to investigate the influence of the interaction between the PPARγ2 genotype and cardiorespiratory fitness on the risk of MetS. Healthy Japanese men (n = 211) and women (n = 505) participated in this study. All subjects were divided into 8 groups according to sex, fitness level (high and low fitness groups), and age (younger, age interacted to produce a significant effect on MetS risk in younger men and that the risk of MetS in the CC genotype group with low cardiorespiratory fitness was significantly higher than that in the corresponding CT+TT genotypes or in the high fitness groups. There was no significant interaction between fitness and genotype in determining MetS risk in middle-aged/older men or in women in any group. With regard to the Pro12Ala genotype of the PPARγ2 gene, there were no significant differences in fitness or genotype effects nor were there any interactions between measurement variables. We concluded that the CC genotype of C1431T in the PPARγ2 gene together with low cardiorespiratory fitness may increase the risk of MetS in younger men (age < 40 yr), even with adjustment for age.

Climate Change and the New Normal for Cardiorespiratory Disease

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Tim K Takaro

2015-01-01

Full Text Available Climate change is already affecting the cardiorespiratory health of populations around the world, and these impacts are expected to increase. The present overview serves as a primer for respirologists who are concerned about how these profound environmental changes may affect their patients. The authors consider recent peer-reviewed literature with a focus on climate interactions with air pollution. They do not discuss in detail cardiorespiratory health effects for which the potential link to climate change is poorly understood. For example, pneumonia and influenza, which affect >500 million people per year, are not addressed, although clear seasonal variation suggests climate-related effects. Additionally, large global health impacts in low-resource countries, including migration precipitated by environmental change, are omitted. The major cardiorespiratory health impacts addressed are due to heat, air pollution and wildfires, shifts in allergens and infectious diseases along with respiratory impacts from flooding. Personal and societal choices about carbon use and fossil energy infrastructure should be informed by their impacts on health, and respirologists can play an important role in this discussion.

Metabolic and cardiorespiratory response in swimmers during head-out immersion: a prospective study.

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Mesfar, Mohamed A; Zendah, Ines; Gharsalli, Houda; Ben Hassen, Chokri; Ghedira, Habib

2012-11-01

Sport represents a stress for the body. Many metabolic and cardiorespiratory changes are known during physical activity.However, litte is known in swimmers particularly during head-out immersion. To determine the metabolic and cardiorespiratory response in swimmers during head-out immersion. The energetic, cardiovascular function and ventilatory requirements of a 10 min steady state arm exercise performed by 13 healthy subjects in air and during immersion up to the hip in 26°C water were compared. The same ergometric work load was achieved with an average maximum oxygen uptake of 3.9 ± 2.63 l/min in air versus 3.55 ± 2.48 l/min in water (p=0.953). During exercise, the average values of minute ventilation, ventilation equivalent for oxygen, ventilation equivalent for CO2, peak expiratory flow, respiratory exchange ratio and heart rate were not different in water and in air. However, first ventilatory threshold was significantly higher in water than in air. The mean value of the first ventilatory threshold was 0.89 ± 0.23 l/min in air, and 1.08 ± 0.23 l/min in water immersion; (p=0.016). These results suggest that training swimmers favoring immersion (weight belts) may improve their aerobic capacity.

Cardiorespiratory screening in elite endurance sports athletes: the Quebec study.

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Turmel, Julie; Poirier, Paul; Bougault, Valérie; Blouin, Evelyne; Belzile, Mireille; Boulet, Louis-Philippe

2012-09-01

Cardiorespiratory disorders are common in athletes. However, these conditions are often underdiagnosed, which potentially results in impaired performance and increased health risks. The aim of this study was to evaluate, in a research setting, the prevalence of cardiorespiratory disorders in athletes in order to determine the potential value of a screening program. One hundred thirty-three athletes were studied. Each subject underwent a physical examination. A eucapnic voluntary hyperventilation (EVH) test and a methacholine inhalation test were performed to confirm the diagnosis of asthma. A cardiovascular evaluation was also performed, including maximal exercise test with electrocardiogram, 24-hour ambulatory blood pressure monitoring, 24-hour Holter monitoring, and blood sampling. Seventy-four (56%) athletes had airway hyperresponsiveness to EVH or the methacholine inhalation test. Among those with airway hyperresponsiveness, 45 (61%) athletes were only hyperresponsive to EVH, and 10 (14%) were only hyperresponsive to the methacholine inhalation test (using the criteria of a PC20 ≤ 4 mg/mL). Thirty-two (24%) athletes had a known diagnosis of asthma, while 34 (26%) athletes received a new asthma diagnosis. Ninety-seven (73%) athletes were sensitized to common airborne allergens. Forty-seven (35%) athletes completed the cardiovascular evaluation. Three (6%) and 7 (15%) athletes had a previous or new diagnosis of cardiovascular disease, respectively. Resting systemic hypertension was documented in 2 (4%) athletes and exaggerated blood pressure response to exercise was found in 12 (26%) athletes. This cardiorespiratory screening data set in athletes showed a high prevalence of exercise-induced asthma and exercise hypertension, which in many cases were not previously diagnosed.

Brain activation during dual-task processing is associated with cardiorespiratory fitness and performance in older adults

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Chelsea N Wong

2015-08-01

Full Text Available Higher cardiorespiratory fitness is associated with better cognitive performance and enhanced brain activation. Yet, the extent to which cardiorespiratory fitness-related brain activation is associated with better cognitive performance is not well understood. In this cross-sectional study, we examined whether the association between cardiorespiratory fitness and executive function was mediated by greater prefrontal cortex activation in healthy older adults. Brain activation was measured during dual-task performance with functional magnetic resonance imaging in a sample of 128 healthy older adults (59-80 years. Higher cardiorespiratory fitness was associated with greater activation during dual-task processing in several brain areas including the anterior cingulate and supplementary motor cortex (ACC/SMA, thalamus and basal ganglia, right motor/somatosensory cortex and middle frontal gyrus, and left somatosensory cortex, controlling for age, sex, education, and gray matter volume. Of these regions, greater ACC/SMA activation mediated the association between cardiorespiratory fitness and dual-task performance. We provide novel evidence that cardiorespiratory fitness may support cognitive performance by facilitating brain activation in a core region critical for executive function.

Relationship between dynapenia and cardiorespiratory functions in healthy postmenopausal women: novel clinical criteria.

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Barbat-Artigas, Seébastien; Dupontgand, Sophie; Fex, Annie; Karelis, Antony D; Aubertin-Leheudre, Mylène

2011-04-01

Muscle strength seems to be a better indicator of physical limitations than skeletal muscle mass is. The purpose of this study was to investigate, using a new developed clinical tool, the relationship between type I dynapenia and cardiorespiratory functions in postmenopausal women. Forty-six postmenopausal women were recruited and divided into two groups (dynapenic vs nondynapenic). Body composition (bioelectrical impedancemetry), muscle strength (dynamometer), cardiorespiratory functions (maximum oxygen consumption and forced expiratory volume in 1 second), resting energy expenditure (indirect calorimetry), and dietary intake (3-d dietary journal) were measured. Type I dynapenia was defined as less than 1.53 kg per skeletal muscle mass (kg) based on handgrip dynamometer. Significant differences were found between dynapenic (n=23) and nondynapenic (n=23) postmenopausal women for cardiorespiratory functions (maximum oxygen consumption, P=0.003; and forced expiratory volume in 1 second, P=0.046). We observed no differences between groups for age, age at menopause, use of hormone therapy, body mass index, waist circumference, fat mass, resting energy expenditure, and total energy intake, which are known to be potential confounders. No differences were observed for cardiorespiratory functions when our population was divided into sarcopenic and nonsarcopenic groups. Type I dynapenic women have significantly poorer cardiorespiratory functions that do nondynapenic women even if they presented the same skeletal muscle mass index. Thus, based on our results, dynapenia could potentially be used as a marker of cardiorespiratory functions. The clinical method developed to identify dynapenic women could be used by health professionals. © 2011 by The North American Menopause Society

Cardiorespiratory fitness modifies the relationship between myocardial function and cerebral blood flow in older adults.

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Johnson, Nathan F; Gold, Brian T; Bailey, Alison L; Clasey, Jody L; Hakun, Jonathan G; White, Matthew; Long, Doug E; Powell, David K

2016-05-01

A growing body of evidence indicates that cardiorespiratory fitness attenuates some age-related cerebral declines. However, little is known about the role that myocardial function plays in this relationship. Brain regions with high resting metabolic rates, such as the default mode network (DMN), may be especially vulnerable to age-related declines in myocardial functions affecting cerebral blood flow (CBF). This study explored the relationship between a measure of myocardial mechanics, global longitudinal strain (GLS), and CBF to the DMN. In addition, we explored how cardiorespiratory affects this relationship. Participants were 30 older adults between the ages of 59 and 69 (mean age=63.73years, SD=2.8). Results indicated that superior cardiorespiratory fitness and myocardial mechanics were positively associated with DMN CBF. Moreover, results of a mediation analysis revealed that the relationship between GLS and DMN CBF was accounted for by individual differences in fitness. Findings suggest that benefits of healthy heart function to brain function are modified by fitness. Copyright © 2015 Elsevier Inc. All rights reserved.

Physical fitness and performance. Cardiorespiratory fitness in girls-change from middle to high school.

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Pfeiffer, Karin A; Dowda, Marsha; Dishman, Rod K; Sirard, John R; Pate, Russell R

2007-12-01

To determine how factors are related to change in cardiorespiratory fitness (CRF) across time in middle school girls followed through high school. Adolescent girls (N = 274, 59% African American, baseline age = 13.6 +/- 0.6 yr) performed a submaximal fitness test (PWC170) in 8th, 9th, and 12th grades. Height, weight, sports participation, and physical activity were also measured. Moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA) were determined by the number of blocks reported on the 3-Day Physical Activity Recall (3DPAR). Individual differences and developmental change in CRF were assessed simultaneously by calculating individual growth curves for each participant, using growth curve modeling. Both weight-relative and absolute CRF increased from 8th to 9th grade and decreased from 9th to 12th grade. On average, girls lost 0.16 kg.m.min.kg.yr in weight-relative PWC170 scores (P interactions between CRF, physical activity, race, BMI, and sports participation.

Sedentary behavior, physical activity and cardiorespiratory fitness on leukocyte telomere length.

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Edwards, Meghan K; Loprinzi, Paul D

2017-01-01

Background: Emerging work is starting to investigate the cumulative effects of moderate-to-vigorous physical activity (MVPA), sedentary behavior and cardiorespiratory fitness on health. The objective of this study was to examine the cumulative and independent associations of MVPA, sedentary behavior and cardiorespiratory fitness on leukocyte telomere length (LTL). Methods: Data from the 1999-2002 National Health and Nutrition Examination Survey (NHANES) were used (N = 1868 adults 20+ years); analyzed in 2016. Sedentary behavior and MVPA were subjectively assessed with cardiorespiratory fitness determined from a submaximal treadmill-based test; participants were classified as above or below the median values for each of these three parameters. A blood sample was obtained from each participant to assess LTL via quantitative polymerase chain reaction, with participants grouped into LTL tertiles. Results: Participants who engaged in higher MVPA, sat less and had higher cardiorespiratory fitness had an increased odds (ranging from 85% to 105%) of being in LTL tertile 3 (vs. 1). In an extended adjusted multinomial logistic regression model, only MVPA was positively associated with LTL (odds ration [OR] = 1.37; 95% CI: 0.99-1.90; P = 0.05). Conclusion: All three behavior characteristics, but particularly MVPA, may be important in preserving LTLs.

The association between physical activity, cardiorespiratory fitness and self-rated health

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Eriksen, Louise; Curtis, Tine; Grønbæk, Morten

2013-01-01

OBJECTIVE: To investigate the joint association between self-reported physical activity as well as cardiorespiratory fitness and self-rated health among healthy women and men. METHOD: Data from 10,416 participants in The Danish Health Examination Survey 2007-2008 which took part in 13 Danish...... municipalities were analyzed. Leisure time physical activity level and self-rated health were based on self-reported questionnaire data. Optimal self-rated health was defined as "very good" or "good" self-rated health. Cardiorespiratory fitness (mL O2·min(-1)·kg(-1)) was estimated from maximal power output...... in a maximal cycle exercise test. RESULTS: A strong dose-response relation between cardiorespiratory fitness and self-rated health as well as between physical activity level and self-rated health among both women and men was found. Within categories of physical activity, odds ratios for optimal self...

The cardiorespiratory effects of detomidine in the primate (Papio ursinus)

OpenAIRE

H. Bosman

1990-01-01

Detomidine is a novel imidazole derivative with a high affinity for a₂-adrenoceptors. The cardiorespiratory effects of this drug were evaluated in the primate (Papio ursinus) under ketamine anaesthesia. The release of noradrenalin is modulated by a₂-adrenoceptors, and this resulted in a longer duration of anaesthesia when ketamine was combined with detomidine in comparison with ketamine alone. Detomidine caused a marked bradycardia, which was not reflex induced, but probably the result of...

Unilateral Arm Crank Exercise Test for Assessing Cardiorespiratory Fitness in Individuals with Hemiparetic Stroke

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Oyake, Kazuaki; Yamaguchi, Tomofumi; Oda, Chihiro

2017-01-01

Cardiorespiratory fitness assessment with leg cycle exercise testing may be influenced by motor impairments in the paretic lower extremity. Hence, this study examined the usefulness of a unilateral arm crank exercise test to assess cardiorespiratory fitness in individuals with stroke, including s...

Comparison of Cardiorespiratory and Metabolic Responses in Kettlebell High-Intensity Interval Training Versus Sprint Interval Cycling.

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Williams, Brian M; Kraemer, Robert R

2015-12-01

The purpose of this study was to determine the effectiveness of a novel exercise protocol we developed for kettlebell high-intensity interval training (KB-HIIT) by comparing the cardiorespiratory and metabolic responses to a standard sprint interval cycling (SIC) exercise protocol. Eight men volunteered for the study and completed 2 preliminary sessions, followed by two 12-minute sessions of KB-HIIT and SIC in a counterbalanced fashion. In the KB-HITT session, 3 circuits of 4 exercises were performed using a Tabata regimen. In the SIC session, three 30-second sprints were performed, with 4 minutes of recovery in between the first 2 sprints and 2.5 minutes of recovery after the last sprint. A within-subjects' design over multiple time points was used to compare oxygen consumption (V[Combining Dot Above]O2), respiratory exchange ratio (RER), tidal volume (TV), breathing frequency (f), minute ventilation (VE), caloric expenditure rate (kcal·min), and heart rate (HR) between the exercise protocols. Additionally, total caloric expenditure was compared. A significant group effect, time effect, and group × time interaction were found for V[Combining Dot Above]O2, RER, and TV, with V[Combining Dot Above]O2 being higher and TV and RER being lower in the KB-HIIT compared with the SIC. Only a significant time effect and group × time interaction were found for f, VE, kcal·min, and HR. Additionally, total caloric expenditure was found to be significantly higher during the KB-HIIT. The results of this study suggest that KB-HIIT may be more attractive and sustainable than SIC and can be effective in stimulating cardiorespiratory and metabolic responses that could improve health and aerobic performance.

Cardiovascular and cardiorespiratory phase synchronization in normovolemic and hypovolemic humans.

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Zhang, Qingguang; Patwardhan, Abhijit R; Knapp, Charles F; Evans, Joyce M

2015-02-01

We investigated whether and how cardiovascular and cardiorespiratory phase synchronization would respond to changes in hydration status and orthostatic stress. Four men and six women were tested during graded head-up tilt (HUT) in both euhydration and dehydration (DEH) conditions. Continuous R-R intervals (RRI), systolic blood pressure (SBP) and respiration were investigated in low (LF 0.04-0.15 Hz) and high (HF 0.15-0.4 Hz) frequency ranges using a phase synchronization index (λ) ranging from 0 (complete lack of interaction) to 1 (perfect interaction) and a directionality index (d), where a positive value of d reflects oscillator 1 driving oscillator 2, and a negative value reflects the opposite driving direction. Surrogate data analysis was used to exclude relationships that occurred by chance. In the LF range, respiration was not synchronized with RRI or SBP, whereas RRI and SBP were phase synchronized. In the HF range, phases among all variables were synchronized. DEH reduced λ among all variables in the HF and did not affect λ between RRI and SBP in the LF region. DEH reduced d between RRI and SBP in the LF and did not affect d among all variables in the HF region. Increasing λ and decreasing d between SBP and RRI were observed in the LF range during HUT. Decreasing λ between SBP and RRI, respiration and RRI, and decreasing d between respiration and SBP were observed in the HF range during HUT. These results show that orthostatic stress disassociated interactions among RRI, SBP and respiration, and that DEH exacerbated the disconnection.

Quantification of cardiovascular and cardiorespiratory coupling during hypoxia with Joint Symbolic Dynamics.

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Reulecke, S; Schulz, S; Bauer, R; Witte, H; Voss, A

2011-01-01

Newborn mammals suffering from moderate hypoxia during or after birth are able to compensate a transitory lack of oxygen by adaptation of their vital functions. However, limited information is available about bivariate couplings of the underlying complex processes controlled by the autonomic nervous system. In this study an animal model of seven newborn piglets (2-3 days old, 1.71 ± 0.15 kg) was used. The aim of this study was to analyze the cardiovascular and cardiorespiratory interactions of autonomous nervous system during sustained hypoxia and the interrelationship of these autonomic time series after induced reoxygenation. For this purpose we applied a new high resolution version of the nonlinear method of Joint Symbolic Dynamics (JSD) for analysis of couplings between heart rate and blood pressure and respiration rate time series, respectively. This new method is characterized by using three defined symbols (JSD3) instead of two and the application of thresholds for the symbol transformation. Our results demonstrate that in contrast to the traditional JSD the comparison of cardiovascular interactions reveals only significant differences between normoxic and hypoxic conditions using JSD3 whereas for cardiorespiratory interactions significant differences were revealed by indices from both JSD2 and JSD3 due to reoxygenation. These results suggest that the application of JSD3 reveals more detailed information about cardiovascular and cardiorespiratory interactions of autonomic regulation and might be useful for monitoring of critical human newborns.

Perceived competence and enjoyment in predicting students' physical activity and cardiorespiratory fitness.

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Gao, Zan

2008-10-01

This study investigated the predictive strength of perceived competence and enjoyment on students' physical activity and cardiorespiratory fitness in physical education classes. Participants (N = 307; 101 in Grade 6, 96 in Grade 7, 110 in Grade 8; 149 boys, 158 girls) responded to questionnaires assessing perceived competence and enjoyment of physical education, then their cardiorespiratory fitness was assessed on the Progressive Aerobic Cardiovascular Endurance Run (PACER) test. Physical activity in one class was estimated via pedometers. Regression analyses showed enjoyment (R2 = 16.5) and perceived competence (R2 = 4.2) accounted for significant variance of only 20.7% of physical activity and, perceived competence was the only significant contributor to cardiorespiratory fitness performance (R2 = 19.3%). Only a small amount of variance here leaves 80% unaccounted for. Some educational implications and areas for research are mentioned.

Joint symbolic dynamics for the assessment of cardiovascular and cardiorespiratory interactions.

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Baumert, Mathias; Javorka, Michal; Kabir, Muammar

2015-02-13

Beat-to-beat variations in heart period provide information on cardiovascular control and are closely linked to variations in arterial pressure and respiration. Joint symbolic analysis of heart period, systolic arterial pressure and respiration allows for a simple description of their shared short-term dynamics that are governed by cardiac baroreflex control and cardiorespiratory coupling. In this review, we discuss methodology and research applications. Studies suggest that analysis of joint symbolic dynamics provides a powerful tool for identifying physiological and pathophysiological changes in cardiovascular and cardiorespiratory control.

Cardiorespiratory fitness modifies the association between dietary fat intake and plasma fatty acids.

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König, D; Väisänen, S B; Bouchard, C; Halle, M; Lakka, T A; Baumstark, M W; Alen, M; Berg, A; Rauramaa, R

2003-07-01

To investigate the relation between (1) cardiorespiratory fitness and plasma saturated, monounsaturated and polyunsaturated fatty acids and (2) the interactions between cardiorespiratory fitness, dietary fat intake and plasma fatty acid composition. Cross-sectional analysis. The subjects were randomly selected, 127 middle-aged Finnish men participating in the DNASCO exercise intervention study. Cardiorespiratory fitness was determined spiroergometrically, dietary intake of macro- and micronutrients by 4-day food records and plasma fatty acids by gas chromatography. The subjects were divided into tertiles of aerobic fitness. Differences between fitness tertiles were not observed for dietary intake of total fat, and saturated, monounsaturated or polyunsaturated fatty acids (percent of total energy). In contrast, plasma saturated fatty acids were significantly lower (P cardiorespiratory fitness are associated with different levels in plasma saturated and polyunsaturated fatty acids and lead to modifications in the association between dietary and plasma fatty acids. These findings can perhaps be explained by a reduced hepatic fatty acid and lipoprotein synthesis as well as by an enhanced muscular lipid utilization, which are commonly seen in those who are physically active and who exhibit a higher level of fitness.

Ballet dancers cardiorespiratory, oxidative and muscle damage responses to classes and rehearsals.

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Rodrigues-Krause, Josianne; Krause, Mauricio; Cunha, Giovani Dos Santos; Perin, Diana; Martins, Jocelito B; Alberton, Cristine Lima; Schaun, Maximiliano I; De Bittencourt, Paulo Ivo Homem; Reischak-Oliveira, Alvaro

2014-01-01

This study aimed to describe and compare ballet dancers' cardiorespiratory responses, muscle damage and oxidative stress levels during a ballet class (practice of isolated ballet exercises performed with barre/hand-rail support and across-the-floor movements to improve technical skills) and rehearsal (practice of ballet choreography involving technical-artistic skills to improve dancers' performance for shows). The 12 advanced female ballet dancers undertook three exercise sessions: maximum effort test, class and rehearsal. Heart rate (HR) and oxygen consumption (VO2) were continuously measured. Lactate was determined before 15 min and after class and rehearsal. Blood was sampled pre, post and 48 h after class and rehearsal for creatine kinase (CK), lipid peroxides (LPO) and glutathione analysis (GSSG/GSH). Class was of lower intensity than rehearsal as shown by VO2, HR and lactate values: VO2 (mL.kg(-1).min(-1)): 14.5±2.1 vs. 19.1±1.7 (p Ballet dancers' muscle damage and oxidative stress responses seem not to be dependent on exercise intensity based on VO2 responses.

Cardiorespiratory fitness, BMI, and risk of hypertension: the HYPGENE study.

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Rankinen, Tuomo; Church, Timothy S; Rice, Treva; Bouchard, Claude; Blair, Steven N

2007-10-01

Cardiorespiratory fitness and regular physical activity are inversely associated with the risk of hypertension, and exercise training has been shown to lower elevated blood pressure (BP). Genetic factors contribute significantly to the interindividual differences in endurance training-induced changes in BP. However, similar data on the genotype-by-fitness interactions on the risk of hypertension are scarce. In 2000, we started a systematic collection of blood samples from all consenting subjects of the Aerobics Center Longitudinal Study (ACLS) with a goal to generate a resource for studies addressing genotype-by-fitness interaction effects on various health-related end points. Here, we introduce the rationale and design of the first study based on the ACLS genetics resource focusing on hypertension as the health outcome (HYPGENE study), and we report the associations of cardiorespiratory fitness and body mass index (BMI) with the risk of hypertension. All HYPGENE subjects (N = 1234) were healthy and normotensive at their first clinic visit. Cases (N = 629) developed hypertension during the follow-up period (mean 8.7 yr), whereas controls (N = 605) remained normotensive (mean follow-up 10.1 yr). Cardiorespiratory fitness was the strongest predictor of the hypertension risk, with each maximal metabolic equivalent unit being associated with a 19% lower risk (95% confidence interval [95% CI], 12-24%). Each baseline BMI unit was associated with a 9% higher hypertension risk (95% CI, 4-13%). However, the association of BMI was greatly attenuated (odds ratio 1.04 [95% CI, 0.99-1.09]) when fitness also was included in the model. The HYPGENE study will provide an excellent resource to address hypotheses regarding the genetic basis of hypertension while taking cardiorespiratory fitness level into account.

"SAFE" LEVEL OF SOMATIC HEALTH IN INDICATORS REGULATION OF CARDIORESPIRATORY SYSTEM AT YOUNG MEN

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Alexander P Romanchuk

2015-12-01

2Lviv State University Physical Culture The aim of this study was to determine the functional state cardiorespiratory system in males younger with "safe" level of somatic health (LSH. Were examined 104 males aged 20,6 ± 0,9 years, engaged in various sports, and had no existing acute and chronic diseases. The survey was conducted using spiroarteriocardiorhythmography (SACR. It is shown that in all studied systems of regulation, regulation except SBP probably marked differences between persons with "safe" and "low" LSH. At the same time, the comparison of "safe" and "medium" LSH differences relate only to the predominance of sympathetic influences on heart rate, decrease suprasegmental effects on DBP, reducing regulatory influences on spontaneous breath and their high-frequency components, reducing of baroreflex sensitivity and cardiac output. Key words: "safe" level of somatic health, regulation of the cardiorespiratory system.

The Effect of Cardiorespiratory Fitness and Obesity on Cancer Mortality in Women and Men.

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Evenson, Kelly R.; Stevens, June; Cai, Jianwen; Thomas, Ratna; Thomas, Olivia

2003-01-01

Investigated the independent and combined effects of cardiorespiratory fitness and obesity on all-cause cancer mortality for women and men. Data from the Lipids Research Clinics Prevalence Study indicated that higher fitness level was a stronger predictor of reduced cancer mortality among men, while high body mass index was a stronger predictor of…

Isoflurane increases cardiorespiratory coordination in rats

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Kabir, Muammar M.; Beig, Mirza I.; Nalivaiko, Eugene; Abbott, Derek; Baumert, Mathias

2008-12-01

Anesthetics such as isoflurane adversely affect heart rate. In this study we analysed the interaction between heart rhythm and respiration at different concentrations of isoflurane and ventilation rates. In two rats, the electrocardiogram (ECG) and respiratory signals were recorded under the influence of isoflurane. For the assessment of cardiorespiratory coordination, we analysed the phase locking between heart rate, computed from the R-R intervals of body surface ECG, and respiratory rate, computed from impedance changes, using Hilbert transform. The changes in heart rate, percentage of synchronization and duration of synchronized epochs at different isoflurane concentrations and ventilation rates were assessed using linear regression model. From this study it appears that the amount of phase locking between cardiac and respiratory rates increases with the increase in concentration of isoflurane. Heart rate and duration of synchronized epochs increased significantly with the increase in the level of isoflurane concentration while respiratory rate was not significantly affected. Cardiorespiratory coordination also showed a considerable increase at the ventilation rates of 50- 55 cpm in both the rats, suggesting that the phase-locking between the cardiac and respiratory oscillators can be increased by breathing at a particular respiratory frequency.

Maternal dietary tryptophan deficiency alters cardiorespiratory control in rat pups.

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Penatti, Eliana M; Barina, Alexis E; Raju, Sharat; Li, Aihua; Kinney, Hannah C; Commons, Kathryn G; Nattie, Eugene E

2011-02-01

Malnutrition during pregnancy adversely affects postnatal forebrain development; its effect upon brain stem development is less certain. To evaluate the role of tryptophan [critical for serotonin (5-HT) synthesis] on brain stem 5-HT and the development of cardiorespiratory function, we fed dams a diet ∼45% deficient in tryptophan during gestation and early postnatal life and studied cardiorespiratory variables in the developing pups. Deficient pups were of normal weight at postnatal day (P)5 but weighed less than control pups at P15 and P25 (P interactions between nutrition, brain stem physiology, and age that are potentially relevant to understanding 5-HT deficiency in the sudden infant death syndrome.

Metabolic risk in schoolchildren is associated with low levels of cardiorespiratory fitness, obesity, and parents' nutritional profile.

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Todendi, Pâmela Ferreira; Valim, Andréia Rosane de Moura; Reuter, Cézane Priscila; Mello, Elza Daniel de; Gaya, Anelise Reis; Burgos, Miria Suzana

2016-01-01

Verify the association between metabolic risk profile in students with different levels of cardiorespiratory fitness and body mass index, as well as the nutritional status of their parents. A cross-sectional study comprising 1.254 schoolchildren aged between seven and 17 years. The metabolic risk profile was calculated by summing the standardized values of high density lipoproteins and low density lipoproteins, triglycerides, glucose and systolic blood pressure. The parents' nutritional status was evaluated by self-reported weight and height data, for body mass index calculating. The body mass index of schoolchildren was classified as underweight/normal weight and overweight/obesity. The cardiorespiratory fitness was assessed by 9-minute running/walk test, being categorized as fit (good levels) and unfit (low levels). Data were analyzed using prevalence ratio values (PR). The data indicates a higher occurrence of developing metabolic risk in schoolchildren whose mother is obese (PR: 1.50; 95% CI: 1.01, 2.23), and even higher for those whose father and mother are obese (PR: 2, 79, 95% CI: 1.41; 5.51). Students who have low levels of cardiorespiratory fitness and overweight/obesity have higher occurrence of presenting metabolic risk profile (PR: 5.25; 95% CI: 3.31; 8.16). the occurrence of developing metabolic risk in schoolchildren increase when they have low levels of cardiorespiratory fitness and overweight/obesity, and the presence of parental obesity. Copyright © 2016 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Cardiorespiratory Coordination in Repeated Maximal Exercise

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Sergi Garcia-Retortillo

2017-06-01

Full Text Available Increases in cardiorespiratory coordination (CRC after training with no differences in performance and physiological variables have recently been reported using a principal component analysis approach. However, no research has yet evaluated the short-term effects of exercise on CRC. The aim of this study was to delineate the behavior of CRC under different physiological initial conditions produced by repeated maximal exercises. Fifteen participants performed 2 consecutive graded and maximal cycling tests. Test 1 was performed without any previous exercise, and Test 2 6 min after Test 1. Both tests started at 0 W and the workload was increased by 25 W/min in males and 20 W/min in females, until they were not able to maintain the prescribed cycling frequency of 70 rpm for more than 5 consecutive seconds. A principal component (PC analysis of selected cardiovascular and cardiorespiratory variables (expired fraction of O2, expired fraction of CO2, ventilation, systolic blood pressure, diastolic blood pressure, and heart rate was performed to evaluate the CRC defined by the number of PCs in both tests. In order to quantify the degree of coordination, the information entropy was calculated and the eigenvalues of the first PC (PC1 were compared between tests. Although no significant differences were found between the tests with respect to the performed maximal workload (Wmax, maximal oxygen consumption (VO2 max, or ventilatory threshold (VT, an increase in the number of PCs and/or a decrease of eigenvalues of PC1 (t = 2.95; p = 0.01; d = 1.08 was found in Test 2 compared to Test 1. Moreover, entropy was significantly higher (Z = 2.33; p = 0.02; d = 1.43 in the last test. In conclusion, despite the fact that no significant differences were observed in the conventionally explored maximal performance and physiological variables (Wmax, VO2 max, and VT between tests, a reduction of CRC was observed in Test 2. These results emphasize the interest of CRC

Thermal and cardiorespiratory newborn adaptations during hot tub bath

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Gentil Gomes da Fonseca Filho

2017-03-01

Full Text Available Objective: To evaluate thermal and cardiorespiratory adaptation during hot tub bath and shower in healthy newborns in the first hours of life. Study design: This is a randomized blind controlled trial, registered in ReBEC (No. RBR-4z26f3 with 184 newborns divided into hot tub group (n=84 and shower (n=100. Newborns from intervention group were immersed in a hot tub with warm water up to the neck, without exposure to air flow, and control group received traditional shower. Heart rate, respiratory rate and temperature were measured before and immediately after bath by an investigator blinded to the type of bath. Results: Groups were similar in gender, gestational age, birth weight, Apgar score at 5th minute and hours of life, p => 0.05. To analyze thermal and cardiorespiratory adjustments, difference between post-bath variables and pre-bath was calculated. In this analysis, it was found statistically significant difference between two types of bath regarding heart rate, respiratory rate and temperature. Hot tub bath decreases heart and respiratory rates and increases temperature, whereas shower provides the opposite effect (0.0001. Conclusion: This study demonstrates that hot tub baths and shower, in healthy newborns, promote thermal and cardiorespiratory adaptations, reflecting thermal, cardiac and respiratory positive reactions after hot tub bath.

Interactions between sleeping position and feeding on cardiorespiratory activity in preterm infants.

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Fifer, William P; Myers, Michael M; Sahni, Rakesh; Ohira-Kist, Kiyoko; Kashyap, Sudha; Stark, Raymond I; Schulze, Karl F

2005-11-01

Infants sleeping in the prone position are at greater risk for sudden infant death syndrome (SIDS). Sleep position-dependent changes in cardiorespiratory activity may contribute to this increased risk. Cardiorespiratory activity is also affected by feeding. Twenty prematurely-born infants were studied at 31-36 weeks postconceptional age while sleeping in the prone and supine positions. Heart rate, respiratory rate, and patterns of variability were recorded during interfeed intervals, and effects of position and time after feeding were analyzed by repeated measures analyses of variance. There were significant effects of both sleeping position and time after feeding. Heart rate is higher and heart period variability is lower in the prone position, and the effects of sleeping position on cardiac functioning are more pronounced during the middle of the intrafeed interval. In preterm infants, autonomic responses to nutrient processing modulate the cardiorespiratory effects of sleeping position. Prone sleeping risk may vary with time after feeding. Copyright 2005 Wiley Periodicals, Inc.

Ambient and Unobtrusive Cardiorespiratory Monitoring Techniques.

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Bruser, Christoph; Antink, Christoph Hoog; Wartzek, Tobias; Walter, Marian; Leonhardt, Steffen

2015-01-01

Monitoring vital signs through unobtrusive means is a goal which has attracted a lot of attention in the past decade. This review provides a systematic and comprehensive review over the current state of the field of ambient and unobtrusive cardiorespiratory monitoring. To this end, nine different sensing modalities which have been in the focus of current research activities are covered: capacitive electrocardiography, seismo- and ballistocardiography, reflective photoplethysmography (PPG) and PPG imaging, thermography, methods relying on laser or radar for distance-based measurements, video motion analysis, as well as methods using high-frequency electromagnetic fields. Current trends in these subfields are reviewed. Moreover, we systematically analyze similarities and differences between these methods with respect to the physiological and physical effects they sense as well as the resulting implications. Finally, future research trends for the field as a whole are identified.

Cardiorespiratory Effects of One-Legged High-Intensity Interval Training in Normoxia and Hypoxia: A Pilot Study

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Verena Menz, Mona Semsch, Florian Mosbach, Martin Burtscher

2016-06-01

Full Text Available A higher-than-average maximal oxygen consumption (VO2max, is closely associated with decreased morbidity and mortality and improved quality of life and acts as a marker of cardiorespiratory fitness. Although there is no consensus about an optimal training method to enhance VO2max, nevertheless training of small muscle groups and repeated exposure to hypoxia seem to be promising approaches. Therefore, this study was aimed at gaining innovative insights into the effects of small muscle group training in normoxia and hypoxia. Thirteen healthy participants were randomly assigned to the hypoxic (HG, n = 7 or normoxic (NG, n = 6 training group. Both groups completed nine high-intensity interval training sessions in 3 wks. The NG performed the training in normoxia (FiO2: 0.21; ~ 600 m and the HG in hypoxia (FiO2: 0.126; ~ 4500 m. Each session consisted of 4 x 4 min one-legged cycling at 90% of maximal heart rate separated by 4 min recovery periods. Before and after the intervention period, VO2max and peak power output (Wmax and responses to submaximal cycling (100 and 150 watts were assessed in a laboratory cycling test. Peak power output significantly improved within both groups (9.6 ± 4.8% and 12.6 ± 8.9% for HG and NG, respectively with no significant interaction (p = 0.277. However, VO2max only significantly increased after training in hypoxia from 45.4 ± 10.1 to 50.0 ± 9.8 ml/min/kg (10.8 ± 6.0%; p = 0.002 with no significant interaction (p = 0.146. The maximal O2-pulse improved within the HG and demonstrated a significant interaction (p = 0.040. One-legged cycling training significantly improved VO2max and peak power output. Training under hypoxic conditions may generate greater effects on VO2max than a similar training in normoxia and is considered as a promising training method for improving cardiorespiratory fitness.

Cardiorespiratory Responses to Pool Floor Walking in People Poststroke.

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Jeng, Brenda; Fujii, Takuto; Lim, Hyosok; Vrongistinos, Konstantinos; Jung, Taeyou

2018-03-01

To compare cardiorespiratory responses between pool floor walking and overground walking (OW) in people poststroke. Cross-sectional study. University-based therapeutic exercise facility. Participants (N=28) were comprised of 14 community-dwelling individuals poststroke (5.57±3.57y poststroke) and 14 age- and sex-matched healthy adults (mean age, 58.00±15.51y; male/female ratio, 9:5). Not applicable. A telemetric metabolic system was used to collect cardiorespiratory variables, including oxygen consumption (V˙o 2 ), energy expenditure (EE), and expired volume per unit time (V˙e), during 6-minute walking sessions in chest-depth water and on land at a matched speed, determined by average of maximum walking speed in water. Individuals poststroke elicited no significant differences in cardiorespiratory responses between pool floor walking and OW. However, healthy controls showed significant increases in mean V˙o 2 values by 94%, EE values by 109%, and V˙e values by 94% (all Pstroke group did not. Our results indicate that people poststroke, unlike healthy adults, do not increase EE while walking in water compared with on land. Unlike stationary walking on an aquatic treadmill, forward locomotion during pool floor walking at faster speeds may have increased drag force, which requires greater EE from healthy adults. Without demanding excessive EE, walking in water may offer a naturally supportive environment for gait training in the early stages of rehabilitation. Copyright © 2017 American Congress of Rehabilitation Medicine. All rights reserved.

The independent roles of cardiorespiratory fitness and sedentary time on chronic conditions and Body Mass Index in older adults.

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Stathokostas, L; Dogra, S; Paterson, D H

2015-10-01

The aim of this paper was to examine the independent influence of cardiorespiratory fitness and sedentary behavior on chronic disease incidence and body composition in older adults. A sample of 292 community dwelling men and women (mean 69.3±8.1 years) underwent maximal treadmill testing and completed questionnaires relating to their leisure-time physical activity, sedentary time, and health. The average V O2 of the sample was approximately 21 ml.kg(-1).min(-1) with the average sedentary time being over 3 hours per day. Cardiorespiratory fitness was found to be a stronger predictor of number of chronic conditions and BMI than total physical activity and sedentary. Those with a higher cardiorespiratory fitness had fewer chronic conditions and a lower BMI. No such associations were seen for either total physical activity levels or sedentary time. Cardiorespiratory fitness is a stronger predictor of health among older adults and further highlights the importance of promoting public health guidelines for cardiorespiratory fitness.

The Relationship between Socioeconomic Status, Family Income, and Measures of Muscular and Cardiorespiratory Fitness in Colombian Schoolchildren.

Science.gov (United States)

Sandercock, Gavin R H; Lobelo, Felipe; Correa-Bautista, Jorge E; Tovar, Gustavo; Cohen, Daniel Dylan; Knies, Gundi; Ramírez-Vélez, Robinson

2017-06-01

To determine the associations between socioeconomic status (SES) and physical fitness in a sample of Colombian youth. Prueba SER is cross-sectional survey of schoolchildren in Bogota, Colombia. Mass, stature, muscular fitness (standing long-jump, handgrip), and cardiorespiratory fitness (20-m shuttle run) were measured in 52?187 schoolchildren 14-16 years of age. Area-level SES was categorized from 1 (very low) to 4 (high) and parent-reported family income was categorized as low, middle, or high. Converting measures into z scores showed stature, muscular, and cardiorespiratory fitness were significantly (z?=?0.3-0.7) below European values. Children in the mid- and high SES groups jumped significantly further than groups with very low SES. Differences were independent of sex but became nonsignificant when adjusted for anthropometric differences. Participants in the mid-SES and high-SES groups had better handgrip scores when adjusted for body dimension. There were, however, no significant between-group differences in cardiorespiratory fitness, which was strongly clustered by school and significantly greater in students from private schools. Area-level SES is associated with measures of muscular fitness in Colombian schoolchildren. These associations were largely explained by the large differences in body dimensions observed between SES groups. When area-level SES is considered, there was no evidence that family income influenced fitness. The clustering of outcomes reaffirms the potential importance of schools and area-level factors in promoting fitness through opportunities for physical activity. Interventions implemented in schools, can improve academic attainment; a factor likely to be important in promoting the social mobility of children from poorer families. Copyright © 2016 Elsevier Inc. All rights reserved.

Cardio-respiratory symptoms in panic disorder: a contribution from cognitive-behaviour therapy

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Anna Lucia Spear King

2011-01-01

Full Text Available Objective: To compare patients with panic disorder with agoraphobia treated with cognitive-behavioural therapy (CBT associated with the medication with patients treated only with medication and verify the behaviour of the cardio-respiratory symptoms of both groups. Methods: Randomized sample in the Psychiatry Institute of the Federal University of Rio de Janeiro, divided in two groups of 25 participants each. Group 1 undertook 10 weekly sessions of CBT with one hour of duration each together with medication. Group 2, Control, were administered medication that only consisted of tricyclic anti-depressants and selective inhibitors of the re-uptake of serotonin. Evaluation instruments were applied at the beginning and to the end of the interventions. Results: According to the applied scales, group 1 showed statistically more significant results than group 2, with: reduction of panic attacks, cardio-respiratory symptoms, anticipatory anxiety, agoraphobia avoidance and fear of bodily sensations. Conclusion: Exposures (in vivo and interoceptive, especially for induction symptom exercises and relaxation, were considered essential to prepare patients with panic disorder to handle future cardio-respiratory symptoms and panic attacks with agoraphobia.

Quantifying cardiorespiratory responses resulting from speed and slope increments during motorized treadmill propulsion among manual wheelchair users.

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Gauthier, Cindy; Grangeon, Murielle; Ananos, Ludivine; Brosseau, Rachel; Gagnon, Dany H

2017-09-01

Cardiorespiratory fitness assessment and training among manual wheelchair (MW) users are predominantly done with an arm-crank ergometer. However, arm-crank ergometer biomechanics differ substantially from MW propulsion biomechanics. This study aimed to quantify cardiorespiratory responses resulting from speed and slope increments during MW propulsion on a motorized treadmill and to calculate a predictive equation based on speed and slope for estimating peak oxygen uptake (VO 2peak ) in MW users. In total, 17 long-term MW users completed 12 MW propulsion periods (PP), each lasting 2min, on a motorized treadmill, in a random order. Each PP was separated by a 2-min rest. PPs were characterized by a combination of 3 speeds (0.6, 0.8 and 1.0m/s) and 4 slopes (0°, 2.7°, 3.6° and 4.8°). Six key cardiorespiratory outcome measures (VO 2 , heart rate, respiratory rate, minute ventilation and tidal volume) were recorded by using a gas-exchange analysis system. Rate of perceived exertion (RPE) was measured by using the modified 10-point Borg scale after each PP. For the 14 participants who completed the test, cardiorespiratory responses increased in response to speed and/or slope increments, except those recorded between the 3.6 o and 4.8 o slope, for which most outcome measures were comparable. The RPE was positively associated with cardiorespiratory response (r s ≥0.85). A VO 2 predictive equation (R 2 =99.7%) based on speed and slope for each PP was computed. This equation informed the development of a future testing protocol to linearly increase VO 2 via 1-min stages during treadmill MW propulsion. Increasing speed and slope while propelling a MW on a motorized treadmill increases cardiorespiratory response along with RPE. RPE can be used to easily and accurately monitor cardiorespiratory responses during MW exercise. The VO 2 can be predicted to some extent by speed and slope during MW propulsion. A testing protocol is proposed to assess cardiorespiratory fitness

The influence of high-intensity compared with moderate-intensity exercise training on cardiorespiratory fitness and body composition in colorectal cancer survivors: a randomised controlled trial.

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Devin, James L; Sax, Andrew T; Hughes, Gareth I; Jenkins, David G; Aitken, Joanne F; Chambers, Suzanne K; Dunn, Jeffrey C; Bolam, Kate A; Skinner, Tina L

2016-06-01

Following colorectal cancer diagnosis and anti-cancer therapy, declines in cardiorespiratory fitness and body composition lead to significant increases in morbidity and mortality. There is increasing interest within the field of exercise oncology surrounding potential strategies to remediate these adverse outcomes. This study compared 4 weeks of moderate-intensity exercise (MIE) and high-intensity exercise (HIE) training on peak oxygen consumption (V̇O2peak) and body composition in colorectal cancer survivors. Forty seven post-treatment colorectal cancer survivors (HIE = 27 months post-treatment; MIE = 38 months post-treatment) were randomised to either HIE [85-95 % peak heart rate (HRpeak)] or MIE (70 % HRpeak) in equivalence with current physical activity guidelines and completed 12 training sessions over 4 weeks. HIE was superior to MIE in improving absolute (p = 0.016) and relative (p = 0.021) V̇O2peak. Absolute (+0.28 L.min(-1), p body composition for colorectal cancer survivors. HIE appears to offer superior improvements in cardiorespiratory fitness and body composition in comparison to current physical activity recommendations for colorectal cancer survivors and therefore may be an effective clinical utility following treatment.

Breath-by-breath analysis of cardiorespiratory interaction for quantifying developmental maturity in premature infants

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Rusin, Craig G.; Hudson, John L.; Lee, Hoshik; Delos, John B.; Guin, Lauren E.; Vergales, Brooke D.; Paget-Brown, Alix; Kattwinkel, John; Lake, Douglas E.; Moorman, J. Randall

2012-01-01

In healthy neonates, connections between the heart and lungs through brain stem chemosensory pathways and the autonomic nervous system result in cardiorespiratory synchronization. This interdependence between cardiac and respiratory dynamics can be difficult to measure because of intermittent signal quality in intensive care settings and variability of heart and breathing rates. We employed a phase-based measure suggested by Schäfer and coworkers (Schäfer C, Rosenblum MG, Kurths J, Abel HH. Nature 392: 239–240, 1998) to obtain a breath-by-breath analysis of cardiorespiratory interaction. This measure of cardiorespiratory interaction does not distinguish between cardiac control of respiration associated with cardioventilatory coupling and respiratory influences on the heart rate associated with respiratory sinus arrhythmia. We calculated, in sliding 4-min windows, the probability density of heartbeats as a function of the concurrent phase of the respiratory cycle. Probability density functions whose Shannon entropy had a interaction. In this way, we analyzed 18 infant-years of data from 1,202 patients in the Neonatal Intensive Care Unit at University of Virginia. We found evidence of interaction in 3.3 patient-years of data (18%). Cardiorespiratory interaction increased several-fold with postnatal development, but, surprisingly, the rate of increase was not affected by gestational age at birth. We find evidence for moderate correspondence between this measure of cardiorespiratory interaction and cardioventilatory coupling and no evidence for respiratory sinus arrhythmia, leading to the need for further investigation of the underlying mechanism. Such continuous measures of physiological interaction may serve to gauge developmental maturity in neonatal intensive care patients and prove useful in decisions about incipient illness and about hospital discharge. PMID:22174403

Leisure-time physical activity, cardiorespiratory fitness and feelings of hopelessness in men

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Viinamäki Heimo

2009-06-01

Full Text Available Abstract Background Leisure-time physical activity (LTPA and cardiorespiratory fitness contribute to mental health. Hopelessness has been linked to impaired mental health, cardiovascular events and mortality. Previous studies have focused on physical exercise and depression. We examined the associations of LTPA and cardiorespiratory fitness with feelings of hopelessness. Methods In this cross-sectional study leisure-time physical activity, maximal oxygen uptake (VO2max, hopelessness and cardiovascular risk factors were assessed in a population-based cohort of 2428 men aged 42 – 60 years old at baseline. Results Men feeling more hopeless about their future and reaching goals were less physically active, less fit and had a higher prevalence of many cardiovascular risk factors than men with lower levels of hopelessness. In a logistic regression model adjusted for age, smoking, alcohol consumption, cardiovascular disease and socioeconomic status, men engaging in less than 60 min/week of moderate-to-vigorous LTPA were 37% (95% CI 11 – 67% more likely to feel hopeless than those engaging in at least 2.5 h/wk of LTPA. After further adjusting for elevated depressive symptoms the association of LTPA and hopelessness remained significant. VO2max was also associated with hopelessness, but not after adjustment for depressive symptoms. Conclusion Moderate and vigorous LTPA and cardiorespiratory fitness were inversely associated with hopelessness in these middle-aged men. These findings suggest that physical inactivity and poor cardiorespiratory fitness is an important associate of hopelessness, a distinct element of low subjective well-being.

Linking Inflammation, Cardiorespiratory Variability, and Neural Control in Acute Inflammation via Computational Modeling.

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Dick, Thomas E; Molkov, Yaroslav I; Nieman, Gary; Hsieh, Yee-Hsee; Jacono, Frank J; Doyle, John; Scheff, Jeremy D; Calvano, Steve E; Androulakis, Ioannis P; An, Gary; Vodovotz, Yoram

2012-01-01

Acute inflammation leads to organ failure by engaging catastrophic feedback loops in which stressed tissue evokes an inflammatory response and, in turn, inflammation damages tissue. Manifestations of this maladaptive inflammatory response include cardio-respiratory dysfunction that may be reflected in reduced heart rate and ventilatory pattern variabilities. We have developed signal-processing algorithms that quantify non-linear deterministic characteristics of variability in biologic signals. Now, coalescing under the aegis of the NIH Computational Biology Program and the Society for Complexity in Acute Illness, two research teams performed iterative experiments and computational modeling on inflammation and cardio-pulmonary dysfunction in sepsis as well as on neural control of respiration and ventilatory pattern variability. These teams, with additional collaborators, have recently formed a multi-institutional, interdisciplinary consortium, whose goal is to delineate the fundamental interrelationship between the inflammatory response and physiologic variability. Multi-scale mathematical modeling and complementary physiological experiments will provide insight into autonomic neural mechanisms that may modulate the inflammatory response to sepsis and simultaneously reduce heart rate and ventilatory pattern variabilities associated with sepsis. This approach integrates computational models of neural control of breathing and cardio-respiratory coupling with models that combine inflammation, cardiovascular function, and heart rate variability. The resulting integrated model will provide mechanistic explanations for the phenomena of respiratory sinus-arrhythmia and cardio-ventilatory coupling observed under normal conditions, and the loss of these properties during sepsis. This approach holds the potential of modeling cross-scale physiological interactions to improve both basic knowledge and clinical management of acute inflammatory diseases such as sepsis and trauma.

Oxytocin's role on the cardiorespiratory activity of endotoxemic rats.

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Elorza-Ávila, Ana Rosa; Reyes-Lagos, José Javier; Hadamitzky, Martin; Peña-Castillo, Miguel Ángel; Echeverría, Juan Carlos; Ortiz-Pedroza, María Del Rocío; Lückemann, Laura; Schedlowski, Manfred; Pacheco-López, Gustavo

2017-02-01

Recent findings concerning oxytocin indicate its anti-inflammatory, cardioprotective and parasympathetic modulating properties. In this study, we investigated the effects of systemically applied oxytocin on the cardiorespiratory activity in a rodent model of moderate endotoxemia. Telemetrically recorded electrocardiogram (ECGs) from animals which received lipopolysaccharide (LPS); oxytocin (Ox); lipopolysaccharide+oxytocin (LPS+Ox), or vehicle (V) were analyzed using the ECG-derived respiration (EDR) technique to estimate the respiratory rate. The mean R-R interval and the spectral parameters of heart rate variability (HRV), such as the natural logarithm of the high frequency (lnHF) and low frequency (lnLF) components were also estimated up to 24h after treatment. The endotoxemic animals (LPS) showed an elevated respiratory rate as well as a reduced mean R-R interval, lnHF and lnLF components compared to controls (V) from +5 to +12h after the treatment. The administration of oxytocin significantly attenuated the hyperventilation produced by the LPS-induced endotoxemia (LPS+Ox) and restored the values of the mean R-R interval and such spectral parameters at different time points. Our results support the existence of a link among the respiratory, cardiovascular, and immune systems in which oxytocin seems to act as a potential cardioprotective peptide by favoring cardiac cholinergic autonomic coupling. As a result, oxytocin diminished animal's endotoxemic tachypnea and restored the cardiorespiratory interactions, which was indicated by the spectral components of HRV. Copyright © 2016 Elsevier B.V. All rights reserved.

Cardiorespiratory Fitness and Incidence of Type 2 Diabetes in United States Veterans on Statin Therapy.

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Kokkinos, Peter; Faselis, Charles; Narayan, Puneet; Myers, Jonathan; Nylen, Eric; Sui, Xuemei; Zhang, Jiajia; Lavie, Carl J

2017-10-01

Impact of cardiorespiratory fitness on statin-related incidence of type 2 diabetes has not been assessed. We assessed the cardiorespiratory fitness and diabetes incidence association in dyslipidemic patients on statins. We identified dyslipidemic patients with a normal exercise test performed during 1986 and 2014 at the Veterans Affairs Medical Centers in Washington, DC or Palo Alto, Calif. The statin-treated patients (n = 4092; age = 58.8 ± 10.9 years) consisted of 2701 Blacks and 1391 Whites. None had evidence of type 2 diabetes prior to statin therapy. We formed 4 fitness categories based on age and peak metabolic equivalents achieved: Least-fit (n = 954), Low-fit (n = 1201), Moderate-fit (n = 1242), and High-fit (n = 695). The non-statin-treated cohort (n = 3001; age = 57.2 ± 11.2 years) with no evidence of type 2 diabetes prior to the exercise test served as controls. Diabetes incidence was 24% higher in statin-treated compared with non-statin-treated patients (P fit, adjusted risk decreased progressively with increasing fitness and was 34% lower for High-fit patients (hazard ratio [HR] 0.66; 95% confidence interval [CI], 0.53-0.82; P fit (HR 1.50; 95% CI, 1.30-1.73; P fit patients (HR 1.22; 95% CI, 1.06-1.41; P = .006). Risk of diabetes in statin-treated dyslipidemic patients was inversely and independently associated with cardiorespiratory fitness. The increased risk was evident only in relatively low-fitness patients. Improving fitness may modulate the potential diabetogenic effects of statins. Published by Elsevier Inc.

Cardiorespiratory fitness and physical activity in children with cancer

NARCIS (Netherlands)

Braam, Katja I.; van Dijk-Lokkart, Elisabeth M.; Kaspers, Gertjan J. L.; Takken, Tim; Huisman, Jaap; Bierings, Marc B.; Merks, Johannes H. M.; van de Heuvel-Eibrink, Marry M.; van Dulmen-den Broeder, Eline; Veening, Margreet A.

2016-01-01

This study assessed cardiorespiratory fitness (CRF), physical activity (PA), and sedentary behavior (SB), as well as factors associated with these outcomes in children during or shortly after cancer treatment. Cross-sectionally, CRF data, obtained by the cardiopulmonary exercise test, and PA and SB

Effect of Exercise on Cardiorespiratory Function in Obese Children with Asthma in Different Moisture Levels

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S Pouyan Majd

2014-09-01

Methods: The present case-control study was carried out with ten obese asthmatic children and fifteen healthy children who performed an exercise protocol in different environments (relative humidity 65 ± 5% versus 35 ± 5%. During exercise, cardiorespiratory parameters were controlled using K4B2. Heart rate, systolic blood pressure and double product were measured with a digital sphygmomanometer and stethoscope polar. Data were analyzed with dependent T test and ANOVA with repeated measures analysis. Results: A significant increase was detected in the markers of HR, SP and DP after exercise in obese children with asthma and healthy children (P< 0.005. However, indexes of cardiorespiratory and exhaustion was significantly higher in obese children with asthma and healthy during exercise in the environment with 65 ± 5% relative humidity, as compared to 35 ± 5% relative humidity. Conclusion: These results indicated that cardiorespiratory function in children with asthma and healthy children were different. Cardiorespiratory responses to exercise in children are influenced by environmental conditions such as humidity, so that humidity has a negative impact on the duration of the activity and load on the heart muscle.

[The changes of physiological reactivity of cardiorespiratory system to respiratory homeostasis with the use of complex stimulation of special work capacity].

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Lysenko, O M

2012-01-01

We present the influence of the program of special additional stimulation of work capacity of high-performance athletes on the sensitivity of cardiorespiratory system to hypercapnic and hypoxic shifts in respiratory homeostasis. We found that under the influence of the pre-start complex a decrease in the sensitivity of ventilator responses to CO2-H+ stimuli in combination with a reduction in the thresholds of the reaction take place. This creates conditions for increased mobilization properties of the cardiorespiratory system and economization of its reaction under conditions of changes of respiratory homeostasis characteristic of intense training and competitive loads in the sport.

An investigation into the clinical reasoning of cardiorespiratory physiotherapists using a simulated patient and simulated high dependency unit

OpenAIRE

Thackray, Debbie

2014-01-01

The ability of physiotherapists to make clinical decisions is understood to be a vital component of achieving expertise and is part of being an autonomous practitioner, yet this complex phenomenon has been under-researched in cardiorespiratory physiotherapy. Educators in this field need to understand what method of clinical reasoning clinicians are using, so that educational strategies can be designed to facilitate the development of clinical reasoning by undergraduate physiotherapy students ...

Anthropomorphic thorax phantom for cardio-respiratory motion simulation in tomographic imaging

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Bolwin, Konstantin; Czekalla, Björn; Frohwein, Lynn J.; Büther, Florian; Schäfers, Klaus P.

2018-02-01

Patient motion during medical imaging using techniques such as computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), or single emission computed tomography (SPECT) is well known to degrade images, leading to blurring effects or severe artifacts. Motion correction methods try to overcome these degrading effects. However, they need to be validated under realistic conditions. In this work, a sophisticated anthropomorphic thorax phantom is presented that combines several aspects of a simulator for cardio-respiratory motion. The phantom allows us to simulate various types of cardio-respiratory motions inside a human-like thorax, including features such as inflatable lungs, beating left ventricular myocardium, respiration-induced motion of the left ventricle, moving lung lesions, and moving coronary artery plaques. The phantom is constructed to be MR-compatible. This means that we can not only perform studies in PET, SPECT and CT, but also inside an MRI system. The technical features of the anthropomorphic thorax phantom Wilhelm are presented with regard to simulating motion effects in hybrid emission tomography and radiotherapy. This is supplemented by a study on the detectability of small coronary plaque lesions in PET/CT under the influence of cardio-respiratory motion, and a study on the accuracy of left ventricular blood volumes.

Phase coupling in the cardiorespiratory interaction.

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Bahraminasab, A; Kenwright, D; Stefanovska, A; Ghasemi, F; McClintock, P V E

2008-01-01

Markovian analysis is applied to derive nonlinear stochastic equations for the reconstruction of heart rate and respiration rate variability data. A model of their 'phase' interactions is obtained for the first time, thereby gaining new insights into the strength and direction of the cardiorespiratory phase coupling. The reconstructed model can reproduce synchronisation phenomena between the cardiac and the respiratory systems, including switches in synchronisation ratio. The technique is equally applicable to the extraction of the multi-dimensional couplings between many interacting subsystems.

Cardiorespiratory fitness, cognition and brain structure after TIA or minor ischemic stroke.

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Boss, H Myrthe; Van Schaik, Sander M; Witkamp, Theo D; Geerlings, Mirjam I; Weinstein, Henry C; Van den Berg-Vos, Renske M

2017-10-01

Background It is not known whether cardiorespiratory fitness is associated with better cognitive performance and brain structure in patients with a TIA or minor ischemic stroke. Aims To examine the association between cardiorespiratory fitness, cognition and brain structure in patients with a TIA and minor stroke. Methods The study population consisted of patients with a TIA or minor stroke with a baseline measurement of the peak oxygen consumption, a MRI scan of brain and neuropsychological assessment. Composite z-scores were calculated for the cognitive domains attention, memory and executive functioning. White matter hyperintensities, microbleeds and lacunes were rated visually. The mean apparent diffusion coefficient was measured in regions of interest in frontal and occipital white matter and in the centrum semiovale as a marker of white matter structure. Normalized brain volumes were estimated by use of Statistical Parametric Mapping. Results In 84 included patients, linear regression analysis adjusted for age, sex and education showed that a higher peak oxygen consumption was associated with higher cognitive z-scores, a larger grey matter volume (B = 0.15 (95% CI 0.05; 0.26)) and a lower mean apparent diffusion coefficient (B = -.004 (95% CI -.007; -.001)). We found no association between the peak oxygen consumption and severe white matter hyperintensities, microbleeds, lacunes and total brain volume. Conclusions These data suggest that cardiorespiratory fitness is associated with better cognitive performance, greater grey matter volume and greater integrity of the white matter in patients with a TIA or minor ischemic stroke. Further prospective trials are necessary to define the effect of cardiorespiratory fitness on cognition and brain structure in patients with TIA or minor stroke.

Compliance in doing Senam Kesegaran Jasmani 1988 exercise improves cardiorespiratory endurance of attention deficit/hyperactivity disorder children

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Listya T. Mirtha

2018-05-01

Full Text Available Background: Physical exercise was hypothesized to be able to improve the behavior of children with attention deficit/hyperactivity disorder (ADHD by improving attention and concentration. Several studies mentioned that physical exercise could make ADHD children calmer, not only as a supportive therapy, but also as a therapeutic therapy. The aim of this study was to evaluate the effects of physical exercise to the behavior of ADHD patients and to analyze the effects of Senam Kesegaran Jasmani 1988 (SKJ 88 exercise compliance to the cardiorespiratory endurance in ADHD children.Methods: This study was an experimental study with 40 subjects from a special needs school in Tangerang, Indonesia. Subjects were given SKJ 88 exercise for 8 weeks, and the level of cardiorespiratory endurance was assessed with 600 m run before and after intervention.Results: 21 subjects (52.5% were compliant, and the rest were very compliant. Although statistical analysis showed that there was no significant difference in cardiorespiratory endurance before and after intervention, the mean results of cardiorespiratory endurance test before intervention was higher than after. Mean time spent in the 600-m run before intervention was 497.9 seconds (SD 73.53, and after intervention was 313.7 seconds (SD 43.28.Conclusion: Based on the statistical test, we concluded that there was significant decrease of time spent for cardiorespiratory endurance test (p<0.001. The reduction of time taken to run 600 m by 184.3 seconds (SD 73.33 showed the improvement of cardiorespiratory endurance after the treatment.

Does cardiorespiratory fitness modify the association between birth weight and insulin resistance in adult life?

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Tomoko Aoyama

Full Text Available OBJECTIVE: Lower birth weight is associated with higher insulin resistance in later life. The aim of this study was to determine whether cardiorespiratory fitness modifies the association of birth weight with insulin resistance in adults. METHODS: The subjects were 379 Japanese individuals (137 males, 242 females aged 20-64 years born after 1943. Insulin resistance was assessed using a homeostasis model assessment of insulin resistance (HOMA-IR, which is calculated from fasting blood glucose and insulin levels. Cardiorespiratory fitness (maximal oxygen uptake, VO2max was assessed by a maximal graded exercise test on a cycle ergometer. Birth weight was reported according to the Maternal and Child Health Handbook records or the subject's or his/her mother's memory. RESULTS: The multiple linear regression analysis revealed that birth weight was inversely associated with HOMA-IR (β = -0.141, p = 0.003, even after adjustment for gender, age, current body mass index, mean blood pressure, triglycerides, HDL cholesterol, and smoking status. Further adjustments for VO2max made little difference in the relationship between birth weight and HOMA-IR (β = -0.148, p = 0.001, although VO2max (β = -0.376, p<0.001 was a stronger predictor of HOMA-IR than birth weight. CONCLUSIONS: The results showed that the association of lower birth weight with higher insulin resistance was little modified by cardiorespiratory fitness in adult life. However, cardiorespiratory fitness was found to be a stronger predictor of insulin resistance than was birth weight, suggesting that increasing cardiorespiratory fitness may have a much more important role in preventing insulin resistance than an individual's low birth weight.

Body image, nutritional status, abdominal strength, and cardiorespiratory fitness in children and adolescents practicing sports.

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Schubert, Alexandre; Januário, Renata Selvatici B; Casonatto, Juliano; Sonoo, Christi Noriko

2013-01-01

To verify the association between nutritional status, physical fitness, and body image in children and adolescents. This cross-sectional study included 401 students (236 boys and 165 girls) aged between 8 and 16 years that were regularly enrolled in sports in the local clubs. The nutritional status was evaluated by the body mass index. Students were assessed for satisfaction with body image, abdominal strength resistance, and cardiorespiratory fitness. The variables were assessed on the same day following a standardized order. In order to verify relationships between variables, the chi-square test was used. Afterwards, the binary logistic regression was applied to identify the magnitude of the associations, considering p<0.05 as significant. Association was found between body image and body mass index (p=0.001), abdominal strength resistance (p=0.005) and cardiorespiratory fitness (p=0.001). The Odds Ratio for presenting the body image insatisfaction for those who have not achieved the expected values for the health criteria in abdominal strength resistance and cardiorespiratory fitness were 2.14 and 2.42 times respectively, and for those with overweight and obesity, 2.87 times. Insatisfaction with body image is associated with body mass index and also with physical fitness, abdominal strength resistance, and cardiorespiratory fitness variables.

Cardiorespiratory effects of inelastic chest wall restriction.

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Miller, Jordan D; Beck, Kenneth C; Joyner, Michael J; Brice, A Glenn; Johnson, Bruce D

2002-06-01

We examined the effects of chest wall restriction (CWR) on cardiorespiratory function at rest and during exercise in healthy subjects in an attempt to approximate the cardiorespiratory interactions observed in clinical conditions that result in restrictive lung and/or chest wall changes and a reduced intrathoracic space. Canvas straps were applied around the thorax and abdomen so that vital capacity was reduced by >35%. Data were acquired at rest and during cycle ergometry at 25 and 45% of peak workloads. CWR elicited significant increases in the flow-resistive work performed on the lung (160%) and the gastric pressure-time integral (>400%) at the higher workload, but it resulted in a decrease in the elastic work performed on the lung (56%) compared with control conditions. With CWR, heart rate increased and stroke volume (SV) fell, resulting in >10% fall in cardiac output at rest and during exercise at matched workloads (P < 0.05). Blood pressure and catecholamines were significantly elevated during CWR exercise conditions (P < 0.05). We conclude that CWR significantly impairs SV during exercise and that a compensatory increase in heart rate does not prevent a significant reduction in cardiac output. O(2) consumption appears to be maintained via increased extraction and a redistribution of blood flow via sympathetic activation.

Central control of cardiorespiratory interactions in fish.

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Taylor, Edwin W; Leite, Cleo A C; Levings, Jennifer J

2009-01-01

Fish control the relative flow rates of water and blood over the gills in order to optimise respiratory gas exchange. As both flows are markedly pulsatile, close beat-to-beat relationships can be predicted. Cardiorespiratory interactions in fish are controlled primarily by activity in the parasympathetic nervous system that has its origin in cardiac vagal preganglionic neurons. Recordings of efferent activity in the cardiac vagus include units firing in respiration-related bursts. Bursts of electrical stimuli delivered peripherally to the cardiac vagus or centrally to respiratory branches of cranial nerves can recruit the heart over a range of frequencies. So, phasic, efferent activity in cardiac vagi, that in the intact fish are respiration-related, can cause heart rate to be modulated by the respiratory rhythm. In elasmobranch fishes this phasic activity seems to arise primarily from central feed-forward interactions with respiratory motor neurones that have overlapping distributions with cardiac neurons in the brainstem. In teleost fish, they arise from increased levels of efferent vagal activity arising from reflex stimulation of chemoreceptors and mechanoreceptors in the orobranchial cavity. However, these differences are largely a matter of emphasis as both groups show elements of feed-forward and feed-back control of cardiorespiratory interactions.

Cardiorespiratory interactions during resistive load breathing.

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Calabrese, P; Perrault, H; Dinh, T P; Eberhard, A; Benchetrit, G

2000-12-01

The addition to the respiratory system of a resistive load results in breathing pattern changes and in negative intrathoracic pressure increases. The aim of this study was to use resistive load breathing as a stimulus to the cardiorespiratory interaction and to examine the extent of the changes in heart rate variability (HRV) and respiratory sinus arrhythmia (RSA) in relation to the breathing pattern changes. HRV and RSA were studied in seven healthy subjects where four resistive loads were applied in a random order during the breath and 8-min recording made in each condition. The HRV spectral power components were computed from the R-R interval sequences, and the RSA amplitude and phase were computed from the sinusoid fitting the instantaneous heart rate within each breath. Adding resistive loads resulted in 1) increasing respiratory period, 2) unchanging heart rate, and 3) increasing HRV and changing RSA characteristics. HRV and RSA characteristics are linearly correlated to the respiratory period. These modifications appear to be linked to load-induced changes in the respiratory period in each individual, because HRV and RSA characteristics are similar at a respiratory period obtained either by loading or by imposed frequency breathing. The present results are discussed with regard to the importance of the breathing cycle duration in these cardiorespiratory interactions, suggesting that these interactions may depend on the time necessary for activation and dissipation of neurotransmitters involved in RSA.

Lack of Association of Estrogen Receptor Alpha Gene Polymorphisms with Cardiorespiratory and Metabolic Variables in Young Women

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Mario Hirata

2012-10-01

Full Text Available This study examined the association of estrogen receptor alpha gene (ESR1 polymorphisms with cardiorespiratory and metabolic parameters in young women. In total, 354 healthy women were selected for cardiopulmonary exercise testing and short-term heart rate (HR variability (HRV evaluation. The HRV analysis was determined by the temporal indices rMSSD (square root of the mean squared differences of successive R–R intervals (RRi divided by the number of RRi minus one, SDNN (root mean square of differences from mean RRi, divided by the number of RRi and power spectrum components by low frequency (LF, high frequency (HF and LF/HF ratio. Blood samples were obtained for serum lipids, estradiol and DNA extraction. ESR1 rs2234693 and rs9340799 polymorphisms were analyzed by PCR and fragment restriction analysis. HR and oxygen uptake (VO2 values did not differ between the ESR1 polymorphisms with respect to autonomic modulation. We not find a relationship between ESR1 T–A, T–G, C–A and C–G haplotypes and cardiorespiratory and metabolic variables. Multiple linear regression analysis demonstrated that VO2, total cholesterol and triglycerides influence HRV (p < 0.05. The results suggest that ESR1 variants have no effect on cardiorespiratory and metabolic variables, while HRV indices are influenced by aerobic capacity and lipids in healthy women.

Comparison of Cardiorespiratory fitness of Nigerians with Low back ...

African Journals Online (AJOL)

The objective of this study was to compare Cardiorespiratory fitness (CRF) of Nigerians with low back pain (LBP) and apparently healthy counterparts. A total of Seventy (70) subjects participated in the study; 35 of them were low back pain patients, while the remaining 35 were apparently healthy adults. For low back pain ...

Associations of Sedentary Behavior, Physical Activity, Cardiorespiratory Fitness, and Body Fat Content With Pain Conditions in Children: The Physical Activity and Nutrition in Children Study.

Science.gov (United States)

Vierola, Anu; Suominen, Anna Liisa; Lindi, Virpi; Viitasalo, Anna; Ikävalko, Tiina; Lintu, Niina; Väistö, Juuso; Kellokoski, Jari; Närhi, Matti; Lakka, Timo A

2016-07-01

We investigated the cross-sectional associations of sedentary behavior, physical activity, cardiorespiratory fitness, and body fat content with pain conditions in prepubertal children. The participants were a population sample of 439 children aged 6 to 8 years. Sedentary behavior, physical activity, and pain conditions were assessed using questionnaires, cardiorespiratory fitness using maximal cycle ergometer test, and body fat percentage using dual-energy X-ray absorptiometry. The associations of sedentary behavior, physical activity, cardiorespiratory fitness, and body fat percentage with the risk of pain conditions were analyzed using multivariate logistic regression. Children in the highest sex-specific third of sedentary behavior had 1.95 (95% confidence interval [CI], 1.20-3.17; P = .007 for trend across thirds) times higher odds of any pain than children in the lowest third. Children in the highest sex-specific third of cardiorespiratory fitness had 46% (odds ratio [OR] = .54; 95% CI, .32-.91; P = .019) lower odds of any pain and 50% (OR = .50; 95% CI, .28-.87; P = .015) lower odds of headache than children in the lowest third. Children in the highest sex-specific third of body fat percentage had 44% (OR = .56; 95% CI, .34-.93; P = .023) lower odds of any pain, 49% (OR = .51; 95% CI, .30-.86; P = .011) lower risk of multiple pain, and 48% (OR = .52; 95% CI, .31-.86; P = .010) lower odds of lower limb pain than children in the lowest third. Physical activity was not associated with pain conditions. These findings suggest that prepubertal children with high levels of sedentary behavior, low levels of cardiorespiratory fitness, and low body fat content have increased likelihood of various pain conditions. This information could be used to develop strategies to prevent chronic pain in childhood. Our findings suggest that low cardiorespiratory fitness, high levels of sedentary behavior, and low body fat content are associated with increased

Assessment of tobacco smoke effects on neonatal cardiorespiratory control using a semi-automated processing approach.

Science.gov (United States)

Al-Omar, Sally; Le Rolle, Virginie; Beuchée, Alain; Samson, Nathalie; Praud, Jean-Paul; Carrault, Guy

2018-05-10

A semi-automated processing approach was developed to assess the effects of early postnatal environmental tobacco smoke (ETS) on the cardiorespiratory control of newborn lambs. The system consists of several steps beginning with artifact rejection, followed by the selection of stationary segments, and ending with feature extraction. This approach was used in six lambs exposed to 20 cigarettes/day for the first 15 days of life, while another six control lambs were exposed to room air. On postnatal day 16, electrocardiograph and respiratory signals were obtained from a 6-h polysomnographic recording. The effects of postnatal ETS exposure on heart rate variability, respiratory rate variability, and cardiorespiratory interrelations were explored. The unique results suggest that early postnatal ETS exposure increases respiratory rate variability and decreases the coupling between cardiac and respiratory systems. Potentially harmful consequences in early life include unstable breathing and decreased adaptability of cardiorespiratory function, particularly during early life challenges, such as prematurity or viral infection. Graphical abstract ᅟ.

Effects of 6-month soccer and traditional physical activity programmes on body composition, cardiometabolic risk factors, inflammatory, oxidative stress markers and cardiorespiratory fitness in obese boys.

Science.gov (United States)

Seabra, André; Katzmarzyk, Peter; Carvalho, Maria José; Seabra, Ana; Coelho-E-Silva, Manuel; Abreu, Sandra; Vale, Susana; Póvoas, Susana; Nascimento, Henrique; Belo, Luís; Torres, Sandra; Oliveira, José; Mota, Jorge; Santos-Silva, Alice; Rêgo, Carla; Malina, Robert M

2016-10-01

Physical activity is important in obesity prevention, but the effectiveness of different physical activity modalities remains to be determined among children. The main purpose of this study was to compare the effects of a 6-month soccer programme and a traditional physical activity programme on changes in body composition, cardiometabolic risk factors, inflammatory and oxidative markers, cardiorespiratory fitness and perceived psychological status in obese boys. Eighty-eight boys (8-12 years; BMI > +2 standard deviations of WHO reference values) participated in one of three groups: soccer, traditional activity and control. Soccer and traditional activity programmes involved 3 sessions per week for 60-90 min at an average intensity of 70-80% of maximal heart rate. Control group participated in activities of normal daily living. All boys participated in school physical education, two sessions per week of 45-90-min. Measurements were taken at baseline and after 6 months, and included body size and composition, cardiometabolic risk factors, inflammatory and oxidative markers, cardiorespiratory fitness and perceived psychological status. Physical activity and dietary intake were assessed before and immediately following the intervention. The three groups had similar characteristics at baseline. After 6 months, both intervention groups had significantly lower relative fatness (% fat), waist circumference and total cholesterol, and higher cardiorespiratory fitness, self-esteem, perceived physical competence and attraction to physical activity compared with control group. In conclusion, physical activity interventions over 6 months positively influenced several indicators of health status among obese boys. The results also suggested that soccer has the potential as an effective tool for the prevention and reduction of childhood obesity and associated consequences.

Parental exercise is associated with Australian children's extracurricular sports participation and cardiorespiratory fitness: A cross-sectional study

Directory of Open Access Journals (Sweden)

Dwyer Terence

2005-04-01

Full Text Available Abstract Background The relationship between parental physical activity and children's physical activity and cardiorespiratory fitness has not been well studied in the Australian context. Given the increasing focus on physical activity and childhood obesity, it is important to understand correlates of children's physical activity. This study aimed to investigate whether parental exercise was associated with children's extracurricular sports participation and cardiorespiratory fitness. Methods The data were drawn from a nationally representative sample (n = 8,484 of 7–15 year old Australian schoolchildren, surveyed as part of the Australian Schools Health and Fitness Survey in 1985. A subset of 5,929 children aged 9–15 years reported their participation in extracurricular sports and their parents' exercise. Cardiorespiratory fitness was measured using the 1.6 km (1-mile run/walk and in addition for children aged 9, 12 or 15 years, using a physical work capacity test (PWC170. Results While the magnitude of the differences were small, parental exercise was positively associated with children's extracurricular sports participation (p p 170 (p = 0.013. In most instances, when only one parent was active, the sex of that parent was not an independent predictor of the child's extracurricular sports participation and cardiorespiratory fitness. Conclusion Parental exercise may influence their children's participation in extracurricular sports and their cardiorespiratory fitness levels. Understanding the correlates of children's extracurricular sport participation is important for the targeting of health promotion and public health interventions, and may influence children's future health status.

Cardiorespiratory Dynamic Response to Mental Stress: A Multivariate Time-Frequency Analysis

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Devy Widjaja

2013-01-01

out continuously in time to evaluate the dynamic response to mental stress and attention. The results show an increased heart and respiratory rate during stress and attention, compared to a resting condition. Also a fast reduction in vagal activity is noted. The partial TF analysis reveals a faster reduction of RRV power related to (3 s than unrelated to (30 s respiration, demonstrating that the autonomic response to mental stress is driven by mechanisms characterized by different temporal scales.

Cardiorespiratory Fitness Is Associated with Selective Attention in Healthy Male High-School Students.

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Wengaard, Eivind; Kristoffersen, Morten; Harris, Anette; Gundersen, Hilde

2017-01-01

Background : Previous studies have shown associations of physical fitness and cognition in children and in younger and older adults. However, knowledge about associations in high-school adolescents and young adults is sparse. Thus, the aim of this study was to evaluate the association of physical fitness, measured as maximal oxygen uptake ([Formula: see text]), muscle mass, weekly training, and cognitive function in the executive domains of selective attention and inhibitory control, in healthy male high-school students. Methods : Fifty-four males (17.9 ± 0.9 years, 72 ± 11 kg and 182 ± 7 cm) completed a [Formula: see text] test, a body composition test and a visual cognitive task based on the Posner cue paradigm with three types of stimuli with different attentional demands (i.e., stimuli presentation following no cue, valid cue or invalid cue presentations). The task consisted of 336 target stimuli, where 56 (17%) of the target stimuli appeared without a cue (no cue), 224 (67%) appeared in the same rectangle as the cue (valid cue) and 56 (17%) appeared in the rectangle opposite to the cue (invalid cue). Mean reaction time (RT) and corresponding errors was calculated for each stimuli type. Total task duration was 9 min and 20 s In addition, relevant background information was obtained in a questionnaire. Results : Linear mixed model analyses showed that higher [Formula: see text] was associated with faster RT for stimuli following invalid cue (Estimate = -2.69, SE = 1.03, p = 0.011), and for stimuli following valid cue (Estimate = -2.08, SE = 1.03, p = 0.048). There was no association of muscle mass and stimuli ( F = 1.01, p = 0.397) or of weekly training and stimuli ( F = 0.99, p = 0.405). Conclusion : The results suggest that cardiorespiratory fitness is associated with cognitive performance in healthy male high-school students in the executive domains of selective attention.

Cardiorespiratory Fitness Is Associated with Selective Attention in Healthy Male High-School Students

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Eivind Wengaard

2017-06-01

Full Text Available Background: Previous studies have shown associations of physical fitness and cognition in children and in younger and older adults. However, knowledge about associations in high-school adolescents and young adults is sparse. Thus, the aim of this study was to evaluate the association of physical fitness, measured as maximal oxygen uptake (V·O2max, muscle mass, weekly training, and cognitive function in the executive domains of selective attention and inhibitory control, in healthy male high-school students.Methods: Fifty-four males (17.9 ± 0.9 years, 72 ± 11 kg and 182 ± 7 cm completed a V·O2max test, a body composition test and a visual cognitive task based on the Posner cue paradigm with three types of stimuli with different attentional demands (i.e., stimuli presentation following no cue, valid cue or invalid cue presentations. The task consisted of 336 target stimuli, where 56 (17% of the target stimuli appeared without a cue (no cue, 224 (67% appeared in the same rectangle as the cue (valid cue and 56 (17% appeared in the rectangle opposite to the cue (invalid cue. Mean reaction time (RT and corresponding errors was calculated for each stimuli type. Total task duration was 9 min and 20 s In addition, relevant background information was obtained in a questionnaire.Results: Linear mixed model analyses showed that higher V·O2max was associated with faster RT for stimuli following invalid cue (Estimate = −2.69, SE = 1.03, p = 0.011, and for stimuli following valid cue (Estimate = −2.08, SE = 1.03, p = 0.048. There was no association of muscle mass and stimuli (F = 1.01, p = 0.397 or of weekly training and stimuli (F = 0.99, p = 0.405.Conclusion: The results suggest that cardiorespiratory fitness is associated with cognitive performance in healthy male high-school students in the executive domains of selective attention.

Effects of Exercise Training on Cardiorespiratory Fitness and Biomarkers of Cardiometabolic Health: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Science.gov (United States)

Lin, Xiaochen; Zhang, Xi; Guo, Jianjun; Roberts, Christian K; McKenzie, Steve; Wu, Wen-Chih; Liu, Simin; Song, Yiqing

2015-01-01

Background Guidelines recommend exercise for cardiovascular health, although evidence from trials linking exercise to cardiovascular health through intermediate biomarkers remains inconsistent. We performed a meta-analysis of randomized controlled trials to quantify the impact of exercise on cardiorespiratory fitness and a variety of conventional and novel cardiometabolic biomarkers in adults without cardiovascular disease. Methods and Results Two researchers selected 160 randomized controlled trials (7487 participants) based on literature searches of Medline, Embase, and Cochrane Central (January 1965 to March 2014). Data were extracted using a standardized protocol. A random-effects meta-analysis and systematic review was conducted to evaluate the effects of exercise interventions on cardiorespiratory fitness and circulating biomarkers. Exercise significantly raised absolute and relative cardiorespiratory fitness. Lipid profiles were improved in exercise groups, with lower levels of triglycerides and higher levels of high-density lipoprotein cholesterol and apolipoprotein A1. Lower levels of fasting insulin, homeostatic model assessment–insulin resistance, and glycosylated hemoglobin A1c were found in exercise groups. Compared with controls, exercise groups had higher levels of interleukin-18 and lower levels of leptin, fibrinogen, and angiotensin II. In addition, we found that the exercise effects were modified by age, sex, and health status such that people aged exercise significantly improved cardiorespiratory fitness and some cardiometabolic biomarkers. The effects of exercise were modified by age, sex, and health status. Findings from this study have significant implications for future design of targeted lifestyle interventions. PMID:26116691

Four birds with one stone? Reparative, neuroplastic, cardiorespiratory, and metabolic benefits of aerobic exercise poststroke.

Science.gov (United States)

Ploughman, Michelle; Kelly, Liam P

2016-12-01

Converging evidence from animal models of stroke and clinical trials suggests that aerobic exercise has effects across multiple targets. The subacute phase is characterized by a period of heightened neuroplasticity when aerobic exercise has the potential to optimize recovery. In animals, low intensity aerobic exercise shrinks lesion size and reduces cell death and inflammation, beginning 24 h poststroke. Also in animals, aerobic exercise upregulates brain-derived neurotrophic factor near the lesion and improves learning. In terms of neuroplastic effects, clinical trial results are less convincing and have only examined effects in chronic stroke. Stroke patients demonstrate cardiorespiratory fitness levels below the threshold required to carry out daily activities. This may contribute to a 'neurorehabilitation ceiling' that limits capacity to practice at a high enough frequency and intensity to promote recovery. Aerobic exercise when delivered 2-5 days per week at moderate to high intensity beginning as early as 5 days poststroke improves cardiorespiratory fitness, dyslipidemia, and glucose tolerance. Based on the evidence discussed and applying principles of periodization commonly used to prepare athletes for competition, we have created a model of aerobic training in subacute stroke in which training is delivered in density blocks (duration × intensity) matched to recovery phases.

Autonomic and cardio-respiratory responses to exercise in Brugada Syndrome patients

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Raoyrin Chanavirut, MSc

2016-10-01

Conclusion: Thai BrS patients had a more rapid rate of restoration of the parasympathetic and smaller level of sympathetic activation after exercise. They had mild hyperkalemia which is reduced according to the exercise. Furthermore, they exhibited impaired cardio-respiratory fitness.

Evaluation of a new device for home cardiorespiratory recording in children.

NARCIS (Netherlands)

Poels, P.J.P.; Schilder, A.G.M.; Berg, S.W. van den; Hoes, A.W.; Joosten, K.F.

2003-01-01

OBJECTIVE: To evaluate the feasibility of using a new home cardiorespiratory recording device (HCRD) in children. DESIGN: Cross-sectional study. PATIENTS: Consecutive children scheduled for adenotonsillectomy to treat habitual snoring and/or apneas at otorhinolaryngology clinics in 2 academic and 7

Low Cardiorespiratory Fitness is Partially Linked to Ventilatory Factors in Obese Adolescents.

Science.gov (United States)

Mendelson, Monique; Michallet, Anne-Sophie; Tonini, Julia; Favre-Juvin, Anne; Guinot, Michel; Wuyam, Bernard; Flore, Patrice

2016-02-01

To examine the role of ventilatory constraint on cardiorespiratory fitness in obese adolescents. Thirty obese adolescents performed a maximal incremental cycling exercise and were divided into 2 groups based on maximal oxygen uptake (VO2peak): those presenting low (L; n = 15; VO2peak: 72.9 ± 8.6% predicted) or normal (N; n = 15; VO2peak: 113.6 ± 19.2% predicted) cardiorespiratory fitness. Both were compared with a group of healthy controls (C; n = 20; VO2peak: 103.1 ± 11.2% predicted). Ventilatory responses were explored using the flow volume loop method. Cardiorespiratory fitness (VO2peak, in % predicted) was lower in L compared with C and N and was moderately associated with the percent predicted forced vital capacity (FVC) (r = .52; p < .05) in L. At peak exercise, end inspiratory point was lower in L compared with N and C (77.4 ± 8.1, 86.4 ± 7.7, and 89.9 ± 7.6% FVC in L, N, and C, respectively; p < .05), suggesting an increased risk of ventilatory constraint in L, although at peak exercise this difference could be attributed to the lower maximal ventilation in L. Forced vital capacity and ventilatory strategy to incremental exercise slightly differed between N and L. These results suggest a modest participation of ventilatory factors to exercise intolerance.

Differential cross-sectional associations of work- and leisure-time sitting, with cardiorespiratory and muscular fitness among working adults

DEFF Research Database (Denmark)

Saidj, Madina; Jørgensen, Torben; Jacobsen, Rikke K

2014-01-01

associations' between sitting time and cardiorespiratory and muscular fitness among adults. The aim of the present study was to examine associations between work- and leisure-time sitting, and key markers of cardiorespiratory and muscular fitness among working adults. METHODS: Working adults (N=2544) aged 18......-69 from Health2006, a Danish population-based study, were included in this cross-sectional study. Sitting time during work and leisure time along with sociodemographic and behavioral covariates, including physical activity, were self-reported. Participants underwent a health examination with assessment...... of cardiorespiratory fitness (step test estimated VO 2Max, systolic and diastolic blood pressure) and muscular fitness (handgrip strength, lower limb extension power). Associations were explored by linear regression. Results Leisure-time sitting time was significantly (P

Does clinical rehabilitation impose sufficient cardiorespiratory strain to improve aerobic fitness?

NARCIS (Netherlands)

Koopman, A.D.; Eken, M.M.; van Bezeij, T.; Valent, L.; Houdijk, J.H.P.

2013-01-01

Objective: To investigate the cardiorespiratory strain experienced by patients over a day and during different types of rehabilitation therapies during a clinical rehabilitation programme. In addition, to investigate the use of the Borg scale as an instrument to monitor exercise intensity. Design:

The Association Between Self-Rated Fitness and Cardiorespiratory Fitness in Adults

DEFF Research Database (Denmark)

Jensen, Karina Gregersen; Rosthøj, Susanne; Linneberg, Allan

2018-01-01

To assess criterion validity of a single item question on self-rated physical fitness against objectively measured cardiorespiratory fitness. From the Health2008 study 749 men and women between 30 and 60 years of age rated their fitness as excellent, very good, good, fair or poor. Cardiorespiratory...... fitness was estimated with the watt-max test. Agreement between self-rated and objectively measured physical fitness was assessed by Cohen's weighted kappa coefficient. Correlation was determined by Goodman & Kruskal's gamma correlation coefficient. All analyses were stratified according to gender. Data...... from 323 men and 426 women were analysed. There was a slight agreement between self-rated and objectively measured fitness in men (weighted kappa: 0.18, [95%CI: 0.13;0.23]) and a fair agreement in women (weighted kappa: 0.27, [95%CI: 0.22;0.32]). In both genders, self-rated fitness was positively...

The 1-min sit-to-stand test in cystic fibrosis - Insights into cardiorespiratory responses.

Science.gov (United States)

Radtke, Thomas; Hebestreit, Helge; Puhan, Milo A; Kriemler, Susi

2017-11-01

We aimed to characterize the cardiopulmonary response during a 1-min sit-to-stand (STS) test and compare peak exercise cardiorespiratory variables to a maximal cardiopulmonary exercise test (CPET) in cystic fibrosis (CF). We further aimed to assess the validity of the STS power index (Power STS ) as a measure of exercise capacity. Fifteen adult CF patients performed spirometry, CPET and the 1-min STS test with respiratory gas analysis. Peak-exercise cardiorespiratory variables during the 1-min STS test correlated strongly (r=0.69-0.98) with those measured during the CPET. Oxygen uptake, carbon dioxide production, heart rate, ventilation, and tidal volume at peak exercise were 24%, 26%, 9%, 10% and 21% lower in the 1-min STS test, while respiratory frequencies were 14% higher. Power STS showed strong to very strong correlations with CPET-derived absolute peak oxygen uptake and maximal workload. The 1-min STS test elicits a substantial but lower cardiorespiratory response compared to a maximal cycle ergometry CPET. While Power STS and STS repetitions are both valid outcome measures of functional capacity, STS repetitions are clinically more practical. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Improved cerebral oxygenation response and executive performance as a function of cardiorespiratory fitness in older women: a fNIRS study

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Cédric T Albinet

2014-10-01

Full Text Available Cardiorespiratory fitness has been shown to protect and enhance cognitive and brain functions, but little is known about the cortical mechanisms that underlie these changes in older adults. In this study, functional NIRS was used to investigate variations in oxyhemoglobin ([HbO2] and in deoxyhemoglobin ([HHb] in the dorsolateral prefrontal cortex (DLPFC during the performance of an executive control task in older women with different levels of cardiorespiratory fitness (VO2max. Thirty-four women aged 60-77 years were classified as high-fit and low-fit based on VO2max measures. They all performed a control counting task and the Random Number Generation (RNG task at two different paces (1 number / 1 s and 1 number / 1.5 s, allowing to manipulate task difficulty, while hemodynamic responses in the bilateral DLPFCs were recorded using continuous-wave NIRS. The behavioral data revealed that the high-fit women showed significantly better performance on the RNG tasks compared with the low-fit women. The high-fit women showed significant increases in [HbO2] responses in both left and right DLPFCs during the RNG task, while the low-fit women showed significantly less activation in the right DLPFC compared with the right DLPFC of the high-fit women and compared with their own left DLPFC. At the level of the whole sample, increases in the [HbO2] responses in the right DLPFC were found to mediate in part the relationship between VO2max level and executive performance during the RNG task at 1.5 s but not at 1 s. These results provide support for the cardiorespiratory fitness hypothesis and suggest that higher levels of aerobic fitness in older women are related to increased cerebral oxygen supply to the DLPFC, sustaining better cognitive performance.

[Prevalence of dyslipidemia in middle-aged adults with NOS3 gene polymorphism and low cardiorespiratory fitness].

Science.gov (United States)

Malagrino, Pamella A; Sponton, Carlos H G; Esposti, Rodrigo D; Franco-Penteado, Carla F; Fernandes, Romulo A; Bezerra, Marcos André C; Albuquerque, Dulcinéia M; Rodovalho, Cynara M; Bacci, Maurício; Zanesco, Angelina

2013-02-01

To evaluate the influence of the interaction between endothelial nitric oxide synthase gene (NOS3) polymorphisms at positions -786T>C, Glu298Asp and intron 4b/a, and cardiorespiratory fitness on plasma nitrite/nitrate levels, blood pressure, lipid profile, and prevalence of cardiometabolic disorders. Ninety-two volunteers were genotyped for NOS3 polymorphisms at positions (-786T>C and Glu298Asp) and (intron 4b/a) and divided according to the genotype: non-polymorphic (NP) and polymorphic (P). After that, they were subdivided according to the cardiorespiratory fitness associated with genotype: high (HNP and HP) and low (LNP and LP). The subjects with polymorphism for the interactions at positions Glu298Asp + intron 4b/a, and Glu298Asp+-786T>C showed the highest values in total cholesterol, as well as dyslipidemia. Our findings show that NOS3 gene polymorphisms at positions -786T>C, Glu298Asp, and intron 4b/a exert negative effects on the lipid profile compared with those who do not carry polymorphisms.

Advancing palliative and end-of-life science in cardiorespiratory populations: The contributions of nursing science.

Science.gov (United States)

Grady, Patricia A

Nursing science has a critical role to inform practice, promote health, and improve the lives of individuals across the lifespan who face the challenges of advanced cardiorespiratory disease. Since 1997, the National Institute of Nursing Research (NINR) has focused attention on the importance of palliative and end-of-life care for advanced heart failure and advanced pulmonary disease through the publication of multiple funding opportunity announcements and by supporting a cadre of nurse scientists that will continue to address new priorities and future directions for advancing palliative and end-of-life science in cardiorespiratory populations. Published by Elsevier Inc.

Altered cardiorespiratory coupling in young male adults with excessive online gaming.

Science.gov (United States)

Chang, Jae Seung; Kim, Eun Young; Jung, Dooyoung; Jeong, Seong Hoon; Kim, Yeni; Roh, Myoung-Sun; Ahn, Yong Min; Hahm, Bong-Jin

2015-09-01

This study aimed to investigate changes in heart rate variability and cardiorespiratory coupling in male college students with problematic Internet use (PIU) excessive gaming type during action video game play to assess the relationship between PIU tendency and central autonomic regulation. Electrocardiograms and respiration were simultaneously recorded from 22 male participants with excessive online gaming and 22 controls during action video game play. Sample entropy (SampEn) was computed to assess autonomic regularity, and cross-SampEn was calculated to quantify autonomic coordination. During video game play, reduced cardiorespiratory coupling (CRC) was observed in individuals with PIU excessive gaming type compared with controls, implicating central autonomic dysregulation. The PIU tendency was associated with the severity of autonomic dysregulation. These findings indicate impaired CRC in PIU excessive gaming type, which may reflect alterations of central inhibitory control over autonomic responses to pleasurable online stimuli. Copyright © 2015 Elsevier B.V. All rights reserved.

Cardiorespiratory fitness of inmates of a maximum security prison in ...

African Journals Online (AJOL)

Prisoners are a special population group who have limited freedom and are subjected to restrictions. They may not be able to enjoy health enhancing leisure and recreational activities or exercise of their choice or at a time they desire. The aim of this study is to determine the level of cardiorespiratory fitness (CRF) of inmates ...

The parasitic copepod Lernaeocera branchialis negatively affects cardiorespiratory function in Gadus morhua

DEFF Research Database (Denmark)

Behrens, Jane W.; Seth, H.; Axelsson, M.

2014-01-01

The parasitic copepod Lernaeocera branchialis had a negative effect on cardiorespiratory function in Atlantic cod Gadus morhua such that it caused pronounced cardiac dysfunction with irregular rhythm and reduced stroke amplitude compared with uninfected fish. In addition, parasite infection...

The associations of cardiorespiratory fitness, adiposity and sports participation with arterial stiffness in youth with chronic diseases or physical disabilities.

Science.gov (United States)

Haapala, Eero A; Lankhorst, Kristel; de Groot, Janke; Zwinkels, Maremka; Verschuren, Olaf; Wittink, Harriet; Backx, Frank Jg; Visser-Meily, Anne; Takken, Tim

2017-07-01

Background The evidence on the associations of cardiorespiratory fitness, body adiposity and sports participation with arterial stiffness in children and adolescents with chronic diseases or physical disabilities is limited. Methods Altogether 140 children and adolescents with chronic diseases or physical disabilities participated in this cross-sectional study. Cardiorespiratory fitness was assessed using maximal exercise test with respiratory gas analyses either using shuttle run, shuttle ride, or cycle ergometer test. Cardiorespiratory fitness was defined as peak oxygen uptake by body weight or fat-free mass. Body adiposity was assessed using waist circumference, body mass index standard deviation score and body fat percentage. Sports participation was assessed by a questionnaire. Aortic pulse wave velocity and augmentation index were assessed by a non-invasive oscillometric tonometry device. Results Peak oxygen uptake/body weight (standardised regression coefficient β -0.222, 95% confidence interval (CI) -0.386 to -0.059, P = 0.002) and peak oxygen uptake/fat-free mass (β -0.173, 95% CI -0.329 to -0.017, P = 0.030) were inversely and waist circumference directly (β 0.245, 95% CI 0.093 to 0.414, P = 0.002) associated with aortic pulse wave velocity. However, the associations of the measures of cardiorespiratory fitness with aortic pulse wave velocity were attenuated after further adjustment for waist circumference. A higher waist circumference (β -0.215, 95% CI -0.381 to -0.049, P = 0.012) and a higher body mass index standard deviation score (β 0.218, 95% CI -0.382 to -0.054, P = 0.010) were related to lower augmentation index. Conclusions Poor cardiorespiratory fitness and higher waist circumference were associated with increased arterial stiffness in children and adolescents with chronic diseases and physical disabilities. The association between cardiorespiratory fitness and arterial stiffness was partly explained by waist

The position of a standard optical computer mouse affects cardiorespiratory responses during the operation of a computer under time constraints.

Science.gov (United States)

Sako, Shunji; Sugiura, Hiromichi; Tanoue, Hironori; Kojima, Makoto; Kono, Mitsunobu; Inaba, Ryoichi

2014-08-01

This study investigated the association between task-induced stress and fatigue by examining the cardiovascular responses of subjects using different mouse positions while operating a computer under time constraints. The study was participated by 16 young, healthy men and examined the use of optical mouse devices affixed to laptop computers. Two mouse positions were investigated: (1) the distal position (DP), in which the subjects place their forearms on the desk accompanied by the abduction and flexion of their shoulder joints, and (2) the proximal position (PP), in which the subjects place only their wrists on the desk without using an armrest. The subjects continued each task for 16 min. We assessed differences in several characteristics according to mouse position, including expired gas values, autonomic nerve activities (based on cardiorespiratory responses), operating efficiencies (based on word counts), and fatigue levels (based on the visual analog scale - VAS). Oxygen consumption (VO(2)), the ratio of inspiration time to respiration time (T(i)/T(total)), respiratory rate (RR), minute ventilation (VE), and the ratio of expiration to inspiration (Te/T(i)) were significantly lower when the participants were performing the task in the DP than those obtained in the PP. Tidal volume (VT), carbon dioxide output rates (VCO(2)/VE), and oxygen extraction fractions (VO(2)/VE) were significantly higher for the DP than they were for the PP. No significant difference in VAS was observed between the positions; however, as the task progressed, autonomic nerve activities were lower and operating efficiencies were significantly higher for the DP than they were for the PP. Our results suggest that the DP has fewer effects on cardiorespiratory functions, causes lower levels of sympathetic nerve activity and mental stress, and produces a higher total workload than the PP. This suggests that the DP is preferable to the PP when operating a computer.

Cardiorespiratory fitness and future risk of pneumonia: a long-term prospective cohort study.

Science.gov (United States)

Kunutsor, Setor K; Laukkanen, Tanjaniina; Laukkanen, Jari A

2017-09-01

We aimed to assess the prospective association of cardiorespiratory fitness (CRF) with the risk of pneumonia. Cardiorespiratory fitness, as measured by maximal oxygen uptake, was assessed using a respiratory gas exchange analyzer in 2244 middle-aged men in the Kuopio Ischemic Heart Disease cohort. We corrected for within-person variability in CRF levels using data from repeat measurements taken several years apart. During a median follow-up of 25.8 years, 369 men received a hospital diagnosis of pneumonia. The age-adjusted regression dilution ratio of CRF was 0.58 (95% confidence interval: 0.53-0.63). Cardiorespiratory fitness was linearly associated with pneumonia risk. The hazard ratio (95% confidence interval) for pneumonia per 1 standard deviation increase in CRF in analysis adjusted for several risk factors for pneumonia was 0.77 (0.68-0.87). The association remained consistent on additional adjustment for total energy intake, socioeconomic status, physical activity, and C-reactive protein 0.82 (0.72-0.94). The corresponding adjusted hazard ratios (95% confidence intervals) were 0.58 (0.41-0.80) and 0.67 (0.48-0.95) respectively, when comparing the extreme quartiles of CRF levels. Our findings indicate a graded inverse and independent association between CRF and the future risk of pneumonia in a general male population. Copyright © 2017 Elsevier Inc. All rights reserved.

Cardiorespiratory evaluation of juvenile rats experimentally envenomed with Tityus serrulatus venom

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MCL Pinto

2010-01-01

Full Text Available Accidental envenomation caused by Tityus serrulatus scorpions is very common in Brazil and may result in serious cardiorespiratory alterations that are frequently fatal to children. In the present study, the effects of T. serrulatus venom on the cardiorespiratory system of recently weaned male Wistar rats were evaluated. Fifteen animals were distributed into three groups (n = 5. The control group A received 400 μL ultrapure water by subcutaneous injection, while the experimental groups B and C were injected with scorpion venom (100 and 450 μg, respectively, in 400 μL water. Electrocardiogram (ECG traces were obtained prior to the experiment, at five-minute intervals up to 30 minutes after treatment. At 40 minutes after envenomation, the animals had severe acute symptoms and were subsequently anesthetized for blood collection by means of intracardiac puncture. Biochemical profiles for the cardiac muscle were established by colorimetric analysis of creatine kinase (CK and CK-MB isoenzyme. Semiquantitative analysis of troponin was performed using the immunochromatographic assay. Following euthanasia, the lungs and hearts were removed and subjected to histopathological examination. All experimental animals had ECG alterations compatible with electrolytic imbalance, myocarditis and alterations of the cardiac conduction system. Envenomed animals had accentuated bradycardia at 25 and 30 minutes after venom inoculation. All experimental animals had myocardial lesions, which were confirmed by increased serum levels of CK and CK-MB, although there were no alterations in the serum concentration of troponin. Pulmonary hemorrhage was detected in whole lungs and microscopically confirmed by the presence of congested capillaries and erythrocytes in the alveolar parenchyma. In conclusion, T. serrulatus venom caused great cardiorespiratory damage to weaned rats.

Mutual information and phase dependencies: measures of reduced nonlinear cardiorespiratory interactions after myocardial infarction.

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Hoyer, Dirk; Leder, Uwe; Hoyer, Heike; Pompe, Bernd; Sommer, Michael; Zwiener, Ulrich

2002-01-01

The heart rate variability (HRV) is related to several mechanisms of the complex autonomic functioning such as respiratory heart rate modulation and phase dependencies between heart beat cycles and breathing cycles. The underlying processes are basically nonlinear. In order to understand and quantitatively assess those physiological interactions an adequate coupling analysis is necessary. We hypothesized that nonlinear measures of HRV and cardiorespiratory interdependencies are superior to the standard HRV measures in classifying patients after acute myocardial infarction. We introduced mutual information measures which provide access to nonlinear interdependencies as counterpart to the classically linear correlation analysis. The nonlinear statistical autodependencies of HRV were quantified by auto mutual information, the respiratory heart rate modulation by cardiorespiratory cross mutual information, respectively. The phase interdependencies between heart beat cycles and breathing cycles were assessed basing on the histograms of the frequency ratios of the instantaneous heart beat and respiratory cycles. Furthermore, the relative duration of phase synchronized intervals was acquired. We investigated 39 patients after acute myocardial infarction versus 24 controls. The discrimination of these groups was improved by cardiorespiratory cross mutual information measures and phase interdependencies measures in comparison to the linear standard HRV measures. This result was statistically confirmed by means of logistic regression models of particular variable subsets and their receiver operating characteristics.

Unilateral Arm Crank Exercise Test for Assessing Cardiorespiratory Fitness in Individuals with Hemiparetic Stroke

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Kazuaki Oyake

2017-01-01

Full Text Available Cardiorespiratory fitness assessment with leg cycle exercise testing may be influenced by motor impairments in the paretic lower extremity. Hence, this study examined the usefulness of a unilateral arm crank exercise test to assess cardiorespiratory fitness in individuals with stroke, including sixteen individuals with hemiparetic stroke (mean ± SD age, 56.4±7.5 years and 12 age- and sex-matched healthy controls. Participants performed the unilateral arm crank and leg cycle exercise tests to measure oxygen consumption (V˙O2 and heart rate at peak exercise. The V˙O2 at peak exercise during the unilateral arm crank exercise test was significantly lower in the stroke group than in the control group (p<0.001. In the stroke group, the heart rate at peak exercise during the unilateral arm crank exercise test did not significantly correlate with the Brunnstrom recovery stages of the lower extremity (p=0.137, whereas there was a significant correlation during the leg cycle exercise test (rho = 0.775, p<0.001. The unilateral arm crank exercise test can detect the deterioration of cardiorespiratory fitness independently of lower extremity motor impairment severity in individuals with hemiparetic stroke. This study is registered with UMIN000014733.

A5 region modulation of the cardiorespiratory responses evoked from parabrachial cell bodies in the anaesthetised rat.

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Dawid Milner, M S; Lara, J P; López de Miguel, M P; López-González, M V; Spyer, K M; González-Barón, S

2003-08-22

We have examined the importance of the A5 region modulating cardiorespiratory responses evoked from the parabrachial complex (PB) in spontaneously breathing rats. Cardiorespiratory changes were analyzed in response to electrical stimulation and glutamate microinjections into the PB (10-20 nl, 1-2 nmol) before and after ipsilateral microinjection of muscimol (50 nl, 0.25 nmol) or lidocaine (50 nl, 0.5 nmol) within the A5 region. Stimulation of medial parabrachial and Kölliker-Fuse nuclei (mPB-KF) evoked a decrease in respiratory rate (Pinteractions between A5 and PB, extracellular recordings of putative A5 neurones were obtained during PB stimulation. Eighty-three A5 cells were recorded, 35 were activated from the mPB-KF (42%). The results indicate that neurones of the A5 region participate in the cardiorespiratory response evoked from the different regions of the PB complex. The possible mechanisms involved in these interactions are discussed.

Physiological coherence in healthy volunteers during laboratory-induced stress and controlled breathing.

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Mejía-Mejía, Elisa; Torres, Robinson; Restrepo, Diana

2018-06-01

Physiological coherence has been related with a general sense of well-being and improvements in health and physical, social, and cognitive performance. The aim of this study was to evaluate the relationship between acute stress, controlled breathing, and physiological coherence, and the degree of body systems synchronization during a coherence-generation exercise. Thirty-four university employees were evaluated during a 20-min test consisting of four stages of 5-min duration each, during which basal measurements were obtained (Stage 1), acute stress was induced using validated mental stressors (Stroop test and mental arithmetic task, during Stage 2 and 3, respectively), and coherence states were generated using a controlled breathing technique (Stage 4). Physiological coherence and cardiorespiratory synchronization were assessed during each stage from heart rate variability, pulse transit time, and respiration. Coherence measurements derived from the three analyzed variables increased during controlled respiration. Moreover, signals synchronized during the controlled breathing stage, implying a cardiorespiratory synchronization was achieved by most participants. Hence, physiological coherence and cardiopulmonary synchronization, which could lead to improvements in health and better life quality, can be achieved using slow, controlled breathing exercises. Meanwhile, coherence measured during basal state and stressful situations did not show relevant differences using heart rate variability and pulse transit time. More studies are needed to evaluate the ability of coherence ratio to reflect acute stress. © 2017 Society for Psychophysiological Research.

Time-dependent changes in cardiorespiratory functions of anesthetized rats exposed to sustained hypoxia.

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Kato, Kouki; Morinaga, Ryosuke; Fushuku, Seigo; Nakamuta, Nobuaki; Yamamoto, Yoshio

2018-07-01

Although cardiovascular responses may be altered by respiratory changes under prolonged hypoxia, the relationship between respiratory and cardiovascular changes remains unknown. The aim of the present study is to clarify cardiorespiratory changes in anesthetized rats during and after hypoxic conditions using simultaneous recordings of cardiorespiratory variables with 20-sec recording intervals. After air breathing for 20 min (pre-exposure period), rats were subjected to 10% O 2 for 2 h (hypoxic exposure period) and then air for 30 min (recovery period). Minute ventilation (V E ), respiratory frequency, tidal volume, arterial blood pressure (BP), and heart rate (HR) were continuously monitored during the experimental period. Just after hypoxic exposure, V E , BP, and HR exhibited an overshoot, undershoot, and overshoot followed by a decrease, respectively. During the remaining hypoxic exposure period, continuous high V E and low BP were observed, whereas HR re-increased. In the recovery period, V E , BP, and HR showed an undershoot, increase, and decrease followed by an increase, respectively. These results suggest that the continuation of enhanced V E and re-increased HR, probably, due to carotid body excitation and accompanying sympathetic activation, during the late period of hypoxic exposure are protective responses to avoid worsening hypoxemia and further circulatory insufficiencies under sustained hypoxia. Copyright © 2018 Elsevier B.V. All rights reserved.

Antihistaminic and cardiorespiratory effects of diphenhydramine hydrochloride in anesthetized dogs undergoing excision of mast cell tumors.

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Sanchez, Andrea; Valverde, Alexander; Sinclair, Melissa; Mosley, Cornelia; Singh, Ameet; Mutsaers, Anthony J; Hanna, Brad; Johnson, Ron; Gu, Yu; Beaudoin-Kimble, Michelle

2017-10-01

OBJECTIVE To evaluate the effects of IV diphenhydramine hydrochloride administration on cardiorespiratory variables in anesthetized dogs undergoing mast cell tumor (MCT) excision. DESIGN Randomized, blinded clinical trial. ANIMALS 16 client-owned dogs with MCTs. PROCEDURES In a standardized isoflurane anesthesia session that included mechanical ventilation, dogs received diphenhydramine hydrochloride (1 mg/kg [0.45 mg/lb], IV; n = 8) or an equivalent volume of saline (0.9% NaCl) solution (IV; control treatment; 8) 10 minutes after induction. Cardiorespiratory variables were recorded throughout anesthesia and MCT excision, and blood samples for determination of plasma diphenhydramine and histamine concentrations were collected prior to premedication (baseline), throughout anesthesia, and 2 hours after extubation. RESULTS Cardiorespiratory values in both treatment groups were acceptable for anesthetized dogs. Mean ± SD diastolic arterial blood pressure was significantly lower in the diphenhydramine versus control group during tumor dissection (52 ± 10 mm Hg vs 62 ± 9 mm Hg) and surgical closure (51 ± 10 mm Hg vs 65 ± 9 mm Hg). Mean arterial blood pressure was significantly lower in the diphenhydramine versus control group during surgical closure (65 ± 12 mm Hg vs 78 ± 11 mm Hg), despite a higher cardiac index value. Plasma histamine concentrations were nonsignificantly higher than baseline during maximal manipulation of the tumor and surgical preparation in the diphenhydramine group and during surgical dissection in the control group. CONCLUSIONS AND CLINICAL RELEVANCE IV administration of diphenhydramine prior to MCT excision had no clear clinical cardiorespiratory benefits over placebo in isoflurane-anesthetized dogs.

Cardiorespiratory fitness, cardiovascular workload and risk factors among cleaners; a cluster randomized worksite intervention

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Korshøj, Mette; Krustrup, Peter; Jørgensen, Marie Birk

2012-01-01

. The clusters will be balanced on the following criteria: Geographical work location, gender, age and seniority. Cleaners are randomized to either I) a reference group, receiving lectures concerning healthy living, or II) an intervention group, performing worksite aerobic exercise. Data collection......ABSTRACT: BACKGROUND: Prevalence of cardiovascular risk factors is unevenly distributed among occupational groups. The working environment, as well as lifestyle and socioeconomic status contribute to the disparity and variation in prevalence of these risk factors. High physical work demands have...... been shown to increase the risk for cardiovascular disease and mortality, contrary to leisure time physical activity. High physical work demands in combination with a low cardiorespiratory fitness infer a high relative workload and an excessive risk for cardiovascular mortality. Therefore, the aim...

Potential neurobiological benefits of exercise in chronic pain and posttraumatic stress disorder: Pilot study.

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Scioli-Salter, Erica; Forman, Daniel E; Otis, John D; Tun, Carlos; Allsup, Kelly; Marx, Christine E; Hauger, Richard L; Shipherd, Jillian C; Higgins, Diana; Tyzik, Anna; Rasmusson, Ann M

2016-01-01

This pilot study assessed the effects of cardiopulmonary exercise testing and cardiorespiratory fitness on plasma neuropeptide Y (NPY), allopregnanolone and pregnanolone (ALLO), cortisol, and dehydroepiandrosterone (DHEA), and their association with pain sensitivity. Medication-free trauma-exposed participants were either healthy (n = 7) or experiencing comorbid chronic pain/posttraumatic stress disorder (PTSD) (n = 5). Peak oxygen consumption (VO2) during exercise testing was used to characterize cardiorespiratory fitness. Peak VO2 correlated with baseline and peak NPY levels (r = 0.66, p exercise-induced changes in ALLO (r = 0.89, p exercise correlated with pain threshold 30 min after exercise (r = 0.65, p exercise-induced increases in ALLO correlated with pain tolerance 30 min after exercise (r = 0.64, p exercise-induced changes in cortisol and DHEA levels were inversely correlated with pain tolerance after exercise (r = -0.69, p exercise, which in turn relate to pain sensitivity. Future work will examine whether progressive exercise training increases cardiorespiratory fitness in association with increases in NPY and ALLO and reductions in pain sensitivity in chronic pain patients with PTSD.

CORRELATION OF PHYSICAL ACTIVITY LEVEL WITH BONE MINERAL DENSITY, CARDIO-RESPIRATORY FITNESS AND BODY COMPOSITION IN POST-MENOPAUSAL WOMEN

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Niyati N Khona

2017-09-01

Full Text Available Background: Due to the hormonal changes in postmenopausal women they are prone for many complications like increased CVD risk factors, osteoporosis, obesity, mood swings and urinary incontinence. Physical inactivity in postmenopausal women leads to higher risk of developing CVD and osteoporosis. The objective was to find out the correlation of physical activity level with BMD, cardio-respiratory fitness and body composition in post-menopausal women Methods: 42 postmenopausal women were included. A detailed clinical evaluation with physical activity level (IPAQ-METS-mins/week, , BMD ( T-Scores, body composition (BMI, waist circumference, BIA & Skin fold calliper for fat %, cardio-respiratory fitness was measured by Balke protocol and VO2peak (ml/kg/min is estimated. Correlation of physical activity level with BMD, cardio-respiratory fitness and body composition were analysed using “Pearson’s product moment correlation co-efficient and Spearman’s rho.” Results: Spearman’s rank correlation rho for IPAQ with VO2 peak was 0.420,BMI was -0.388 and visceral fat was -0.384 indicating moderate positive correlation between IPAQ and cardio-respiratory fitness and weak negative correlation between IPAQ and BMI and visceral fat. Pearson’s product moment correlation coefficient of IPAQ with BMD was 0.147, body fat was -0.234 and waist circumference was -0.256 indicating no correlation. P value was significant for correlation of IPAQ with CRF (0.006, BMI (0.011 and Visceral fat (0.012. Conclusion: There is moderate positive correlation between IPAQ and cardio-respiratory fitness, weak negative correlation between IPAQ and BMI and visceral fat and no correlation between IPAQ and BMD, body fat and waist circumference

Associations of object control motor skill proficiency, game play competence, physical activity and cardiorespiratory fitness among primary school children.

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Miller, Andrew; Eather, Narelle; Duncan, Mitch; Lubans, David Revalds

2018-06-18

This study investigated if object control relates to children's game play competence, and examined these competencies as correlates of physical activity and cardiorespiratory fitness. Game play (Game Performance Assessment Instrument), object control (The Test Gross Motor Development-3), moderate-to-vigorous physical activity (Accelerometry), and cardiorespiratory fitness (20-metre shuttle) assessments were completed for 107 children (57% Female, 43% Male) aged 9-12 years (M 10.53, SD 0.65). Two-level regression of object control on game play competence, and object control and game play competence on physical activity and cardiorespiratory fitness assessed associations. Object control competence was positively associated with game play competence (Std. B = 0.25, t (104.77) = 2.38, p = 0.001). Game play competence (Std. B = 0.33, t (99.81) = 5.21, p competence (Std. B = 0.20, t (106.93) = 2.96, p = 0.003). Likewise, game competence (Std. B = 0.39, t (104.41) = 4.36, p fitness than object control competence (Std. B = 0.22, t (106.69) = 2.63, p = 0.002). Object control and game competence are both important as correlates of physical activity and cardiorespiratory fitness in children.

Cardiorespiratory fitness modulates the acute flow-mediated dilation response following high-intensity but not moderate-intensity exercise in elderly men.

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Bailey, Tom G; Perissiou, Maria; Windsor, Mark; Russell, Fraser; Golledge, Jonathan; Green, Daniel J; Askew, Christopher D

2017-05-01

Impaired endothelial function is observed with aging and in those with low cardiorespiratory fitness (V̇o 2peak ). Improvements in endothelial function with exercise training are somewhat dependent on the intensity of exercise. While the acute stimulus for this improvement is not completely understood, it may, in part, be due to the flow-mediated dilation (FMD) response to acute exercise. We examined the hypothesis that exercise intensity alters the brachial (systemic) FMD response in elderly men and is modulated by V̇o 2peak Forty-seven elderly men were stratified into lower (V̇o 2peak = 24.3 ± 2.9 ml·kg -1 ·min -1 ; n = 27) and higher fit groups (V̇o 2peak = 35.4 ± 5.5 ml·kg -1 ·min -1 ; n = 20) after a test of cycling peak power output (PPO). In randomized order, participants undertook moderate-intensity continuous exercise (MICE; 40% PPO) or high-intensity interval cycling exercise (HIIE; 70% PPO) or no-exercise control. Brachial FMD was assessed at rest and 10 and 60 min after exercise. FMD increased after MICE in both groups {increase of 0.86% [95% confidence interval (CI), 0.17-1.56], P = 0.01} and normalized after 60 min. In the lower fit group, FMD was reduced after HIIE [reduction of 0.85% (95% CI, 0.12-1.58), P = 0.02] and remained decreased at 60 min. In the higher fit group, FMD was unchanged immediately after HIIE and increased after 60 min [increase of 1.52% (95% CI, 0.41-2.62), P exercise control, FMD was reduced in both groups after 60 min ( P = 0.05). Exercise intensity alters the acute FMD response in elderly men and V̇o 2peak modulates the FMD response following HIIE but not MICE. The sustained decrease in FMD in the lower fit group following HIIE may represent a signal for vascular adaptation or endothelial fatigue. NEW & NOTEWORTHY This study is the first to show that moderate-intensity continuous cycling exercise increased flow-mediated dilation (FMD) transiently before normalization of FMD after 1 h, irrespective of

The prevalence of heat-related cardiorespiratory symptoms: the vulnerable groups identified from the National FINRISK 2007 Study

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Näyhä, Simo; Rintamäki, Hannu; Donaldson, Gavin; Hassi, Juhani; Jousilahti, Pekka; Laatikainen, Tiina; Jaakkola, Jouni J. K.; Ikäheimo, Tiina M.

2017-04-01

The prevalence of heat-related cardiorespiratory symptoms among vulnerable groups is not well known. We therefore estimated the prevalence of heat-related cardiorespiratory symptoms among the Finnish population and their associations with social and individual vulnerability factors. The data came from the National FINRISK 2007 Study, in which 4007 men and women aged 25-74 answered questions on heat-related cardiorespiratory symptoms in the Oulu Cold and Heat Questionnaire 2007. Logistic regression was used to calculate odds ratios (ORs), their 95 % confidence intervals (CIs), and model-predicted prevalence figures. The prevalence of heat-related cardiorespiratory symptoms was 12 %. It increased with age, from 3 % at the age of 25 years to 28 % at the age of 75 years. The symptoms were associated with pre-existing lung (OR 3.93; CI 3.01-5.13) and cardiovascular diseases (OR 2.27; 1.78-2.89); being a pensioner (OR 2.91; 1.65-5.28), unemployed (OR 2.82; 1.47-5.48), or working in agriculture (OR 2.27; 1.14-4.46) compared with working in industry; having only basic vs academic education (OR 1.98; 1.31-3.05); being female (OR 1.94; 1.51-2.50); being heavy vs light alcohol consumer (OR 1.89; 1.02-3.32); undertaking hard vs light physical work (OR 1.48;1.06-2.07); and being inactive vs active in leisure time (OR 1.97; 1.39-2.81). The adjusted prevalence of symptoms showed a wide range of variation, from 3 to 61 % depending on sex, age, professional field, education, and pre-existing lung and cardiovascular diseases. In conclusion, heat-related cardiorespiratory symptoms are commonly perceived among people with pre-existing lung or cardiovascular disease, agricultural workers, unemployed, pensioners, and people having only basic education. This information is needed for any planning and targeting measures to reduce the burden of summer heat.

Branchial CO(2) receptors and cardiorespiratory adjustments during hypercarbia in Pacific spiny dogfish (Squalus acanthias).

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McKendry, J E; Milsom, W K; Perry, S F

2001-04-01

Adult Pacific spiny dogfish (Squalus acanthias) were exposed to acute (approximately 20 min) hypercarbia while we monitored arterial blood pressure, systemic vascular resistance (R(S)), cardiac output (V(b)) and frequency (fh) as well as ventilatory amplitude (V(AMP)) and frequency (f(V)). Separate series of experiments were conducted on control, atropinized (100 nmol kg(-1)) and branchially denervated fish to investigate putative CO(2)-chemoreceptive sites on the gills and their link to the autonomic nervous system and cardiorespiratory reflexes.In untreated fish, moderate hypercarbia (water CO(2 )partial pressure; Pw(CO2)=6.4+/-0.1 mmHg) (1 mmHg=0.133 kPa) elicited significant increases in V(AMP) (of approximately 92 %) and f(V) (of approximately 18 %) as well as decreases in fh (of approximately 64 %), V.(b) (approximately 29 %) and arterial blood pressure (of approximately 11 %); R(S) did not change significantly. Denervation of the branchial branches of cranial nerves IX and X to the pseudobranch and each gill arch eliminated all cardiorespiratory responses to hypercarbia. Prior administration of the muscarinic receptor antagonist atropine also abolished the hypercarbia-induced ventilatory responses and virtually eliminated all CO(2)-elicited cardiovascular adjustments. Although the atropinized dogfish displayed a hypercarbic bradycardia, the magnitude of the response was significantly attenuated (36+/-6 % decrease in fh in controls versus 9+/-2 % decrease in atropinized fish; means +/- s.e.m.).Thus, the results of the present study reveal the presence of gill CO(2) chemoreceptors in dogfish that are linked to numerous cardiorespiratory reflexes. In addition, because all cardiorespiratory responses to hypercarbia were abolished or attenuated by atropine, the CO(2) chemoreception process and/or one or more downstream elements probably involve cholinergic (muscarinic) neurotransmission.

Determinant factors of cardiorespiratory fitness in Portuguese adolescents of different ethnicities. DOI: 10.5007/1980-0037.2011v13n4p243

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Diana Aguiar Santos

2011-08-01

Full Text Available Cardiorespiratory fitness is an important health indicator in young people. The aim of this study was to investigate the effects of age, gender, body adiposity, and ethnicity on cardiorespiratory fitness in a sample of Portuguese adolescents. The sample consisted of 266 adolescents aged 12-18 years [112 boys (80 Caucasians and 32 African-Portuguese, AP and 154 girls (109 Caucasians and 45 AP]. Percent body fat was estimated with a hand-to-hand bioelectrical impedance device (BF300, OMROM. Cardiorespiratory fitness was assessed by a shuttle run test (Fitnessgram battery. Multiple regression models were used for statistical analysis. The results showed that girls presented lower maximal oxygen consumption and higher percent body fat than boys. Cardiorespiratory fitness was lower in Caucasian than in AP girls. Multiple regression analysis showed that percent body fat, age and the interaction of age with being Caucasian and age with female gender were significant determinants that were negatively associated with cardiorespiratory fitness. The results suggest that maximal oxygen consumption is lower in adolescents with higher adiposity and in older adolescents. The findings highlight the importance of promoting physical fitness in schools across ages, especially in older adolescents, adjusting for determinant factors such as gender and ethnicity

Bidirectional Cardio-Respiratory Interactions in Heart Failure.

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Radovanović, Nikola N; Pavlović, Siniša U; Milašinović, Goran; Kirćanski, Bratislav; Platiša, Mirjana M

2018-01-01

We investigated cardio-respiratory coupling in patients with heart failure by quantification of bidirectional interactions between cardiac (RR intervals) and respiratory signals with complementary measures of time series analysis. Heart failure patients were divided into three groups of twenty, age and gender matched, subjects: with sinus rhythm (HF-Sin), with sinus rhythm and ventricular extrasystoles (HF-VES), and with permanent atrial fibrillation (HF-AF). We included patients with indication for implantation of implantable cardioverter defibrillator or cardiac resynchronization therapy device. ECG and respiratory signals were simultaneously acquired during 20 min in supine position at spontaneous breathing frequency in 20 healthy control subjects and in patients before device implantation. We used coherence, Granger causality and cross-sample entropy analysis as complementary measures of bidirectional interactions between RR intervals and respiratory rhythm. In heart failure patients with arrhythmias (HF-VES and HF-AF) there is no coherence between signals ( p respiratory signal in HF-VES. Cross-sample entropy analysis revealed the strongest synchrony between respiratory and RR signal in HF-VES group. Beside respiratory sinus arrhythmia there is another type of cardio-respiratory interaction based on the synchrony between cardiac and respiratory rhythm. Both of them are altered in heart failure patients. Respiratory sinus arrhythmia is reduced in HF-Sin patients and vanished in heart failure patients with arrhythmias. Contrary, in HF-Sin and HF-VES groups, synchrony increased, probably as consequence of some dominant neural compensatory mechanisms. The coupling of cardiac and respiratory rhythm in heart failure patients varies depending on the presence of atrial/ventricular arrhythmias and it could be revealed by complementary methods of time series analysis.

The effect of cardiorespiratory fitness and obesity on cancer mortality in women and men.

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Evenson, Kelly R; Stevens, June; Cai, Jianwen; Thomas, Ratna; Thomas, Olivia

2003-02-01

The purpose of this study was to determine the independent and combined effects of cardiorespiratory fitness and obesity on all-cause cancer mortality for women and men. Using the Lipids Research Clinics Prevalence Study, we examined the relationship of fitness and obesity on cancer mortality among 2585 women and 2890 men followed from 1972-1976 to 1998. Cardiorespiratory fitness was measured using a treadmill test and obesity was assessed using body mass index (BMI) calculated from measured height and weight. Gender-specific hazard ratios (HR) were calculated from proportional hazard models, which included covariates for age, education, smoking, alcohol intake, Keys score, and menopause (women only). Adjusted cancer mortality was significantly lower in the most fit quintile relative to the other four quintiles for men (HR = 0.47; 95% CI, 0.27-0.81) but not for women (HR = 0.84; 95% CI, 0.52-1.36). Adjusted cancer mortality was significantly higher in the highest BMI quintile relative to the other four BMI quintiles for women (HR = 1.49; 95% CI, 1.06-2.09) but not for men (HR = 1.05; 95% CI, 0.77-1.43). Further adjustment for BMI on fitness and adjustment for fitness on BMI did not meaningfully change the HR. There were no significant interactions between fitness and obesity in predicting cancer mortality for either women or men. In this study, high fitness was a stronger predictor of cancer mortality in men, whereas high BMI was a stronger predictor of cancer mortality in women.

Differential control of central cardiorespiratory interactions by hypercapnia and the effect of prenatal nicotine.

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Huang, Zheng-Gui; Griffioen, Kathleen J S; Wang, Xin; Dergacheva, Olga; Kamendi, Harriet; Gorini, Christopher; Bouairi, Euguenia; Mendelowitz, David

2006-01-04

Hypercapnia evokes a strong cardiorespiratory response including gasping and a pronounced bradycardia; however, the mechanism responsible for these survival responses initiated in the brainstem is unknown. To examine the effects of hypercapnia on the central cardiorespiratory network, we used an in vitro medullary slice that allows simultaneous examination of rhythmic respiratory-related activity and inhibitory synaptic neurotransmission to cardioinhibitory vagal neurons (CVNs). Hypercapnia differentially modulated inhibitory neurotransmission to CVNs; whereas hypercapnia selectively depressed spontaneous glycinergic IPSCs in CVNs without altering respiratory-related increases in glycinergic neurotransmission, it decreased both spontaneous and inspiratory-associated GABAergic IPSCs. Because maternal smoking is the highest risk factor for sudden infant death syndrome (SIDS) and prenatal nicotine exposure is proposed to be the link between maternal smoking and SIDS, we examined the cardiorespiratory responses to hypercapnia in animals exposed to nicotine in the prenatal and perinatal period. In animals exposed to prenatal nicotine, hypercapnia evoked an exaggerated depression of GABAergic IPSCs in CVNs with no significant change in glycinergic neurotransmission. Hypercapnia altered inhibitory neurotransmission to CVNs at both presynaptic and postsynaptic sites. Although the results obtained in this study in vitro cannot be extrapolated with certainty to in vivo responses, the results of this study provide a likely neurochemical mechanism for hypercapnia-evoked bradycardia and the dysregulation of this response with exposure to prenatal nicotine, creating a higher risk for SIDS.

Acid Gastroesophageal Reflux Disease and Apparent Life-Threatening Events: Simultaneous pH-metry and Cardiorespiratory Monitoring.

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Macchini, Francesco; Morandi, Anna; Cognizzoli, Paola; Farris, Giorgio; Gentilino, Valerio; Zanini, Andrea; Leva, Ernesto

2017-02-01

To investigate the prevalence and the characteristics of gastroesophageal reflux disease (GERD) in infants with apparent life threatening events (ALTE). Infants with at least one episode of ALTE in absence of predisposing factors were included. All infants underwent a cardiorespiratory recording with simultaneous 24-hour pH-monitoring. Patients were divided into 3 groups according to the severity of GERD: A. Reflux Index (RI) 7%. Monthly evaluations were performed and the anti-reflux therapy was maintained till normalization of monitoring and clinic. 41 infants were enrolled. GERD was found in 80% of patients (moderate in 54%, severe in 27%). A normalization of the cardiorespiratory tracks was recorded on average after 1 month for group A, 7 months for the group B and 9.5 months for group C. A significant difference was registered between group A and both group B and C (P < 0.0001), as well as between the group B and C (P < 0.05). GERD influences significantly the time of normalization of the cardiorespiratory monitoring in infants with ALTE. GERD diagnosis and treatment are mandatory in these patients. Copyright © 2016. Published by Elsevier B.V.

The cardiorespiratory effects of detomidine in the primate (Papio ursinus

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H. Bosman

1990-07-01

Full Text Available Detomidine is a novel imidazole derivative with a high affinity for a₂-adrenoceptors. The cardiorespiratory effects of this drug were evaluated in the primate (Papio ursinus under ketamine anaesthesia. The release of noradrenalin is modulated by a₂-adrenoceptors, and this resulted in a longer duration of anaesthesia when ketamine was combined with detomidine in comparison with ketamine alone. Detomidine caused a marked bradycardia, which was not reflex induced, but probably the result of a decreased sympathetic outflow. Various conducting disturbances were observed in the electrocardiogram, also probably the result of decreased sympathetic tone to the heart. The effect of detomidine on the respiratory system was minimal. Detomidine proved to be a useful drug to use in combination with ketamine for the induction of anaesthesia in primates. It should, however, not be used during cardiovascular studies.

Instantaneous Transfer Entropy for the Study of Cardiovascular and Cardiorespiratory Nonstationary Dynamics.

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Valenza, Gaetano; Faes, Luca; Citi, Luca; Orini, Michele; Barbieri, Riccardo

2018-05-01

Measures of transfer entropy (TE) quantify the direction and strength of coupling between two complex systems. Standard approaches assume stationarity of the observations, and therefore are unable to track time-varying changes in nonlinear information transfer with high temporal resolution. In this study, we aim to define and validate novel instantaneous measures of TE to provide an improved assessment of complex nonstationary cardiorespiratory interactions. We here propose a novel instantaneous point-process TE (ipTE) and validate its assessment as applied to cardiovascular and cardiorespiratory dynamics. In particular, heartbeat and respiratory dynamics are characterized through discrete time series, and modeled with probability density functions predicting the time of the next physiological event as a function of the past history. Likewise, nonstationary interactions between heartbeat and blood pressure dynamics are characterized as well. Furthermore, we propose a new measure of information transfer, the instantaneous point-process information transfer (ipInfTr), which is directly derived from point-process-based definitions of the Kolmogorov-Smirnov distance. Analysis on synthetic data, as well as on experimental data gathered from healthy subjects undergoing postural changes confirms that ipTE, as well as ipInfTr measures are able to dynamically track changes in physiological systems coupling. This novel approach opens new avenues in the study of hidden, transient, nonstationary physiological states involving multivariate autonomic dynamics in cardiovascular health and disease. The proposed method can also be tailored for the study of complex multisystem physiology (e.g., brain-heart or, more in general, brain-body interactions).

A cardiorespiratory classifier of voluntary and involuntary electrodermal activity

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Sejdic Ervin

2010-02-01

Full Text Available Abstract Background Electrodermal reactions (EDRs can be attributed to many origins, including spontaneous fluctuations of electrodermal activity (EDA and stimuli such as deep inspirations, voluntary mental activity and startling events. In fields that use EDA as a measure of psychophysiological state, the fact that EDRs may be elicited from many different stimuli is often ignored. This study attempts to classify observed EDRs as voluntary (i.e., generated from intentional respiratory or mental activity or involuntary (i.e., generated from startling events or spontaneous electrodermal fluctuations. Methods Eight able-bodied participants were subjected to conditions that would cause a change in EDA: music imagery, startling noises, and deep inspirations. A user-centered cardiorespiratory classifier consisting of 1 an EDR detector, 2 a respiratory filter and 3 a cardiorespiratory filter was developed to automatically detect a participant's EDRs and to classify the origin of their stimulation as voluntary or involuntary. Results Detected EDRs were classified with a positive predictive value of 78%, a negative predictive value of 81% and an overall accuracy of 78%. Without the classifier, EDRs could only be correctly attributed as voluntary or involuntary with an accuracy of 50%. Conclusions The proposed classifier may enable investigators to form more accurate interpretations of electrodermal activity as a measure of an individual's psychophysiological state.

Inference of a Nonlinear Stochastic Model of the Cardiorespiratory Interaction

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Smelyanskiy, V. N.; Luchinsky, D. G.; Stefanovska, A.; McClintock, P. V.

2005-03-01

We reconstruct a nonlinear stochastic model of the cardiorespiratory interaction in terms of a set of polynomial basis functions representing the nonlinear force governing system oscillations. The strength and direction of coupling and noise intensity are simultaneously inferred from a univariate blood pressure signal. Our new inference technique does not require extensive global optimization, and it is applicable to a wide range of complex dynamical systems subject to noise.

Graded associations between cardiorespiratory fitness, fatness, and blood pressure in children and adolescents

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Klasson-Heggebø, L.; Andersen, Lars Bo; Wennlöf, A.H.

2006-01-01

Objective: To measure the graded relation between cardiorespiratory fitness and sum of skinfolds, waist circumference, and blood pressure in children and adolescents participating in the European youth heart study. Methods: The participants were 4072 children and adolescents (aged 9 and 15) from...

Associations of birth size and duration of breast feeding with cardiorespiratory fitness in childhood: findings from the Avon Longitudinal Study of Parents and Children (ALSPAC)

International Nuclear Information System (INIS)

Lawlor, Debbie A.; Cooper, Ashley R.; Bain, Chris; Davey Smith, George; Irwin, Amanda; Riddoch, Chris; Ness, Andy

2008-01-01

Objectives: To explore the developmental origins of cardiorespiratory fitness. Methods: We examined the associations of birth size and duration of breast feeding with cardiorespiratory fitness assessed at the 9 year follow-up examination in 3612 participants of the Avon Longitudinal Study of Parents and Children (ALSPAC). We used physical work capacity at a heart rate of 170 beats per minute (PWC 170 ) as our assessment of cardiorespiratory fitness. This was estimated using standard regression methods from parameters measured using an electronically braked cycle ergometer. Results: Birth weight, length and ponderal index were all positively associated with cardiorespiratory fitness in both sexes, with no strong evidence of a difference in effect between girls and boys. Work capacity increased by 1.12 W (95% CI: 0.83, 1.40) on average per 1 standard deviation (SD) greater birth weight. This association was not affected by adjustment for socioeconomic position and maternal smoking during pregnancy; there was some attenuation with adjustment for both maternal and paternal height and body mass index and more marked attenuation with adjustment for the child's height and body mass index. In the fully adjusted model work capacity increased by 0.51 W (95% CI: 0.21, 0.81) per SD birth weight. Whether an individual had been breastfed and duration of breastfeeding were not associated with cardiorespiratory fitness in any models. Conclusion: Our results provide some support for a role of intrauterine factors in determining cardiorespiratory fitness in childhood

Improvements in fundamental movement skill competency mediate the effect of the SCORES intervention on physical activity and cardiorespiratory fitness in children.

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Cohen, Kristen E; Morgan, Philip J; Plotnikoff, Ronald C; Barnett, Lisa M; Lubans, David R

2015-01-01

Numerous studies have identified a positive association between fundamental movement skill (FMS) competency and physical activity in children; however, the causal pathways have not been established. The aim of this study is to determine if changes in FMS competency mediated the effect of the Supporting Children's Outcomes using Rewards, Exercise and Skills (SCORES) intervention on physical activity and cardiorespiratory fitness in children. Eight primary schools (25 classes) and 460 children (aged 8.5 ± 0.6, 54% girls) were randomised to the SCORES intervention or control group for the 12-month study. The outcomes were accelerometer-determined moderate-to-vigorous physical activity (MVPA) and cardiorespiratory fitness. The hypothesised mediators were actual FMS competency and perceived sport competence. Mediation analyses were conducted using multilevel linear analysis in MPlus. From the original sample, 138 (30.0%) and 370 (80.4%) children provided useable physical activity and cardiorespiratory fitness data at post-test assessments. There were significant treatment effects for locomotor skills and overall FMSs. Changes in MVPA were associated with changes in object-control skills, overall FMSs and perceived competence. The overall FMSs had a significant mediating effect on MVPA (AB = 2.09, CI = 0.01-4.55). Overall FMSs (AB = 1.19, CI = 0.002-2.79) and locomotor skills (AB = 0.74, CI = 0.01-1.69) had a significant mediating effect on cardiorespiratory fitness. The results of this study conclude that actual but not perceived movement skill competency mediated the effect of the SCORES intervention on physical activity and cardiorespiratory fitness.

Simulation can contribute a part of cardiorespiratory physiotherapy clinical education: two randomized trials.

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Blackstock, Felicity C; Watson, Kathryn M; Morris, Norman R; Jones, Anne; Wright, Anthony; McMeeken, Joan M; Rivett, Darren A; O'Connor, Vivienne; Peterson, Raymond F; Haines, Terry P; Watson, Geoffrey; Jull, Gwendolen Anne

2013-02-01

Simulated learning environments (SLEs) are used worldwide in health professional education, including physiotherapy, to train certain attributes and skills. To date, no randomized controlled trial (RCT) has evaluated whether education in SLEs can partly replace time in the clinical environment for physiotherapy cardiorespiratory practice. Two independent single-blind multi-institutional RCTs were conducted in parallel using a noninferiority design. Participants were volunteer physiotherapy students (RCT 1, n = 176; RCT 2, n = 173) entering acute care cardiorespiratory physiotherapy clinical placements. Two SLE models were investigated as follows: RCT 1, 1 week in SLE before 3 weeks of clinical immersion; RCT 2, 2 weeks of interspersed SLE/clinical immersion (equivalent to 1 SLE week) within the 4-week clinical placement. Students in each RCT were stratified on academic grade and randomly allocated to an SLE plus clinical immersion or clinical immersion control group. The primary outcome was competency to practice measured in 2 clinical examinations using the Assessment of Physiotherapy Practice. Secondary outcomes were student perception of experience and clinical educator and patient rating of student performance. There were no significant differences in student competency between the SLE and control groups in either RCT, although students in the interspersed group (RCT 2) achieved a higher score in 5 of 7 Assessment of Physiotherapy Practice standards (all P Students rated the SLE experience positively. Clinical educators and patients reported comparability between groups. An SLE can replace clinical time in cardiorespiratory physiotherapy practice. Part education in the SLE satisfied clinical competency requirements, and all stakeholders were satisfied.

Parabrachial complex glutamate receptors modulate the cardiorespiratory response evoked from hypothalamic defense area.

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Díaz-Casares, A; López-González, M V; Peinado-Aragonés, C A; González-Barón, S; Dawid-Milner, M S

2012-08-16

To characterize the possible role of glutamate in the interaction between Hypothalamic Defense Area (HDA) and Parabrachial complex (PBc) nuclei, cardiorespiratory changes were analyzed in response to electrical stimulation of the HDA (1 ms pulses, 30-50 μA given at 100 Hz for 5s) before and after the microinjection of the nonspecific glutamate receptor antagonist kynurenic acid (50 nl, 5 nmol), NMDA receptor antagonist MK-801 (50 nl, 50 nmol), non-NMDA receptor antagonist CNQX (50 nl, 50 nmol) or metabotropic glutamate receptor antagonist MCPG (50 nl, 5 nmol) within the PBc. HDA stimulation evoked an inspiratory facilitatory response, consisting of an increase in respiratory rate (pHDA stimulation. Similarly, the magnitude of the tachycardia and the pressor response was decreased after the microinjection of MK-801 (pHDA stimulation but the respiratory response persisted unchanged after MK-801 or CNQX microinjection into the lPB. Kynurenic acid within the medial parabrachial region (mPB) abolished the tachycardia (pHDA stimulation. MK-801 and CNQX microinjection in this region decreased the magnitude of the tachycardia (pHDA stimulation was not changed after the microinjection of kynurenic acid, MK-801 or CNQX within the mPB. No changes were observed in the cardiorespiratory response evoked to HDA stimulation after MCPG microinjection within lPB and mPB. These results indicate that glutamate PBc receptors are involved in the cardiorespiratory response evoked from the HDA. The possible mechanisms involved in these interactions are discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

Cardio-respiratory development in bird embryos: new insights from a venerable animal model

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Warren W. Burggren

Full Text Available ABSTRACT The avian embryo is a time-honored animal model for understanding vertebrate development. A key area of extensive study using bird embryos centers on developmental phenotypic plasticity of the cardio-respiratory system and how its normal development can be affected by abiotic factors such as temperature and oxygen availability. Through the investigation of the plasticity of development, we gain a better understanding of both the regulation of the developmental process and the embryo's capacity for self-repair. Additionally, experiments with abiotic and biotic stressors during development have helped delineate not just critical windows for avian cardio-respiratory development, but the general characteristics (e.g., timing and dose-dependence of critical windows in all developing vertebrates. Avian embryos are useful in exploring fetal programming, in which early developmental experiences have implications (usually negative later in life. The ability to experimentally manipulate the avian embryo without the interference of maternal behavior or physiology makes it particularly useful in future studies of fetal programming. The bird embryo is also a key participant in studies of transgenerational epigenetics, whether by egg provisioning or effects on the germline that are transmitted to the F1 generation (or beyond. Finally, the avian embryo is heavily exploited in toxicology, in which both toxicological testing of potential consumer products as well as the consequences of exposure to anthropogenic pollutants are routinely carried out in the avian embryo. The avian embryo thus proves useful on numerous experimental fronts as an animal model that is concurrently both of adequate complexity and sufficient simplicity for probing vertebrate cardio-respiratory development.

Stress and disorders of the stress system.

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Chrousos, George P

2009-07-01

All organisms must maintain a complex dynamic equilibrium, or homeostasis, which is constantly challenged by internal or external adverse forces termed stressors. Stress occurs when homeostasis is threatened or perceived to be so; homeostasis is re-established by various physiological and behavioral adaptive responses. Neuroendocrine hormones have major roles in the regulation of both basal homeostasis and responses to threats, and are involved in the pathogenesis of diseases characterized by dyshomeostasis or cacostasis. The stress response is mediated by the stress system, partly located in the central nervous system and partly in peripheral organs. The central, greatly interconnected effectors of this system include the hypothalamic hormones arginine vasopressin, corticotropin-releasing hormone and pro-opiomelanocortin-derived peptides, and the locus ceruleus and autonomic norepinephrine centers in the brainstem. Targets of these effectors include the executive and/or cognitive, reward and fear systems, the wake-sleep centers of the brain, the growth, reproductive and thyroid hormone axes, and the gastrointestinal, cardiorespiratory, metabolic, and immune systems. Optimal basal activity and responsiveness of the stress system is essential for a sense of well-being, successful performance of tasks, and appropriate social interactions. By contrast, excessive or inadequate basal activity and responsiveness of this system might impair development, growth and body composition, and lead to a host of behavioral and somatic pathological conditions.

Activity of cardiorespiratory networks revealed by transsynaptic virus expressing GFP.

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Irnaten, M; Neff, R A; Wang, J; Loewy, A D; Mettenleiter, T C; Mendelowitz, D

2001-01-01

A fluorescent transneuronal marker capable of labeling individual neurons in a central network while maintaining their normal physiology would permit functional studies of neurons within entire networks responsible for complex behaviors such as cardiorespiratory reflexes. The Bartha strain of pseudorabies virus (PRV), an attenuated swine alpha herpesvirus, can be used as a transsynaptic marker of neural circuits. Bartha PRV invades neuronal networks in the CNS through peripherally projecting axons, replicates in these parent neurons, and then travels transsynaptically to continue labeling the second- and higher-order neurons in a time-dependent manner. A Bartha PRV mutant that expresses green fluorescent protein (GFP) was used to visualize and record from neurons that determine the vagal motor outflow to the heart. Here we show that Bartha PRV-GFP-labeled neurons retain their normal electrophysiological properties and that the labeled baroreflex pathways that control heart rate are unaltered by the virus. This novel transynaptic virus permits in vitro studies of identified neurons within functionally defined neuronal systems including networks that mediate cardiovascular and respiratory function and interactions. We also demonstrate superior laryngeal motorneurons fire spontaneously and synapse on cardiac vagal neurons in the nucleus ambiguus. This cardiorespiratory pathway provides a neural basis of respiratory sinus arrhythmias.

The association between cardiorespiratory fitness and risk of all-cause mortality among women with impaired fasting glucose or undiagnosed diabetes mellitus.

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Lyerly, G William; Sui, Xuemei; Lavie, Carl J; Church, Timothy S; Hand, Gregory A; Blair, Steven N

2009-09-01

To evaluate the independent and joint associations among cardiorespiratory fitness (CRF), body mass index, and risk of mortality from any cause among women with impaired fasting glucose (IFG) or undiagnosed diabetes mellitus (DM). Female patients (N=3044; mean age, 47.4 years) with IFG or undiagnosed DM completed a maximal exercise treadmill test (between January 26, 1971, and March 21, 2001). The women had no history of a cardiovascular disease event or diagnosed DM at baseline. Cardiorespiratory fitness was defined categorically as low (bottom 20%), moderate (middle 40%), or high (upper 40%) according to previously published Aerobics Center Longitudinal Study guidelines. Body mass index was calculated as the weight in kilograms divided by the height in meters squared (kg/m(2)). During a 16-year follow-up period, 171 deaths occurred. There was an inverse association between CRF and all-cause mortality risk. Women with moderate or high CRF were at lower risk of mortality (moderate CRF, 35% lower; high CRF, 36% lower; P(trend)=.03) than those with low CRF. An exercise capacity lower than 7 metabolic equivalents was associated with a 1.5-fold higher risk of death than an exercise capacity of 9 metabolic equivalents or higher (P(trend)=.05). The multivariate adjusted hazard ratios (HRs), including adjustments for CRF, were higher for heavier patients than for patients of normal weight (overweight patients: HR, 0.86; 95% confidence interval, 0.57-1.30; obese patients: HR, 1.19; 95% confidence interval, 0.70-2.03; P(trend)=.84). Combined analyses showed that women who were overweight or obese and unfit (low CRF) were at more than twice the risk of death than women who were of normal weight and fit (moderate or high CRF). Cardiorespiratory fitness, not body mass index, is a significant predictor of all-cause mortality among women with IFG or undiagnosed DM. Assessing CRF levels provides important prognostic information independent of traditional risk factors.

Bidirectional Cardio-Respiratory Interactions in Heart Failure

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Nikola N. Radovanović

2018-03-01

Full Text Available We investigated cardio-respiratory coupling in patients with heart failure by quantification of bidirectional interactions between cardiac (RR intervals and respiratory signals with complementary measures of time series analysis. Heart failure patients were divided into three groups of twenty, age and gender matched, subjects: with sinus rhythm (HF-Sin, with sinus rhythm and ventricular extrasystoles (HF-VES, and with permanent atrial fibrillation (HF-AF. We included patients with indication for implantation of implantable cardioverter defibrillator or cardiac resynchronization therapy device. ECG and respiratory signals were simultaneously acquired during 20 min in supine position at spontaneous breathing frequency in 20 healthy control subjects and in patients before device implantation. We used coherence, Granger causality and cross-sample entropy analysis as complementary measures of bidirectional interactions between RR intervals and respiratory rhythm. In heart failure patients with arrhythmias (HF-VES and HF-AF there is no coherence between signals (p < 0.01, while in HF-Sin it is reduced (p < 0.05, compared with control subjects. In all heart failure groups causality between signals is diminished, but with significantly stronger causality of RR signal in respiratory signal in HF-VES. Cross-sample entropy analysis revealed the strongest synchrony between respiratory and RR signal in HF-VES group. Beside respiratory sinus arrhythmia there is another type of cardio-respiratory interaction based on the synchrony between cardiac and respiratory rhythm. Both of them are altered in heart failure patients. Respiratory sinus arrhythmia is reduced in HF-Sin patients and vanished in heart failure patients with arrhythmias. Contrary, in HF-Sin and HF-VES groups, synchrony increased, probably as consequence of some dominant neural compensatory mechanisms. The coupling of cardiac and respiratory rhythm in heart failure patients varies depending on the

Chronic effects of strength training vs. Hydro aerobics on functional and cardiorespiratory ability in postmenopausal women.

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Novaes, Giovanni S; Novaes, Jefferson S; Vilaça-Alves, José; Silva, Gabriel Costa E; Garrido, Nuno D; Furtado, Hélio; Reis, Victor M

2014-09-29

The current study aimed to compare the effects of two exercise programs (Strength Training and Hydro Gymnastics) on the functional and cardiorespiratory abilities of Portuguese postmenopausal women. The study population consisted of 38 volunteers (age: 66.9 ± 6.1 years, body mass: 73.70 ± 10.38 kg, and body height: 1.55 ± 0.10 m). Subjects were randomly divided into two experimental groups and one control group: one group performed 24 weeks of strength training (GST; n = 14), another performed 24 weeks of hydro gymnastics (GH; n = 17) and a control group (CG; n = 7), where the subjects continued with their regular daily activities without involvement in any physical exercise program. Three assessments were performed: before the beginning of the program, 12 weeks after the start of the training program and 24 weeks after the start of the program. To assess the functional ability of the participants, several tests proposed by Jones and Rikli (2002) were performed. To evaluate the cardiorespiratory ability of the participants, a modified treadmill Bruce test was applied. Significant differences (ptraining methods in the tests, which primarily demanded muscular strength. Body mass and the body mass index showed significant differences during the three stages of assessment in the GST group (pfunctional and cardiorespiratory abilities of Portuguese postmenopausal women.

The position of a standard optical computer mouse affects cardiorespiratory responses during the operation of a computer under time constraints

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Shunji Sako

2014-08-01

Full Text Available Objectives: This study investigated the association between task-induced stress and fatigue by examining the cardiovascular responses of subjects using different mouse positions while operating a computer under time constraints. Material and Methods: The study was participated by 16 young, healthy men and examined the use of optical mouse devices affixed to laptop computers. Two mouse positions were investigated: (1 the distal position (DP, in which the subjects place their forearms on the desk accompanied by the abduction and flexion of their shoulder joints, and (2 the proximal position (PP, in which the subjects place only their wrists on the desk without using an armrest. The subjects continued each task for 16 min. We assessed differences in several characteristics according to mouse position, including expired gas values, autonomic nerve activities (based on cardiorespiratory responses, operating efficiencies (based on word counts, and fatigue levels (based on the visual analog scale – VAS. Results: Oxygen consumption (VO2, the ratio of inspiration time to respiration time (Ti/Ttotal, respiratory rate (RR, minute ventilation (VE, and the ratio of expiration to inspiration (Te/Ti were significantly lower when the participants were performing the task in the DP than those obtained in the PP. Tidal volume (VT, carbon dioxide output rates (VCO2/VE, and oxygen extraction fractions (VO2/VE were significantly higher for the DP than they were for the PP. No significant difference in VAS was observed between the positions; however, as the task progressed, autonomic nerve activities were lower and operating efficiencies were significantly higher for the DP than they were for the PP. Conclusions: Our results suggest that the DP has fewer effects on cardiorespiratory functions, causes lower levels of sympathetic nerve activity and mental stress, and produces a higher total workload than the PP. This suggests that the DP is preferable to the PP when

Immediate Effects of Smoking on Cardiorespiratory Responses During Dynamic Exercise: Arm Versus Leg Ergometry

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Chien-Liang eChen

2015-12-01

Full Text Available Purpose: This study compared the immediate effects of smoking on cardiorespiratory responses to dynamic arm and leg exercises. Methods: This randomized crossover study recruited 14 college students. Each participant underwent 2 sets of arm-cranking (AC and leg-cycling (LC exercise tests. The testing sequences of the control trial (participants refrained from smoking for 8 hours before testing and the experimental trial (participants smoked 2 cigarettes were randomly chosen. We observed immediate changes in pulmonary function and heart rate variability after smoking and before the exercise test. The participants then underwent graded exercise tests of their arms and legs, respectively, until reaching exhaustion. We compared the peak work achieved and the time to exhaustion during the exercise tests with various cardiorespiratory indices [i.e., heart rate, oxygen consumption (VO2, minute ventilation (VE]. The main effects of the time and the trial, as well as their interaction effects on outcome measures, were investigated using repeated measure ANOVA.Results: Five minutes after smoking, the participants exhibited reduced forced vital capacities and forced expiratory volumes in the first second (P < .05, in addition to elevated resting heart rates (P < .001. The high-frequency, low-frequency, and the total power of the heart rate variability were also reduced (P < .05 at rest. For the exercise test periods, smoking reduced the time to exhaustion (P = .005 and the ventilatory threshold (P < .05 in the LC tests, whereas there were no significant effects in the AC tests. A trend analysis revealed a significant (P < .001 trial-by-time interaction effect for heart rate, VO2, and VE during the graded exercise test. Lower VO2 and VE levels were exhibited in the exercise response of the smoking trial than in that of the control LC trials, whereas there was no discernable inter-trial difference in the AC trials. Moreover, the differences in heart rate

Cardiorespiratory fitness and academic performance association is mediated by weight status in adolescents: DADOS study.

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Beltran-Valls, María Reyes; Adelantado-Renau, Mireia; Castro-Piñero, Jose; Sánchez-López, Mairena; Moliner-Urdiales, Diego

2018-04-28

The aim of our study was to examine the mediation effect of weight status on the association between cardiorespiratory fitness (CRF) and academic performance (AP). Two hundred sixty-nine adolescents (140 boys) aged 13.9 ± 0.3 years old from the DADOS study were included in this cross-sectional analysis. CRF was assessed by the 20-m shuttle run test and estimated maximum oxygen uptake was used in the analysis. AP was assessed through the final academic grades and the Science Research Associates Test of Educational Abilities for assessing reasoning, verbal, and numeric abilities. Weight status was assessed by body mass index (kg/m 2 ). Boot-strapped mediation procedures were performed and indirect effects (IE) with confidence intervals (CI) not including zero were considered statistically significant. Mediation analysis revealed that weight status acted as a mediator of the relationship of CRF with reasoning ability (IE = 0.039; CI = 0.001; 0.091) and the final grades in Math (IE = 0.011; CI = 0.002; 0.025), Language (IE = 0.013; CI = 0.004; 0.027), and GPA (IE = 0.011; CI = 0.003; 0.023). Our data show that the influence of CRF on academic performance is mediated by weight status in adolescents. We suggest that our data could be considered by educators, families, and policy makers, so that active lifestyles might be promoted when designing programs aimed to improve AP among adolescents. What is Known: • Academic performance is associated with both, cardiorespiratory fitness and weight status. • The role of weight status in the association between cardiorespiratory fitness and academic performance is poorly understood. What is New: • We support the scarce research investigating the mediating role of weight status as mechanism in the association between fitness and academic performance in youth. • Previous knowledge is expanded by suggesting that cardiorespiratory fitness is related to weight status which in turn may

Transient cardio-respiratory responses to visually induced tilt illusions

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Wood, S. J.; Ramsdell, C. D.; Mullen, T. J.; Oman, C. M.; Harm, D. L.; Paloski, W. H.

2000-01-01

Although the orthostatic cardio-respiratory response is primarily mediated by the baroreflex, studies have shown that vestibular cues also contribute in both humans and animals. We have demonstrated a visually mediated response to illusory tilt in some human subjects. Blood pressure, heart and respiration rate, and lung volume were monitored in 16 supine human subjects during two types of visual stimulation, and compared with responses to real passive whole body tilt from supine to head 80 degrees upright. Visual tilt stimuli consisted of either a static scene from an overhead mirror or constant velocity scene motion along different body axes generated by an ultra-wide dome projection system. Visual vertical cues were initially aligned with the longitudinal body axis. Subjective tilt and self-motion were reported verbally. Although significant changes in cardio-respiratory parameters to illusory tilts could not be demonstrated for the entire group, several subjects showed significant transient decreases in mean blood pressure resembling their initial response to passive head-up tilt. Changes in pulse pressure and a slight elevation in heart rate were noted. These transient responses are consistent with the hypothesis that visual-vestibular input contributes to the initial cardiovascular adjustment to a change in posture in humans. On average the static scene elicited perceived tilt without rotation. Dome scene pitch and yaw elicited perceived tilt and rotation, and dome roll motion elicited perceived rotation without tilt. A significant correlation between the magnitude of physiological and subjective reports could not be demonstrated.

Assessing the accuracy of algorithm-derived cardiorespiratory fitness in surgical patients: a prospective cohort study.

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Hammal, Fadi; Quaife, Tanis; Purich, Kieran; Haennel, Robert; Gragasin, Ferrante S; Martin-Feeney, Daniella San; Finegan, Barry A

2017-04-01

To determine if a non-exercise algorithm-derived assessment of cardiorespiratory fitness (CRF A ) accurately predicted estimated values obtained using a six-minute walk test (CRF 6MWD ) and the Duke Activity Status Index (CRF DASI ). Following research ethics board approval, an observational cohort study was conducted in selected, consenting patients undergoing elective surgery. Participants completed questionnaires assessing their self-reported exercise capacity. Their height, weight, waist circumference, and vital signs were measured. A six-minute walk test was performed twice with a 45-min rest interval between tests. The correlation between CRF A and both CRF 6MWD and CRF DASI was determined. Two hundred forty-two participants were included. Mean age was 62 (range 45-88 yr); 150 (62%) were male, 87 (36%) self-reported walking or jogging > 16 km per week, and 49 (20%) were current smokers. The CRF A and CRF 6MWD were highly correlated (Pearson r = 0.878; P 427 m in the six-minute walk test, CRF A , CRF 6MWD , and CRF DASI were equivalent. A non-exercise algorithm can estimate cardiorespiratory fitness in patients presenting for elective surgery. The variables required to compute CRF A can be obtained in a clinic setting without the need to engage in formal exercise testing. Further evaluation of CRF A as a predictor of long-term outcome in patients is warranted.

The Sexual Dimorphic Association of Cardiorespiratory Fitness to Working Memory in Children

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Drollette, Eric S.; Scudder, Mark R.; Raine, Lauren B.; Davis Moore, R.; Pontifex, Matthew B.; Erickson, Kirk I.; Hillman, Charles H.

2016-01-01

The present investigation examined the sexual dimorphic patterns of cardiorespiratory fitness to working memory in preadolescent children (age range: 7.7-10.9). Data were collected in three separate studies (Study 1: n = 97, 42 females; Study 2: n = 95, 45 females; Study 3: n = 84, 37 females). All participants completed a cardiorespiratory…

Measurement of cardiorespiratory fitness in children from two commonly used field tests after accounting for body fatness and maturity.

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Hamlin, Michael J; Fraser, Meegan; Lizamore, Catherine A; Draper, Nick; Shearman, Jeremy P; Kimber, Nicholas E

2014-03-27

Body fat and maturation both influence cardiorespiratory fitness, however few studies have taken these variables into account when using field tests to predict children's fitness levels. The purpose of this study was to determine the relationship between two field tests of cardiorespiratory fitness (20 m Maximal Multistage Shuttle Run [20-MST], 550 m distance run [550-m]) and direct measurement of VO2max after adjustment for body fatness and maturity levels. Fifty-three participants (25 boys, 28 girls, age 10.6 ± 1.2 y, mean ± SD) had their body fat levels estimated using bioelectrical impedance (16.6% ± 6.0% and 20.0% ± 5.8% for boys and girls, respectively). Participants performed in random order, the 20-MST and 550-m run followed by a progressive treadmill test to exhaustion during which gas exchange measures were taken. Pearson correlation coefficient analysis revealed that the participants' performance in the 20-MST and 550-m run were highly correlated to VO2max obtained during the treadmill test to exhaustion (r = 0.70 and 0.59 for 20-MST and 550-m run, respectively). Adjusting for body fatness and maturity levels in a multivariate regression analysis increased the associations between the field tests and VO2max (r = 0.73 for 20-MST and 0.65 for 550-m). We may conclude that both the 20-MST and the 550-m distance run are valid field tests of cardiorespiratory fitness in New Zealand 8-13 year old children and incorporating body fatness and maturity levels explains an additional 5-7% of the variance.

Cardiorespiratory fitness and adiposity in breast cancer survivors: is meeting current physical activity recommendations really enough?

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Santos-Lozano, Alejandro; Ramos, Javier; Alvarez-Bustos, Alejandro; Cantos, Blanca; Alejo, Lidia B; Pagola, Itziar; Soria, Ana; Maximiano, Constanza; Fiuza-Luces, Carmen; Soares-Miranda, Luisa; Lucia, Alejandro; Ruiz-Casado, Ana

2018-02-05

Breast cancer (BC) survivors are becoming increasingly predisposed to cardiovascular disease (CVD) mortality. Low cardiorespiratory fitness and physical activity (PA) levels, as well as high values of adiposity indices, contribute to CVD risk. We evaluated adiposity, cardiorespiratory profile, and PA levels in two independent cohorts of BC survivors. Data were collected from two groups (99% women) from different areas of Madrid (Spain): group 1, n = 110, age 51.4 ± 9.7 years, median time from diagnosis 365 days (95% confidence interval [CI], 354-401), and group 2, n = 93, age 54.7 ± 8.9 years, 1714 days (95% CI, 1502-1938). We estimated peak oxygen uptake (VO 2peak ) and measured body mass index (BMI), waist circumference (WC), waist-to-hip index, and accelerometry-determined PA. Both groups had values of BMI in the overweight range (25.3 ± 4.3 and 27.1 ± 5.1 kg/m 2 , p = 0.003). Estimated VO 2peak levels were lower in group 2 than in group 1 (28.1 ± 9.1 and 23.7 ± 8.8 ml/kg/min, p < 0.001), although levels in both groups were low. Yet, the majority of participants in both groups (81 and 88%, p = 0.234) met international PA recommendations (235 ± 196 and 351 ± 173 min/week of moderate-vigorous PA, p < 0.001). Both groups had very low levels of vigorous PA. These results were essentially independent of type of treatment (anthracycline/radiotherapy). We found a poor cardiorespiratory profile in two independent BC cohorts that differed in median time from diagnosis (as well in socioeconomic status), supporting the notion that implementation of PA (possibly focusing on vigorous PA) and dietary intervention is urgently needed in this patient population.

Restless legs syndrome in adolescents: relationship with sleep quality, cardiorespiratory fitness and body fat

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Christoforos D. Giannaki

Full Text Available Objective: The aim of the current study was to investigate the relationship between restless legs syndrome (RLS and cardiorespiratory fitness, body composition and sleep quality in a sample of adolescents. Methods: One hundred fifty seven volunteer adolescents (16.6 ± 0.7 yrs participated in the study. Sleep quality was assessed by the Pittsburg sleep quality index. Cardiorespiratory fitness was assessed by the 20 m shuttle run test and body composition by bioelectrical impedance analysis. Results: The prevalence of RLS was 5.1%. The adolescents with RLS were found to exhibit significantly higher body fat levels (p=0.019 and poorer sleep quality score (p=0.000 compared with their free-RLS counterparts. Conclusions: Adolescents with RLS are subjects of higher body fat and impaired sleep quality compared with adolescents without RLS. Early diagnosis and appropriate management of RLS is essential in the adolescents.

Adolescents' sleep in low-stress and high-stress (exam) times: a prospective quasi-experiment.

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Dewald, Julia F; Meijer, Anne Marie; Oort, Frans J; Kerkhof, Gerard A; Bögels, Susan M

2014-01-01

This prospective quasi-experiment (N = 175; mean age = 15.14 years) investigates changes in adolescents' sleep from low-stress (regular school week) to high-stress times (exam week), and examines the (moderating) role of chronic sleep reduction, baseline stress, and gender. Sleep was monitored over three consecutive weeks using actigraphy. Adolescents' sleep was more fragmented during the high-stress time than during the low-stress time, meaning that individuals slept more restless during stressful times. However, sleep efficiency, total sleep time, and sleep onset latency remained stable throughout the three consecutive weeks. High chronic sleep reduction was related to later bedtimes, later sleep start times, later sleep end times, later getting up times, and more time spent in bed. Furthermore, low chronic sleep reduction and high baseline stress levels were related to more fragmented sleep during stressful times. This study shows that stressful times can have negative effects on adolescents' sleep fragmentation, especially for adolescents with low chronic sleep reduction or high baseline stress levels.

Psychosocial Variables Associated with Body Composition and Cardiorespiratory Fitness in Middle School Students

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Greenleaf, Christy A.; Petrie, Trent A.; Martin, Scott B.

2010-01-01

This study examined the associations among self-esteem, depression, physical self-concept, and body satisfaction among 1,022 middle school students who were in the FITNESSGRAM[R] Healthy Fitness Zone[TM] (HFZ) compared to those in the Needs Improvement Zone (NIZ) for body composition and cardiorespiratory fitness. After controlling for…

Assessment of a new piezoelectric transducer sensor for noninvasive cardiorespiratory monitoring of newborn infants in the NICU.

Science.gov (United States)

Sato, Shinichi; Ishida-Nakajima, Wako; Ishida, Akira; Kawamura, Masanari; Miura, Shinobu; Ono, Kyoichi; Inagaki, Nobuya; Takada, Goro; Takahashi, Tsutomu

2010-01-01

Electrocardiogram (ECG) and impedance pneumography (IPG), the most widely used techniques for cardiorespiratory monitoring in the neonatal intensive care unit (NICU), have the disadvantage of causing skin damage when used for very premature newborn infants. To prevent skin damage, we designed a new piezoelectric transducer (PZT) sensor. To assess the potential of the PZT sensor for cardiorespiratory monitoring in the NICU. The PZT sensor was placed under a folded towel under a neonate to detect an acoustic cardiorespiratory signal, from which heart rate (HR) and breathing rate (BR) were calculated, together with simultaneous ECG/IPG recording for 1-9 days for long and brief (1-min) assessment. The brief assessment showed average correlation coefficients of 0.92 +/- 0.12 and 0.95 +/- 0.02 between instantaneous HRs/BRs detected by the PZT sensor and ECG/IPG in 27 and 11 neonates examined. During the long assessment, the HR detection rate by the PZT sensor was approximately 10% lower than that by ECG (82.6 +/- 12.9 vs. 91.8 +/- 4.1%; p = 0.001, n = 27), although comparable (90.3 +/- 4.1 vs. 92.5 +/- 3.4%, p = 0.081) in approximately 70% (18/27) of neonates examined; BR detection rate was comparable between the PZT sensor and IPG during relatively stable signal conditions (95.9 +/- 4.0 vs. 95.3 +/- 3.5%; p = 0.38, n = 11). The PZT sensor caused neither skin damage nor body movement increase in all neonates examined. The PZT sensor is noninvasive and does not cause skin irritation, and we believe it does provide a reliable, accurate cardiorespiratory monitoring tool for use in the NICU, although the issue of mechanical-ventilation noise remains to be solved. Copyright 2010 S. Karger AG, Basel.

Physical activity, Cardio-Respiratory Fitness, and Metabolic Traits in Rural Mexican Tarahumara

DEFF Research Database (Denmark)

Christensen, Dirk Lund; Alcala-Sanchez, Imelda; Leal-Berumen, Irene

2012-01-01

Objectives: To study the association between physical activity energy expenditure (PAEE) and cardio-respiratory fitness (CRF) with key metabolic traits and anthropometric measures in the Tarahumara of Mexico. Methods: A cross-sectional study was carried out in five rural communities in Chihuahua...... suggests high levels of overweight and hypertension in the Tarahumara, and points to fitness and physical activity as potential intervention targets although findings should be confirmed in larger samples.......) to estimate CRF. Random blood glucose level and resting blood pressure (BP) were measured with standard anthropometrics. Results: Mean (SD) PAEE was 71.2 (30.3) kJ kg21 day21 and CRF was 36.6 (6.5) mlO2 min21 kg21. Mean (SD) glucose was 127.9 (32.4) mg/dl, with 3.3% having diabetes. Mean (SD) systolic...

Higher cardiorespiratory and muscular fitness in males could not be attributed to physical activity, sports practice or sedentary behavior in young people

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Diogo Henrique Constantino Coledam

2018-03-01

Full Text Available The purpose of the present study was to analyze if the association between sex with cardiorespiratory and muscular fitness is independent of physical activity, sports practice and sedentary behavior in young people. A cross-sectional study involving 729 participants aged 10 to 17 years. Physical activity, sports practice and sedentary behavior were assessed through a questionnaire. Cardiorespiratory fitness was measured using 20m shuttle run test and were analyzed: VO2max, number of laps and health-related criteria. Muscular fitness was assessed with 90o push-up test and number of repetition and health-related criteria was analyzed. Multiple linear regression was used to estimate β coeficients and Poisson regression estimated prevalence ratios (PR. Male sex was associated to higher cardiorespiratory fitness (VO2max β = 9.04 to 9.77, Laps PR=1.67 to 1.80, health-related criteria PR=2.03 to 2.09 and the same occurred with muscular fitness (repetitions PR=2.81 to 3.01, health-related criteria PR=1.91 to 2.09. Similarly, the stratification of the sample according to physical activity, sports practice and sedentary behavior did not change the associations between sex with cardiorespiratory (VO2max β=8.07 to 10.00, Laps PR=1.49 to 1.85, health-related criteria PR=1.64 to 2.27 and muscular fitness (repetitions PR=2.24 to 3.22, health-related criteria PR=1.76 to 2.06. These data suggest that higher cardiorespiratory and muscular fitness in males could not be attributed to physical activity, sports practice or sedentary behavior in young people.

Cardiorespiratory Responses and Prediction of Peak Oxygen Uptake during the Shuttle Walking Test in Healthy Sedentary Adult Men

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Neves, Camila D. C.; Lacerda, Ana Cristina Rodrigues; Lage, Vanessa K. S.; Lima, Liliana P.; Fonseca, Sueli F.; de Avelar, Núbia C. P.; Teixeira, Mauro M.; Mendonça, Vanessa A.

2015-01-01

Background The application of the Shuttle Walking Test (SWT) to assess cardiorespiratory fitness and the intensity of this test in healthy participants has rarely been studied. This study aimed to assess and correlate the cardiorespiratory responses of the SWT with the cardiopulmonary exercise testing (CEPT) and to develop a regression equation for the prediction of peak oxygen uptake (VO2 peak) in healthy sedentary adult men. Methods In the first stage of this study, 12 participants underwent the SWT and the CEPT on a treadmill. In the second stage, 53 participants underwent the SWT twice. In both phases, the VO2 peak, respiratory exchange ratio (R), and heart rate (HR) were evaluated. Results Similar results in VO2 peak (P>0.05), R peak (P>0.05) and predicted maximum HR (P>0.05) were obtained between the SWT and CEPT. Both tests showed strong and significant correlations of VO2 peak (r = 0.704, P = 0.01) and R peak (r = 0.737, P0.05) was found. Conclusions The SWT produced maximal cardiorespiratory responses comparable to the CEPT, and the developed equation showed viability for the prediction of VO2 peak in healthy sedentary men. PMID:25659094

Is Moderate Intensity Exercise Training Combined with High Intensity Interval Training More Effective at Improving Cardiorespiratory Fitness than Moderate Intensity Exercise Training Alone?

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Brendon H. Roxburgh, Paul B. Nolan, Ryan M. Weatherwax, Lance C. Dalleck

2014-09-01

Full Text Available The purpose of this study was to compare the effectiveness of either continuous moderate intensity exercise training (CMIET alone vs. CMIET combined with a single weekly bout of high intensity interval training (HIIT on cardiorespiratory fitness. Twenty nine sedentary participants (36.3 ± 6.9 yrs at moderate risk of cardiovascular disease were recruited for 12 weeks of exercise training on a treadmill and cycle ergometer. Participants were randomised into three groups: CMIET + HIIT (n = 7; 8-12 x 60 sec at 100% VO2max, 150 sec active recovery, CMIET (n = 6; 30 min at 45-60% oxygen consumption reserve (VO2R and a sedentary control group (n = 7. Participants in the CMIET + HIIT group performed a single weekly bout of HIIT and four weekly sessions of CMIET, whilst the CMIET group performed five weekly CMIET sessions. Probabilistic magnitude-based inferences were determined to assess the likelihood that the true value of the effect represents substantial change. Relative VO2max increased by 10.1% (benefit possible relative to control in in the CMIET + HIIT group (32.7 ± 9.2 to 36.0 ± 11.5 mL·kg-1·min-1 and 3.9% (benefit possible relative to control in the CMIET group (33.2 ± 4.0 to 34.5 ± 6.1 mL·kg-1·min-1, whilst there was a 5.7% decrease in the control group (30.0 ± 4.6 to 28.3 ± 6.5 mL·kg-1·min-1. It was ‘unclear’ if a clinically significant difference existed between the effect of CMIET + HIIT and CMIET on the change in VO2max. Both exercising groups showed clinically meaningful improvements in VO2max. Nevertheless, it remains ‘unclear’ whether one type of exercise training regimen elicits a superior improvement in cardiorespiratory fitness relative to its counterpart.

Associations between accelerometer-assessed sedentary behavior, physical activity and objectively-measured cardiorespiratory fitness with red blood cell distribution width.

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Edwards, Meghan K; Loprinzi, Paul D

2016-10-15

Emerging work identifies red blood cell distribution width (RDW) as a unique biomarker independently associated with cardiovascular disease and mortality. Encouragingly, recent research demonstrates individual associations of sedentary behavior, physical activity and cardiorespiratory fitness with RDW. However, no study has evaluated their independent and combined associations on RDW, which was this study's purpose. Data from the 2003-2004 National Health and Nutrition Examination Survey were used (N=627 adults 20-49yrs). Sedentary behavior and MVPA were objectively assessed (accelerometry) with cardiorespiratory fitness determined from a submaximal treadmill-based test. Participants were classified as above or below the median values for each of these three parameters, with a PACS (Physical Activity Cardiorespiratory Sedentary) score ranging from 0 to 3, indicating the participant number of these three positive characteristics. A blood sample was obtained from each participant to assess RDW. Only above median MVPA (OR=0.47; 95% CI: 0.32-0.68) was independently associated with a reduced odds of having an elevated RDW. With regard to the additive model, and after adjustment, the odds ratio (95% CI) for the PACS score of 1 (vs. 0), 2 (vs. 0), and 3 (vs. 0), respectively, were 0.81 (0.45-1.45; P=0.46), 0.66 (0.44-0.99; P=0.04) and 0.35 (0.18-0.68; P=0.004). When considering sedentary behavior, MVPA, and cardiorespiratory fitness, only MVPA was associated with reduced odds of elevated RDW, but those with all three characteristics had the lowest odds of elevated RDW. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Evaluating the effectiveness of the integrated use of sporting plays to optimize the cardiorespiratory system functional state of students 18–19 years old

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Inna Cherednichenko

2016-08-01

Full Text Available Purpose: to evaluate the effectiveness of the integrated use of sports in improving the functional state of the cardiovascular and respiratory systems of the 18–19 year-old students in the breakout sessions in terms of higher education. Materials and Methods: the study included 25 female students aged 18–19 years who were engaged in sports games within the section physical education classes in high school. To assess the functional status cardiorespiratory physiological systems using traditional methods and computer program "Oberig". Results: the study of students experimental group (n=11 who were involved in the program to the integrated use of means of sports (volleyball, basketball, handball were recorded significantly higher, compared to the students in the control group (n=14 who engaged in one kind of sports (volleyball, indicators of functional status of their cardiorespiratory system of the body. Conclusions: the author confirmed the high efficiency program of physical education for students 18–19 years of integrated use of sports facilities, which contributes to a substantial optimization of the functional state of their body.

Assessing cardiorespiratory capacity in older adults with major depression and Alzheimer disease

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Marcos Felipe Zanco

2016-03-01

Full Text Available ABSTRACT Objective To assess cardiorespiratory capacity through subjective and objective tests in older adults diagnosed with major depression (MDD, Alzheimer disease (AD and healthy older adults. Methods Fifty seven subjects (72 ± 7.9 years were divided into three groups: MDD (n = 20, AD (n = 17 and Healthy (n = 20. The subjects answered Hamilton Scale (HAM-D, Mini-Mental State Examination (MMSE, Veterans Specific Activity Questionnaire (VSAQ and 2-minute Step test. Results MDD and AD showed lower scores than healthy group for Nomogram VSAQ (p < 0.001 and 2-minute Step (p = 0.009; p = 0.008, respectively. Adjusted for age and educational level, no differences among groups were observed for Step (MDD, p = 0.097; AD, p = 0.102. AD group did not present differences to healthy group for Step, when adjusting for MMSE (p = 0.261. Conclusions Despite the lower cardiorespiratory fitness of elderly patients with DM and DA have been found in both evaluations, the results should be viewed with caution, since the tests showed low correlation and different risk classifications of functional loss. In addition, age, level educational and cognitive performance are variables that can influence the performance objective evaluation.

Cardiorespiratory adaptation to breath-holding in air: Analysis via a cardiopulmonary simulation model.

Science.gov (United States)

Albanese, Antonio; Limei Cheng; Ursino, Mauro; Chbat, Nicolas W

2015-01-01

Apnea via breath-holding (BH) in air induces cardiorespiratory adaptation that involves the activation of several reflex mechanisms and their complex interactions. Hence, the effects of BH in air on cardiorespiratory function can become hardly predictable and difficult to be interpreted. Particularly, the effect on heart rate is not yet completely understood because of the contradicting results of different physiological studies. In this paper we apply our previously developed cardiopulmonary model (CP Model) to a scenario of BH with a twofold intent: (1) further validating the CP Model via comparison against experimental data; (2) gaining insights into the physiological reasoning for such contradicting experimental results. Model predictions agreed with published experimental animal and human data and indicated that heart rate increases during BH in air. Changes in the balance between sympathetic and vagal effects on heart rate within the model proved to be effective in inverting directions of the heart rate changes during BH. Hence, the model suggests that intra-subject differences in such sympatho-vagal balance may be one of the reasons for the contradicting experimental results.

Red fox (Vulpes vulpes) as a potential reservoir host of cardiorespiratory parasites in Bosnia and Herzegovina.

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Hodžić, Adnan; Alić, Amer; Klebić, Ismar; Kadrić, Mirsad; Brianti, Emanuele; Duscher, Georg Gerhard

2016-06-15

Red fox (Vulpes vulpes) is considered as reservoir of different cardiorespiratory parasites of veterinary and medical importance. Since data on cardiorespiratory parasites in foxes in Bosnia and Herzegovina are still lacking, the aims of the present study were to (i) investigate the prevalence and geographical distribution of these parasites, (ii) determine genetic diversity of detected parasite species, and (iii) to estimate the role of foxes in the transmission cycle to companion animals and humans. Four species, morphologically and molecularly identified as Eucoleus boehmi (64.6%; 51/79), Eucoleus aerophilus (69.7%; 154/221), Crenosoma vulpis (45.7%; 101/221) and Linguatula serrata (1.3%; 1/79) were retrieved from nasal cavity and lungs in 184 (83.3%) animals. The occurrence of heartworms, Angiostrongylus vasorum and Dirofilaria immitis was not detected by necropsy or PCR. Furthermore, three distinct haplotypes of E. aerophilus (I, III, XV) and two of C. vulpis (I, II) previously reported in pet animals and wild carnivores were confirmed in this study. A new haplotype of C. vulpis (designated as haplotype V) was also identified based on 12S rRNA gene for the first time. The present study indicates a high prevalence and wide distribution of nasal and lung nematodes in fox population in Bosnia and Herzegovina, and supports the existence of transmission patterns between wildlife and pet animals. Copyright © 2016 Elsevier B.V. All rights reserved.

Mining highly stressed areas, part 1.

CSIR Research Space (South Africa)

Johnson, R

1995-12-01

Full Text Available The aim of this long-term project has been to focus on the extreme high-stress end of the mining spectrum. Such high stress conditions will prevail in certain ultra-deep mining operation of the near future, and are already being experienced...

Cardiorespiratory interactions in patients with atrial flutter.

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Masè, Michela; Disertori, Marcello; Ravelli, Flavia

2009-01-01

Respiratory sinus arrhythmia (RSA) is generally known as the autonomically mediated modulation of the sinus node pacemaker frequency in synchrony with respiration. Cardiorespiratory interactions have been largely investigated during sinus rhythm, whereas little is known about interactions during reentrant arrhythmias. In this study, cardiorespiratory interactions at the atrial and ventricular level were investigated during atrial flutter (AFL), a supraventricular arrhythmia based on a reentry, by using cross-spectral analysis and computer modeling. The coherence and phase between respiration and atrial (gamma(AA)(2), phi(AA)) and ventricular (gamma(RR)(2), phi(RR)) interval series were estimated in 20 patients with typical AFL (68.0 +/- 8.8 yr) and some degree of atrioventricular (AV) conduction block. In all patients, atrial intervals displayed oscillations strongly coupled and in phase with respiration (gamma(AA)(2)= 0.97 +/- 0.05, phi(AA) = 0.71 +/- 0.31 rad), corresponding to a paradoxical lengthening of intervals during inspiration. The modulation pattern was frequency independent, with in-phase oscillations and short time delays (0.40 +/- 0.15 s) for respiratory frequencies in the range 0.1-0.4 Hz. Ventricular patterns were affected by AV conduction type. In patients with fixed AV conduction, ventricular intervals displayed oscillations strongly coupled (gamma(RR)(2)= 0.97 +/- 0.03) and in phase with respiration (phi(RR) = 1.08 +/- 0.80 rad). Differently, in patients with variable AV conduction, respiratory oscillations were secondary to Wencheback rhythmicity, resulting in a decreased level of coupling (gamma(RR)(2)= 0.50 +/- 0.21). Simulations with a simplified model of AV conduction showed ventricular patterns to originate from the combination of a respiratory modulated atrial input with the functional properties of the AV node. The paradoxical frequency-independent modulation pattern of atrial interval, the short time delays, and the complexity of

Transient spontaneous remission in congenital MLL-AF10 rearranged acute myeloid leukemia presenting with cardiorespiratory failure and meconium ileus.

Science.gov (United States)

Gyárfás, Tobias; Wintgens, Juergen; Biskup, Wolfgang; Oschlies, Ilske; Klapper, Wolfram; Siebert, Reiner; Bens, Susanne; Haferlach, Claudia; Meisel, Roland; Kuhlen, Michaela; Borkhardt, Arndt

2016-12-01

Neonatal leukemia is a rare disease with an estimated prevalence of about one to five in a million neonates. The majority being acute myeloid leukemia (AML), neonatal leukemia can present with a variety of symptoms including hyperleucocytosis, cytopenia, hepatosplenomegaly, and skin infiltrates. Chromosomal rearrangements including mixed lineage leukemia (MLL) translocations are common in neonatal AML. A female neonate born at 34 weeks gestation presented with cardiorespiratory failure, hepatosplenomegaly, pancytopenia, and coagulopathy. She required intensive care treatment including mechanical ventilation, high-dose catecholamine therapy, and multiple transfusions. Small intestinal biopsy obtained during laparotomy for meconium ileus revealed an infiltrate by an undifferentiated monoblastic, MLL-rearranged leukemia. No other manifestations of leukemia could be detected. After spontaneous clinical remission, lasting 5 months without any specific treatment, the patient presented with leukemia cutis and full-blown monoblastic leukemia. MLL-AF10-rearranged AML could be re-diagnosed and successfully treated with chemotherapy and hematopoietic stem cell transplantation. Our patient exhibited a unique manifestation of neonatal MLL-AF10 rearranged AML with cardiorespiratory failure and intestinal infiltration. It highlights the importance of leukemia in the differential diagnosis of neonatal distress, congenital hematological abnormalities, and skin lesions.

Cardiorespiratory fitness and physical activity level in adolescents

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Viviane Schultz Straatmann

2014-12-01

Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n1p21   More objective methods to detect inactive adolescents may help identify young people that are vulnerable to obesity and other chronic diseases. The objective of this study was to examine the association between classifications obtained with the cardiorespiratory fitness test and physical activity level in adolescents, as well as the agreement between tertiles and z-score distribution of the variables generated with these methods (distance covered and total physical activity score. A cross-sectional study was conducted using a random sample of 639 adolescents (61% girls aged 12 to 19 years (mean age of 16 ± 1.8 and categorized into two age groups: 12-13 and 14-19 years, from public schools in Niterói, Rio de Janeiro, Brazil. Cardiorespiratory fitness was assessed by a 9-min run/walk test (T9 and physical activity level by the International Physical Activity Questionnaire (IPAQ. The chi-square test (or Fisher’s exact test and Kruskal-Wallis test were applied for the evaluation of associations, and the weighted kappa coefficient and intraclass correlation coefficient were used to investigate agreement between variables. A level of significance of p<0.05 was adopted. A significant association between the classifications obtained with the two methods was only observed for adolescents aged ≥ 14 years. However, there was agreement between the variables generated with the two methods in both age groups. The median distance covered in the T9 increased according to tertiles of total physical activity score. An association between the classifications obtained with the IPAQ and T9 was only found for older adolescents. However, the continuous variables and variables categorized into tertiles generated with the methods were associated and showed agreement in both age groups.

[The binomial symptom index for the evaluation of temporal association between cardiorespiratory symptoms and gastroesophageal reflux in neonates].

Science.gov (United States)

Barriga-Rivera, Alejandro; Moya, María José; Lopez-Alonso, Manuel

2016-11-01

The evaluation of symptom association between gastroesophageal reflux and cardiorespiratory events in preterm infants remains unclear. This paper describes a conservative approach to decision-making of anti-reflux surgery through symptom association analysis. Forty-three neonates with potentially reflux-related cardiorespiratory symptoms underwent synchronized esophageal impedance-pH and cardiorespiratory monitoring. Three indices were considered to evaluate symptom association, the symptom index (SI), the symptom sensitivity index (SSI) and the symptom association probability (SAP). A conservative strategy was adopted regarding the decision of anti-reflux surgery, and therefore, patients were scheduled for laparoscopic Nissen fundoplication if the three indices showed a positive assessment of symptom association. Retrospectively, these indices and the binomial symptom index (BSI) were contrasted against the decision of anti-reflux surgery using different windows of association. Thirteen patients showed positive symptom association but only two underwent anti-reflux surgery. The SI and the SSI showed an increasing trend with the width of the window of association. The SAP was affected randomly by slightly altering the windowing parameters. The BSI showed the best performance with the two-minute window (κ =0.78) CONCLUSIONS: The pathology under study is known to improve with maturity. However, the severity of cardiorespiratory symptoms may threaten the neonate's life and therefore, in some occasions, invasive treatments must be considered to protect life. The BSI provides a good prediction of a combination of positive SI, SSI and SAP, which may improve clinical decisions. However, further clinical studies are required to prove the BSI as an optimal predictor of clinical outcomes. Copyright © 2015 Asociación Española de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

Role of creatine kinase isoenzymes on muscular and cardiorespiratory endurance: genetic and molecular evidence.

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Echegaray, M; Rivera, M A

2001-01-01

The ability to perform well in activities that require muscular and cardiorespiratory endurance is a trait influenced, in a considerable part, by the genetic make-up of individuals. Early studies of performance and recent scans of the human genome have pointed at various candidate genes responsible for the heterogeneity of these phenotypes within the population. Among these are the genes for the various creatine kinase (CK) isoenzyme subunits. CK and phosphocreatine (PCr) form an important metabolic system for temporal and spatial energy buffering in cells with large variations in energy demand. The different CK isoenzyme subunits (CK-M and CK-B) are differentially expressed in the tissues of the body. Although CK-M is the predominant form in both skeletal and cardiac muscle, CK-B is expressed to a greater extent in heart than in skeletal muscle. Studies in humans and mice have shown that the expression of CK-B messenger RNA (mRNA) and the abundance and activity of the CK-MB dimer increase in response to cardiorespiratory endurance training. Increases in muscle tissue CK-B content can be energetically favourable because of its lower Michaelis constant (Km) for ADP. The activity of the mitochondrial isoform of CK (Scmit-CK) has also been significantly and positively correlated to oxidative capacity and to CK-MB activity in muscle. In mice where the CK-M gene has been knocked out, significant increases in fatigue resistance together with cellular adaptations increasing aerobic capacity have been observed. These observations have led to the notion that this enzyme may be responsible for fatigue under normal circumstances, most likely because of the local cell compartment increase in inorganic phosphate concentration. Studies where the Scmit-CK gene was knocked out have helped demonstrate that this isoenzyme is very important for the stimulation of aerobic respiration. Human studies of CK-M gene sequence variation have shown a significant association between a

Physical inactivity, neurological disability, and cardiorespiratory fitness in multiple sclerosis.

Science.gov (United States)

Motl, R W; Goldman, M

2011-02-01

We examined the associations among physical activity, neurological disability, and cardiorespiratory fitness in two studies of individuals with multiple sclerosis (MS). Study 1 included 25 women with relapsing-remitting MS (RRMS) who undertook an incremental exercise test for measuring peak oxygen (VO₂(peak) ) consumption, wore an accelerometer during a 7-day period, and completed the Godin Leisure-Time Exercise Questionnaire (GLTEQ). Study 2 was a follow-up of Study 1 and included 24 women with RRMS who completed the self-reported Expanded Disability Status Scale (EDSS), undertook an incremental exercise test, wore an accelerometer during a 7-day period, and completed the GLTEQ. Study 1 indicated that VO₂(peak) was significantly correlated with accelerometer counts (pr = 0.69) and GLTEQ scores (pr = 0.63) even after controlling for age and MS duration. Study 2 indicated that VO₂(peak) was significantly correlated with accelerometer counts (pr = 0.50), GLTEQ scores (pr = 0.59), and EDSS scores (pr = -0.43) even after controlling for age and MS duration; there was a moderate partial correlation between accelerometer counts and EDSS scores (pr = -0.43). Multiple linear regression analysis indicated that both accelerometer counts (β = 0.32) and EDSS scores (β = -0.40) had statistically significant associations with VO₂(peak). The findings indicate that physical inactivity and neurological disability might represent independent risk factors for reduced levels of cardiorespiratory fitness in this population. © 2010 John Wiley & Sons A/S.

Cardiorespiratory and metabolic responses during straight and bent knee cycling.

Science.gov (United States)

Mandroukas, K; Angelopoulou, N; Christoulas, K; Vrabas, I S

2000-06-01

This study examined the influence of knee angle on the cardiorespiratory system loading during submaximal and maximal stationary cycle ergometry. Experimental design and participants: eighteen untrained women (age: 21+/-1.88 years, weight: 57+/-5.75 kg, height: 165+/-5.03 cm, values are mean+/-SD) volunteered as subjects and underwent two-cycle ergometer incremental (Jaeger ER900) tests: 1) straight knee (180 degrees), 2) bent knee (140 degrees). oxygen uptake (VO2), ventilation (VE) and respiratory exchange ratio (RER) were measured continuously during each test using an open circuit spirometry and blood lactate concentration was determined by means of an enzymatic method. Comparing cycling with "straight knee" to cycling with "bent knee" at 50 W, heart rate (HR), V(E) and VO2 were significantly higher (10.6%, 12.5%, 17.8%). At 100 W, blood lactate was significantly lower (10.8%) while VO2 and RER was higher (5.5%, 7.1%). During maximal exercise, the total exercise time was significantly longer (11.2%) and VE, VO2 and HR were significantly higher during cycling with "straight knee" compared to cycling with "bent knee". No significant difference in peak lactate was evident between the two sitting positions. The results of this study indicate that cycling with bent knee requires lower oxygen uptake while pedaling with straight knee is the only way to reach VO2max during cycle testing, since the cardiorespiratory system is fully taxed.

The role of water metabolism in the heat stress syndrome with the use of radioisotopes in cattle

International Nuclear Information System (INIS)

Abdel-Samiee, A.M.

1982-01-01

Due to the importance of water metabolism in thermo - regulation especially under heat stress, this investigation was carried out to study the effect of high ambient temperature, separated from other climatic factors which were maintained constant, on live body weight, water metabolism components, total body water, total body solids, water turnover rate, biological half life - time of tritiated water and rectal temperature and cardiorespiratory rate. Twelve dry friesian cows of 3 - years old were placed in metabolic cages inside climatic chambers. Animals were subjected to two successive treatments. First, mild treatment, where the environmental temperature and relative humidity were kept constant at 16 C and 62%, respective for 7 - hours a day. The second treatment (heat stress treatment), where the environmental temperature and relative humidity were 39 C and 62% R.H.,respectively for 7 hours a day

Efficacy of Ashwagandha (Withania somnifera [L.] Dunal) in improving cardiorespiratory endurance in healthy athletic adults.

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Choudhary, Bakhtiar; Shetty, A; Langade, Deepak G

2015-01-01

Ashwagandha (Withania somnifera [L.] Dunal) has been traditionally used for various actions ranging from vitalizer, improve endurance and stamina, promote longevity, improve immunity, and male and female fertility. However, clinical studies are needed to prove the clinical efficacy of this herb, especially in cardiovascular endurance and physical performance. This prospective, double-blind, randomized, and placebo-controlled study evaluated the efficacy of Ashwagandha roots extract in enhancing cardiorespiratory endurance and improving the quality of life (QOL) in 50 healthy male/female athletic adults. Cardiorespiratory endurance was assessed by measuring the oxygen consumption at peak physical exertion (VO2 max) levels during a 20 m shuttle run test. The World Health Organization self-reported QOL questionnaire (physical health, psychological health, social relationships, and environmental factors) was used to assess the QOL. Student's t-test was used to compare the differences in a mean and change from baseline VO2 max levels, whereas Wilcoxon signed-rank test was used to assess changes in QOL scores from baseline in the two groups. There was a greater increase from baseline (P < 0.0001) in the mean VO2 max with KSM-66 Ashwagandha (n = 24) compared to placebo (n = 25) at 8 weeks (4.91 and 1.42, respectively) and at 12 weeks (5.67 and 1.86 respectively). The QOL scores for all subdomains significantly improved to a greater extent in the Ashwagandha group at 12 weeks compared to placebo (P < 0.05). The findings suggest that Ashwagandha root extract enhances the cardiorespiratory endurance and improves QOL in healthy athletic adults.

Cardiorespiratory upregulation during seawater acclimation in rainbow trout: effects on gastrointestinal perfusion and postprandial responses.

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Brijs, Jeroen; Gräns, Albin; Ekström, Andreas; Olsson, Catharina; Axelsson, Michael; Sandblom, Erik

2016-05-01

Increased gastrointestinal blood flow is essential for euryhaline fishes to maintain osmotic homeostasis during the initial phase of a transition from freshwater to seawater. However, the cardiorespiratory responses and hemodynamic changes required for a successful long-term transition to seawater remain largely unknown. In the present study, we simultaneously measured oxygen consumption rate (ṀO2), cardiac output (CO), heart rate (HR), and gastrointestinal blood flow (GBF) in rainbow trout (Oncorhynchus mykiss) acclimated to either freshwater or seawater for at least 6 wk. Seawater-acclimated trout displayed significantly elevated ṀO2 (day: 18%, night: 19%), CO (day: 22%, night: 48%), and GBF (day: 96%, night: 147%), demonstrating that an overall cardiorespiratory upregulation occurs during seawater acclimation. The elevated GBF was achieved via a combination of increased CO, mediated through elevated stroke volume (SV), and a redistribution of blood flow to the gastrointestinal tract. Interestingly, virtually all of the increase in CO of seawater-acclimated trout was directed to the gastrointestinal tract. Although unfed seawater-acclimated trout displayed substantially elevated cardiorespiratory activity, the ingestion of a meal resulted in a similar specific dynamic action (SDA) and postprandial GBF response as in freshwater-acclimated fish. This indicates that the capacity for the transportation of absorbed nutrients, gastrointestinal tissue oxygen delivery, and acid-base regulation is maintained during digestion in seawater. The novel findings presented in this study clearly demonstrate that euryhaline fish upregulate cardiovascular function when in seawater, while retaining sufficient capacity for the metabolic and cardiovascular changes associated with the postprandial response. Copyright © 2016 the American Physiological Society.

Role of the parabrachial complex in the cardiorespiratory response evoked from hypothalamic defense area stimulation in the anesthetized rat.

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Díaz-Casares, Amelia; López-González, Manuel Víctor; Peinado-Aragonés, Carlos Antonio; Lara, José Pablo; González-Barón, Salvador; Dawid-Milner, Marc Stefan

2009-07-07

To analyze the role of parabrachial complex (PBc) in the modulation of cardiorespiratory response evoked from the hypothalamic defense area (HDA), cardiorespiratory changes were analyzed in spontaneously breathing anesthetised rats in response to electrical stimulation of the HDA (1 ms pulses, 30-50 microA, 100 Hz for 5 s) before and after the microinjection of muscimol (50 nl, 0.25 nmol, 5 s) within the PBc. HDA stimulation evoked an inspiratory facilitatory response, consisting of an increase in respiratory rate (pHDA stimulation (pHDA stimulation. The respiratory response persisted unchanged. Finally, extracellular recording of putative neurons from these regions were obtained during HDA stimulation to confirm functional interaction between HDA and parabrachial regions. 105 pontine cells were recorded during HDA stimulation, 57 from the lPB and 48 from the mPB-KF. In mPB-KF 34/48 (71%) and in lPB 38/57 (67%) cells were influenced from HDA. The results indicate that neurons from different regions of the PBc have an important function in mediating the cardiorespiratory response evoked from the HDA. The possible mechanisms involved in these interactions are discussed.

The efficacy of unsupervised home-based exercise regimens in comparison to supervised lab-based exercise training upon cardio-respiratory health facets

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Blackwell, J.; Atherton, Philip J.; Smith, Kenneth; Doleman, Brett; Williams, John P.; Lund, Jonathan N.; Phillips, Bethan E.

2017-01-01

Abstract Supervised high?intensity interval training (HIIT) can rapidly improve cardiorespiratory fitness (CRF). However, the effectiveness of time?efficient unsupervised home?based interventions is unknown. Eighteen volunteers completed either: laboratory?HIIT (L?HIIT); home?HIIT (H?HIIT) or home?isometric hand?grip training (H?IHGT). CRF improved significantly in L?HIIT and H?HIIT groups, with blood pressure improvements in the H?IHGT group only. H?HIIT offers a practical, time?efficient ex...

Effectiveness of functional training on cardiorespiratory parameters: a systematic review and meta-analysis of randomized controlled trials.

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Rezende Barbosa, Marianne Penachini da Costa de; Oliveira, Vinicius Cunha; Silva, Anne Kastelianne França da; Pérez-Riera, Andrés Ricardo; Vanderlei, Luiz Carlos

2017-07-28

Functional training is a new training vision that was prepared from the gesture imitation of daily activities. Although your use has become popular in clinical practice, the influence of the several cardiorespiratory adjustments performed during the functional training in different populations and conditions is unknown. So, the aim of this systematic review was to gather information in the literature regarding the influence of functional training on cardiorespiratory parameters. We conducted search strategies on MEDLINE, PEDro, EMBASE, SportDiscus and Cochrane to identify randomized controlled trials investigating the effects of functional training on cardiorespiratory parameters. Methodological quality of the included studies was assessed using the PEDro scale. Grading of Recommendations Assessment, Development and Evaluation (GRADE) summarized the evidence. Five original studies were included. Effects favoured functional training on oxygen consumption (VO 2 ) at intermediate-term follow-up: weighted mean difference -1·0 (95% CI: 5·4-3·3), P = 0·642, and a small and not clinically important effect observed on VO 2 favouring control at intermediate-term follow-up (i.e. mean difference of 1·30 (95% CI 1·07-1·53), Pfunctional training is better than other interventions to improve cardiovascular parameters. This result encourages new searches about the theme. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

High Glucose Inhibits Neural Stem Cell Differentiation Through Oxidative Stress and Endoplasmic Reticulum Stress.

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Chen, Xi; Shen, Wei-Bin; Yang, Penghua; Dong, Daoyin; Sun, Winny; Yang, Peixin

2018-06-01

Maternal diabetes induces neural tube defects by suppressing neurogenesis in the developing neuroepithelium. Our recent study further revealed that high glucose inhibited embryonic stem cell differentiation into neural lineage cells. However, the mechanism whereby high glucose suppresses neural differentiation is unclear. To investigate whether high glucose-induced oxidative stress and endoplasmic reticulum (ER) stress lead to the inhibition of neural differentiation, the effect of high glucose on neural stem cell (the C17.2 cell line) differentiation was examined. Neural stem cells were cultured in normal glucose (5 mM) or high glucose (25 mM) differentiation medium for 3, 5, and 7 days. High glucose suppressed neural stem cell differentiation by significantly decreasing the expression of the neuron marker Tuj1 and the glial cell marker GFAP and the numbers of Tuj1 + and GFAP + cells. The antioxidant enzyme superoxide dismutase mimetic Tempol reversed high glucose-decreased Tuj1 and GFAP expression and restored the numbers of neurons and glial cells differentiated from neural stem cells. Hydrogen peroxide treatment imitated the inhibitory effect of high glucose on neural stem cell differentiation. Both high glucose and hydrogen peroxide triggered ER stress, whereas Tempol blocked high glucose-induced ER stress. The ER stress inhibitor, 4-phenylbutyrate, abolished the inhibition of high glucose or hydrogen peroxide on neural stem cell differentiation. Thus, oxidative stress and its resultant ER stress mediate the inhibitory effect of high glucose on neural stem cell differentiation.

Global Association of Air Pollution and Cardiorespiratory Diseases: A Systematic Review, Meta-Analysis, and Investigation of Modifier Variables

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Adams, Matthew D.; Arain, Altaf; Papatheodorou, Stefania; Koutrakis, Petros; Mahmoud, Moataz

2018-01-01

Background. Little is known about the health risks of air pollution and cardiorespiratory diseases, globally, across regions and populations, which may differ because of external factors. Objectives. We systematically reviewed the evidence on the association between air pollution and cardiorespiratory diseases (hospital admissions and mortality), including variability by energy, transportation, socioeconomic status, and air quality. Search Methods. We conducted a literature search (PubMed and Web of Science) for studies published between 2006 and May 11, 2016. Selection Criteria. We included studies if they met all of the following criteria: (1) considered at least 1 of these air pollutants: carbon monoxide, sulfur dioxide, nitrogen dioxide, ozone, or particulate matter (PM2.5 or PM10); (2) reported risk for hospital admissions, mortality, or both; (3) presented individual results for respiratory diseases, cardiovascular diseases, or both; (4) considered the age groups younger than 5 years, older than 65 years, or all ages; and (5) did not segregate the analysis by gender. Data Collection and Analysis. We extracted data from each study, including location, health outcome, and risk estimates. We performed a meta-analysis to estimate the overall effect and to account for both within- and between-study heterogeneity. Then, we applied a model selection (least absolute shrinkage and selection operator) to assess the modifier variables, and, lastly, we performed meta-regression analyses to evaluate the modifier variables contributing to heterogeneity among studies. Main Results. We assessed 2183 studies, of which we selected 529 for in-depth review, and 70 articles fulfilled our study inclusion criteria. The 70 studies selected for meta-analysis encompass more than 30 million events across 28 countries. We found positive associations between cardiorespiratory diseases and different air pollutants. For example, when we considered only the association between PM2.5 and

Stress and High Blood Pressure: What's the Connection?

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Stress and high blood pressure: What's the connection? Stress and long-term high blood pressure may not be linked, but taking steps to reduce your stress can improve your general health, including your blood ...

Effects of high-intensity interval training on fatigue and quality of life in testicular cancer survivors.

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Adams, Scott C; DeLorey, Darren S; Davenport, Margie H; Fairey, Adrian S; North, Scott; Courneya, Kerry S

2018-05-08

Testicular cancer survivors (TCS) are at increased risk of cancer-related fatigue (CRF), psychosocial impairment, and poor mental health-related quality of life (HRQoL). Here, we examine the effects of high-intensity interval training (HIIT) on patient-reported outcomes (PROs) in TCS. Secondarily, we explore cardiorespiratory fitness as a mediator of intervention effects and select baseline characteristics as moderators of intervention effects. TCS (n = 63) were randomly assigned to 12 weeks of supervised HIIT or usual care (UC). PROs included CRF, depression, anxiety, stress, self-esteem, sleep quality, and HRQoL assessed at baseline, post-intervention, and 3-month follow-up. TCS (median 7 years postdiagnosis) completed 99% of training sessions and achieved 98% of target training intensity. ANCOVA revealed that, compared to UC, HIIT significantly improved post-intervention CRF (p = 0.003), self-esteem (p = 0.029), and multiple HRQoL domains (ps ≤ 0.05). Effects on CRF (p = 0.031) and vitality (p = 0.015) persisted at 3-month follow-up. Cardiorespiratory fitness changes mediated CRF and HRQoL improvements. CRF effects were larger for TCS with an inactive lifestyle, lower fitness, higher testosterone, and clinical fatigue at baseline. HIIT significantly improves CRF and HRQoL in TCS. Mediation by cardiorespiratory fitness and moderation by clinical characteristics suggests opportunities for targeted exercise interventions to optimise PROs in TCS.

Effect of 11 months of yoga training on cardiorespiratory responses during the actual practice of Surya Namaskar.

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Sinha, Biswajit; Sinha, Tulika Dasgupta

2014-01-01

Surya Namaskar (SN), a popular traditional Indian yogic practice, includes practicing 12 physical postures with alternate forward and backward bending movement of the body along with deep breathing maneuvers. The practice of SN has become popular among yoga practitioners and other fitness conscious people. The long-term effect of practicing SN and other yogic practices on cardiorespiratory responses during SN are lacking. The present study was conducted to study the effect of yogic training on various cardiorespiratory responses during the SN practice in yoga trainees after a time interval of 3, 6, and 11 months. The present study was conducted on 9 healthy male Army soldiers who underwent training in various yoga postures including SN, meditation, and pranayama for 1 h daily for 11 months. First, second, and third phase of the study was conducted in the laboratory after completion of 3, 6, and 11 months of the yoga training. The participants performed SN along with other yogic practices in the laboratory as per their daily practice schedule. The cardiorespiratory responses of the volunteers were recorded during actual practice of SN. One-way repeated measure ANOVA followed by Tukey HSD. Oxygen consumption and heart rate during actual practice of SN was 0.794 ± 0.252, 0.738 ± 0.229, and 0.560 ± 0.165 L/min and 92.1 ± 11.6, 97.9 ± 7.3 and 87.4 ± 9.2 beats/min respectively at 1(st) , 2(nd) , and 3(rd) phase of yoga training. Minute ventilation and tidal volume also reduced from 19.9 ± 4.65 to 17.8 ± 4.41 L/min and 1.091 ± 0.021 to 0.952 L/breath from 1(st) phase to 3(rd) phase of yoga training. However, respiratory parameters like breathing rate (fR) did not show any reduction across the three phases. The results of the present study indicated that yogic training caused conditioning of cardiorespiratory parameters except fR, which did not reduce across three phases of training.

Upper GI examinations in older premature infants with persistent apnea: Correlation with simultaneous cardiorespiratory monitoring

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Itani, Y.; Niitsu, N.; Oono, T.; Fujioka, M.; Nishimura, G.

1988-09-01

Upper gastrointestinal examinations with simultaneous cardiorespiratory monitoring were performed in 39 older premature infants with persistent apnea. Swallowing incoordination was documented to be causatively related to persistent apnea in such infants, especially with feeding. Direct relationship between apnea and gastroesophageal reflux was not documented in this study.

Modulations of Heart Rate, ECG, and Cardio-Respiratory Coupling Observed in Polysomnography

Directory of Open Access Journals (Sweden)

Thomas Penzel

2016-10-01

Full Text Available The cardiac component of cardio-respiratory polysomnography is covered by ECG and heart rate recordings. However their evaluation is often underrepresented in summarizing reports. As complements to EEG, EOG, and EMG, these signals provide diagnostic information for autonomic nervous activity during sleep. This review presents major methodological developments in sleep research regarding heart rate, ECG and cardio-respiratory couplings in a chronological (historical sequence. It presents physiological and pathophysiological insights related to sleep medicine obtained by new technical developments. Recorded nocturnal ECG facilitates conventional heart rate variability analysis, studies of cyclical variations of heart rate, and analysis of ECG waveform. In healthy adults, the autonomous nervous system is regulated in totally different ways during wakefulness, slow-wave sleep, and REM sleep. Analysis of beat-to-beat heart-rate variations with statistical methods enables us to estimate sleep stages based on the differences in autonomic nervous system regulation. Furthermore, up to some degree, it is possible to track transitions from wakefulness to sleep by analysis of heart-rate variations. ECG and heart rate analysis allow assessment of selected sleep disorders as well. Sleep disordered breathing can be detected reliably by studying cyclical variation of heart rate combined with respiration-modulated changes in ECG morphology (amplitude of R wave and T wave.

Modulations of Heart Rate, ECG, and Cardio-Respiratory Coupling Observed in Polysomnography.

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Penzel, Thomas; Kantelhardt, Jan W; Bartsch, Ronny P; Riedl, Maik; Kraemer, Jan F; Wessel, Niels; Garcia, Carmen; Glos, Martin; Fietze, Ingo; Schöbel, Christoph

2016-01-01

The cardiac component of cardio-respiratory polysomnography is covered by ECG and heart rate recordings. However, their evaluation is often underrepresented in summarizing reports. As complements to EEG, EOG, and EMG, these signals provide diagnostic information for autonomic nervous activity during sleep. This review presents major methodological developments in sleep research regarding heart rate, ECG, and cardio-respiratory couplings in a chronological (historical) sequence. It presents physiological and pathophysiological insights related to sleep medicine obtained by new technical developments. Recorded nocturnal ECG facilitates conventional heart rate variability (HRV) analysis, studies of cyclical variations of heart rate, and analysis of ECG waveform. In healthy adults, the autonomous nervous system is regulated in totally different ways during wakefulness, slow-wave sleep, and REM sleep. Analysis of beat-to-beat heart-rate variations with statistical methods enables us to estimate sleep stages based on the differences in autonomic nervous system regulation. Furthermore, up to some degree, it is possible to track transitions from wakefulness to sleep by analysis of heart-rate variations. ECG and heart rate analysis allow assessment of selected sleep disorders as well. Sleep disordered breathing can be detected reliably by studying cyclical variation of heart rate combined with respiration-modulated changes in ECG morphology (amplitude of R wave and T wave).

Exploring the clinical decision-making used by experienced cardiorespiratory physiotherapists: A mixed method qualitative design of simulation, video recording and think aloud techniques.

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Thackray, Debbie; Roberts, Lisa

2017-02-01

The ability of physiotherapists to make clinical decisions is a vital component of being an autonomous practitioner, yet this complex phenomenon has been under-researched in cardiorespiratory physiotherapy. The purpose of this study was to explore clinical decision-making (CDM) by experienced physiotherapists in a scenario of a simulated patient experiencing acute deterioration of their respiratory function. The main objective of this observational study was to identify the actions, thoughts, and behaviours used by experienced cardiorespiratory physiotherapists in their clinical decision-making processes. A mixed-methods (qualitative) design employing observation and think-aloud, was adopted using a computerised manikin in a simulated environment. The participants clinically assessed the manikin programmed with the same clinical signs, under standardised conditions in the clinical skills practice suite, which was set up as a ward environment. Experienced cardiorespiratory physiotherapists, recruited from clinical practice within a 50-mile radius of the University(*). Participants were video-recorded throughout the assessment and treatment and asked to verbalise their thought processes using the 'think-aloud' method. The recordings were transcribed verbatim and managed using a Framework approach. Eight cardiorespiratory physiotherapists participated (mean 7years clinical experience, range 3.5-16years. CDM was similar to the collaborative hypothetico-deductive model, five-rights nursing model, reasoning strategies, inductive reasoning and pattern recognition. However, the CDM demonstrated by the physiotherapists was complex, interactive and iterative. Information processing occurred continuously throughout the whole interaction with the patient, and the specific cognitive skills of recognition, matching, discriminating, relating, inferring, synthesising and prediction were identified as being used sequentially. The findings from this study were used to develop a new

Panic Anxiety in Humans with Bilateral Amygdala Lesions: Pharmacological Induction via Cardiorespiratory Interoceptive Pathways.

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Khalsa, Sahib S; Feinstein, Justin S; Li, Wei; Feusner, Jamie D; Adolphs, Ralph; Hurlemann, Rene

2016-03-23

We previously demonstrated that carbon dioxide inhalation could induce panic anxiety in a group of rare lesion patients with focal bilateral amygdala damage. To further elucidate the amygdala-independent mechanisms leading to aversive emotional experiences, we retested two of these patients (B.G. and A.M.) to examine whether triggering palpitations and dyspnea via stimulation of non-chemosensory interoceptive channels would be sufficient to elicit panic anxiety. Participants rated their affective and sensory experiences following bolus infusions of either isoproterenol, a rapidly acting peripheral β-adrenergic agonist akin to adrenaline, or saline. Infusions were administered during two separate conditions: a panic induction and an assessment of cardiorespiratory interoception. Isoproterenol infusions induced anxiety in both patients, and full-blown panic in one (patient B.G.). Although both patients demonstrated signs of diminished awareness for cardiac sensation, patient A.M., who did not panic, reported a complete lack of awareness for dyspnea, suggestive of impaired respiratory interoception. These findings indicate that the amygdala may play a role in dynamically detecting changes in cardiorespiratory sensation. The induction of panic anxiety provides further evidence that the amygdala is not required for the conscious experience of fear induced via interoceptive sensory channels. We found that monozygotic twins with focal bilateral amygdala lesions report panic anxiety in response to intravenous infusions of isoproterenol, a β-adrenergic agonist similar to adrenaline. Heightened anxiety was evident in both twins, with one twin experiencing a panic attack. The twin who did not panic displayed signs of impaired cardiorespiratory interoception, including a complete absence of dyspnea sensation. These findings highlight that the amygdala is not strictly required for the experience of panic anxiety, and suggest that neural systems beyond the amygdala are also

The relationship between cell phone use, physical and sedentary activity, and cardiorespiratory fitness in a sample of U.S. college students

Science.gov (United States)

2013-01-01

Background Today’s cell phones increase opportunities for activities traditionally defined as sedentary behaviors (e.g., surfing the internet, playing video games). People who participate in large amounts of sedentary behaviors, relative to those who do not, tend to be less physically active, less physically fit, and at greater risk for health problems. However, cell phone use does not have to be a sedentary behavior as these devices are portable. It can occur while standing or during mild-to-moderate intensity physical activity. Thus, the relationship between cell phone use, physical and sedentary activity, and physical fitness is unclear. The purpose of this study was to investigate these relationships among a sample of healthy college students. Methods Participants were first interviewed about their physical activity behavior and cell phone use. Then body composition was assessed and the validated self-efficacy survey for exercise behaviors completed. This was followed by a progressive exercise test on a treadmill to exhaustion. Peak oxygen consumption (VO2 peak) during exercise was used to measure cardiorespiratory fitness. Hierarchical regression was used to assess the relationship between cell phone use and cardiorespiratory fitness after controlling for sex, self-efficacy, and percent body fat. Interview data was transcribed, coded, and Chi-square analysis was used to compare the responses of low and high frequency cell phone users. Results Cell phone use was significantly (p = 0.047) and negatively (β = −0.25) related to cardio respiratory fitness independent of sex, self-efficacy, and percent fat which were also significant predictors (p < 0.05). Interview data offered several possible explanations for this relationship. First, high frequency users were more likely than low frequency users to report forgoing opportunities for physical activity in order to use their cell phones for sedentary behaviors. Second, low frequency users were more

Quantification of cardiorespiratory interactions based on joint symbolic dynamics.

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Kabir, Muammar M; Saint, David A; Nalivaiko, Eugene; Abbott, Derek; Voss, Andreas; Baumert, Mathias

2011-10-01

Cardiac and respiratory rhythms are highly nonlinear and nonstationary. As a result traditional time-domain techniques are often inadequate to characterize their complex dynamics. In this article, we introduce a novel technique to investigate the interactions between R-R intervals and respiratory phases based on their joint symbolic dynamics. To evaluate the technique, electrocardiograms (ECG) and respiratory signals were recorded in 13 healthy subjects in different body postures during spontaneous and controlled breathing. Herein, the R-R time series were extracted from ECG and respiratory phases were obtained from abdomen impedance belts using the Hilbert transform. Both time series were transformed into ternary symbol vectors based on the changes between two successive R-R intervals or respiratory phases. Subsequently, words of different symbol lengths were formed and the correspondence between the two series of words was determined to quantify the interaction between cardiac and respiratory cycles. To validate our results, respiratory sinus arrhythmia (RSA) was further studied using the phase-averaged characterization of the RSA pattern. The percentage of similarity of the sequence of symbols, between the respective words of the two series determined by joint symbolic dynamics, was significantly reduced in the upright position compared to the supine position (26.4 ± 4.7 vs. 20.5 ± 5.4%, p cardiorespiratory interaction that is highly sensitive to the effects of orthostatic challenge.

Managing Stress to Control High Blood Pressure

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... Aortic Aneurysm More Managing Stress to Control High Blood Pressure Updated:Jan 29,2018 The importance of stress ... This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP • Know Your ...

Effect of a primary health-care-based controlled trial for cardiorespiratory fitness in refugee women

Directory of Open Access Journals (Sweden)

Johansson Sven-Erik

2010-08-01

Full Text Available Abstract Background Refugee women have a high risk of coronary heart disease with low physical activity as one possible mediator. Furthermore, cultural and environmental barriers to increasing physical activity have been demonstrated. The aim of the study was to evaluate the combined effect of an approximate 6-month primary health care- and community-based exercise intervention versus an individual written prescription for exercise on objectively assessed cardiorespiratory fitness in low-active refugee women. Methods A controlled clinical trial, named "Support for Increased Physical Activity", was executed among 243 refugee women recruited between November 2006 and April 2008 from two deprived geographic areas in southern Stockholm, Sweden. One geographic area provided the intervention group and the other area the control group. The control group was on a higher activity level at both baseline and follow-up, which was taken into consideration in the analysis by applying statistical models that accounted for this. Relative aerobic capacity and fitness level were assessed as the two main outcome measures. Results The intervention group increased their relative aerobic capacity and the percentage with an acceptable fitness level (relative aerobic capacity > 23 O2ml·kg·min-1 to a greater extent than the control group between baseline and the 6-month follow-up, after adjusting for possible confounders (P = 0.020. Conclusions A combined primary health-care and community-based exercise programme (involving non-profit organizations can be an effective strategy to increase cardiorespiratory fitness among low-active refugee women. Trial Registration ClinicalTrials.gov ID: NCT00747942

New perspectives concerning feedback influences on cardiorespiratory control during rhythmic exercise and on exercise performance.

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Dempsey, Jerome A

2012-09-01

The cardioaccelerator and ventilatory responses to rhythmic exercise in the human are commonly viewed as being mediated predominantly via feedforward 'central command' mechanisms, with contributions from locomotor muscle afferents to the sympathetically mediated pressor response. We have assessed the relative contributions of three types of feedback afferents on the cardiorespiratory response to voluntary, rhythmic exercise by inhibiting their normal 'tonic' activity in healthy animals and humans and in chronic heart failure. Transient inhibition of the carotid chemoreceptors during moderate intensity exercise reduced muscle sympathetic nerve activity (MSNA) and increased limb vascular conductance and blood flow; and reducing the normal level of respiratory muscle work during heavier intensity exercise increased limb vascular conductance and blood flow. These cardiorespiratory effects were prevented via ganglionic blockade and were enhanced in chronic heart failure and in hypoxia. Blockade of μ opioid sensitive locomotor muscle afferents, with preservation of central motor output via intrathecal fentanyl: (a) reduced the mean arterial blood pressure (MAP), heart rate and ventilatory responses to all steady state exercise intensities; and (b) during sustained high intensity exercise, reduced O(2) transport, increased central motor output and end-exercise muscle fatigue and reduced endurance performance. We propose that these three afferent reflexes - probably acting in concert with feedforward central command - contribute significantly to preserving O(2) transport to locomotor and to respiratory muscles during exercise. Locomotor muscle afferents also appear to provide feedback concerning the metabolic state of the muscle to influence central motor output, thereby limiting peripheral fatigue development.

Detection of Nocturnal Slow Wave Sleep Based on Cardiorespiratory Activity in Healthy Adults.

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Long, Xi; Fonseca, Pedro; Aarts, Ronald M; Haakma, Reinder; Rolink, Jerome; Leonhardt, Steffen

2017-01-01

Human slow wave sleep (SWS) during bedtime is paramount for energy conservation and memory consolidation. This study aims at automatically detecting SWS from nocturnal sleep using cardiorespiratory signals that can be acquired with unobtrusive sensors in a home-based scenario. From the signals, time-dependent features are extracted for continuous 30-s epochs. To reduce the measuring noise, body motion artifacts, and/or within-subject variability in physiology conveyed by the features, and thus, enhance the detection performance, we propose to smooth the features over each night using a spline fitting method. In addition, it was found that the changes in cardiorespiratory activity precede the transitions between SWS and the other sleep stages (non-SWS). To this matter, a novel scheme is proposed that performs the SWS detection for each epoch using the feature values prior to that epoch. Experiments were conducted with a large dataset of 325 overnight polysomnography (PSG) recordings using a linear discriminant classifier and tenfold cross validation. Features were selected with a correlation-based method. Results show that the performance in classifying SWS and non-SWS can be significantly improved when smoothing the features and using the preceding feature values of 5-min earlier. We achieved a Cohen's Kappa coefficient of 0.57 (at an accuracy of 88.8%) using only six selected features for 257 recordings with a minimum of 30-min overnight SWS that were considered representative of their habitual sleeping pattern at home. These features included the standard deviation, low-frequency spectral power, and detrended fluctuation of heartbeat intervals as well as the variations of respiratory frequency and upper and lower respiratory envelopes. A marked drop in Kappa to 0.21 was observed for the other nights with SWS time of less than 30 min, which were found to more likely occur in elderly. This will be the future challenge in cardiorespiratory-based SWS detection.

High temperature aqueous stress corrosion testing device

International Nuclear Information System (INIS)

Bornstein, A.N.; Indig, M.E.

1975-01-01

A description is given of a device for stressing tensile samples contained within a high temperature, high pressure aqueous environment, thereby permitting determination of stress corrosion susceptibility of materials in a simple way. The stressing device couples an external piston to an internal tensile sample via a pull rod, with stresses being applied to the sample by pressurizing the piston. The device contains a fitting/seal arrangement including Teflon and weld seals which allow sealing of the internal system pressure and the external piston pressure. The fitting/seal arrangement allows free movement of the pull rod and the piston

A 45-second self-test for cardiorespiratory fitness: heart rate-based estimation in healthy individuals

NARCIS (Netherlands)

Sartor, F.; Bonato, M.; Papini, G.; Bosio, A.; Mohammed, R.; Bonomi, A.G.; Moore, J.P.; Merati, G.; Della Torre, A.; Kubis, H.P.

2016-01-01

Cardio-respiratory fitness (CRF) is a widespread essential indicator in Sports Science as well as in Sports Medicine. This study aimed to develop and validate a prediction model for CRF based on a 45 second self-test, which can be conducted anywhere. Criterion validity, test re-test study was set up

All-cause mortality risk as a function of sedentary behavior, moderate-to-vigorous physical activity and cardiorespiratory fitness.

Science.gov (United States)

Edwards, Meghan K; Loprinzi, Paul D

2016-09-01

Emerging work demonstrates individual associations of sedentary behavior, moderate-to-vigorous physical activity (MVPA) and cardiorespiratory fitness (CRF) on mortality risk. Limited research has evaluated all three of these parameters in a model when considering mortality risk, and their potential additive association on mortality risk has not been fully evaluated, which was the purpose of this study. Data from the 2003-2006 National Health and Nutrition Examination Survey were used (N = 2,295 adults 20-85 yrs), with follow-up through 2011. Sedentary behavior and MVPA were objectively assessed (accelerometry) with cardiorespiratory estimated from a prediction equation taking into consideration participant demographic, anthropometric and behavioral characteristics. Using the median values, a PACS (Physical Activity Cardiorespiratory Sedentary) score was created that ranged from 0-3, indicating the number of these three positive characteristics. Those with below median sedentary behavior did not have a reduced all-cause mortality risk (HR = 0.59; 95% CI: 0.34-1.04; P = 0.07), but those with above median MVPA (HR = 0.35; 95% CI: 0.15-0.82; P = 0.02) and above median CRF did (HR = 0.20; 95% CI: 0.09-0.43; P sedentary behavior, were independently associated with reduced mortality risk. Adults with all three characteristics (below median sedentary and above median MVPA and CRF), however, had the lowest mortality risk.

Maximal and anaerobic threshold cardiorespiratory responses during deepwater running

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Ana Carolina Kanitz

2014-12-01

Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n1p41   Aquatic exercises provide numerous benefits to the health of their practitioners. To secure these benefits, it is essential to have proper prescriptions to the needs of each individual and, therefore, it is important to study the cardiorespiratory responses of different activities in this environment. Thus, the aim of this study was to compare the cardiorespiratory responses at the anaerobic threshold (AT between maximal deep-water running (DWR and maximal treadmill running (TMR. In addition, two methods of determining the AT (the heart rate deflection point [HRDP] and ventilatory method [VM] are compared in the two evaluated protocols. Twelve young women performed the two maximal protocols. Two-factor ANOVA for repeated measures with a post-hoc Bonferroni test was used (α < 0.05. Significantly higher values of maximal heart rate (TMR: 33.7 ± 3.9; DWR: 22.5 ± 4.1 ml.kg−1.min−1 and maximal oxygen uptake (TMR: 33.7 ± 3.9; DWR: 22.5 ± 4.1 ml.kg−1.min−1 in TMR compared to the DWR were found. Furthermore, no significant differences were found between the methods for determining the AT (TMR: VM: 28.1 ± 5.3, HRDP: 26.6 ± 5.5 ml.kg−1.min−1; DWR: VM: 18.7 ± 4.8, HRDP: 17.8 ± 4.8 ml.kg−1.min−1. The results indicate that a specific maximal test for the trained modality should be conducted and the HRDP can be used as a simple and practical method of determining the AT, based on which the training intensity can be determined

The relationship between cell phone use, physical and sedentary activity, and cardiorespiratory fitness in a sample of U.S. college students.

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Lepp, Andrew; Barkley, Jacob E; Sanders, Gabriel J; Rebold, Michael; Gates, Peter

2013-06-21

Today's cell phones increase opportunities for activities traditionally defined as sedentary behaviors (e.g., surfing the internet, playing video games). People who participate in large amounts of sedentary behaviors, relative to those who do not, tend to be less physically active, less physically fit, and at greater risk for health problems. However, cell phone use does not have to be a sedentary behavior as these devices are portable. It can occur while standing or during mild-to-moderate intensity physical activity. Thus, the relationship between cell phone use, physical and sedentary activity, and physical fitness is unclear. The purpose of this study was to investigate these relationships among a sample of healthy college students. Participants were first interviewed about their physical activity behavior and cell phone use. Then body composition was assessed and the validated self-efficacy survey for exercise behaviors completed. This was followed by a progressive exercise test on a treadmill to exhaustion. Peak oxygen consumption (VO2 peak) during exercise was used to measure cardiorespiratory fitness. Hierarchical regression was used to assess the relationship between cell phone use and cardiorespiratory fitness after controlling for sex, self-efficacy, and percent body fat. Interview data was transcribed, coded, and Chi-square analysis was used to compare the responses of low and high frequency cell phone users. Cell phone use was significantly (p = 0.047) and negatively (β = -0.25) related to cardio respiratory fitness independent of sex, self-efficacy, and percent fat which were also significant predictors (p cell phone use indicated a broader pattern of sedentary behaviors apart from cell phone use, such as watching television. Cell phone use, like traditional sedentary behaviors, may disrupt physical activity and reduce cardiorespiratory fitness.

Prevalence of heartworm infection in cats with signs of cardiorespiratory abnormalities

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Atkins, C.; DeFrancesco, T.; Miller, M.; Meurs, K.; Keene, B.

1998-01-01

To determine prevalence of heartworm infection in a population of pet cats with cardiorespiratory abnormalities and to determine relative usefulness of clinical signs and tests in diagnosis of heartworm disease. Prospective case series. 100 client-owned cats with clinical signs of cardiorespiratory abnormalities. Cats were evaluated using CBC, modified Knott test, ELISA for serologic detection of heartworm antigen and antibodies to heartworms, thoracic radiography, and echocardiography. Cats were considered infected if they had circulating microfilaria, heartworm antigens in serum, or if heartworms were detected by echocardiography or on necropsy. Cats were considered suspicious for infection if they had 2 of the following: serum antibodies to heartworms, eosinophilia or basophilia, or indicative radiographic findings. 9 cats were infected with heartworms, resulting in a prevalence of 9%; 26 cats had evidence of heartworm exposure (i.e., serum antibodies to heartworms). Twenty cats were considered suspicious for heartworm infection. Some outdoor exposure was reported twice as often in heartworm-infected cats, compared with noninfected and suspicious cats. However, a third of infected cats were reportedly housed totally indoors. Cough and dyspnea were strong indicators of heartworm disease. Eight of 9 infected cats had serum antibodies to heartworms and heartworm antigen in serum. Thoracic radiography and echocardiography indicated heartworm infection in 6 and 7 of the 9 cats, respectively. Cough or dyspnea may indicate heartworm disease in cats; serologic tests, echocardiography, and radiography are most useful diagnostic procedures. Although living indoors is protective, it may not preclude heartworm infection in cats

Motor competence and cardiorespiratory fitness have greater influence on body fatness than physical activity across time

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Lima, R A; Pfeiffer, K A; Bugge, A

2017-01-01

We investigated the longitudinal associations among physical activity (PA), motor competence (MC), cardiorespiratory fitness (VO2peak ), and body fatness across 7 years, and also analyzed the possible mediation effects of PA, MC, and VO2peak on the relationships with body fatness. This was a seven...

High-Risk Stress Fractures: Diagnosis and Management.

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McInnis, Kelly C; Ramey, Lindsay N

2016-03-01

Stress fractures are common overuse injuries in athletes. They occur during periods of increased training without adequate rest, disrupting normal bone reparative mechanisms. There are a host of intrinsic and extrinsic factors, including biochemical and biomechanical, that put athletes at risk. In most stress fractures, the diagnosis is primarily clinical, with imaging indicated at times, and management focused on symptom-free relative rest with advancement of activity as tolerated. Overall, stress fractures in athletes have an excellent prognosis for return to sport, with little risk of complication. There is a subset of injuries that have a greater risk of fracture progression, delayed healing, and nonunion and are generally more challenging to treat with nonoperative care. Specific locations of high-risk stress fracture include the femoral neck (tension side), patella, anterior tibia, medial malleolus, talus, tarsal navicular, proximal fifth metatarsal, and great toe sesamoids. These sites share a characteristic region of high tensile load and low blood flow. High-risk stress fractures require a more aggressive approach to evaluation, with imaging often necessary, to confirm early and accurate diagnosis and initiate immediate treatment. Treatment consists of nonweight-bearing immobilization, often with a prolonged period away from sport, and a more methodic and careful reintroduction to athletic activity. These stress fractures may require surgical intervention. A high index of suspicion is essential to avoid delayed diagnosis and optimize outcomes in this subset of stress fractures. Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Cardiorespiratory Fitness, Sedentary Behaviour and Physical Activity Are Independently Associated with the Metabolic Syndrome, Results from the SCAPIS Pilot Study.

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Örjan Ekblom

Full Text Available Previous studies on the relation between lifestyle and the metabolic syndrome lack one or several aspects of the physical activity pattern in the analyses or cardiorespiratory fitness. Likewise, both uni- and triaxial accelerometry have been used, though, the predictive validity of these two modes has not been compared.The aims of the present study were firstly to investigate the independent relation between cardiorespiratory fitness and physical activity pattern to the metabolic syndrome (MetS and secondly to examine the predictive validity of uni- and triaxial accelerometry, respectively.Data was extracted from the SCAPIS pilot study (n=930, mean age 57.7 yrs. Physical activity pattern was assessed by accelerometry. Cardiorespiratory fitness was estimated using cycle ergometry. MetS was defined per the Adult Treatment Panel III from the National Cholesterol Education Program definition.Time spent sedentary (OR: 2.38, 95% CI: 1.54-4.24 for T3 vs T1, in light intensity (OR: 0.50, 95% CI: 0.28-0.90 and in moderate-to-vigorous activity (OR: 0.33, 95% CI: 0.18-0.61, as well as cardiorespiratory fitness (OR: 0.24, 95% CI:0.12-0.48, were all independently related to the prevalence of MetS after adjustment for potential confounders, fitness and/or the other aspects of the physical activity pattern. In addition, we found that triaxial analyses were more discriminant, with ORs farther away from the reference group and additional significant ORs.The finding that several aspects of the physical activity pattern reveal independent relations to the MetS makes new possible targets for behaviour change of interest, focusing on both exercise and everyday life. When assessing the risk status of a patient, it is advised that triaxial accelerometry is used.

Effects of a 12-Week Hatha Yoga Intervention on Cardiorespiratory Endurance, Muscular Strength and Endurance, and Flexibility in Hong Kong Chinese Adults: A Controlled Clinical Trial

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Caren Lau

2015-01-01

Full Text Available Objective. To examine the effects of a 12-week Hatha yoga intervention on cardiorespiratory endurance, muscular strength and endurance, and flexibility in Chinese adults. Methods. 173 adults (aged 52.0 ± 7.5 years were assigned to either the yoga intervention group (n=87 or the waitlist control group (n=86. 19 dropped out from the study. Primary outcomes were changes in cardiorespiratory endurance (resting heart rate (HR and maximal oxygen uptake (VO2max, muscular strength and endurance (curl-up and push-up tests, and lower back and hamstring flexibility (the modified back-saver sit-and-reach (MBS test. Results. Compared to controls, the yoga group achieved significant improvements in VO2max (P<0.01, curl-up (P<0.05 and push-up (P<0.001 tests, and the MBS left and right leg tests (both P<0.001 in both genders. Significant change was also found for resting HR between groups in women (P<0.05 but not in men. Further analysis comparing participants between younger and older subgroups yielded similar findings, except that the older participants in the yoga group failed to improve resting HR or the curl-up test versus control. Adherence (89% and attendance (94% were high. No serious adverse events occurred. Conclusion. A 12-week Hatha yoga intervention has favorable effects on cardiorespiratory endurance, muscular strength and endurance, and flexibility in Chinese adults.

Effect of 11 months of yoga training on cardiorespiratory responses during the actual practice of Surya Namaskar

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Biswajit Sinha

2014-01-01

Full Text Available Background: Surya Namaskar (SN, a popular traditional Indian yogic practice, includes practicing 12 physical postures with alternate forward and backward bending movement of the body along with deep breathing maneuvers. The practice of SN has become popular among yoga practitioners and other fitness conscious people. The long-term effect of practicing SN and other yogic practices on cardiorespiratory responses during SN are lacking. Aim: The present study was conducted to study the effect of yogic training on various cardiorespiratory responses during the SN practice in yoga trainees after a time interval of 3, 6, and 11 months. Materials and Methods: The present study was conducted on 9 healthy male Army soldiers who underwent training in various yoga postures including SN, meditation, and pranayama for 1 h daily for 11 months. First, second, and third phase of the study was conducted in the laboratory after completion of 3, 6, and 11 months of the yoga training. The participants performed SN along with other yogic practices in the laboratory as per their daily practice schedule. The cardiorespiratory responses of the volunteers were recorded during actual practice of SN. Statistical Analysis: One-way repeated measure ANOVA followed by Tukey HSD. Results: Oxygen consumption and heart rate during actual practice of SN was 0.794 ± 0.252, 0.738 ± 0.229, and 0.560 ± 0.165 L/min and 92.1 ± 11.6, 97.9 ± 7.3 and 87.4 ± 9.2 beats/min respectively at 1 st , 2 nd , and 3 rd phase of yoga training. Minute ventilation and tidal volume also reduced from 19.9 ± 4.65 to 17.8 ± 4.41 L/min and 1.091 ± 0.021 to 0.952 L/breath from 1 st phase to 3 rd phase of yoga training. However, respiratory parameters like breathing rate (f R did not show any reduction across the three phases. Conclusion: The results of the present study indicated that yogic training caused conditioning of cardiorespiratory parameters except f R, which did not reduce across three

Cardiorespiratory and cardiovascular interactions in cardiomyopathy patients using joint symbolic dynamic analysis.

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Giraldo, Beatriz F; Rodriguez, Javier; Caminal, Pere; Bayes-Genis, Antonio; Voss, Andreas

2015-01-01

Cardiovascular diseases are the first cause of death in developed countries. Using electrocardiographic (ECG), blood pressure (BP) and respiratory flow signals, we obtained parameters for classifying cardiomyopathy patients. 42 patients with ischemic (ICM) and dilated (DCM) cardiomyopathies were studied. The left ventricular ejection fraction (LVEF) was used to stratify patients with low risk (LR: LVEF>35%, 14 patients) and high risk (HR: LVEF≤ 35%, 28 patients) of heart attack. RR, SBP and TTot time series were extracted from the ECG, BP and respiratory flow signals, respectively. The time series were transformed to a binary space and then analyzed using Joint Symbolic Dynamic with a word length of three, characterizing them by the probability of occurrence of the words. Extracted parameters were then reduced using correlation and statistical analysis. Principal component analysis and support vector machines methods were applied to characterize the cardiorespiratory and cardiovascular interactions in ICM and DCM cardiomyopathies, obtaining an accuracy of 85.7%.

Outdoor time is associated with physical activity, sedentary time, and cardiorespiratory fitness in youth.

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Schaefer, Lee; Plotnikoff, Ronald C; Majumdar, Sumit R; Mollard, Rebecca; Woo, Meaghan; Sadman, Rashik; Rinaldi, Randi Lynn; Boulé, Normand; Torrance, Brian; Ball, Geoff D C; Veugelers, Paul; Wozny, Paul; McCargar, Linda; Downs, Shauna; Lewanczuk, Richard; Gleddie, Douglas; McGavock, Jonathan

2014-09-01

To determine whether time spent outdoors was associated with increased moderate-to-vigorous physical activity (MVPA) and related health benefits in youth. We performed a cross-sectional study of 306 youth aged 13.6 ± 1.4 years. The exposure of interest was self-reported time spent outdoors after school, stratified into three categories: none, some, and most/all of the time. The main outcome of interest was accelerometer-derived MVPA (Actical: 1500 to >6500 counts/min). Secondary outcomes included sedentary behavior, cardiorespiratory fitness, overweight status, and blood pressure. Among the 306 youth studied, those who reported spending most/all of their after-school time outdoors (n = 120) participated in more MVPA (61.0 ± 24.3 vs 39.9 ± 19.1 min/day; adjusted P outdoors (n = 52). No differences in overweight/obesity or blood pressure were observed across the groups. Time spent outdoors is positively associated with MVPA and cardiorespiratory fitness in youth and negatively associated with sedentary behavior. Experimental trials are needed to determine whether strategies designed to increase time spent outdoors exert a positive influence on physical activity and fitness levels in youth. Copyright © 2014 Elsevier Inc. All rights reserved.

Changes in Cardiorespiratory Responses and Kinematics with Hippotherapy in Youth with and without Cerebral Palsy

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Rigby, Brandon Rhett; Gloeckner, Adam Robert; Sessums, Suzanne; Lanning, Beth Anne; Grandjean, Peter Walter

2017-01-01

Purpose: The purpose of this study was to characterize pelvic displacement and cardiorespiratory responses to simulated horseback riding and walking in youth with cerebral palsy and to compare responses to youth without cerebral palsy before and after 8 weeks of hippotherapy. Method: Eight youth with cerebral palsy (M[subscript age] = 10 ± 4…

Acute Cardiorespiratory and Metabolic Responses During Exoskeleton-Assisted Walking Overground Among Persons with Chronic Spinal Cord Injury

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Hartigan, Clare; Kandilakis, Casey; Pharo, Elizabeth; Clesson, Ismari

2015-01-01

Background: Lower extremity robotic exoskeleton technology is being developed with the promise of affording people with spinal cord injury (SCI) the opportunity to stand and walk. The mobility benefits of exoskeleton-assisted walking can be realized immediately, however the cardiorespiratory and metabolic benefits of this technology have not been thoroughly investigated. Objective: The purpose of this pilot study was to evaluate the acute cardiorespiratory and metabolic responses associated with exoskeleton-assisted walking overground and to determine the degree to which these responses change at differing walking speeds. Methods: Five subjects (4 male, 1 female) with chronic SCI (AIS A) volunteered for the study. Expired gases were collected during maximal graded exercise testing and two, 6-minute bouts of exoskeleton-assisted walking overground. Outcome measures included peak oxygen consumption (V̇O2peak), average oxygen consumption (V̇O2avg), peak heart rate (HRpeak), walking economy, metabolic equivalent of tasks for SCI (METssci), walk speed, and walk distance. Results: Significant differences were observed between walk-1 and walk-2 for walk speed, total walk distance, V̇O2avg, and METssci. Exoskeleton-assisted walking resulted in %V̇O2peak range of 51.5% to 63.2%. The metabolic cost of exoskeleton-assisted walking ranged from 3.5 to 4.3 METssci. Conclusion: Persons with motor-complete SCI may be limited in their capacity to perform physical exercise to the extent needed to improve health and fitness. Based on preliminary data, cardiorespiratory and metabolic demands of exoskeleton-assisted walking are consistent with activities performed at a moderate intensity. PMID:26364281

Acute Cardiorespiratory and Metabolic Responses During Exoskeleton-Assisted Walking Overground Among Persons with Chronic Spinal Cord Injury.

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Evans, Nicholas; Hartigan, Clare; Kandilakis, Casey; Pharo, Elizabeth; Clesson, Ismari

2015-01-01

Lower extremity robotic exoskeleton technology is being developed with the promise of affording people with spinal cord injury (SCI) the opportunity to stand and walk. The mobility benefits of exoskeleton-assisted walking can be realized immediately, however the cardiorespiratory and metabolic benefits of this technology have not been thoroughly investigated. The purpose of this pilot study was to evaluate the acute cardiorespiratory and metabolic responses associated with exoskeleton-assisted walking overground and to determine the degree to which these responses change at differing walking speeds. Five subjects (4 male, 1 female) with chronic SCI (AIS A) volunteered for the study. Expired gases were collected during maximal graded exercise testing and two, 6-minute bouts of exoskeleton-assisted walking overground. Outcome measures included peak oxygen consumption (V̇O2peak), average oxygen consumption (V̇O2avg), peak heart rate (HRpeak), walking economy, metabolic equivalent of tasks for SCI (METssci), walk speed, and walk distance. Significant differences were observed between walk-1 and walk-2 for walk speed, total walk distance, V̇O2avg, and METssci. Exoskeleton-assisted walking resulted in %V̇O2peak range of 51.5% to 63.2%. The metabolic cost of exoskeleton-assisted walking ranged from 3.5 to 4.3 METssci. Persons with motor-complete SCI may be limited in their capacity to perform physical exercise to the extent needed to improve health and fitness. Based on preliminary data, cardiorespiratory and metabolic demands of exoskeleton-assisted walking are consistent with activities performed at a moderate intensity.

Immediate Effects of Smoking on Cardiorespiratory Responses During Dynamic Exercise: Arm Vs. Leg Ergometry.

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Chen, Chien-Liang; Tang, Jing-Shia; Li, Ping-Chia; Chou, Pi-Ling

2015-01-01

This study compared the immediate effects of smoking on cardiorespiratory responses to dynamic arm and leg exercises. This randomized crossover study recruited 14 college students. Each participant underwent two sets of arm-cranking (AC) and leg-cycling (LC) exercise tests. The testing sequences of the control trial (participants refrained from smoking for 8 h before testing) and the experimental trial (participants smoked two cigarettes immediately before testing) were randomly chosen. We observed immediate changes in pulmonary function and heart rate variability after smoking and before the exercise test. The participants then underwent graded exercise tests of their arms and legs until reaching exhaustion. We compared the peak work achieved and time to exhaustion during the exercise tests with various cardiorespiratory indices [i.e., heart rate, oxygen consumption (VO2), minute ventilation (VE)]. The differences between the smoking and control trials were calculated using paired t-tests. For the exercise test periods, VO2, heart rate, and VE values were calculated at every 10% increment of the maximal effort time. The main effects of the time and trial, as well as their trial-by-time (4 × 10) interaction effects on the outcome measures, were investigated using repeated measure ANOVA with trend analysis. 5 min after smoking, the participants exhibited reduced forced vital capacities and forced expiratory volumes in the first second (P exercise test periods, smoking reduced the time to exhaustion (P = 0.005) and the ventilatory threshold (P exercise test (all P exercise response of the smoking trial than in those of the control LC trials, whereas no discernable inter-trial difference was observed in the AC trials. Moreover, the differences in heart rate and VE response between the LC and AC exercises were significantly smaller after the participants smoked. This study verified that smoking significantly decreased performance and cardiorespiratory responses to leg

Daily energy expenditure, cardiorespiratory fitness and glycaemic control in people with type 1 diabetes.

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John Joseph Valletta

Full Text Available Encouraging daily physical activity improves cardiorespiratory fitness and many cardiovascular risk factors. However, increasing physical activity often creates a challenge for people with type 1 diabetes, because of difficulties maintaining euglycemia in the face of altered food intake and adjustments to insulin doses. Our aim was to examine the triangular relationship between glucose control measured by continuous glucose monitoring system (CGMS, objective measures of total daily energy expenditure (TEE recorded by a multi-sensory monitoring device, and cardiorespiratory fitness (CRF, in free-living subjects with type 1 diabetes.Twenty-three individuals (12 women with type 1 diabetes who were free from micro- and macrovascular complications were recruited. TEE and glucose control were monitored simultaneously for up to 12 days, using a multi-sensory device and CGMS respectively. CRF was recorded as V02 max from a maximal treadmill test with the Bruce protocol.Subjects (mean±SD were aged 37±11 years, with BMI = 26.5±5.1 kg.m⁻², HbA1c = 7.7±1.3% (61±14 mmol/mol and V02 max (ml.min⁻¹.kg⁻¹  = 39.9±8.4 (range 22.4-58.6. TEE (36.3±5.5 kcal.kg⁻¹.day⁻¹ was strongly associated with CRF(39.9±8.4 ml.min⁻¹.kg⁻¹ independently of sex (r = 0.63, p<0.01. However, neither TEE (r = -0.20, p = 0.36 nor CRF (r = -0.20, p = 0.39; adjusted for sex, were significantly associated with mean glycaemia measured by CGMS.Higher levels of energy expenditure (due to a more active lifestyle are associated with increased cardiorespiratory fitness, but not necessarily better glycaemic control. Since increased levels of energy expenditure and good glycaemic control are both needed to protect against diabetes-related complications our data suggest they need to be achieved independently.

The Impact of Cardiorespiratory Fitness on Age-Related Lipids and Lipoproteins

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Park, Yong-Moon Mark; Sui, Xuemei; Liu, Junxiu; Zhou, Haiming; Kokkinos, Peter F.; Lavie, Carl J.; Hardin, James W.; Blair, Steven N.

2015-01-01

Background Evidence on the effect of cardiorespiratory fitness (CRF) on age-related longitudinal changes of lipids and lipoproteins is scarce. Objectives This study sought to assess the longitudinal, aging trajectory of lipids and lipoproteins for the life course in adults, and to determine whether CRF modifies the age-associated trajectory of lipids and lipoproteins. Methods Data came from 11,418 men, 20 to 90 years of age, without known high cholesterol, high triglycerides, cardiovascular disease, and cancer at baseline and during follow-up from the Aerobics Center Longitudinal Study. There were 43,821 observations spanning 2 to 25 (mean 3.5) health examinations between 1970 and 2006. CRF was quantified by a maximal treadmill exercise test. Marginal models using generalized estimating equations were applied. Results Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and non-high-density lipoprotein cholesterol (non-HDL-C) presented similar inverted U-shaped quadratic trajectories with aging: gradual increases were noted until the mid-40s to early 50s, with subsequent declines (all p lipoproteins in young to middle-aged men than in older men. Conclusions Our investigation reveals a differential trajectory of lipids and lipoproteins with aging according to CRF in healthy men, and suggests that promoting increased CRF levels may help delay the development of dyslipidemia. PMID:25975472

The effect of cardiorespiratory fitness on age-related lipids and lipoproteins.

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Park, Yong-Moon Mark; Sui, Xuemei; Liu, Junxiu; Zhou, Haiming; Kokkinos, Peter F; Lavie, Carl J; Hardin, James W; Blair, Steven N

2015-05-19

Evidence on the effect of cardiorespiratory fitness (CRF) on age-related longitudinal changes of lipids and lipoproteins is scarce. This study sought to assess the longitudinal aging trajectory of lipids and lipoproteins for the life course in adults and to determine whether CRF modifies the age-associated trajectory of lipids and lipoproteins. Data came from 11,418 men, 20 to 90 years of age, without known high cholesterol, high triglycerides, cardiovascular disease, and cancer at baseline and during follow-up from the Aerobics Center Longitudinal Study. There were 43,821 observations spanning 2 to 25 health examinations (mean 3.5 examinations) between 1970 and 2006. CRF was quantified by a maximal treadmill exercise test. Marginal models using generalized estimating equations were applied. Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides, and non-high-density lipoprotein cholesterol (non-HDL-C) presented similar inverted U-shaped quadratic trajectories with aging: gradual increases were noted until age mid-40s to early 50s, with subsequent declines (all p lipoproteins in young to middle-age men than in older men. Our investigation reveals a differential trajectory of lipids and lipoproteins with aging according to CRF in healthy men and suggests that promoting increased CRF levels may help delay the development of dyslipidemia. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Cardiorespiratory dynamics measured from continuous ECG monitoring improves detection of deterioration in acute care patients: A retrospective cohort study

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Clark, Matthew T.; Calland, James Forrest; Enfield, Kyle B.; Voss, John D.; Lake, Douglas E.; Moorman, J. Randall

2017-01-01

Background Charted vital signs and laboratory results represent intermittent samples of a patient’s dynamic physiologic state and have been used to calculate early warning scores to identify patients at risk of clinical deterioration. We hypothesized that the addition of cardiorespiratory dynamics measured from continuous electrocardiography (ECG) monitoring to intermittently sampled data improves the predictive validity of models trained to detect clinical deterioration prior to intensive care unit (ICU) transfer or unanticipated death. Methods and findings We analyzed 63 patient-years of ECG data from 8,105 acute care patient admissions at a tertiary care academic medical center. We developed models to predict deterioration resulting in ICU transfer or unanticipated death within the next 24 hours using either vital signs, laboratory results, or cardiorespiratory dynamics from continuous ECG monitoring and also evaluated models using all available data sources. We calculated the predictive validity (C-statistic), the net reclassification improvement, and the probability of achieving the difference in likelihood ratio χ2 for the additional degrees of freedom. The primary outcome occurred 755 times in 586 admissions (7%). We analyzed 395 clinical deteriorations with continuous ECG data in the 24 hours prior to an event. Using only continuous ECG measures resulted in a C-statistic of 0.65, similar to models using only laboratory results and vital signs (0.63 and 0.69 respectively). Addition of continuous ECG measures to models using conventional measurements improved the C-statistic by 0.01 and 0.07; a model integrating all data sources had a C-statistic of 0.73 with categorical net reclassification improvement of 0.09 for a change of 1 decile in risk. The difference in likelihood ratio χ2 between integrated models with and without cardiorespiratory dynamics was 2158 (p value: <0.001). Conclusions Cardiorespiratory dynamics from continuous ECG monitoring detect

The effects of four weeks of creatine supplementation and high-intensity interval training on cardiorespiratory fitness: a randomized controlled trial

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Cramer Joel T

2009-11-01

Full Text Available Abstract Background High-intensity interval training has been shown to be a time-efficient way to induce physiological adaptations similar to those of traditional endurance training. Creatine supplementation may enhance high-intensity interval training, leading to even greater physiological adaptations. The purpose of this study was to determine the effects of high-intensity interval training (HIIT and creatine supplementation on cardiorespiratory fitness and endurance performance (maximal oxygen consumption (VO2PEAK, time-to-exhaustion (VO2PEAKTTE, ventilatory threshold (VT, and total work done (TWD in college-aged men. Methods Forty-three recreationally active men completed a graded exercise test to determine VO2PEAK, VO2PEAKTTE, and VT. In addition, participants completed a time to exhaustion (TTE ride at 110% of the maximum workload reached during the graded exercise test to determine TWD (TTE (sec × W = J. Following testing, participants were randomly assigned to one of three groups: creatine (creatine citrate (Cr; n = 16, placebo (PL; n = 17, or control (n = 10 groups. The Cr and PL groups completed four weeks of HIIT prior to post-testing. Results Significant improvements in VO2PEAK and VO2PEAKTTE occurred in both training groups. Only the Cr group significantly improved VT (16% vs. 10% improvement in PL. No changes occurred in TWD in any group. Conclusion In conclusion, HIIT is an effective and time-efficient way to improve maximal endurance performance. The addition of Cr improved VT, but did not increase TWD. Therefore, 10 g of Cr per day for five days per week for four weeks does not seem to further augment maximal oxygen consumption, greater than HIIT alone; however, Cr supplementation may improve submaximal exercise performance.

Influence of sedentary behavior, physical activity, and cardiorespiratory fitness on the atherogenic index of plasma.

Science.gov (United States)

Edwards, Meghan K; Blaha, Michael J; Loprinzi, Paul D

Atherogenic index of plasma (AIP), calculated as LOG 10 (triglycerides/high-density lipoprotein-cholesterol), may have greater utility over other metrics in predicting risk for cardiovascular disease (CVD). Previous work demonstrates the associations of physical activity (PA), sedentary behavior, and cardiorespiratory fitness (CRF) with triglycerides high-density lipoprotein (HDL-C) and CVD. Limited research has examined these parameters and their potential additive associations with AIP, which was the purpose of this study. Data from the 2003-2004 National Health and Nutrition Examination Survey (NHANES) were used (N = 307 adults 20-49 years). Sedentary behavior and moderate-to-vigorous physical activity (MVPA) were assessed via accelerometry. CRF was assessed via submaximal treadmill testing. Using median values, a PACS (Physical Activity Cardiorespiratory Sedentary) score (ranging from 0-3) was created, indicating the number of these positive characteristics (eg, above median CRF) each participant possessed. Above median MVPA was associated with significantly lower AIP values (β = -0.09; 95% CI, -0.17 to -0.01; P = .03), whereas above-median CRF (β = -0.0009; 95% CI, -0.09 to 0.08; P = .98) and below-median sedentary behavior (β = -0.02; 95% CI, -0.13 to 0.08; P = .60) were not. Compared to those with a PACS score of 0, those with a score of 1 or 2 did not have significantly reduced AIP values (β = 0.02; 95% CI, -0.06 to 0.10; P = .59, and β = 0.007; 95% CI, -0.12 to 0.13; P = .90, respectively); however, those with a score of 3 did (β = -0.14; 95% CI, -0.28 to -0.001; P = .04). Interventions targeting improvements in lipid profile (AIP) may wish to promote adequate MVPA over CRF or decreased sedentary behavior. Copyright © 2016 National Lipid Association. Published by Elsevier Inc. All rights reserved.

Cardiorespiratory Fitness after Transient Ischemic Attack and Minor Ischemic Stroke : Baseline Data of the MoveIT Study

NARCIS (Netherlands)

Boss, H. Myrthe; Deijle, Inger A.; Van Schaik, Sander M.; de Melker, Edwin C.; van den Berg, Bob T.J.; Weinstein, Henry C.; Geerlings, Mirjam I.; Kappelle, L. Jaap; Van den Berg-Vos, Renske M.

2017-01-01

Background Cardiorespiratory fitness (CRF) is reduced in patients with stroke. It is unclear whether it is also reduced in patients with a transient ischemic attack (TIA) or minor stroke. We investigated the CRF in patients with a recent TIA or minor stroke and explored which determinants are

Evidence of the Role of Physical Activity and Cardiorespiratory Fitness in the Prevention of Coronary Heart Disease.

Science.gov (United States)

Leon, Arthur S.; Norstrom, Jane

1995-01-01

This paper presents epidemiologic evidence on the contributions of physical inactivity and reduced cardiorespiratory fitness to risk of coronary heart disease (CHD). The types and dose of physical activity to reduce risk of CHD and plausible biologic mechanisms for the partial protective effect are reviewed. (Author/SM)

The cardiorespiratory interaction: a nonlinear stochastic model and its synchronization properties

Science.gov (United States)

Bahraminasab, A.; Kenwright, D.; Stefanovska, A.; McClintock, P. V. E.

2007-06-01

We address the problem of interactions between the phase of cardiac and respiration oscillatory components. The coupling between these two quantities is experimentally investigated by the theory of stochastic Markovian processes. The so-called Markov analysis allows us to derive nonlinear stochastic equations for the reconstruction of the cardiorespiratory signals. The properties of these equations provide interesting new insights into the strength and direction of coupling which enable us to divide the couplings to two parts: deterministic and stochastic. It is shown that the synchronization behaviors of the reconstructed signals are statistically identical with original one.

Comfort food is comforting to those most stressed: evidence of the chronic stress response network in high stress women.

Science.gov (United States)

Tomiyama, A Janet; Dallman, Mary F; Epel, Elissa S

2011-11-01

Chronically stressed rodents who are allowed to eat calorie-dense "comfort" food develop greater mesenteric fat, which in turn dampens hypothalamic-pituitary-adrenocortical (HPA) axis activity. We tested whether similar relations exist in humans, at least cross-sectionally. Fifty-nine healthy premenopausal women were exposed to a standard laboratory stressor to examine HPA response to acute stress and underwent diurnal saliva sampling for basal cortisol and response to dexamethasone administration. Based on perceived stress scores, women were divided into extreme quartiles of low versus high stress categories. We found as hypothesized that the high stress group had significantly greater BMI and sagittal diameter, and reported greater emotional eating. In response to acute lab stressor, the high stress group showed a blunted cortisol response, lower diurnal cortisol levels, and greater suppression in response to dexamethasone. These cross-sectional findings support the animal model, which suggests that long-term adaptation to chronic stress in the face of dense calories result in greater visceral fat accumulation (via ingestion of calorie-dense food), which in turn modulates HPA axis response, resulting in lower cortisol levels. Copyright © 2011 Elsevier Ltd. All rights reserved.

Evidence for glutamatergic mechanisms in the vagal sensory pathway initiating cardiorespiratory reflexes in the shorthorn sculpin Myoxocephalus scorpius.

Science.gov (United States)

Sundin, L; Turesson, J; Taylor, E W

2003-03-01

Glutamate is a major neurotransmitter of chemoreceptor and baroreceptor afferent pathways in mammals and therefore plays a central role in the development of cardiorespiratory reflexes. In fish, the gills are the major sites of these receptors, and, consequently, the terminal field (sensory area) of their afferents (glossopharyngus and vagus) in the medulla must be an important site for the integration of chemoreceptor and baroreceptor signals. This investigation explored whether fish have glutamatergic mechanisms in the vagal sensory area (Xs) that could be involved in the generation of cardiorespiratory reflexes. The locations of the vagal sensory and motor (Xm) areas in the medulla were established by the orthograde and retrograde axonal transport of the neural tract tracer Fast Blue following its injection into the ganglion nodosum. Glutamate was then microinjected into identified sites within the Xs in an attempt to mimic chemoreceptor- and baroreceptor-induced reflexes commonly observed in fish. By necessity, the brain injections were performed on anaesthetised animals that were fixed by 'eye bars' in a recirculating water system. Blood pressure and heart rate were measured using an arterial cannula positioned in the afferent branchial artery of the 3rd gill arch, and ventilation was measured by impedance probes sutured onto the operculum. Unilateral injection of glutamate (40-100 nl, 10 mmol l(-1)) into the Xs caused marked cardiorespiratory changes. Injection (0.1-0.3 mm deep) in different rostrocaudal, medial-lateral positions induced a bradycardia, either increased or decreased blood pressure, ventilation frequency and amplitude and, sometimes, an initial apnea. Often these responses occurred simultaneously in various different combinations but, occasionally, they appeared singly, suggesting specific projections into the Xs for each cardiorespiratory variable and local determination of the modality of the response. Response patterns related to

Cardiorespiratory resistance profile in elderly women with overweight in SESC of Nova Friburgo/Rio de Janeiro/Brasil of Physical Activity Program

Directory of Open Access Journals (Sweden)

Helio Lemos Furtado

2008-03-01

Full Text Available The study objective was to investigate if one physical activity program promotes significant improvements in the cardiorespiratory capacity in elderly. They had participated of study 71 feminine elderly people, being divided in four groups in the respective age band: G1 (60-64 years old; n=29, G2 (65-69 years old; n=22, G3 (70-74 years old; n=11 and G4 (75-79 years old; n=09. The cardiorespiratory fitness was evaluated through the 6 minutes walked test (Rikli and Jones 1998. After that, for normality verification had been used the Shapiro-Wilk test, with significance level <0,05, was used program SPSS 10,0 for Windows. Analyzing the covered distance changeable, one got the following averages: G1=526 m, G2=509,7 m, G3=491,3 m and G4=479,4 m, can be concluded that the G1 did not only get its value inside of the reference band. Considering the possibility of not the specific of the prescription physical exercise for each age band presented by the studied groups, the physical activity program was capable to provide 60.5% elderly, a satisfactory profile for the cardio-respiratory resistance.

Cardiorespiratory resistance profile in elderly women with overweight in SESC of Nova Friburgo/Rio de Janeiro - Brasil of physical activity program

Directory of Open Access Journals (Sweden)

H.L. Furtado

2008-01-01

Full Text Available The study objective was to investigate if one physical activity program promotes significant improvements in the cardiorespiratory capacity in elderly. They had participated of study 71 feminine elderly people, being divided in four groups in the respective age band: : G1 (60-64 years old; n=29, G2 (65-69 years old; n=22, G3 (70-74 years old; n=11 e G4 (75-79 years old; n=09. The cardiorespiratory fitness was evaluated through the 6 minutes walked test (Rikli and Jones 1998. After that, for normality verification had been used the Shapiro-Wilk test, with significance level < 0,05, was used program SPSS 10,0 for Windows. Analyzing the covered distance changeable, one got the following averages: G1 = 526 m, G2 = 509,7m, G3 = 491,3 m and G4 = 479,4 m, can be concluded that the G1 did not only get its value inside of the reference band. Considering the possibility of not the specific of the prescription physical exercise for each age band presented by the studied groups, the physical activity program was capable to provide 60.5% elderly, a satisfactory profile for the cardio-respiratory resistance.

Ageing and cardiorespiratory response to hypoxia.

Science.gov (United States)

Lhuissier, François J; Canouï-Poitrine, Florence; Richalet, Jean-Paul

2012-11-01

The risk of severe altitude-induced diseases is related to ventilatory and cardiac responses to hypoxia and is dependent on sex, age and exercise training status. However, it remains unclear how ageing modifies these physiological adaptations to hypoxia. We assessed the physiological responses to hypoxia with ageing through a cross-sectional 20 year study including 4675 subjects (2789 men, 1886 women; 14-85 years old) and a longitudinal study including 30 subjects explored at a mean 10.4 year interval. The influence of sex, training status and menopause was evaluated. The hypoxia-induced desaturation and the ventilatory and cardiac responses to hypoxia at rest and exercise were measured. In men, ventilatory response to hypoxia increased (P ageing. Cardiac response to hypoxia was blunted with ageing in both sexes (P ageing. These adaptive responses were less pronounced or absent in post-menopausal women (P ageing in men while cardiac response is blunted with ageing in both sexes. Training aggravates desaturation at exercise in hypoxia, improves the ventilatory response and limits the ageing-induced blunting of cardiac response to hypoxia. Training limits the negative effects of menopause in cardiorespiratory adaptations to hypoxia.

SEDflume - High Shear Stress Flume

Data.gov (United States)

Federal Laboratory Consortium — The U.S. Army Corps of Engineers High Shear Stress flume (SEDflume) is designed for estimating erosion rates of fine-grained and mixed fine/coarse grained sediments...

Association between Cardiorespiratory Fitness and Lung Health from Young Adulthood to Middle Age.

Science.gov (United States)

Benck, Lillian R; Cuttica, Michael J; Colangelo, Laura A; Sidney, Stephen; Dransfield, Mark T; Mannino, David M; Jacobs, David R; Lewis, Cora E; Zhu, Na; Washko, George R; Liu, Kiang; Carnethon, Mercedes R; Kalhan, Ravi

2017-05-01

Beyond the risks of smoking, there are limited data on factors associated with change in lung function over time. To determine whether cardiorespiratory fitness was longitudinally associated with preservation of lung health. Prospective data were collected from 3,332 participants in the Coronary Artery Risk Development in Young Adults study aged 18-30 in 1985 who underwent treadmill exercise testing at baseline visit, and 2,735 participants with a second treadmill test 20 years later. The association between cardiorespiratory fitness and covariate adjusted decline in lung function was evaluated. Higher baseline fitness was associated with less decline in lung function. When adjusted for age, height, race-sex group, peak lung function, and years from peak lung function, each additional minute of treadmill duration was associated with 1.00 ml/yr less decline in FEV 1 (P fitness was associated with greater annual decline in lung function. Each 1-minute decline in treadmill duration between baseline and Year 20 was associated with 2.54 ml/yr greater decline in FEV 1 (P fitness over 20 years were associated with preservation of lung health. Greater cardiopulmonary fitness in young adulthood, less decline in fitness from young adulthood to middle age, and achieving increased fitness from young adulthood to middle age are associated with less decline in lung health over time. Clinical trial registered with www.clinicaltrials.gov (NCT 00005130).

Six months of dance intervention enhances postural, sensorimotor, and cognitive performance in elderly without affecting cardio-respiratory functions

Science.gov (United States)

Kattenstroth, Jan-Christoph; Kalisch, Tobias; Holt, Stephan; Tegenthoff, Martin; Dinse, Hubert R.

2013-01-01

During aging, sensorimotor, cognitive and physical performance decline, but can improve by training and exercise indicating that age-related changes are treatable. Dancing is increasingly used as an intervention because it combines many diverse features making it a promising neuroplasticity-inducing tool. We here investigated the effects of a 6-month dance class (1 h/week) on a group of healthy elderly individuals compared to a matched control group (CG). We performed a broad assessment covering cognition, intelligence, attention, reaction time, motor, tactile, and postural performance, as well as subjective well-being and cardio-respiratory performance. After 6 months, in the CG no changes, or further degradation of performance was found. In the dance group, beneficial effects were found for dance-related parameters such as posture and reaction times, but also for cognitive, tactile, motor performance, and subjective well-being. These effects developed without alterations in the cardio-respiratory performance. Correlation of baseline performance with the improvement following intervention revealed that those individuals, who benefitted most from the intervention, were those who showed the lowest performance prior to the intervention. Our findings corroborate previous observations that dancing evokes widespread positive effects. The pre-post design used in the present study implies that the efficacy of dance is most likely not based on a selection bias of particularly gifted individuals. The lack of changes of cardio-respiratory fitness indicates that even moderate levels of physical activity can in combination with rich sensorimotor, cognitive, social, and emotional challenges act to ameliorate a wide spectrum of age-related decline. PMID:23447455

Six months of dance intervention enhances postural, sensorimotor, and cognitive performance in elderly without affecting cardio-respiratory functions

Directory of Open Access Journals (Sweden)

Jan-Christoph eKattenstroth

2013-02-01

Full Text Available During aging, sensorimotor, cognitive and physical performance decline, but can improve by training and exercise indicating that age-related changes are treatable. Dancing is increasingly used as an intervention because it combines many diverse features making it a promising neuroplasticity-inducing tool. We here investigated the effects of a 6-months dance class (1 h/week on a group of healthy elderly individuals compared to a matched control group. We performed a broad assessment covering cognition, intelligence, attention, reaction time, motor, tactile, and postural performance, as well as subjective well-being and cardio-respiratory performance. After 6 months, in the control group no changes, or further degradation of performance was found. In the dance group, beneficial effects were found for dance-related parameters such as posture and reaction times, but also for cognitive, tactile, motor performance, and subjective well-being. These effects developed without alterations in the cardio-respiratory performance. Correlation of baseline performance with the improvement following intervention revealed that those individuals, who benefitted most from the intervention, were those who showed the lowest performance prior to the intervention. Our findings corroborate previous observations that dancing evokes widespread positive effects. The pre-post design used in the present study implies that the efficacy of dance is most likely not based on a selection bias of particularly gifted individuals. The lack of changes of cardio-respiratory fitness indicates that even moderate levels of physical activity can in combination with rich sensorimotor, cognitive, social, and emotional challenges act to ameliorate a wide spectrum of age-related decline.

Stress concentration effects in high pressure components

International Nuclear Information System (INIS)

Aller, J.E.

1990-01-01

This paper examines the stress concentration effects of sideholes in thick walled, high pressure cylinders. It has been shown that the theoretical stress concentration factor at the intersection of a small crossbore in a closed end, thick walled cylinder varies between 3.0 and 4.0. Tests have shown that this effect can be greatly reduced in practice by carefully radiusing the bore intersection and autofrettaging the cylinder. It has also been shown that the minimum stress concentration factor occurs when the main bore and sidehole or crossbore have the same diameter, and the radius of the intersection is approximately equal to the sidehole radius. When the bore and sidehole intersection angle decreases from 90 degrees, the stress concentration factor increases significantly. Knowledge of these fundamental relationships can be used in maintaining, as well ad designing, high pressure equipment

Cardiorespiratory Fitness and Body Composition of Soccer Referees; Do These Correlate With Proper Performance?

Science.gov (United States)

Mazaheri, Reza; Halabchi, Farzin; Seif Barghi, Tohid; Mansournia, Mohammad Ali

2016-03-01

The elite-level referee is exposed to similar physical demands to those placed on a midfield soccer player. They have an important responsibility to implement the rules of the game. So, good health and performance of soccer referees have a great importance. The purpose of this study was to assess the cardiorespiratory fitness and body composition of all 78 soccer referees officiating at the Iranian Premier League and determine the correlation between these parameters and performance. In a cross-sectional study, all referees selected for the competitions were enrolled. Participants underwent exercise stress test, pulmonary function test and body composition assessment. Then the weekly scores of each referee, assessed by qualified supervisors of national federation were obtained using the FIFA standard form throughout the season (34 weeks) and registered. Among 78 participants (including 32 center and 46 side referees), mean and standard deviation of age, body mass index, percent of body fat, VO2max and performance scores were 37 ± 3.8, 23.6 ± 2.1, 20.7 ± 3.9, 59.9 ± 7.1 and 85.8 ± 0.25, respectively. No significant correlation between referees' mean score and selected parameters were found. It seems that the acquired scores of top-class referees may be influenced by multiple factors other than the laboratory findings of cardiopulmonary fitness and body composition.

Adolescents' sleep in low-stress and high-stress (exam) times: a prospective quasi-experiment

NARCIS (Netherlands)

Dewald, J.F.; Meijer, A.M.; Oort, F.J.; Kerkhof, G.A.; Bögels, S.M.

2014-01-01

This prospective quasi-experiment (N=175; mean age: 15.14 years) investigates changes in adolescents' sleep from low-stress (regular school week) to high-stress times (exam week) and examines the (moderating) role of chronic sleep reduction, baseline stress, and gender. Sleep was monitored over

Adolescents' Sleep in Low-Stress and High-Stress (Exam) Times: A Prospective Quasi-Experiment

NARCIS (Netherlands)

Dewald, Julia F.; Meijer, Anne Marie; Oort, Frans J.; Kerkhof, Gerard A.; Bögels, Susan M.

2014-01-01

This prospective quasi-experiment (N = 175; mean age = 15.14 years) investigates changes in adolescents' sleep from low-stress (regular school week) to high-stress times (exam week), and examines the (moderating) role of chronic sleep reduction, baseline stress, and gender. Sleep was monitored over

Cardio-respiratory Physiology of the European Eel (em>Agunilla anguilla)em> in Extreme Environments

DEFF Research Database (Denmark)

Methling, Caroline

The main objective of this PhD thesis was to study the cardio-respiratory capabilities of the European eel (Anguilla anguilla) under extreme conditions. Three environmental conditions were studied i.e. temperature, dissolved oxygen and carbon dioxide, while a fourth condition was physiological an......), body wave speed (v) and Strouhal number (St). The results demonstrate that energy expenditure, swimming performance and efficiency all are significantly affected in migrating eels fitted with external tags....

Differential cardiorespiratory effects of endomorphin 1, endomorphin 2, DAMGO, and morphine.

Science.gov (United States)

Czapla, M A; Gozal, D; Alea, O A; Beckerman, R C; Zadina, J E

2000-09-01

The novel endogenous mu-opioid receptor (MOR) agonists endomorphin 1 (EM1) and 2 (EM2) were tested for their cardiorespiratory effects in conscious, freely behaving rats. After systemic (intravenous) administration of EM1, EM2, or the selective MOR agonist DAMGO, analgesia, minute ventilation (V E), heart rate (HR) and mean arterial blood pressure (BP) were measured. The threshold dose for analgesia was similar for all 3 peptides ( approximately 900 nmol/kg). All 3 compounds elicited biphasic V E responses, with marked, short-lived V E depressions (4-6 s) followed by more sustained V E increases (10-12 min). However, compared with responses elicited by EM2 or DAMGO, EM1 decreased V E only at higher doses, and produced greater V E stimulation. Morphine produced a V E decrease, but no subsequent V E increase. EM2 and DAMGO decreased HR and BP, while EM1 decreased HR, but did not decrease BP in conscious rats at doses up to 9,600 nmol/kg. In anesthetized rats, all 3 peptides decreased HR and BP. The decreases in V E, HR, and BP were blocked by the MOR antagonist, naloxone HCI (NIx). Only the HR and BP responses, however, were blocked by naloxone-methiodide (MeNIx), indicating central mediation of V E responses and peripheral mediation of cardiovascular responses. We conclude that MOR-selective compounds vary in their cardiorespiratory response characteristics which could be linked to differential cellular actions. The results support the concept that the analgesic, respiratory, and cardiovascular effects of MOR agonists can be dissociated and that EM1-like compounds could provide the basis for novel, safer analgesics.

The relative roles of external and internal CO(2) versus H(+) in eliciting the cardiorespiratory responses of Salmo salar and Squalus acanthias to hypercarbia.

Science.gov (United States)

Perry, S F; McKendry, J E

2001-11-01

Fish breathing hypercarbic water encounter externally elevated P(CO(2)) and proton levels ([H(+)]) and experience an associated internal respiratory acidosis, an elevation of blood P(CO(2)) and [H(+)]. The objective of the present study was to assess the potential relative contributions of CO(2) versus H(+) in promoting the cardiorespiratory responses of dogfish (Squalus acanthias) and Atlantic salmon (Salmo salar) to hypercarbia and to evaluate the relative contributions of externally versus internally oriented receptors in dogfish. In dogfish, the preferential stimulation of externally oriented branchial chemoreceptors using bolus injections (50 ml kg(-1)) of CO(2)-enriched (4 % CO(2)) sea water into the buccal cavity caused marked cardiorespiratory responses including bradycardia (-4.1+/-0.9 min(-1)), a reduction in cardiac output (-3.2+/-0.6 ml min(-1) kg(-1)), an increase in systemic vascular resistance (+0.3+/-0.2 mmHg ml min(-1) kg(-1)), arterial hypotension (-1.6+/-0.2 mmHg) and an increase in breathing amplitude (+0.3+/-0.09 mmHg) (means +/- S.E.M., N=9-11). Similar injections of CO(2)-free sea water acidified to the corresponding pH of the hypercarbic water (pH 6.3) did not significantly affect any of the measured cardiorespiratory variables (when compared with control injections). To preferentially stimulate putative internal CO(2)/H(+) chemoreceptors, hypercarbic saline (4 % CO(2)) was injected (2 ml kg(-1)) into the caudal vein. Apart from an increase in arterial blood pressure caused by volume loading, internally injected CO(2) was without effect on any measured variable. In salmon, injection of hypercarbic water into the buccal cavity caused a bradycardia (-13.9+/-3.8 min(-1)), a decrease in cardiac output (-5.3+/-1.2 ml min(-1) kg(-1)), an increase in systemic resistance (0.33+/-0.08 mmHg ml min(-1) kg(-1)) and increases in breathing frequency (9.7+/-2.2 min(-1)) and amplitude (1.2+/-0.2 mmHg) (means +/- S.E.M., N=8-12). Apart from a small increase

Sleep in High Stress Occupations

Science.gov (United States)

Flynn-Evans, Erin

2014-01-01

High stress occupations are associated with sleep restriction, circadian misalignment and demanding workload. This presentation will provide an overview of sleep duration, circadian misalignment and fatigue countermeasures and performance outcomes during spaceflight and commercial aviation.

Adaptation and survival of plants in high stress habitats via fungal endophyte conferred stress tolerance

Science.gov (United States)

Rodriguez, Rusty J.; Woodward, Claire; Redman, Regina S.

2010-01-01

From the Arctic to the Antarctic, plants thrive in diverse habitats that impose different levels of adaptive pressures depending on the type and degree of biotic and abiotic stresses inherent to each habitat (Stevens, 1989). At any particular location, the abundance and distribution of individual plant species vary tremendously and is theorized to be based on the ability to tolerate a wide range of edaphic conditions and habitat-specific stresses (Pianka, 1966). The ability of individual plant species to thrive in diverse habitats is commonly referred to as phenotypic plasticity and is thought to involve adaptations based on changes in the plant genome (Givnish, 2002; Pan et al., 2006; Robe and Griffiths, 2000; Schurr et al., 2006). Habitats that impose high levels of abiotic stress are typically colonized with fewer plant species compared to habitats imposing low levels of stress. Moreover, high stress habitats have decreased levels of plant abundance compared to low stress habitats even though these habitats may occur in close proximity to one another (Perelman et al., 2007). This is particularly interesting because all plants are known to perceive, transmit signals, and respond to abiotic stresses such as drought, heat, and salinity (Bartels and Sunkar, 2005; Bohnert et al., 1995). Although there has been extensive research performed to determine the genetic, molecular, and physiological bases of how plants respond to and tolerate stress, the nature of plant adaptation to high stress habitats remains unresolved (Leone et al., 2003; Maggio et al., 2003; Tuberosa et al., 2003). However, recent evidence indicates that a ubiquitous aspect of plant biology (fungal symbiosis) is involved in the adaptation and survival of at least some plants in high stress habitats (Rodriguez et al., 2008).

Cardiorespiratory benefits of group exercise among adults with serious mental illness.

Science.gov (United States)

Jerome, Gerald J; Young, Deborah Rohm; Dalcin, Arlene T; Wang, Nae-Yuh; Gennusa, Joseph; Goldsholl, Stacy; Appel, Lawrence J; Daumit, Gail L

2017-10-01

This study examined cardiorespiratory fitness (CRF) among adults with serious mental illness (SMI) participating in group exercise classes. Overweight and obese adults with SMI were randomized to either a control condition or a weight management condition with group exercise classes (n = 222). Submaximal bicycle ergometry was used to assess CRF at baseline, 6 and 18 months. Those with ≥ 66% participation in the exercise classes had a lower heart rate response at 6 and 18 month follow-up. Participation in group exercise classes was associated with improved short and long term cardiovascular fitness among adults with SMI. Copyright © 2017 Elsevier B.V. All rights reserved.

Cardiorespiratory fitness and TV viewing in relation to metabolic risk factors in Portuguese adolescents.

Science.gov (United States)

Mota, Jorge; Santos, Rute; Moreira, Carla; Martins, Clarice; Gaya, Anelise; Santos, Maria Paula; Ribeiro, José Carlos; Vale, Susana

2013-03-01

The purpose of this study was to examine whether adolescents who have high levels of cardiorespiratory fitness (CRF) co-existing with low levels of television (TV) viewing present a better metabolic risk profile compared to their low fit and high TV viewing counterparts. A total of 372 students (aged 12-15 years old) comprised the sample of this study. Anthropometric data (body mass index and waist circumference) was collected. CRF was calculated based upon the 20 metres shuttle run test. A questionnaire was used to estimate weekly TV viewing. Information about biological maturity and parental education was collected. Participants were then categorized into one of four category profiles according to the scores they achieved: low TV-Fit; high TV-Fit; low TV-Unfit and high TV-Unfit. Metabolic risk score (MRS) was calculated based on the sum of the Z-scores of all the metabolic variables analysed. Logistic regression analyses indicated that the high TV-Unfit group was almost 3-times more likely to be assigned to the high MRS group (OR = 2.85, 95% CI = 1.08-7.50) compared to their low TV-Fit group counterparts. The data showed that the high TV-Unfit group was associated with an increased metabolic risk in adolescents after adjustment for gender, age, biological maturity and parental education.

Cytokine Responses to Acute Exercise in Healthy Older Adults: The Effect of Cardiorespiratory Fitness

Directory of Open Access Journals (Sweden)

Mark T. Windsor

2018-03-01

Full Text Available Markers of chronic inflammation increase with aging, and are associated with cardiovascular disease prevalence and mortality. Increases in fitness with exercise training have been associated with lower circulating concentrations of cytokines known to have pro-inflammatory actions (such as interleukin-6 [IL-6] and higher circulating concentrations of anti-inflammatory cytokines (interleukin-10 [IL-10]. However, the effect of cardiorespiratory fitness on acute cytokine responses to a single bout of exercise in healthy older individuals is unknown. We compared the response of plasma cytokines IL-6, tumor necrosis factor-alpha (TNF-α and IL-10 to a bout of moderate-intensity continuous and higher-intensity interval exercise between older individuals with higher and lower levels of cardiorespiratory fitness. Sixteen lower-fit (VO2peak: 22.6±2.8 mL.kg−1.min−1 and fourteen higher-fit participants (VO2peak: 37.4±5.9 mL.kg−1.min−1 completed three 24 min experimental protocols in a randomized order: (1 moderate-intensity continuous exercise (40% of peak power output [PPO]; (2 higher-intensity interval exercise (12 × 1 min intervals at 70% PPO separated by 1 min periods at 10% PPO; or (3 non-exercise control. Plasma cytokines were measured at rest, immediately after, and during 90 min of recovery following exercise or control. Plasma IL-6 concentrations at baseline were greater in the higher-fit compared to the lower-fit group (P = 0.02, with no difference in plasma IL-10 or TNF-α concentrations at baseline between groups. Plasma IL-6 and IL-10 concentrations in both groups increased immediately after all protocols (IL-6: P = 0.02, IL-10: P < 0.01. However, there was no difference in the IL-6 and IL-10 response between the exercise and non-exercise (control protocols. After all protocols, no changes in plasma TNF-α concentrations were observed in either the higher- or lower-fit groups. In this study, basal concentrations of circulating IL-6

Cardiorespiratory fitness of a Brazilian regional sample distributed in different tables.

Science.gov (United States)

Belli, Karlyse Claudino; Callegaro, Carine C; Calegaro, Carine; Richter, Cleusa Maria; Klafke, Jonatas Zeni; Stein, Ricardo; Viecili, Paulo Ricardo Nazario

2012-09-01

Most classification tables of cardiorespiratory fitness (CRF) used in clinical practice are international and have not been validated for the Brazilian population. That can result in important discrepancies when that classification is extrapolated to our population. To assess the use of major CRF tables available in a Brazilian population sample of the Central High Plan of the state of Rio Grande do Sul (RS). This study assessed the retrospective data of 2,930 individuals, living in 36 cities of the Central High Plan of the state of RS, and considered the following: presence of risk factors for cardiovascular disease and estimated maximum oxygen consumption (VO2peak) values obtained through exercise test with Bruce protocol. To classify CRF, the individuals were distributed according to sex, inserted in their respective age groups in the Cooper, American Heart Association (AHA) and Universidade Federal de São Paulo (Unifesp) tables, and classified according to their VO2peak. Women had lower VO2peak values as compared with those of men (23.5 ± 8.5 vs. 31.7 ± 10.8 mL.kg-1.min-1, p Unifesp x AHA). Our findings indicate important discrepancy in the CRF classification levels of the tables assessed. Future studies could assess whether international tables could be used for the Brazilian population and populations of different regions of Brazil.

Identification of coupling direction: Application to cardiorespiratory interaction

Science.gov (United States)

Rosenblum, Michael G.; Cimponeriu, Laura; Bezerianos, Anastasios; Patzak, Andreas; Mrowka, Ralf

2002-04-01

We consider the problem of experimental detection of directionality of weak coupling between two self-sustained oscillators from bivariate data. We further develop the method introduced by Rosenblum and Pikovsky [Phys. Rev. E 64, 045202 (2001)], suggesting an alternative approach. Next, we consider another framework for identification of directionality, based on the idea of mutual predictability. Our algorithms provide directionality index that shows whether the coupling between the oscillators is unidirectional or bidirectional, and quantifies the asymmetry of bidirectional coupling. We demonstrate the efficiency of three different algorithms in determination of directionality index from short and noisy data. These techniques are then applied to analysis of cardiorespiratory interaction in healthy infants. The results reveal that the direction of coupling between cardiovascular and respiratory systems varies with the age within the first 6 months of life. We find a tendency to change from nearly symmetric bidirectional interaction to nearly unidirectional one (from respiration to the cardiovascular system).

Cardiorespiratory system monitoring using a developed acoustic sensor.

Science.gov (United States)

Abbasi-Kesbi, Reza; Valipour, Atefeh; Imani, Khadije

2018-02-01

This Letter proposes a wireless acoustic sensor for monitoring heartbeat and respiration rate based on phonocardiogram (PCG). The developed sensor comprises a processor, a transceiver which operates at industrial, scientific and medical band and the frequency of 2.54 GHz as well as two capacitor microphones which one for recording the heartbeat and another one for respiration rate. To evaluate the precision of the presented sensor in estimating heartbeat and respiration rate, the sensor is tested on the different volunteers and the obtained results are compared with a gold standard as a reference. The results reveal that root-mean-square error are determined sensor estimate sounds of [Formula: see text] to [Formula: see text] obtained PCG signal with sensitivity and specificity 98.1% and 98.3% in turn that make 3% improvement than previous works. The results prove that the sensor can be appropriate candidate for recognising abnormal condition in the cardiorespiratory system.

A high-temperature silicon-on-insulator stress sensor

International Nuclear Information System (INIS)

Wang Zheyao; Tian Kuo; Zhou Youzheng; Pan Liyang; Liu Litian; Hu Chaohong

2008-01-01

A piezoresistive stress sensor is developed using silicon-on-insulator (SOI) wafers and calibrated for stress measurement for high-temperature applications. The stress sensor consists of 'silicon-island-like' piezoresistor rosettes that are etched on the SOI layer. This eliminates leakage current and enables excellent electrical insulation at high temperature. To compensate for the measurement errors caused by the misalignment of the piezoresistor rosettes with respect to the crystallographic axes, an anisotropic micromachining technique, tetramethylammonium hydroxide etching, is employed to alleviate the misalignment issue. To realize temperature-compensated stress measurement, a planar diode is fabricated as a temperature sensor to decouple the temperature information from the piezoresistors, which are sensitive to both stress and temperature. Design, fabrication and calibration of the piezoresistors are given. SOI-related characteristics such as piezoresistive coefficients and temperature coefficients as well as the influence of the buried oxide layer are discussed in detail

The effect of Sub-maximal exercise-rehabilitation program on cardio-respiratory endurance indexes and oxygen pulse in patients with spastic cerebral palsy

Directory of Open Access Journals (Sweden)

M Izadi

2006-05-01

Full Text Available Background: Physical or cardio-respiratory fitness are of the best important physiological variables in children with cerebral palsy (CP, but the researches on exercise response of individuals with CP are limited. Our aim was to determine the effect of sub-maximal rehabilitation program (aerobic exercise on maximal oxygen uptake, oxygen pulse and cardio- respiratory physiological variables of children with moderate to severe spastic cerebral palsy diplegia and compare with able-bodied children. Methods: In a controlled clinical trial study, 15 children with diplegia spastic cerebral palsy, were recruited on a voluntarily basis (experimental group and 18 subjects without neurological impairments selected as control group. In CP group, aerobic exercise program performed on the average of exercise intensity (144 beat per minute of heart rate, 3 times a week for 3 months. The time of each exercise session was 20-25 minutes. Dependent variables were measured in before (pretest and after (post test of rehabilitation program through Mac Master Protocol on Tantories cycle ergometer in CP group and compared with the control group. Results: The oxygen pulse (VO2/HR during ergometery protocol was significantly lower in CP group than normal group (P<0.05. No significant statistical difference in maximal oxygen uptake (VO2 max was found between groups. The rehabilitation program leads to little increase of this variable in CP group. After sub-maximal exercise in pretest and post test, the heart rate of patient group was greater than control group, and aerobic exercise leads to significant decrease in heart rate in CP patients(P<0.05. Conclusion: The patients with spastic cerebral palsy, because of high muscle tone, severe spasticity and involuntarily movements have higher energy cost and lower aerobic fitness than normal people. The rehabilitation exercise program can improve physiological function of muscle and cardio-respiratory endurance in these

The effect on cardiorespiratory fitness after an 8-week period of commuter cycling - A randomized controlled study in adults

DEFF Research Database (Denmark)

Møller, Niels Christian; Østergaard, Lars; Gade, Jens Raaberg

2011-01-01

OBJECTIVE: This study investigated the effect of commuter cycling on cardiorespiratory fitness in men and women. Secondary outcomes included body fat and blood pressure measurements. METHODS: In February 2009, 48 volunteers from the Island of Funen, Denmark were randomly assigned to either "no ch...

Whole-Body High-Intensity Interval Training Induce Similar Cardiorespiratory Adaptations Compared With Traditional High-Intensity Interval Training and Moderate-Intensity Continuous Training in Healthy Men.

Science.gov (United States)

Schaun, Gustavo Z; Pinto, Stephanie S; Silva, Mariana R; Dolinski, Davi B; Alberton, Cristine L

2018-05-07

Schaun, GZ, Pinto, SS, Silva, MR, Dolinski, DB, and Alberton, CL. Sixteen weeks of whole-body high-intensity interval training induce similar cardiorespiratory responses compared with traditional high-intensity interval training and moderate-intensity continuous training in healthy men. J Strength Cond Res XX(X): 000-000, 2018-Low-volume high-intensity interval training (HIIT) protocols that use the body weight as resistance could be an interesting and inexpensive alternative to traditional ergometer-based high-intensity interval training (HIIT-T) and moderate-intensity continuous training (MICT). Therefore, our aim was to compare the effects of 16 weeks of whole-body HIIT (HIIT-WB), HIIT-T, and MICT on maximal oxygen uptake (V[Combining Dot Above]O2max), second ventilatory threshold (VT2), and running economy (RE) outcomes. Fifty-five healthy men (23.7 ± 0.7 years, 1.79 ± 0.01 m, 78.5 ± 1.7 kg) were randomized into 3 training groups (HIIT-T = 17; HIIT-WB = 19; MICT = 19) for 16 weeks (3× per week). The HIIT-T group performed eight 20-second bouts at 130% of the velocity associated to V[Combining Dot Above]O2max (vV[Combining Dot Above]O2max) interspersed by 10-second passive recovery on a treadmill, whereas HIIT-WB group performed the same protocol but used calisthenics exercises at an all-out intensity instead of treadmill running. Finally, MICT group exercised for 30 minutes at 90-95% of the heart rate (HR) associated to VT2. After the intervention, all groups improved V[Combining Dot Above]O2max, vV[Combining Dot Above]O2max, time to exhaustion (Tmax), VT2, velocity associated with VT2 (vVT2), and time to reach VT2 (tVT2) significantly (p HIIT-T compared with HIIT-WB (p HIIT-WB can be as effective as traditional HIIT while also being time-efficient compared with MICT to improve health-related outcomes after 16 weeks of training. However, HIIT-T and MICT seem preferable to enhance performance-related outcomes compared with HIIT-WB.

Cardiorespiratory fitness, pulmonary function and C-reactive protein levels in nonsmoking individuals with diabetes

International Nuclear Information System (INIS)

Francisco, C.O.; Catai, A.M.; Moura-Tonello, S.C.G.; Lopes, S.L.B.; Benze, B.G.; Del Vale, A.M.; Leal, A.M.O.

2014-01-01

The objective of this study was to evaluate cardiorespiratory fitness and pulmonary function and the relationship with metabolic variables and C-reactive protein (CRP) plasma levels in individuals with diabetes mellitus (DM). Nineteen men with diabetes and 19 age- and gender-matched control subjects were studied. All individuals were given incremental cardiopulmonary exercise and pulmonary function tests. In the exercise test, maximal workload (158.3±22.3 vs 135.1±25.2, P=0.005), peak heart rate (HR peak : 149±12 vs 139±10, P=0.009), peak oxygen uptake (VO 2peak : 24.2±3.2 vs 18.9±2.8, P<0.001), and anaerobic threshold (VO 2VT : 14.1±3.4 vs 12.2±2.2, P=0.04) were significantly lower in individuals with diabetes than in control subjects. Pulmonary function test parameters, blood pressure, lipid profile (triglycerides, HDL, LDL, and total cholesterol), and CRP plasma levels were not different in control subjects and individuals with DM. No correlations were observed between hemoglobin A1C (HbA1c), CRP and pulmonary function test and cardiopulmonary exercise test performance. In conclusion, the results demonstrate that nonsmoking individuals with DM have decreased cardiorespiratory fitness that is not correlated with resting pulmonary function parameters, HbA1c, and CRP plasma levels

Cardiorespiratory fitness, pulmonary function and C-reactive protein levels in nonsmoking individuals with diabetes

Energy Technology Data Exchange (ETDEWEB)

Francisco, C.O.; Catai, A.M.; Moura-Tonello, S.C.G. [Universidade Federal de São Carlos, Departamento de Fisioterapia, São Carlos, SP, Brasil, Departamento de Fisioterapia, Universidade Federal de São Carlos, São Carlos, SP (Brazil); Lopes, S.L.B. [Universidade Federal de São Carlos, Departamento de Medicina, São Carlos, SP, Brasil, Departamento de Medicina, Universidade Federal de São Carlos, São Carlos, SP (Brazil); Benze, B.G. [Universidade Federal de São Carlos, Departamento de Estatística, São Carlos, SP, Brasil, Departamento de Estatística, Universidade Federal de São Carlos, São Carlos, SP (Brazil); Del Vale, A.M.; Leal, A.M.O. [Universidade Federal de São Carlos, Departamento de Medicina, São Carlos, SP, Brasil, Departamento de Medicina, Universidade Federal de São Carlos, São Carlos, SP (Brazil)

2014-04-15

The objective of this study was to evaluate cardiorespiratory fitness and pulmonary function and the relationship with metabolic variables and C-reactive protein (CRP) plasma levels in individuals with diabetes mellitus (DM). Nineteen men with diabetes and 19 age- and gender-matched control subjects were studied. All individuals were given incremental cardiopulmonary exercise and pulmonary function tests. In the exercise test, maximal workload (158.3±22.3 vs 135.1±25.2, P=0.005), peak heart rate (HR{sub peak}: 149±12 vs 139±10, P=0.009), peak oxygen uptake (VO{sub 2peak}: 24.2±3.2 vs 18.9±2.8, P<0.001), and anaerobic threshold (VO{sub 2VT}: 14.1±3.4 vs 12.2±2.2, P=0.04) were significantly lower in individuals with diabetes than in control subjects. Pulmonary function test parameters, blood pressure, lipid profile (triglycerides, HDL, LDL, and total cholesterol), and CRP plasma levels were not different in control subjects and individuals with DM. No correlations were observed between hemoglobin A1C (HbA1c), CRP and pulmonary function test and cardiopulmonary exercise test performance. In conclusion, the results demonstrate that nonsmoking individuals with DM have decreased cardiorespiratory fitness that is not correlated with resting pulmonary function parameters, HbA1c, and CRP plasma levels.

Randomised controlled trial of informal team sports for cardiorespiratory fitness and health benefit in Pacific adults.

Science.gov (United States)

Biddle, Mark G; Vincent, Grace; McCambridge, Alana; Britton, Gabrielle; Dewes, Ofa; Elley, C Raina; Moyes, Simon A; Edge, Johann

2011-12-01

Rates of obesity, Type 2 diabetes and cardiovascular disease are high among Pacific people in New Zealand. Physical activity is recommended in the prevention and management of these conditions. Community-based, 'small-sided game' group activities may be an effective and culturally appropriate way to promote physical activity within Pacific communities. To assess the effectiveness of small-sided games-based exercise on fitness and health parameters among Pacific adults over four weeks. Twenty untrained (13 female) Pacific adults were randomised to intervention or control. Intervention participants were offered 45 minutes of small-sided games three times per week for four weeks. Control participants were offered one-month gym membership after the trial. Primary outcomes included cardiorespiratory fitness (VO₂peak) and leg strength (maximal concentric force of quadriceps at 60°/second) measured at baseline and four weeks. Secondary outcomes included glycaemia, lipid profile, blood pressure (BP), and inflammatory markers. Multivariable regression models were used to assess differences between groups, adjusting for baseline values, age and gender. At baseline, mean age was 34.8 years (SD 12.6), BMI 36.3 (6.7), systolic BP 127.7 mmHg (12.1), HbA1c 6.1% (1.9), VO₂peak 2.5 L/min (0.6) and leg strength 170.0 N.m (57.4). Sixteen participants completed the trial. Change in outcomes were greater in intervention than control participants in absolute VO₂peak (0.9 L/min (p=0.003)), leg strength (17.8 N.m (p=0.04)) and HDL (0.12 mmol/L (p=0.02)). There were no other significant differences. Small-sided games appear to be a promising means for improving the health and cardiorespiratory fitness and reducing the risk of diabetes and cardiovascular disease in Pacific adults.

Uma análise entre índices pressóricos, obesidade e capacidade cardiorrespiratória em escolares Comparison analysis of blood pressure, obesity, and cardio-respiratory fitness in schoolchildren

Directory of Open Access Journals (Sweden)

Miria Suzana Burgos

2010-06-01

diseases, especially obesity, hypertension, and diabetes mellitus. Early intervention can prevent the development of these complications. OBJECTIVE: To determine the presence of cardiovascular risk (obesity and hypertension in schoolchildren and its potential interactions with cardio-respiratory fitness. METHODS: This was a cross-sectional study conducted in a stratified cluster sample of 1,666 schoolchildren, aged between 7 and 17 years, 873 (52.4% of them male and 793 (47.6% of them female. The following variables were evaluated: systolic blood pressure (SBP, diastolic blood pressure (DBP, body mass index (BMI, body fat percentage (BF %, and cardio-respiratory fitness. SBP and DBP were correlated with waist circumference (WC, waist-hip ratio (WHR, sum of skin folds (ΣSF, and cardio-respiratory fitness. RESULTS: A BMI assessment of the students showed that 26.7% of them were overweight or obese, and 35.9% had body fat percentage over moderately high. As to blood pressure, we found that 13.9% and 12.1% of the students were borderline or hypertensive, for SBP and DBP, respectively. There was an association among hypertension, obesity, and cardio-respiratory fitness. There was a significant correlation of SBP and DBP with all variables, and also a weak to moderate correlation with age, weight, height, BMI, and waist circumference. CONCLUSION: The presence of hypertension associated with obesity and its effects on cardio-respiratory fitness stress the importance of recommending, since childhood, a more active and healthy lifestyle.

Cardiac reactivity and preserved performance under stress: two sides of the same coin?

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Pattyn, Nathalie; Mairesse, Olivier; Cortoos, Aisha; Morais, José; Soetens, Eric; Roelands, Bart; van den Nest, Annick; Kolinsky, Régine

2014-07-01

In the present experiment, cognitive control under stress was investigated using a real-life paradigm, namely an evaluation flight for military student pilots. The magnitude of cognitive interference on color-word, numerical and emotional Stroop paradigms was studied during a baseline recording and right before the test flight. Cardio-respiratory parameters were simultaneously assessed during rest and the performance of the Stroop tasks. Cognitive data suggested a different speed/accuracy trade-off under stress, and no modulation of the interference effect for color words or numerical stimuli. However, we observed a major increase in error rates for specific emotional stimuli related to the evaluation situation in the stress condition. The increase in cognitive interference from emotional stimuli, expressed as an increase in error rates, was correlated to the decreased cardiac reactivity to challenge in the stress situation. This relationship is discussed in the framework of Sanders' (1983) model of stress and performance. In terms of future research, this link warrants a fruitful lead to be followed for investigating the causal mechanism of performance decrements under the influence of stress. Copyright © 2013 Elsevier B.V. All rights reserved.

High-intensity interval training versus moderate-intensity continuous training within cardiac rehabilitation: a systematic review and meta-analysis.

Science.gov (United States)

Hannan, Amanda L; Hing, Wayne; Simas, Vini; Climstein, Mike; Coombes, Jeff S; Jayasinghe, Rohan; Byrnes, Joshua; Furness, James

2018-01-01

Aerobic capacity has been shown to be inversely proportionate to cardiovascular mortality and morbidity and there is growing evidence that high-intensity interval training (HIIT) appears to be more effective than moderate-intensity continuous training (MICT) in improving cardiorespiratory fitness within the cardiac population. Previously published systematic reviews in cardiovascular disease have neither investigated the effect that the number of weeks of intervention has on cardiorespiratory fitness changes, nor have adverse events been collated. We aimed to undertake a systematic review and meta-analysis of randomized controlled trials (RCTs) within the cardiac population that investigated cardiorespiratory fitness changes resulting from HIIT versus MICT and to collate adverse events. A critical narrative synthesis and meta-analysis was conducted after systematically searching relevant databases up to July 2017. We searched for RCTs that compared cardiorespiratory fitness changes resulting from HIIT versus MICT interventions within the cardiac population. Seventeen studies, involving 953 participants (465 for HIIT and 488 for MICT) were included in the analysis. HIIT was significantly superior to MICT in improving cardiorespiratory fitness overall (SMD 0.34 mL/kg/min; 95% confidence interval [CI; 0.2-0.48]; p HIIT intervention (n=9). However, some adverse events (n=5) were not classified by intervention group. HIIT is superior to MICT in improving cardiorespiratory fitness in participants of cardiac rehabilitation (CR). Improvements in cardiorespiratory fitness are significant for CR programs of >6-week duration. Programs of 7-12 weeks' duration resulted in the largest improvements in cardiorespiratory fitness for patients with coronary artery disease. HIIT appears to be as safe as MICT for CR participants.

High-intensity interval training versus moderate-intensity continuous training within cardiac rehabilitation: a systematic review and meta-analysis

Science.gov (United States)

Hannan, Amanda L; Hing, Wayne; Simas, Vini; Climstein, Mike; Coombes, Jeff S; Jayasinghe, Rohan; Byrnes, Joshua; Furness, James

2018-01-01

Background Aerobic capacity has been shown to be inversely proportionate to cardiovascular mortality and morbidity and there is growing evidence that high-intensity interval training (HIIT) appears to be more effective than moderate-intensity continuous training (MICT) in improving cardiorespiratory fitness within the cardiac population. Previously published systematic reviews in cardiovascular disease have neither investigated the effect that the number of weeks of intervention has on cardiorespiratory fitness changes, nor have adverse events been collated. Objective We aimed to undertake a systematic review and meta-analysis of randomized controlled trials (RCTs) within the cardiac population that investigated cardiorespiratory fitness changes resulting from HIIT versus MICT and to collate adverse events. Methods A critical narrative synthesis and meta-analysis was conducted after systematically searching relevant databases up to July 2017. We searched for RCTs that compared cardiorespiratory fitness changes resulting from HIIT versus MICT interventions within the cardiac population. Results Seventeen studies, involving 953 participants (465 for HIIT and 488 for MICT) were included in the analysis. HIIT was significantly superior to MICT in improving cardiorespiratory fitness overall (SMD 0.34 mL/kg/min; 95% confidence interval [CI; 0.2–0.48]; pHIIT intervention (n=9). However, some adverse events (n=5) were not classified by intervention group. Conclusion HIIT is superior to MICT in improving cardiorespiratory fitness in participants of cardiac rehabilitation (CR). Improvements in cardiorespiratory fitness are significant for CR programs of >6-week duration. Programs of 7–12 weeks’ duration resulted in the largest improvements in cardiorespiratory fitness for patients with coronary artery disease. HIIT appears to be as safe as MICT for CR participants. PMID:29416382

Effects of high mean stress on the high-cycle fatigue behavior of PWA 1480

International Nuclear Information System (INIS)

Majumdar, S.; Antolovich, S.; Milligan, W.

1985-03-01

PWA 1480 is a potential candidate material for use in the high-pressure fuel turbine blade of the Space Shuttle Main Engine. As an engine material it will be subjected to high-cycle fatigue loading superimposed on a high mean stress due to combined centrifugal and thermal loadings. This paper describes results obtained in an ongoing program to determine the effects of a high mean stress on the high-cycle fatigue behavior of this material

Maximal cardiorespiratory fitness testing in individuals with chronic stroke with cognitive impairment: practice test effects and test-retest reliability.

Science.gov (United States)

Olivier, Charles; Doré, Jean; Blanchet, Sophie; Brooks, Dina; Richards, Carol L; Martel, Guy; Robitaille, Nancy-Michelle; Maltais, Désirée B

2013-11-01

To evaluate, for individuals with chronic stroke with cognitive impairment, (1) the effects of a practice test on peak cardiorespiratory fitness test results; (2) cardiorespiratory fitness test-retest reliability; and (3) the relationship between individual practice test effects and cognitive impairment. Cross-sectional. Rehabilitation center. A convenience sample of 21 persons (men [n=12] and women [n=9]; age range, 48-81y; 44.9±36.2mo poststroke) with cognitive impairments who had sufficient lower limb function to perform the test. Not applicable. Peak oxygen consumption (Vo(2)peak, ml·kg(-1)·min(-1)). Test-retest reliability of Vo(2)peak was excellent (intraclass correlation coefficient model 2,1 [ICC2,1]=.94; 95% confidence interval [CI], .86-.98). A paired t test showed that there was no significant difference for the group for Vo(2)peak obtained from 2 symptom-limited cardiorespiratory fitness tests performed 1 week apart on a semirecumbent cycle ergometer (test 2-test 1 difference, -.32ml·kg(-1)·min(-1); 95% CI, -.69 to 1.33ml·kg(-1)·min(-1); P=.512). Individual test-retest differences in Vo(2)peak were, however, positively related to general cognitive function as measured by the Mini-Mental State Examination (ρ=.485; Preliably measured in this group without a practice test. General cognitive function, however, may influence the effect of a practice test in that those with lower general cognitive function appear to respond differently to a practice test than those with higher cognitive function. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

The Impact of Cardiorespiratory Fitness Levels on the Risk of Developing Atherogenic Dyslipidemia.

Science.gov (United States)

Breneman, Charity B; Polinski, Kristen; Sarzynski, Mark A; Lavie, Carl J; Kokkinos, Peter F; Ahmed, Ali; Sui, Xuemei

2016-10-01

Low cardiorespiratory fitness has been established as a risk factor for cardiovascular-related morbidity. However, research about the impact of fitness on lipid abnormalities, including atherogenic dyslipidemia, has produced mixed results. The purpose of this investigation is to examine the influence of baseline fitness and changes in fitness on the development of atherogenic dyslipidemia. All participants completed at least 3 comprehensive medical examinations performed by a physician that included a maximal treadmill test between 1976 and 2006 at the Cooper Clinic in Dallas, Texas. Atherogenic dyslipidemia was defined as a triad of lipid abnormalities: low high-density-lipoprotein cholesterol ([HDL-C] dyslipidemia during an average of 8.85 years of follow-up. High baseline fitness was protective against the development of atherogenic dyslipidemia in comparison with those with low fitness (odds ratio [OR] 0.57; 95% confidence interval [CI], 0.37-0.89); however, this relationship became nonsignificant after controlling for baseline HDL-C, LDL-C, and TG levels. Participants who maintained fitness over time had lower odds of developing atherogenic dyslipidemia than those with a reduction in fitness (OR 0.56; 95% CI, 0.34-0.91) after adjusting for baseline confounders and changes in known risk factors. High fitness at baseline and maintenance of fitness over time are protective against the development of atherogenic dyslipidemia. Copyright © 2016 Elsevier Inc. All rights reserved.

Into the pressure cooker: Student stress in college preparatory high schools.

Science.gov (United States)

Feld, Lauren D; Shusterman, Anna

2015-06-01

The goals of this study were to (1) measure psychological, physiological, and behavioral indicators of stress, (2) assess the relationship between stress and student attitudes, and (3) explore coping behaviors in response to stress, among a sample of students in two academically high-achieving environments. Three hundred thirty-three students in grades 9 through 12 from two college-preparatory high schools completed a cross-sectional online survey that included the Students' Life Satisfaction Scale, School Attitude Assessment Questionnaire-Revised, and assessments for stress-related indicators, including eating, sleeping and exercise, and strategies they utilized for coping with stress. Students reported a high prevalence of physical and psychological correlates of stress, and related unhealthy behaviors such as widespread and chronic sleep deprivation and rushed meals. The results suggest areas to focus attention for identifying and addressing maladaptive responses to stress among high-achieving student populations. Copyright © 2015 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Validity of a Newly-Designed Rectilinear Stepping Ergometer Submaximal Exercise Test to Assess Cardiorespiratory Fitness

OpenAIRE

Rubin Zhang, Likui Zhan, Shaoming Sun, Wei Peng, Yining Sun

2017-01-01

The maximum oxygen uptake (V̇O2 max), determined from graded maximal or submaximal exercise tests, is used to classify the cardiorespiratory fitness level of individuals. The purpose of this study was to examine the validity and reliability of the YMCA submaximal exercise test protocol performed on a newly-designed rectilinear stepping ergometer (RSE) that used up and down reciprocating vertical motion in place of conventional circular motion and giving precise measurement of workload, to det...

Effectiveness of a physical activity program on weight, physical fitness, occupational stress, job satisfaction and quality of life of overweight employees in high-tech industries: a randomized controlled study.

Science.gov (United States)

Fang, Yun-Ya; Huang, Chien-Yuan; Hsu, Mei-Chi

2018-03-27

This study aimed to examine the effectiveness of a physical activity (PA) program on weight control, physical fitness, occupational stress, job satisfaction and quality of life of overweight and sedentary employees in high-tech industries. Participants in the intervention group (n = 37) were instructed to carry out a PA program at moderate intensity for 60 min/session, 3 sessions/week for 12 weeks. Those in the control group (n = 38) received no PA program and were asked to continue their routine lifestyle. Evaluations were performed at baseline and at the end of the intervention. Results of structured questionnaires and blood biochemistry tests and evaluations of physical fitness were analyzed. The PA program effectively reduced the number of risk factors for metabolic syndrome and body fat percentage, and improved physical fitness such as flexibility, muscular strength and endurance and cardiorespiratory endurance. The intervention also significantly decreased levels of serum triglyceride, total cholesterol and low-density lipoprotein cholesterol. Significant positive effects on work control, interpersonal relationships at work, global job satisfaction and quality of life were also demonstrated. This study showed that a PA program can be helpful in improving physical, physiological and psychological outcomes for overweight and sedentary employees in high-tech industries.

A 12-month exercise intervention decreased stress symptoms and increased mental resources among working adults – Results perceived after a 12-month follow-up

Directory of Open Access Journals (Sweden)

Oili Kettunen

2015-02-01

Full Text Available Introduction This study evaluated the effect of a 12-month physical exercise intervention accompanied by a 12-month followup evaluating stress symptoms (SS, mental resources (MR and cardiorespiratory fitness (CRF in healthy, working adults. We hypothesized that the stress symptoms would decrease and mental resources would increase during the intervention and that these results are associated with changes in CRF. Material and methods The study group included healthy adults (N = 371. Three hundred thirty eight participants (212 women, 126 men were allocated in the exercise group and 33 in the control group (17 women and 16 men. For the analysis, the exercise group was divided into subgroups according to the baseline SS and MR. Stress symptoms and MR were measured using the Occupational Stress Questionnaire. Results During the 12-month exercise intervention, SS decreased by 16% (p < 0.0001, MR increased by 8% (p < 0.0001 and CRF increased by 7% (p < 0.0001 in the exercise group, while no changes occurred in the control group (ANCOVA, p < 0.01. In the exercise group, the results (SS, MR, and CRF remained improved during the follow-up. There was a positive correlation between the change in SS and the change in CRF (r = 0.19, p < 0.01. In the subgroup having the highest SS at baseline, SS during the intervention decreased most (26% (ANCOVA, p < 0.0001. Conclusions One year physical exercise intervention improved mental well-being among working adults and this was associated with an improvement in cardiorespiratory fitness. The positive changes remained after the 12-month follow-up.

The effect of aging and cardiorespiratory fitness on the lung diffusing capacity response to exercise in healthy humans.

Science.gov (United States)

Coffman, Kirsten E; Carlson, Alex R; Miller, Andrew D; Johnson, Bruce D; Taylor, Bryan J

2017-06-01

Aging is associated with deterioration in the structure and function of the pulmonary circulation. We characterized the lung diffusing capacity for carbon monoxide (DL CO ), alveolar-capillary membrane conductance (Dm CO ), and pulmonary-capillary blood volume (Vc) response to discontinuous incremental exercise at 25, 50, 75, and 90% of peak work (W peak ) in four groups: 1 ) Young [27 ± 3 yr, maximal oxygen consumption (V̇o 2max ): 110 ± 18% age predicted]; 2) Young Highly Fit (27 ± 3 yr, V̇o 2max : 147 ± 8% age predicted); 3 ) Old (69 ± 5 yr, V̇o 2max : 116 ± 13% age predicted); and 4 ) Old Highly Fit (65 ± 5 yr, V̇o 2max : 162 ± 18% age predicted). At rest and at 90% W peak , DL CO , Dm CO , and Vc were decreased with age. At 90% W peak , DL CO , Dm CO , and Vc were greater in Old Highly Fit vs. Old adults. The slope of the DL CO -cardiac output (Q̇) relationship from rest to end exercise at 90% W peak was not different between Young, Young Highly Fit, Old, and Old Highly Fit (1.35 vs. 1.44 vs. 1.10 vs. 1.35 ml CO ·mmHg -1 ·liter blood -1 , P = 0.388), with no evidence of a plateau in this relationship during exercise; this was also true for Dm CO -Q̇ and Vc-Q̇. V̇o 2max was positively correlated with 1 ) DL CO , Dm CO , and Vc at rest; and 2 ) the rest to end exercise change in DL CO , Dm CO , and Vc. In conclusion, these data suggest that despite the age-associated deterioration in the structure and function of the pulmonary circulation, expansion of the pulmonary capillary network does not become limited during exercise in healthy individuals regardless of age or cardiorespiratory fitness level. NEW & NOTEWORTHY Healthy aging is a crucial area of research. This article details how differences in age and cardiorespiratory fitness level affect lung diffusing capacity, particularly during high-intensity exercise. We conclude that highly fit older adults do not experience a limit in lung diffusing capacity during

Perspectives of Canadian Final-Year Physiotherapy Students on Cardiorespiratory Physiotherapy as a Career Choice

Science.gov (United States)

Araujo, Tamara; Romano, Julia Marie; Camp, Pat G.; Hall, Mark; Mathur, Sunita; Brooks, Dina

2016-01-01

Purpose: To investigate the opinions of final-year Canadian physiotherapy students of cardiorespiratory physiotherapy (CRP) and the factors influencing their decision about whether to pursue a career in CRP. Methods: A cross-sectional online survey was completed by final-year Master of Science of Physical Therapy students from three of the largest English-speaking physiotherapy schools in Canada. Results: A total of 120 students responded to the survey (overall response rate was 44%). Fifteen students (12.5%) responded that they were extremely or quite interested in specializing in CRP. The most common factors that positively influenced students' decision to consider specializing in CRP were job accessibility, potential salary, and experiences in the area, and the most common factors that negatively influenced their decision were the clinical aspects of the area, their experiences in the area, job accessibility, and the influence of others. The most common factors that positively influenced students' opinion of CRP were their clinical supervisor, educator, or lecturer; their own clinical experience; and evidence in the literature, and the most common factors that negatively influenced their opinion were their own clinical experience and their peers. Conclusion: Strategies focusing on increasing awareness of the role of physiotherapists in the care of patients with cardiorespiratory conditions, exposing students to the positive impact that physiotherapists have in this practice area, and good mentorship experiences may promote the attractiveness of this specialty. PMID:27909378

Cardiorespiratory interactions and blood flow generation during cardiac arrest and other states of low blood flow.

Science.gov (United States)

Sigurdsson, Gardar; Yannopoulos, Demetris; McKnite, Scott H; Lurie, Keith G

2003-06-01

Recent advances in cardiopulmonary resuscitation have shed light on the importance of cardiorespiratory interactions during shock and cardiac arrest. This review focuses on recently published studies that evaluate factors that determine preload during chest compression, methods that can augment preload, and the detrimental effects of hyperventilation and interrupting chest compressions. Refilling of the ventricles, so-called ventricular preload, is diminished during cardiovascular collapse and resuscitation from cardiac arrest. In light of the potential detrimental effects and challenges of large-volume fluid resuscitations, other methods have increasing importance. During cardiac arrest, active decompression of the chest and impedance of inspiratory airflow during the recoil of the chest work by increasing negative intrathoracic pressure and, hence, increase refilling of the ventricles and increase cardiac preload, with improvement in survival. Conversely, increased frequency of ventilation has detrimental effects on coronary perfusion pressure and survival rates in cardiac arrest and severe shock. Prolonged interruption of chest compressions for delivering single-rescuer ventilation or analyzing rhythm before shock delivery is associated with decreased survival rate. Cardiorespiratory interactions are of profound importance in states of cardiovascular collapse in which increased negative intrathoracic pressure during decompression of the chest has a favorable effect and increased intrathoracic pressure with ventilation has a detrimental effect on survival rate.

Higher cardio-respiratory fitness is associated with increased mental and physical quality of life in people with bipolar disorder: A controlled pilot study.

Science.gov (United States)

Vancampfort, Davy; Hagemann, Noemi; Wyckaert, Sabine; Rosenbaum, Simon; Stubbs, Brendon; Firth, Joseph; Schuch, Felipe B; Probst, Michel; Sienaert, Pascal

2017-10-01

The aim of this study was to investigate whether cardiorespiratory fitness among outpatients with bipolar disorder is associated with health related quality of life (HRQL) and explore differences versus healthy controls. Outpatients with bipolar disorder and healthy controls matched for age, sex and body mass index completed the 36-item Short Form Health Survey, the Positive-and-Negative-Affect-Schedule (PANAS), a maximal cardiorespiratory fitness test, and wore a Sensewear Armband to measure physical activity and sedentary behavior for eight days. Unpaired t-tests, Pearson correlations and backward regression analyses were performed. Outpatients with bipolar disorder (n = 20; 14♀; 47.9 ± 7.9 years) had a significantly lower physical and mental HRQL than healthy controls (n = 20; 14♀; 47.8 ± 7.6 years), a lower maximum oxygen uptake (VO 2 max) and were more sedentary. While no significant correlates were found for HRQL in controls, higher VO 2 max values and lower PANAS negative affect scores predicted better physical and mental HRQL in people with bipolar disorder. The final regression model explained 68% and 58% of the variability in physical and mental HRQL respectively. Cardiorespiratory fitness is associated with mental and physical HRQL among people with bipolar disorder. The current study offers novel targets for scientific investigation and clinical interventions to increase HRQL in people with bipolar disorder. Copyright © 2017 Elsevier B.V. All rights reserved.

Achieving high aspect ratio wrinkles by modifying material network stress.

Science.gov (United States)

Chen, Yu-Cheng; Wang, Yan; McCarthy, Thomas J; Crosby, Alfred J

2017-06-07

Wrinkle aspect ratio, or the amplitude divided by the wavelength, is hindered by strain localization transitions when an increasing global compressive stress is applied to synthetic material systems. However, many examples from living organisms show extremely high aspect ratios, such as gut villi and flower petals. We use three experimental approaches to demonstrate that these high aspect ratio structures can be achieved by modifying the network stress in the wrinkle substrate. We modify the wrinkle stress and effectively delay the strain localization transition, such as folding, to larger aspect ratios by using a zero-stress initial wavy substrate, creating a secondary network with post-curing, or using chemical stress relaxation materials. A wrinkle aspect ratio as high as 0.85, almost three times higher than common values of synthetic wrinkles, is achieved, and a quantitative framework is presented to provide understanding the different strategies and predictions for future investigations.

5-Hydroxytryptamine 1A/7 and 4alpha receptors differentially prevent opioid-induced inhibition of brain stem cardiorespiratory function.

Science.gov (United States)

Wang, Xin; Dergacheva, Olga; Kamendi, Harriet; Gorini, Christopher; Mendelowitz, David

2007-08-01

Opioids evoke respiratory depression, bradycardia, and reduced respiratory sinus arrhythmia, whereas serotonin (5-HT) agonists stimulate respiration and cardiorespiratory interactions. This study tested whether serotonin agonists can prevent the inhibitory effects of opioids on cardiorespiratory function. Spontaneous and rhythmic inspiratory-related activity and gamma-aminobutyric acid (GABA) neurotransmission to premotor parasympathetic cardioinhibitory neurons in the nucleus ambiguus were recorded simultaneously in an in vitro thick slice preparation. The mu-opioid agonist fentanyl inhibited respiratory frequency. The 5-hydroxytryptamine 1A/7 receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin increased respiratory frequency by itself and also prevented the fentanyl-induced respiratory depression. The 5-hydroxytryptamine 4alpha agonist BIMU-8 did not by itself change inspiratory activity but prevented the mu-opioid-mediated respiratory depression. Both spontaneous and inspiratory-evoked GABAergic neurotransmission to cardiac vagal neurons were inhibited by fentanyl. 8-Hydroxy-2-(di-n-propylamino)tetralin inhibited spontaneous but not inspiratory-evoked GABAergic activity to parasympathetic cardiac neurons. However, 8-hydroxy-2-(di-n-propylamino)tetralin differentially altered the opioid-mediated depression of inspiratory-evoked GABAergic activity but did not change the opioid-induced reduction in spontaneous GABAergic neurotransmission. In contrast, BIMU-8 did not alter GABAergic neurotransmission to cardiac vagal neurons by itself but prevented the fentanyl depression of both spontaneous and inspiratory-elicited GABAergic neurotransmission to cardiac vagal neurons. In the presence of tetrodotoxin, the inhibition of GABAergic inhibitory postsynaptic currents with fentanyl is prevented by coapplication of BIMU-8, indicating that BIMU-8 acts at presynaptic GABAergic terminals to prevent fentanyl-induced depression. These results suggest that activation of 5

Preliminary evidence that exercise dependence is associated with blunted cardiac and cortisol reactions to acute psychological stress.

Science.gov (United States)

Heaney, Jennifer L J; Ginty, Annie T; Carroll, Douglas; Phillips, Anna C

2011-02-01

Low or blunted cardiovascular and cortisol reactions to acute psychological stress have been shown to characterise those with a tobacco or alcohol dependency. The present study tested the hypothesis that exercise dependency would be similarly associated with blunted reactivity. Young female exercisers (N=219) were screened by questionnaire for exercise dependence. Ten women with probable exercise dependence and 10 non dependent controls were selected for laboratory stress testing. Cardiovascular activity and salivary cortisol were measured at rest and in response to a 10-min mental arithmetic stress task. The exercise dependent women showed blunted cardiac reactions to the stress task and blunted cortisol at 10, 20, and 30 minute post stress exposure. These effects could not be accounted for in terms of group differences in stress task performance, nor could the cardiac effects be attributed to group differences in cardio-respiratory fitness. It would seem that low stress reactivity is characteristic of a wide range of dependencies, and is not confined to substance dependence. Our results offer further support for the hypothesis that blunted stress reactivity may be a peripheral marker of a central motivational dysregulation. Copyright © 2010 Elsevier B.V. All rights reserved.

Cardiorespiratory demand and rate of perceived exertion during overground walking with a robotic exoskeleton in long-term manual wheelchair users with chronic spinal cord injury: A cross-sectional study.

Science.gov (United States)

Escalona, Manuel J; Brosseau, Rachel; Vermette, Martin; Comtois, Alain Steve; Duclos, Cyril; Aubertin-Leheudre, Mylène; Gagnon, Dany H

2018-07-01

Many wheelchair users adopt a sedentary lifestyle, which results in progressive physical deconditioning with increased risk of musculoskeletal, cardiovascular and endocrine/metabolic morbidity and mortality. Engaging in a walking program with an overground robotic exoskeleton may be an effective strategy for mitigating these potential negative health consequences and optimizing fitness in this population. However, additional research is warranted to inform the development of adapted physical activity programs incorporating this technology. To determine cardiorespiratory demands during sitting, standing and overground walking with a robotic exoskeleton and to verify whether such overground walking results in at least moderate-intensity physical exercise. We enrolled 13 long-term wheelchair users with complete motor spinal cord injury in a walking program with an overground robotic exoskeleton. Cardiorespiratory measures and rate of perceived exertion (RPE) were recorded by using a portable gas analyzer system during sitting, standing and four 10m walking tasks with the robotic exoskeleton. Each participant also performed an arm crank ergometer test to determine maximal cardiorespiratory ability (i.e., peak heart rate and O 2 uptake [HR peak , VO 2peak ]). Cardiorespiratory measures increased by a range of 9%-35% from sitting to standing and further increased by 22%-52% from standing to walking with the robotic exoskeleton. During walking, median oxygen cost (O 2Walking ), relative HR (%HR peak ), relative O 2 consumption (%VO 2peak ) and respiratory exchange ratio (RER) reached 0.29mL/kg/m, 82.9%, 41.8% and 0.9, respectively, whereas median RPE reached 3.2/10. O 2Walking was moderately influenced by total number of sessions and steps taken with the robotic exoskeleton since the start of the walking program. Overground walking with the robotic exoskeleton over a short distance allowed wheelchair users to achieve a moderate-intensity level of exercise. Hence, an

The Role of Perceived and Actual Motor Competency on Children's Physical Activity and Cardiorespiratory Fitness during Middle Childhood

Science.gov (United States)

Gu, Xiangli; Thomas, Katherine Thomas; Chen, Yu-Lin

2017-01-01

Purpose: Guided by Stodden et al.'s (2008) conceptual model, the purpose of this study was to examine the associations among perceived competence, actual motor competence (MC), physical activity (PA), and cardiorespiratory fitness in elementary children. The group differences were also investigated as a function of MC levels. Methods: A…

Grain Flow at High Stresses

Science.gov (United States)

McSaveney, M. J.

2015-12-01

The transport mechanism of rapid long-runout rock avalanches was a hotly debated topic when I came on the scene in 1967. So how come it is still debated today? My explanation is that it is the expected outcome of peer review, poor comprehension, and technological advances outpacing intellectual advances. Why think about the problem when we can model it! So let us think about the problem. Shreve thought that rock avalanches fell upon and trapped a layer of air. What physics was he thinking about? It is how feathers and tissue papers fall. When my rock avalanches fly, they fly like unlubricated bricks using the physics of projectiles and ballistics. But the main transport mechanism is not flight. The dominant impression from watching a rock avalanche in motion is of fluid flow, as Heim described it in 1882. A rock avalanche is a very large grain flow. Bagnold studied dispersive grain flows, but why should one assume that rock avalanches are dispersive grain flows as many do. The more common grain flow type is a dense grain flow and rock avalanches are dense grain flows in which the weight can and does generate very high stresses at grain contacts. Brittle rock deforms elastically up to its compressive strength, whereupon it breaks, releasing elastic strain as transient elastic strain (seismic energy to a seismologist, acoustic energy to a physicist). Melosh and others have shown that acoustic energy can fluidize a grain mass. There is no exotic physics behind grain flow at high stress. When grains break, the released elastic strain has to go somewhere, and it goes somewhere principally by transmission though grain contacts. Depending on the state of stress at the grain contact, the contact will pass the stress or will slip at conventional values of Coulomb friction. Enough thinking! A physical model of the entire process is too big for any laboratory. So whose numerical model will do it?

Friction & Wear Under Very High Electromagnetic Stress

National Research Council Canada - National Science Library

Cowan, Richard S; Danyluk, Steven; Moon, Francis; Ford, J. C; Brenner, Donald W

2004-01-01

This document summarizes initial progress toward advancing the fundamental understanding of the friction, wear and mechanics of interfaces subjected to extreme electromagnetic stress, high relative...

Internal Stresses in Wires for High Field Magnets

International Nuclear Information System (INIS)

Han, K.; Embury, J.D.; Lawson, A.C.; Von Dreele, R.B.; Wood, J.T.; Richardson, J.W. Jr.

1998-01-01

The codeformation of Cu-Ag or Cu-Nb composite wires used for high field magnets has a number of important microstructural consequences, including the production of very fine scale structures, the development of very high internal surface area to volume ratios during the drawing and the storage of defects at interphase interfaces. In addition, the fabrication and codeformation of phases which differ in crystal structure, thermal expansion, elastic modulus and lattice parameter lead to the development of short wavelength internal stresses. These internal stresses are measured by neutron diffraction and transmission electron microscopy as a function of the imposed drawing strain. The internal stresses lead to important changes in elastic plastic response which can be related to both magnet design and service life and these aspects will be described in detail

Cardiorespiratory Fitness and Adiposity as Determinants of Metabolic Health-Pooled Analysis of Two Twin Cohorts

DEFF Research Database (Denmark)

Jukarainen, Sakari; Holst, René; Dalgård, Christine

2017-01-01

Context: The joint effects of cardiorespiratory fitness (CRF) and body composition on metabolic health are not well known. Objective: To examine the associations of CRF, fat-free mass index (FFMI), and fat mass index (FMI) with metabolic health in individual twins and controlling for genetic...... and shared environmental effects by studying monozygotic intrapair differences. Design, Setting, and Participants: Two cross-sectional samples of healthy adult monozygotic and dizygotic twins were drawn from population-based Danish and Finnish national twin registries (n = 996 and n = 309). Main Measures...

Muscle strength, power and cardiorespiratory fitness are associated with bone mineral density in men aged 31-60 years

DEFF Research Database (Denmark)

Schwarz, Peter; Jørgensen, Niklas; Nielsen, Barbara

2014-01-01

BACKGROUND: Osteoporotic fractures represent a growing economical burden to society, not only because of fractures in women, but also because of an increasing number of fractures in men. AIMS: In this cross-sectional study we aimed to investigate the association of muscular and cardio-respiratory......BACKGROUND: Osteoporotic fractures represent a growing economical burden to society, not only because of fractures in women, but also because of an increasing number of fractures in men. AIMS: In this cross-sectional study we aimed to investigate the association of muscular and cardio......-respiratory fitness with BMD at the spine and hip in men. RESULTS: The association between independent variables maximal aerobic capacity (VO(2max)), leg power and hand grip strength, and dependent variables BMD at the spine and total hip was explored in a series of linear regression models successively adjusted.......011) with BMD at total hip. CONCLUSIONS: We found that cardiorespiratory fitness was associated with BMD in men. Furthermore, hand grip strength and leg power were associated with increasing BMD at the lumbar spine and total hip in men, respectively. Further prospective studies are needed to further investigate...

Adaption of cardio-respiratory balance during day-rest compared to deep sleep--an indicator for quality of life?

Science.gov (United States)

von Bonin, Dietrich; Grote, Vincent; Buri, Caroline; Cysarz, Dirk; Heusser, Peter; Moser, Max; Wolf, Ursula; Laederach, Kurt

2014-11-30

Heart rate and breathing rate fluctuations represent interacting physiological oscillations. These interactions are commonly studied using respiratory sinus arrhythmia (RSA) of heart rate variability (HRV) or analyzing cardiorespiratory synchronization. Earlier work has focused on a third type of relationship, the temporal ratio of respiration rate and heart rate (HRR). Each method seems to reveal a specific aspect of cardiorespiratory interaction and may be suitable for assessing states of arousal and relaxation of the organism. We used HRR in a study with 87 healthy subjects to determine the ability to relax during 5 day-resting periods in comparison to deep sleep relaxation. The degree to which a person during waking state could relax was compared to somatic complaints, health-related quality of life, anxiety and depression. Our results show, that HRR is barely connected to balance (LF/HF) in HRV, but significantly correlates to the perception of general health and mental well-being as well as to depression. If relaxation, as expressed in HRR, during day-resting is near to deep sleep relaxation, the subjects felt healthier, indicated better mental well-being and less depressive moods. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Cardiorespiratory Fitness Attenuates the Influence of Amyloid on Cognition.

Science.gov (United States)

Schultz, Stephanie A; Boots, Elizabeth A; Almeida, Rodrigo P; Oh, Jennifer M; Einerson, Jean; Korcarz, Claudia E; Edwards, Dorothy F; Koscik, Rebecca L; Dowling, Maritza N; Gallagher, Catherine L; Bendlin, Barbara B; Christian, Bradley T; Zetterberg, Henrik; Blennow, Kaj; Carlsson, Cynthia M; Asthana, Sanjay; Hermann, Bruce P; Sager, Mark A; Johnson, Sterling C; Stein, James H; Okonkwo, Ozioma C

2015-11-01

The aim of this study was to examine cross-sectionally whether higher cardiorespiratory fitness (CRF) might favorably modify amyloid-β (Aβ)-related decrements in cognition in a cohort of late-middle-aged adults at risk for Alzheimer's disease (AD). Sixty-nine enrollees in the Wisconsin Registry for Alzheimer's Prevention participated in this study. They completed a comprehensive neuropsychological exam, underwent 11C Pittsburgh Compound B (PiB)-PET imaging, and performed a graded treadmill exercise test to volitional exhaustion. Peak oxygen consumption (VO2peak) during the exercise test was used as the index of CRF. Forty-five participants also underwent lumbar puncture for collection of cerebrospinal fluid (CSF) samples, from which Aβ42 was immunoassayed. Covariate-adjusted regression analyses were used to test whether the association between Aβ and cognition was modified by CRF. There were significant VO2peak*PiB-PET interactions for Immediate Memory (p=.041) and Verbal Learning & Memory (p=.025). There were also significant VO2peak*CSF Aβ42 interactions for Immediate Memory (p<.001) and Verbal Learning & Memory (p<.001). Specifically, in the context of high Aβ burden, that is, increased PiB-PET binding or reduced CSF Aβ42, individuals with higher CRF exhibited significantly better cognition compared with individuals with lower CRF. In a late-middle-aged, at-risk cohort, higher CRF is associated with a diminution of Aβ-related effects on cognition. These findings suggest that exercise might play an important role in the prevention of AD.

Mining highly stressed areas, part 2.

CSIR Research Space (South Africa)

Johnson, R

1995-12-01

Full Text Available A questionnaire related to mining at great depth and in very high stress conditions has been completed with the assistance of mine rock mechanics personnel on over twenty mines in all mining districts, and covering all deep level mines...

Cardiorespiratory fitness and physical function in children with cancer from diagnosis throughout treatment

DEFF Research Database (Denmark)

Thorsteinsson, Troels; Larsen, Hanne Baekgaard; Schmiegelow, Kjeld

2017-01-01

treatment as well as the feasibility of physical activity intervention in the Rehabilitation including Social and Physical activity and Education in Children and Teenagers with Cancer study. PATIENTS AND METHODS: The study included children diagnosed from January 2013 to April 2016 with paediatric cancer...... programme with no dropouts. Strenuous physical exercise and physiological testing during paediatric cancer treatment was safe and feasible, with only five minor adverse events during the intervention. Cardiorespiratory fitness was significantly lower in children with cancer than norms for healthy age...... with cancer have significantly lower physical capacity and functionality than healthy age-matched norms. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov: NCT01772862....

Cardiorespiratory Fitness and Body Composition Responses to Different Intensities and Frequencies of Exercise Training in Colorectal Cancer Survivors.

Science.gov (United States)

Devin, James L; Jenkins, David G; Sax, Andrew T; Hughes, Gareth I; Aitken, Joanne F; Chambers, Suzanne K; Dunn, Jeffrey C; Bolam, Kate A; Skinner, Tina L

2018-06-01

Deteriorations in cardiorespiratory fitness (V˙o 2peak ) and body composition are associated with poor prognosis after colorectal cancer treatment. However, the optimal intensity and frequency of aerobic exercise training to improve these outcomes in colorectal cancer survivors is unknown. This trial compared 8 weeks of moderate-intensity continuous exercise (MICE; 50 minutes; 70% peak heart rate [HR peak ]; 24 sessions), with high-intensity interval exercise (HIIE; 4 × 4 minutes; 85%-95% HR peak ) at an equivalent (HIIE; 24 sessions) and tapered frequency (HIIE-T; 16 sessions) on V˙o 2peak and on lean and fat mass, measured at baseline, 4, 8, and 12 weeks. Increases in V˙o 2peak were significantly greater after both 4 (+3.0 mL·kg -1 ·min -1 , P = .008) and 8 (+2.3 mL·kg -1 ·min -1 , P = .049) weeks of HIIE compared to MICE. After 8 weeks, there was a significantly greater reduction in fat mass after HIIE compared to MICE (-0.7 kg, P = .038). Four weeks after training, the HIIE group maintained elevated V˙o 2peak (+3.3 mL·kg -1 ·min -1 , P = .006) and reduced fat mass (-0.7 kg, P = .045) compared to the MICE group, with V˙o 2peak in the HIIE-T also being superior to the MICE group (+2.8 mL·kg -1 ·min -1 , P = .013). Compared to MICE, HIIE promotes superior improvements and short-term maintenance of V˙o 2peak and fat mass improvements. HIIE training at a reduced frequency also promotes maintainable cardiorespiratory fitness improvements. In addition to promoting accelerated and superior benefits to the current aerobic exercise guidelines, HIIE promotes clinically relevant improvements even with a substantial reduction in exercise training and for a period after withdrawal. Copyright © 2018 Elsevier Inc. All rights reserved.

Level of physical activity, cardiorespiratory fitness and nutritional status of higher education institution servers

Directory of Open Access Journals (Sweden)

Leonardo Vidal Andreato

2017-04-01

Full Text Available Objective: to evaluate the level of physical activity, cardiorespiratory fitness and nutritional status of Brazilian higher education institution servers. Method: 134 public servants (80 men and 54 women were evaluated to estimate body mass index (BMI, waist circumference (WC, waist/hip ratio (WHR, aerobic fitness and blood pressure at rest. Results: most of the servers were classified as insufficiently active (62%. BMI results show a high prevalence of obesity (39% mild and 33% moderate. WC showed a prevalence of high (30% and very high risk (27%, and WHR showed a prevalence of high (28% or very high risk (12%. The ergometric test showed that 41% of the servers presented very poor (17% or poor (24% aerobic fitness and 23%, regular aerobic fitness. Considering blood pressure, 15% of the servers presented blood pressure considered as borderline and 30% considered as hypertension. No associations were found between physical condition (active or inactive with WC (χ2 = 3.4, p = 0.179, WHR (χ2 = 7.0, p = 0.073, aerobic fitness (χ2 = 4.3, p = 0.368 and blood pressure (χ2 = 2.9, p = 0.734. Although no association was observed between physical activity and BMI (χ2 = 7.6, p = 0.062, significance values (p < 0.07 suggested an association trend, with worse ratings for the sedentary group. Closing remarks: among higher education institution servers, there is high prevalence of physical inactivity, obesity and risk factors, and the majority of the sample had aerobic fitness below recommended levels.

Lack of effect of high-protein vs. high-carbohydrate meal intake on stress-related mood and eating behavior

Directory of Open Access Journals (Sweden)

Lemmens Sofie G

2011-12-01

Full Text Available Abstract Background Consumption of meals with different macronutrients, especially high in carbohydrates, may influence stress-related eating behavior. We aimed to investigate whether consumption of high-protein vs. high-carbohydrate meals influences stress-related mood, food reward, i.e. 'liking' and 'wanting', and post-meal energy intake. Methods Participants (n = 38, 19m/19f, age = 25 ± 9 y, BMI = 25.0 ± 3.3 kg/m2 came to the university four times, fasted, once for a stress session receiving a high-protein meal, once for a rest session receiving a high-protein meal, once for a stress session receiving a high-carbohydrate meal and once for a rest session receiving a high-carbohydrate meal (randomized cross-over design. The high-protein and high-carbohydrate test meals (energy percentage protein/carbohydrate/fat 65/5/30 vs. 6/64/30 matched for energy density (4 kJ/g and daily energy requirements (30%. Stress was induced using an ego-threatening test. Pre- and post-meal 'liking' and 'wanting' (for bread, filling, drinks, dessert, snacks, stationery (non-food alternative as control was measured by means of a computer test. Following the post-meal 'wanting' measurement, participants received and consumed their wanted food items (post-meal energy intake. Appetite profile (visual analogue scales, mood state (Profile Of Mood State and State Trait Anxiety Inventory questionnaires, and post-meal energy intake were measured. Results Participants showed increased feelings of depression and anxiety during stress (P Conclusions Consumption of a high-protein vs. high-carbohydrate meal appears to have limited impact on stress-related eating behavior. Only participants with high disinhibition showed decreased subsequent 'wanting' and energy intake during rest; this effect disappeared under stress. Acute stress overruled effects of consumption of high-protein foods. Trial registration The study was registered in the Dutch Trial Register (NTR1904. The

Evaluation of cardiorespiratory and biochemical effects of ketamine-propofol and guaifenesin-ketamine-xylazine anesthesia in donkeys (Equus asinus).

Science.gov (United States)

Molinaro Coelho, Cássia M; Duque Moreno, Juan C; Goulart, Daniel da S; Caetano, Leandro B; Soares, Lorena K; Coutinho, Gustavo H; Alves, Geraldo Es; da Silva, Luiz Antonio F

2014-11-01

To evaluate the cardiorespiratory and biochemical effects of ketamine-propofol (KP) or guaifenesin-ketamine-xylazine (GKX) anesthesia in donkeys. Prospective crossover trial. Eight healthy, standard donkeys, aged 10 ± 5 years and weighing 153 ± 23 kg. Donkeys were premedicated with 1.0 mg kg(-1) of xylazine (IV) in both treatments. Eight donkeys were administered ketamine (1.5 mg kg(-1)) and propofol (0.5 mg kg(-1) for induction, and anesthesia was maintained by constant rate infusion (CRI) of ketamine (0.05 mg kg(-1) minute(-1)) and propofol (0.15 mg kg(-1) minute(-1)) in the KP treatment. After 10 days, diazepam (0.05 mg kg(-1)) and ketamine (2.2 mg kg(-1)) were administered for induction, and anesthesia was maintained by a CRI (2.0 mL kg(-1) hour(-1)) of ketamine (2.0 mg mL(-1), xylazine (0.5 mg mL(-1)) and guaifenesin (50 mg mL(-1)) solution. Quality of anesthesia was assessed along with cardiorespiratory and biochemical measurements. Anesthetic induction took longer in GKX than in KP. The induction was considered good in 7/8 with KP and in 6/8 in GKX. Anesthetic recovery was classified as good in 7/8 animals in both treatments. Xylazine administration decreased heart rate (HR) in both treatments, but in KP the HR increased and was higher than GKX throughout the anesthetic period. Respiratory rate was higher in GKX than in KP. PaO(2) decreased significantly in both groups during the anesthetic period. Glucose concentrations [GLU] increased and rectal temperature and PCV decreased in both treatments. Arterial lactate [LAC] increased at recovery compared with all time points in KP. [GLU] and calcium were higher in GKX than in KP at recovery. These protocols induced significant hypoxemia but no other cardiorespiratory or metabolic changes. These protocols could be used to maintain anesthesia in donkeys, however, they were not tested in animals undergoing surgery. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia

Parenting stress and parent support among mothers with high and low education.

Science.gov (United States)

Parkes, Alison; Sweeting, Helen; Wight, Daniel

2015-12-01

Current theorizing and evidence suggest that parenting stress might be greater among parents from both low and high socioeconomic positions (SEP) compared with those from intermediate levels because of material hardship among parents of low SEP and employment demands among parents of high SEP. However, little is known about how this socioeconomic variation in stress relates to the support that parents receive. This study explored whether variation in maternal parenting stress in a population sample was associated with support deficits. To obtain a clearer understanding of support deficits among mothers of high and low education, we distinguished subgroups according to mothers' migrant and single-parent status. Participants were 5,865 mothers from the Growing Up in Scotland Study, who were interviewed when their children were 10 months old. Parenting stress was greater among mothers with either high or low education than among mothers with intermediate education, although it was highest for those with low education. Support deficits accounted for around 50% of higher stress among high- and low-educated groups. Less frequent grandparent contact mediated parenting stress among both high- and low-educated mothers, particularly migrants. Aside from this common feature, different aspects of support were relevant for high- compared with low-educated mothers. For high-educated mothers, reliance on formal childcare and less frequent support from friends mediated higher stress. Among low-educated mothers, smaller grandparent and friend networks and barriers to professional parent support mediated higher stress. Implications of differing support deficits are discussed. (c) 2015 APA, all rights reserved).

Effect of 11 months of yoga training on cardiorespiratory responses during the actual practice of Surya Namaskar

OpenAIRE

Sinha, Biswajit; Sinha, Tulika Dasgupta

2014-01-01

Background: Surya Namaskar (SN), a popular traditional Indian yogic practice, includes practicing 12 physical postures with alternate forward and backward bending movement of the body along with deep breathing maneuvers. The practice of SN has become popular among yoga practitioners and other fitness conscious people. The long-term effect of practicing SN and other yogic practices on cardiorespiratory responses during SN are lacking. Aim: The present study was conducted to study the effec...

High salt intake enhances swim stress-induced PVN vasopressin cell activation and active stress coping.

Science.gov (United States)

Mitchell, N C; Gilman, T L; Daws, L C; Toney, G M

2018-07-01

Stress contributes to many psychiatric disorders; however, responsivity to stressors can vary depending on previous or current stress exposure. Relatively innocuous heterotypic (differing in type) stressors can summate to result in exaggerated neuronal and behavioral responses. Here we investigated the ability of prior high dietary sodium chloride (salt) intake, a dehydrating osmotic stressor, to enhance neuronal and behavioral responses of mice to an acute psychogenic swim stress (SS). Further, we evaluated the contribution of the osmo-regulatory stress-related neuropeptide arginine vasopressin (VP) in the hypothalamic paraventricular nucleus (PVN), one of only a few brain regions that synthesize VP. The purpose of this study was to determine the impact of high dietary salt intake on responsivity to heterotypic stress and the potential contribution of VPergic-mediated neuronal activity on high salt-induced stress modulation, thereby providing insight into how dietary (homeostatic) and environmental (psychogenic) stressors might interact to facilitate psychiatric disorder vulnerability. Salt loading (SL) with 4% saline for 7 days was used to dehydrate and osmotically stress mice prior to exposure to an acute SS. Fluid intake and hematological measurements were taken to quantify osmotic dehydration, and serum corticosterone levels were measured to index stress axis activation. Immunohistochemistry (IHC) was used to stain for the immediate early gene product c-Fos to quantify effects of SL on SS-induced activation of neurons in the PVN and extended amygdala - brain regions that are synaptically connected and implicated in responding to osmotic stress and in modulation of SS behavior, respectively. Lastly, the role of VPergic PVN neurons and VP type 1 receptor (V1R) activity in the amygdala in mediating effects of SL on SS behavior was evaluated by quantifying c-Fos activation of VPergic PVN neurons and, in functional experiments, by nano-injecting the V1R selective

Oxidative stress and the high altitude environment

Directory of Open Access Journals (Sweden)

Jakub Krzeszowiak

2013-03-01

Full Text Available In the recent years there has been considerable interest in mountain sports, including mountaineering, owing to the general availability of climbing clothing and equipment as well trainings and professional literature. This raised a new question for the environmental and mountain medicine: Is mountaineering harmful to health? Potential hazards include the conditions existing in the alpine environment, i.e. lower atmospheric pressure leading to the development of hypobaric hypoxia, extreme physical effort, increased UV radiation, lack of access to fresh food, and mental stress. A reasonable measure of harmfulness of these factors is to determine the increase in the level of oxidative stress. Alpine environment can stimulate the antioxidant enzyme system but under specific circumstances it may exceed its capabilities with simultaneous consumption of low-molecular antioxidants resulting in increased generation of reactive oxygen species (ROS. This situation is referred to as oxidative stress. Rapid and uncontrolled proliferation of reactive oxygen species leads to a number of adverse changes, resulting in the above-average damage to the lipid structures of cell membranes (peroxidation, proteins (denaturation, and nucleic acids. Such situation within the human body cannot take place without resultant systemic consequences. This explains the malaise of people returning from high altitude and a marked decrease in their physical fitness. In addition, a theory is put forward that the increase in the level of oxidative stress is one of the factors responsible for the onset of acute mountain sickness (AMS. However, such statement requires further investigation because the currently available literature is inconclusive. This article presents the causes and effects of development of oxidative stress in the high mountains.

The Relationship between Selected Anthropometric Indices and Cardiorespiratory Fitness in Apparently Healthy Young Adults in a Nigerian Community

OpenAIRE

C. N. Ofiaeli; A. V. Egwuonwu; M. J. Nwankwo; Y. E. Ihegihu; U. P. Okonkwo

2017-01-01

Background and Aim: Cardiorespiratory fitness (CRF) is a useful tool for establishment of baseline fitness status and monitoring of physical activity level. Therefore, it may by extension serve as health risk index. However, studies that have determined the correlation between anthropometric indices and CRF in apparently healthy young adults is difficult to find in other to preempt preventive actions before pathology develops. Materials and Methods: Using a descriptive correlational resea...

Elevated level of serum triglyceride among high risk stress bank ...

African Journals Online (AJOL)

The objective of this study was to estimate lipid profile among high risk stress bank employees' correlated with heart disorders in Riyadh, Saudi Arabia. A total of 129 patients with high risk stress employees were involved in this study, which were divided into 69 males and 60 females between the age of 25 to 55 years.

Cardio-respiratory interactions and relocation of heartbeats within the respiratory cycle during spontaneous and paced breathing

International Nuclear Information System (INIS)

Lopes, T C; Beda, A; Granja-Filho, P C N; Jandre, F C; Giannella-Neto, A

2011-01-01

The capability of respiratory sinus arrhythmia (RSA) to generate privileged locations for the occurrence of R-peaks within the respiratory cycle has been questioned in recent works, challenging the hypothesis that RSA might play a role in improving pulmonary gas exchange. We assessed such a capability submitting healthy humans to spontaneous and paced breathing (SB and PB) protocols, estimating the fraction of beats occurring during inspiration, at low, medium, and high respiratory volumes, and during the first and second half of inspiration and expiration. Then, the same fractions were computed assuming a random uniform distribution of heartbeats, and the differences were compared. The results found are as follows: (1) during PB at 6 rpm, heartbeats redistribute toward inspiration; (2) during SB and PB at 12 rpm, heartbeats tend to cluster when respiratory volume is high; (3) since such redistributions are limited in magnitude, it is possible that its physiological relevance is marginal, for instance, in terms of within-cycle variations in lung perfusion; (4) two groups of subjects with considerably different levels of RSA showed similar redistribution of heartbeats, suggesting that this phenomenon might be an underlying effect of the overall cardio-respiratory interactions, and not directly of RSA

Cardiorespiratory phase synchronization during normal rest and inward-attention meditation.

Science.gov (United States)

Wu, Shr-Da; Lo, Pei-Chen

2010-06-11

The cardiac and respiratory systems can be viewed as two self-sustained oscillators with various interactions between them. In this study, the cardiorespiratory phase synchronization (CRPS) quantified by synchrogram was investigated to explore the phase synchronization between these two systems. The synchrogram scheme was applied to electrocardiogram (ECG) and respiration signals. Particular focus was the distinct cardiac-respiratory regulation phenomena intervened by inward-attention meditation and normal relaxation. Four synchronization parameters were measured: frequency ratio, lasting length, number of epochs, and total length. The results showed that normal rest resulted in much weaker CRPS. Statistical analysis reveals that the number of synchronous epochs and the total synchronization length significantly increase (p=0.024 and 0.034 respectively) during meditation. Furthermore, a predominance of 4:1 and 5:1 rhythm-ratio synchronizations was observed during meditation. Consequently, this study concludes that CRPS can be enhanced during meditation, compared with normal relaxation, and reveals a predominance of specific frequency ratios. Copyright (c) 2008 Elsevier Ireland Ltd. All rights reserved.

Psychological stress in high level sailors during competition

Directory of Open Access Journals (Sweden)

Luciana Segato

2010-09-01

Full Text Available The purpose of this work was to investigate the psychological stress present in elite sailors in a competition. Based on a descriptive field research, 31 elite sailors volunteered to participate. They answered the Perceived Stress Scale (Cohen & Williamson, 1988 and also specific questions on self-control, sources and strategies of coping. Data were analyzed by using descriptive and inferential (Student t test and Pearson's correlation statistics. These athletes revealed low and moderate scores (M = 20.00, DP = 6.83 of stress originated from both intrinsic (ship troubles, team disorders and extrinsic (study, working and training, family and financial problems sources. The group reported good stress control during competition through the use of cognitive (avoidance and somatic (listening music, resting/sleeping, talk to friends strategies. It is important that sailors are able to control and cope with high levels of psychological stress and to understand how to proceed when under unstable and unexpected situations that arise during competition.

Psychological stress in high level sailors during competition

Directory of Open Access Journals (Sweden)

L. Segato

2010-01-01

Full Text Available The purpose of this work was to investigate the psychological stress present in elite sailors in a competition. Based on a descriptive field research, 31 elite sailors volunteered to participate. They answered the Perceived Stress Scale (Cohen & Williamson, 1988 and also specific questions on self-control, sources and strategies of coping. Data were analyzed by using descriptive and inferential (Student t test and Pearson's correlation statistics. These athletes revealed low and moderate scores (M = 20.00, DP = 6.83 of stress originated from both intrinsic (ship troubles, team disorders and extrinsic (study, working and training, family and financial problems sources. The group reported good stress control during competition through the use of cognitive (avoidance and somatic (listening music, resting/sleeping, talk to friends strategies. It is important that sailors are able to control and cope with high levels of psychological stress and to understand how to proceed when under unstable and unexpected situations that arise during competition.

Association Between Cardiorespiratory Fitness and the Determinants of Glycemic Control Across the Entire Glucose Tolerance Continuum

DEFF Research Database (Denmark)

Solomon, Thomas P. J.; Malin, Steven K.; Karstoft, Kristian

2015-01-01

OBJECTIVE: Cardiorespiratory fitness (VO2max) is associated with glycemic control, yet the relationship between VO2max and the underlying determinants of glycemic control is less clear. Our aim was to determine whether VO2max is associated with insulin sensitivity, insulin secretion, and the disp...... fitness and compromised pancreatic β-cell compensation across the entire glucose tolerance continuum provides additional evidence highlighting the importance of fitness in protection against the onset of a fundamental pathophysiological event that leads to type 2 diabetes....

Fitness as a determinant of arterial stiffness in healthy adult men: a cross-sectional study.

Science.gov (United States)

Chung, Jinwook; Kim, Milyang; Jin, Youngsoo; Kim, Yonghwan; Hong, Jeeyoung

2018-01-01

Fitness is known to influence arterial stiffness. This study aimed to assess differences in cardiorespiratory endurance, muscular strength, and flexibility according to arterial stiffness, based on sex and age. We enrolled 1590 healthy adults (men: 1242, women: 348) who were free of metabolic syndrome. We measured cardiorespiratory endurance in an exercise stress test on a treadmill, muscular strength by a grip test, and flexibility by upper body forward-bends from a standing position. The brachial-ankle pulse wave velocity test was performed to measure arterial stiffness before the fitness test. Cluster analysis was performed to divide the patients into groups with low (Cluster 1) and high (Cluster 2) arterial stiffness. According to the k-cluster analysis results, Cluster 1 included 624 men and 180 women, and Cluster 2 included 618 men and 168 women. Men in the middle-aged group with low arterial stiffness demonstrated higher cardiorespiratory endurance, muscular strength, and flexibility than those with high arterial stiffness. Similarly, among men in the old-aged group, the cardiorespiratory endurance and muscular strength, but not flexibility, differed significantly according to arterial stiffness. Women in both clusters showed similar cardiorespiratory endurance, muscular strength, and flexibility regardless of their arterial stiffness. Among healthy adults, arterial stiffness was inversely associated with fitness in men but not in women. Therefore, fitness seems to be a determinant for arterial stiffness in men. Additionally, regular exercise should be recommended for middle-aged men to prevent arterial stiffness.

Mean stress effects on high-cycle fatigue of Alloy 718

International Nuclear Information System (INIS)

Korth, G.E.

1980-07-01

This report covers an investigation of the effects of tensile mean stress on the high-cycle fatigue properties of Alloy 718. Three test temperatures (24, 427, and 649 degree C) were employed, and there were tests in both strain and load control. Results were compared with three different models: linear Modified-Goodman, Peterson cubic, and stress-strain parameter. The linear Modified-Goodman model gave good correlation with actual test data for low and moderate mean stress values, but the stress-strain parameter showed excellent correlation over the entire range of possible mean stresses and therefore is recommended for predicting mean stress effects of Alloy 718. 13 refs., 12 figs

Cardiorespiratory fitness alters the influence of a polygenic risk score on biomarkers of AD.

Science.gov (United States)

Schultz, Stephanie A; Boots, Elizabeth A; Darst, Burcu F; Zetterberg, Henrik; Blennow, Kaj; Edwards, Dorothy F; Koscik, Rebecca L; Carlsson, Cynthia M; Gallagher, Catherine L; Bendlin, Barbara B; Asthana, Sanjay; Sager, Mark A; Hogan, Kirk J; Hermann, Bruce P; Cook, Dane B; Johnson, Sterling C; Engelman, Corinne D; Okonkwo, Ozioma C

2017-04-25

To examine whether a polygenic risk score (PRS) derived from APOE4, CLU, and ABCA7 is associated with CSF biomarkers of Alzheimer disease (AD) pathology and whether higher cardiorespiratory fitness (CRF) modifies the association between the PRS and CSF biomarkers. Ninety-five individuals from the Wisconsin Registry for Alzheimer's Prevention were included in these cross-sectional analyses. They were genotyped for APOE4 , CLU , and ABCA7 , from which a PRS was calculated for each participant. The participants underwent lumbar puncture for CSF collection. β-Amyloid 42 (Aβ 42 ), Aβ 40 , total tau (t-tau), and phosphorylated tau (p-tau) were quantified by immunoassays, and Aβ 42 /Aβ 40 and tau/Aβ 42 ratios were computed. CRF was estimated from a validated equation incorporating sex, age, body mass index, resting heart rate, and self-reported physical activity. Covariate-adjusted regression analyses were used to test for associations between the PRS and CSF biomarkers. In addition, by including a PRS×CRF term in the models, we examined whether these associations were modified by CRF. A higher PRS was associated with lower Aβ 42 /Aβ 40 ( p interactions for Aβ 42 /Aβ 40 ( p = 0.003), t-tau/Aβ 42 ( p = 0.003), and p-tau/Aβ 42 ( p = 0.001). Specifically, the association between the PRS and these CSF biomarkers was diminished in those with higher CRF. In a late-middle-aged cohort, CRF attenuates the adverse influence of genetic vulnerability on CSF biomarkers. These findings support the notion that increased cardiorespiratory fitness may be beneficial to those at increased genetic risk for AD. © 2017 American Academy of Neurology.

Phenome data - High-sugar stress - DGBY | LSDB Archive [Life Science Database Archive metadata

Lifescience Database Archive (English)

Full Text Available switchLanguage; BLAST Search Image Search Home About Archive Update History Data ...s.zip File size: 90KB File name: Original file: High-sugar_stress.xls File URL: ftp://ftp.biosciencedbc.jp/archive/dgby/LATEST/Hi... Center for Protein Sequences） About This Database Database Description Download License Update History of Thi...s Database Site Policy | Contact Us Phenome data - High-sugar stress - DGBY | LSDB Archive ... ...List Contact us DGBY Phenome data - High-sugar stress Data detail Data name Phenome data - High-sugar stress

The efficacy of unsupervised home-based exercise regimens in comparison to supervised laboratory-based exercise training upon cardio-respiratory health facets.

Science.gov (United States)

Blackwell, James; Atherton, Philip J; Smith, Kenneth; Doleman, Brett; Williams, John P; Lund, Jonathan N; Phillips, Bethan E

2017-09-01

Supervised high-intensity interval training (HIIT) can rapidly improve cardiorespiratory fitness (CRF). However, the effectiveness of time-efficient unsupervised home-based interventions is unknown. Eighteen volunteers completed either: laboratory-HIIT (L-HIIT); home-HIIT (H-HIIT) or home-isometric hand-grip training (H-IHGT). CRF improved significantly in L-HIIT and H-HIIT groups, with blood pressure improvements in the H-IHGT group only. H-HIIT offers a practical, time-efficient exercise mode to improve CRF, away from the laboratory environment. H-IHGT potentially provides a viable alternative to modify blood pressure in those unable to participate in whole-body exercise. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Cardiorespiratory parameters in draught horses before and after short term draught work pulling loads.

Science.gov (United States)

Pérez, R; Recabarren, S E; Mora, G; Jara, C; Quijada, G; Hetz, E

1992-04-01

In order to establish the relationship between draught force and cardiorespiratory responses to exercise heart rate (HR), respiratory rate (RR), arterial and venous blood gases, pH, hemoglobin concentration and temperature were measured in five draught horses during rest, immediately after exercise and 30 min post-exercise under field conditions. A wagon equipped with an odometer and a hydraulic dynamometer was used for measuring distance and draught force. The wagon was loaded with 946 kg for the low load, 1,979 kg for the medium load and 2,994 kg for the high load, and drawn for a distance of 1,500 m. Draught force and load weight were linearly related. The response of the draught horse to low and medium load exercise was characterized by a moderate increase in HR, RR and temperature with no significant changes in arterial blood gases and pH. An increase in HR, RR and temperature was observed, whereas no changes in arterial PO2 and increases in venous PO2 were noticed after high load exercise. Slight increase in venous lactic acid concentration as a result of high load exercise was observed, suggesting that some anaerobic work was performed. However this was insufficient to produce changes in blood pH. The increase in metabolic requirements during the three levels of draught exercise was associated with increases in arterial hemoglobin concentration and oxygen content of blood.

Cardiorespiratory fitness and body mass index values in 9-year-old rural Norwegian children

DEFF Research Database (Denmark)

Resaland, G K; Mamen, A; Anderssen, S A

2009-01-01

AIM: To describe cardiorespiratory fitness and body mass index (BMI) values in a representative population of 9-year-old Norwegian children in two rural communities and compare present values with previous findings. METHODS: Two hundred and fifty-nine 9-year-old children were invited, and 256......, children's BMI values seem to have increased substantially. This increase is most pronounced in girls. When assessing these differences using the PI, this increase is less marked. Comparing maximal oxygen uptake data with that in earlier Nordic studies, there is no evidence that fitness has declined among...... 9-year olds. However, the limitations of the few earlier studies make reliable comparisons difficult....

The discriminatory value of cardiorespiratory interactions in distinguishing awake from anaesthetised states: a randomised observational study.

Science.gov (United States)

Kenwright, D A; Bernjak, A; Draegni, T; Dzeroski, S; Entwistle, M; Horvat, M; Kvandal, P; Landsverk, S A; McClintock, P V E; Musizza, B; Petrovčič, J; Raeder, J; Sheppard, L W; Smith, A F; Stankovski, T; Stefanovska, A

2015-12-01

Depth of anaesthesia monitors usually analyse cerebral function with or without other physiological signals; non-invasive monitoring of the measured cardiorespiratory signals alone would offer a simple, practical alternative. We aimed to investigate whether such signals, analysed with novel, non-linear dynamic methods, would distinguish between the awake and anaesthetised states. We recorded ECG, respiration, skin temperature, pulse and skin conductivity before and during general anaesthesia in 27 subjects in good cardiovascular health, randomly allocated to receive propofol or sevoflurane. Mean values, variability and dynamic interactions were determined. Respiratory rate (p = 0.0002), skin conductivity (p = 0.03) and skin temperature (p = 0.00006) changed with sevoflurane, and skin temperature (p = 0.0005) with propofol. Pulse transit time increased by 17% with sevoflurane (p = 0.02) and 11% with propofol (p = 0.007). Sevoflurane reduced the wavelet energy of heart (p = 0.0004) and respiratory (p = 0.02) rate variability at all frequencies, whereas propofol decreased only the heart rate variability below 0.021 Hz (p cardiorespiratory synchronisation time was increased (p < 0.05). A classification analysis based on an optimal set of discriminatory parameters distinguished with 95% success between the awake and anaesthetised states. We suggest that these results can contribute to the design of new monitors of anaesthetic depth based on cardiovascular signals alone. © 2015 The Authors. Anaesthesia published by John Wiley & Sons Ltd on behalf of Association of Anaesthetists of Great Britain and Ireland.

Cardiorespiratory fitness: relationship with the immune system of adolescents

Directory of Open Access Journals (Sweden)

Anderson Zampier Ulbrich

2009-01-01

Full Text Available http://dx.doi.org/10.5007/1980-0037.2009v11n4p478 This work to investigate the relationship between cardiorespiratory fitness with count of cells in the immune system (IS in adolescents. The sample was composed by 102 boys (B and 131 (G girls (12 to 17 years-old. BMI was calculated and categorized (Cole et al. and absolute and relative VO2máx was obtained through the shuttle run test (Léger et al. and categorized according to Rodrigues et al. Maturation stage was assessing (Tanner. The cells of IS by leukogram was obtained. It was hypothesized (H that individuals with higher VO2máx could present a higher ratio of chances in the counting of cells in the SI. Was used frequency distribution, Student t test, ANOVAs one-way and binary logistic regression (p< 0.05. The overweight was demonstrated that 27.8% (B 13.2% (G. The values of VO2máx were between 29 to 59 ml.kg-1.min-1 and 25 to 53 ml.kg-1.min-1 to B and G, respectively. The average of IS cells differ between B and G, and in greater range in the: Leukocytes (B = 5697.1 cel.ml and G = 6496.9 cel.ml; t= 3,959 p = 0,000, Segmented (B= 3288,1 cel.ml and G= 4023,8 cel.ml; t= 4,145; p= 0,000, and neutrophils (B = 3306,9 cel.ml and G = 4101.2 cel.ml; t= 4,431 , p= 0,000 in G, while Eosinophils (B = 286.1 cel.ml and G = 211.1 cel.ml; t= 2,644; p= 0,009 had a higher count for B. There were differences between the maturational stages only between puberty stage and pos puberty for Leukocytes and Segmented in G. The analyses of relative VO2máx indicated the M with low cardiorespiratory fitness is 4,6; 2,76; 3,57 respectively have more chances of eosinophils, lymphocytes and monocytes below the 50th percentile, as well as to observe the absolute VO2máx, the R with regular fitness is 9,0; 5,16; 9,65 respectively have more chances of leukocytes, monocytes and neutrophils below the 50th percentile. The M showed that the regular fitness has 3.0 times more chances to have leukocytes and neutrophils below

The Effect of Tai Chi on Cardiorespiratory Fitness for Coronary Disease Rehabilitation: A Systematic Review and Meta-Analysis

Directory of Open Access Journals (Sweden)

Ying-li Yang

2018-01-01

Full Text Available Background: Tai Chi that originated in China as a martial art is an aerobic exercise with low-to-moderate intensity and may play a role in cardiac rehabilitation.Aim: To systematically review the effect of Tai Chi on cardiorespiratory fitness for coronary disease rehabilitation.Methods: We performed a search for Chinese and English studies in the following databases: PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Chinese Biomedical Literature Database, China Knowledge Resource Integrated Database, Wanfang Data, and China Science and Technology Journal Database. The search strategy included terms relating to or describing Tai Chi and coronary disease, and there were no exclusion criteria for other types of diseases or disorders. Further, bibliographies of the related published systematic reviews were also reviewed. The searches, data extraction, and risk of bias (ROB assessments were conducted by two independent investigators. Differences were resolved by consensus. RevMan 5.3.0 was used to analyze the study results. We used quantitative synthesis if the included studies were sufficiently homogeneous and performed subgroup analyses for studies with different control groups. To minimize bias in our findings, we used GRADEpro to grade the available evidence.Results: Five studies were enrolled—two randomized controlled trials (RCTs and three nonrandomized controlled trials (N-RCTs—that included 291 patients. All patients had coronary disease. ROB assessments showed a relatively high selection and detection bias. Meta-analyses showed that compared to other types of low- or moderate-intensity exercise, Tai Chi could significantly improve VO2max [MD = 4.71, 95% CI (3.58, 5.84, P < 0.00001], but it seemed less effective at improving VO2max as compared to high-intensity exercise. This difference, however, was not statistically significant [MD = −1.10, 95% CI (−2.46, 0.26, P = 0.11]. The GRADEpro showed a low level of the

Stress corrosion cracking of several high strength ferrous and nickel alloys

Science.gov (United States)

Nelson, E. E.

1971-01-01

The stress corrosion cracking resistance of several high strength ferrous and nickel base alloys has been determined in a sodium chloride solution. Results indicate that under these test conditions Multiphase MP35N, Unitemp L605, Inconel 718, Carpenter 20Cb and 20Cb-3 are highly resistant to stress corrosion cracking. AISI 410 and 431 stainless steels, 18 Ni maraging steel (250 grade) and AISI 4130 steel are susceptible to stress corrosion cracking under some conditions.

Physical activity energy expenditure vs cardiorespiratory fitness level in impaired glucose metabolism

DEFF Research Database (Denmark)

Lidegaard, Lærke P; Hansen, Anne-Louise Smidt; Johansen, Nanna B

2015-01-01

Aim/hypothesis: Little is known about the relative roles of physical activity energy expenditure (PAEE) and cardiorespiratory fitness (CRF) as determinants of glucose regulation. The aim of this study was to examine the associations of PAEE and CRF with markers of glucose metabolism, and to test...... the hypothesis that CRF modifies the association between PAEE and glucose metabolism. Methods: We analysed cross-sectional data from 755 adults from the Danish ADDITION-PRO study. On the basis of OGTT results, participants without known diabetes were classified as having normal glucose tolerance, isolated...... impaired fasting glycaemia (i-IFG), isolated impaired glucose tolerance (i-IGT), combined IFG + IGT or screen-detected diabetes mellitus. Markers of insulin sensitivity and beta cell function were determined. PAEE was measured using a combined heart rate and movement sensor. CRF (maximal oxygen uptake...

An Investigation of the Correlation among Sources of Stress, Perceived Stress, and Coping styles in High School Students

Directory of Open Access Journals (Sweden)

Farhadh Asghari

2016-07-01

Full Text Available Background and Objectives: Coping with stress is an important issue, especially in regard to source of stress and perceived stress in adolescence period. In this research, the correlation among stress sources, perceived stress, and coping styles was investigated in high school students. Methods: The present research was a descriptive correlational study. The research sample consisted of 575 high school students from the families of personnel of Bushehr University of Medical Sciences in education year 2014-15 who were selected by multistage cluster sampling method. Stress source scale, perceived stress scale and Tehran coping styles scale, were used for data collection. The data were analyzed using statistical methods, including Pearson correlation coefficient and multivariate regression analysis. Results: In this study, 50% of students had perceived stress higher than cut-off point. Stress sources of students were related to school and maturity. There was a positive correlation between problem-oriented coping style and perceived stress, and there was a negative and inverse correlation between problem-oriented coping style and stress related to school and maturity. There was a positive correlation between positive emotion-oriented coping style and perceived stress, but there was a negative and inverse correlation between problem-oriented coping style and stress related to school and maturity. There was no significant correlation between emotion-oriented coping style and stress related to school, maturity, family, and peers. There was a positive correlation between negative emotion-oriented coping style and stress related to school, maturity, and peers. Conclusion: According to the findings of this study, the level of correlation was not significant and no significant relationship could be found between the variables with this level of correlation. Therefore, it is suggested that more extensive researches be conducted on the relationship between

Machine Learning for High-Throughput Stress Phenotyping in Plants.

Science.gov (United States)

Singh, Arti; Ganapathysubramanian, Baskar; Singh, Asheesh Kumar; Sarkar, Soumik

2016-02-01

Advances in automated and high-throughput imaging technologies have resulted in a deluge of high-resolution images and sensor data of plants. However, extracting patterns and features from this large corpus of data requires the use of machine learning (ML) tools to enable data assimilation and feature identification for stress phenotyping. Four stages of the decision cycle in plant stress phenotyping and plant breeding activities where different ML approaches can be deployed are (i) identification, (ii) classification, (iii) quantification, and (iv) prediction (ICQP). We provide here a comprehensive overview and user-friendly taxonomy of ML tools to enable the plant community to correctly and easily apply the appropriate ML tools and best-practice guidelines for various biotic and abiotic stress traits. Copyright © 2015 Elsevier Ltd. All rights reserved.

A non-exercise prediction model for estimation of cardiorespiratory fitness in adults. DOI: http://dx.doi.org/10.5007/1980-0037.2012v14n3p287

Directory of Open Access Journals (Sweden)

Magnus Benetti

2012-05-01

Full Text Available The most accurate tool for assessment of cardiorespiratory fitness is cardiopulmonary exercise testing (CPET. However, CPET requires expensive equipment, trained technicians and time, which limits their use in population studies. In view of this issue, the present study aims to develop regression equations for predicting the cardiorespiratory fitness of adults using simple measurement variables. The study used data from 8,293 subjects, 5,291 male and 3,235 female (age range, 18 to 65 years. The sample was recruited in Florianopolis, Santa Catarina. To develop equations for prediction of peak oxygen uptake (VO2peak, the data associated were: fitness, age, body mass, height, resting heart rate, hypertension, diabetes, dyslipidemia and smoking. After statistical analyses, two equations for men and two for women were developed. The complete equations showed an adjusted R2 = 0.531 and a standard error of estimate (SEE = 7.15 ml-1∙kg-1∙min for men and R2 = 0.436 and SEE = 5.68 ml-1∙kg-1∙min for women. We conclude that the model developed for prediction of cardiorespiratory fitness is feasible and practical for prediction of VO2peak in epidemiological studies or when CPET cannot be performed.

Sickness Presenteeism Among Health Care Workers and the Effect of BMI, Cardiorespiratory Fitness, and Muscle Strength

DEFF Research Database (Denmark)

Christensen, Jeanette Reffstrup; Kongstad, Malte Bue; Sjøgaard, Gisela

2015-01-01

OBJECTIVES: The primary objective of this study was to assess the relationship between sickness presenteeism and body mass index (BMI), cardiorespiratory fitness (CRF), and maximal voluntary contraction (MVC). METHODS: Female health care workers (n = 139) were analyzed cross-sectional as well...... as longitudinal after 3 and 12-month follow-up. Sickness presenteeism was assessed as a summed score using validated questions from three questionnaires: Health and Work Performance Questionnaire, Work Ability Index, and Quantity and Quality Method. CRF was assessed by a maximal cycling test and MVC from four...

High-electric-field-stress-induced degradation of SiN passivated AlGaN/GaN high electron mobility transistors

International Nuclear Information System (INIS)

Wen-Ping, Gu; Huan-Tao, Duan; Jin-Yu, Ni; Yue, Hao; Jin-Cheng, Zhang; Qian, Feng; Xiao-Hua, Ma

2009-01-01

AlGaN/GaN high electron mobility transistors (HEMTs) are fabricated by employing SiN passivation, this paper investigates the degradation due to the high-electric-field stress. After the stress, a recoverable degradation has been found, consisting of the decrease of saturation drain current I Dsat , maximal transconductance g m , and the positive shift of threshold voltage V TH at high drain-source voltage V DS . The high-electric-field stress degrades the electric characteristics of AlGaN/GaN HEMTs because the high field increases the electron trapping at the surface and in AlGaN barrier layer. The SiN passivation of AlGaN/GaN HEMTs decreases the surface trapping and 2DEG depletion a little during the high-electric-field stress. After the hot carrier stress with V DS = 20 V and V GS = 0 V applied to the device for 10 4 sec, the SiN passivation decreases the stress-induced degradation of I Dsat from 36% to 30%. Both on-state and pulse-state stresses produce comparative decrease of I Dsat , which shows that although the passivation is effective in suppressing electron trapping in surface states, it does not protect the device from high-electric-field degradation in nature. So passivation in conjunction with other technological solutions like cap layer, prepassivation surface treatments, or field-plate gate to weaken high-electric-field degradation should be adopted. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Associations between air temperature and cardio-respiratory mortality in the urban area of Beijing, China: a time-series analysis

OpenAIRE

Liu, Liqun; Breitner, Susanne; Pan, Xiaochuan; Franck, Ulrich; Leitte, Arne Marian; Wiedensohler, Alfred; von Klot, Stephanie; Wichmann, H-Erich; Peters, Annette; Schneider, Alexandra

2011-01-01

Abstract Background Associations between air temperature and mortality have been consistently observed in Europe and the United States; however, there is a lack of studies for Asian countries. Our study investigated the association between air temperature and cardio-respiratory mortality in the urban area of Beijing, China. Methods Death counts for cardiovascular and respiratory diseases for adult residents (≥15 years), meteorological parameters and concentrations of particulate air pollution...

Overexpression of monoubiquitin improves photosynthesis in transgenic tobacco plants following high temperature stress.

Science.gov (United States)

Tian, Fengxia; Gong, Jiangfeng; Zhang, Jin; Feng, Yanan; Wang, Guokun; Guo, Qifang; Wang, Wei

2014-09-01

The ubiquitin/26S proteasome system (Ub/26S) is implicated in abiotic stress responses in plants. In this paper, transgenic tobacco plants overexpressing Ta-Ub2 from wheat were used to study the functions of Ub in the improvement of photosynthesis under high temperature (45°C) stress. We observed higher levels of Ub conjugates in transgenic plants under high temperature stress conditions compared to wild type (WT) as a result of the constitutive overexpression of Ta-Ub2, suggesting increased protein degradation by the 26S proteasome system under high temperature stress. Overexpressing Ub increased the photosynthetic rate (Pn) of transgenic tobacco plants, consistent with the improved ATPase activity in the thylakoid membrane and enhanced efficiency of PSII photochemistry. The higher D1 protein levels following high temperature stress in transgenic plants than WT were also observed. These findings imply that Ub may be involved in tolerance of photosynthesis to high temperature stress in plants. Compared with WT, the transgenic plants showed lower protein carbonylation and malondialdehyde (MDA) levels, less reactive oxygen species (ROS) accumulation, but higher antioxidant enzyme activity under high temperature stress. These findings suggest that the improved antioxidant capacity of transgenic plants may be one of the most important mechanisms underlying Ub-regulated high temperature tolerance. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Job Satisfaction, Stress and Coping Strategies among Moroccan High School Teachers.

Science.gov (United States)

Benmansour, Naima

1998-01-01

Studied job stress, job satisfaction, and coping strategies through self-report measures from 153 Moroccan high school teachers. Results show that 45% of the teachers were satisfied with their jobs, but over half reported high levels of stress, negatively correlated with job satisfaction. Factor analysis of 16 coping strategies produced four…

White Mountain Research Station: 25 years of high-altitude research. [organization and functions of test facility for high altitude research

Science.gov (United States)

Pace, N.

1973-01-01

The organization and functions of a test facility for conducting research projects at high altitudes are discussed. The projects conducted at the facility include the following: (1) bird physiology, (2) cardiorespiratory physiology, (3) endocrinological studies, (4) neurological studies, (5) metabolic studies, and (6) geological studies.

Associations between Objectively Measured Physical Activity, Cardiorespiratory Fitness and Risk Factors for Metabolic Syndrome in 12- to 15-Year-Old Tianjin City Children

Science.gov (United States)

Tan, Sijie; Wang, Jianxiong; Zhang, Yibing; Zhang, Chen

2015-01-01

Objective: The study aim was to explore associations between daily physical activity level, cardiorespiratory fitness and metabolic syndrome among Chinese children. Design: We conducted a school-based, cross-sectional study. Setting: Participants including 112 boys and 121 girls were recruited from three schools in the urban suburbs of Tianjin…

Stress analysis in high-temperature superconductors under pulsed field magnetization

Science.gov (United States)

Wu, Haowei; Yong, Huadong; Zhou, Youhe

2018-04-01

Bulk high-temperature superconductors (HTSs) have a high critical current density and can trap a large magnetic field. When bulk superconductors are magnetized by the pulsed field magnetization (PFM) technique, they are also subjected to a large electromagnetic stress, and the resulting thermal stress may cause cracking of the superconductor due to the brittle nature of the sample. In this paper, based on the H-formulation and the law of heat transfer, we can obtain the distributions of electromagnetic field and temperature, which are in qualitative agreement with experiment. After that, based on the dynamic equilibrium equations, the mechanical response of the bulk superconductor is determined. During the PFM process, the change in temperature has a dramatic effect on the radial and hoop stresses, and the maximum radial and hoop stress are 24.2 {{MPa}} and 22.6 {{MPa}}, respectively. The mechanical responses of a superconductor for different cases are also studied, such as the peak value of the applied field and the size of bulk superconductors. Finally, the stresses are also presented for different magnetization methods.

Cardiorespiratory responses of a dance session designed for older women: A cross sectional study.

Science.gov (United States)

Rodrigues-Krause, Josianne; Farinha, Juliano Boufleur; Ramis, Thiago Rozales; Boeno, Francesco Pinto; Dos Santos, Gabriela Cristina; Krause, Mauricio; Reischak-Oliveira, Alvaro

2018-06-04

Dancing has been increasingly used as a type of exercise intervention to improve cardiovascular fitness of older people. However, it is unclear which may be the exercise intensity of the dance sessions. To describe cardiorespiratory responses of a dance session for older women, and to identify intensity zones in relation to peak oxygen consumption (VO 2 peak), first and second ventilatory thresholds (VT1 and VT2). Ten women (66 ± 5 yrs., BMI 27 ± 4) were examined on three occasions: Familiarization, maximum effort and dance sessions. Incremental treadmill test: 5 km/h, 2% slope each min, until maximum effort. Dance class (60 min): warm-up (20 min), across-the-floor (10 min), choreography (15 min), show (10 min) and cool-down (5 min). Ventilatory parameters were measured continuously (breath-by-breath). VO 2 (mL·kg -1 ·min -1 ): Maximum effort: VO 2 peak (23.3 ± 4.3), VT1 (17.2 ± 3.5) and VT2 (20.9 ± 3.4). Dancing: warm-up (12.8 ± 2.4, ~55%VO 2 peak), across-the-floor (14.2 ± 2.4 ~62%VO 2 peak), choreography (14.6 ± 3.2 ~63%VO 2 peak) and show (16.1 ± 3.3, ~69% VO 2 peak). Show was similar to VT1. Cardiorespiratory demands of a dance class for older women are at low aerobic intensity. Show was similar to VT1, indicating that a dance class may be modulated to improve aerobic fitness, at least at initial stages of training. Copyright © 2018 Elsevier Inc. All rights reserved.

A novel approach for evaluating the effects of odor stimulation on dynamic cardiorespiratory functions.

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Eriko Kawai

Full Text Available We aimed to develop a novel method to quantitatively evaluate the effects of odor stimulation on cardiorespiratory functions over time, and to examine the potential usefulness of clinical aromatherapy. Eighteen subjects participated. Nine people were assigned to each of the two resting protocols. Protocol 1: After resting for 2 min in a sitting position breathing room air, the subject inhaled either air or air containing sweet marjoram essential oil from the Douglas bag for 6 min, Protocol 2: After resting for 5 min in a supine position, the subject inhaled the essential oil for 10 min, and then recovered for 10 min breathing room air. All subjects inhaled the essential oil through a face mask attached to one-way valve, and beat-to-beat heart rate (HR and arterial blood pressure (BP as well as breath-by-breath respiratory variables were continuously recorded. In both protocols, during fragrance inhalation of the essential oil, time-dependent decrease in mean BP and HR were observed (P<0.05. During post-inhalation recovery, the significant fragrance-induced bradycardic effect lasted at least 5 min (- 3.1 ± 3.9% vs. pre-inhalation baseline value, p<0.05. The mean BP response at the start of odor stimulation was approximated by a first-order exponential model. However, such fragrance-induced changes were not observed in the respiratory variables. We established a novel approach to quantitatively and accurately evaluate the effects of quantitative odor stimulation on dynamic cardiorespiratory functions, and the duration of the effect. This methodological approach may be useful for scientific evaluation of aromatherapy as an approach to integrated medicine, and the mechanisms of action of physiological effects in fragrance compounds.

Residual stress in a thick section high strength T-butt weld

International Nuclear Information System (INIS)

Pearce, S.V.; Linton, V.M.; Oliver, E.C.

2008-01-01

Residual stresses in a structure are generated as a result of the various fabrication and welding processes used to make the component. Being able to quantify these residual stresses is a key step in determining the continuing integrity of a structure in service. In this work, the residual stresses around a high strength, quenched and tempered steel T-butt web to curved plate weld have been measured using neutron strain scanning. The results show that the residual stresses near the weld were dominated by the welding residual stresses, while the stresses further from the weld were dominated by the bending residual stresses. The results suggest that the combination of welding-induced residual stress and significant pre-welding residual stress, as in the case of a thick bent section of plate can significantly alter the residual stress profile from that in a flat plate

Highly stressed carbon film coatings on silicon potential applications

CERN Multimedia

Sharda, T

2002-01-01

The fabrication of highly stressed and strongly adhered nanocrystalline diamond films on Si substrates is presented. A microwave plasma CVD method with controlled and continuous bias current density was used to grow the films. The stress/curvature of the films can be varied and controlled by altering the BCD. Potential applications for these films include particle physics and x-ray optics.

Effect of complex training on carbon monoxide, cardiorespiratory function, and body mass among college students at the initial stage of stopping smoking.

Science.gov (United States)

Kim, Seungsuk

2017-08-01

[Purpose] This study aimed to analyze the effects of complex training on carbon monoxide, cardiorespiratory function, and body mass among college students with the highest smoking rate among all age group. [Subjects and Methods] A total of 40 college students voluntarily participated in this study. All subjects smoked and were randomly divided into two groups: the experimental group (N=20) and the control group (N=20). The experimental group underwent complex training (30 min of training five times a week for 12 weeks) while the control group did not participate in such training. The complex training consisted of two parts: aerobic exercise (walking and running) and resistance exercise (weight training). [Results] Two-way ANOVA with repeated measures revealed significant interactions among CO, VO2max, HRmax, VEmax, body fat, and skeletal muscle mass, indicating that the changes were significantly different among groups. [Conclusion] A 12 week of complex physical exercise program would be an effective way to support a stop-smoking campaign as it quickly eliminates CO from the body and improves cardiorespiratory function and body condition.

The Relationship between Serum 25-Hydroxyvitamin D Concentration, Cardiorespiratory Fitness, and Insulin Resistance in Japanese Men

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Xiaomin Sun

2014-12-01

Full Text Available Here, we aim to investigate the independent and combined associations of serum 25-hydroxyvitamin D (25(OHD and cardiorespiratory fitness (CRF with glucose metabolism. Fasting blood samples of 107 men aged 40–79 years were analyzed for 25(OHD, glucose, insulin, glycated hemoglobin, and lipid profile. Homeostasis model assessment of insulin resistance index (HOMA-IR was calculated from the fasting concentrations of glucose and insulin. Visceral fat area (VFA was determined by magnetic resonance imaging and CRF by measuring maximal oxygen uptake. Median 25(OHD concentration was 36.3 nmol/L, while the prevalence of 25(OHD deficiency was 74.8%. Participants with high CRF had significantly lower HOMA-IR, glycated hemoglobin, and insulin values than participants with low CRF (p < 0.05. Higher 25(OHD concentration was strongly correlated with lower HOMA-IR and insulin values independent of VFA (p < 0.01 but significantly affected by CRF. In the high CRF group, participants with higher 25(OHD concentration had lower HOMA-IR values than participants with low 25(OHD concentration (p < 0.05. Higher 25(OHD and CRF are crucial for reducing insulin resistance regardless of abdominal fat. In addition, higher 25(OHD concentration may strengthen the effect of CRF on reducing insulin resistance in middle-aged and elderly Japanese men with high CRF.

Cardiorespiratory fitness and the metabolic syndrome: Roles of inflammation and abdominal obesity

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Wedell-Neergaard, Anne-Sophie; Krogh-Madsen, Rikke; Petersen, Gitte Lindved; Hansen, Åse Marie; Pedersen, Bente Klarlund; Lund, Rikke

2018-01-01

Objective Individuals with metabolic syndrome have increased risk of type 2 diabetes and cardiovascular disease. We aimed to test the hypothesis that a high level of cardiorespiratory fitness (CR-fitness), counteracts accumulation of visceral fat, decreases inflammation and lowers risk factors of the metabolic syndrome. Method The study sample included 1,293 Danes (age 49–52 years) who from 2009 to 2011 participated in the Copenhagen Aging and Midlife Biobank, including a questionnaire, physical tests, and blood samples. Multiple linear regression models were performed with CR-fitness as exposure and plasma levels of cytokines and high sensitive C-reactive protein as outcomes and measures of abdominal obesity were added to test if they explained the potential association. Similarly, multiple linear regression models were performed with CR-fitness as exposure and factors of the metabolic syndrome as outcomes and the potential explanation by inflammatory biomarkers were tested. All models were adjusted for the effect of age, sex, smoking, alcohol consumption, socio-economic status, and acute inflammatory events within the preceding two weeks. Results CR-fitness was inversely associated with high sensitive C-reactive protein, Interleukin (IL)-6, and IL-18, and directly associated with the anti-inflammatory cytokine IL-10, but not associated with tumor necrosis factor alpha, interferon gamma or IL-1β. Abdominal obesity could partly explain the significant associations. Moreover, CR-fitness was inversely associated with an overall metabolic syndrome score, as well as triglycerides, glycated haemoglobin A1c, systolic blood pressure, diastolic blood pressure and directly associated with high-density lipoprotein. Single inflammatory biomarkers and a combined inflammatory score partly explained these associations. Conclusion Data suggest that CR-fitness has anti-inflammatory effects that are partly explained by a reduction in abdominal obesity and a decrease in the

A tensile stage for high-stress low-strain fibre studies

DEFF Research Database (Denmark)

Pauw, Brian Richard; Vigild, Martin Etchells; Mortensen, Kell

2011-01-01

Determining the effects of stress on the internal structure of high-performance fibres may provide insight into their structure-property relationships. The deformation of voids inside a poly(p-phenylene terephthalamide) (PPTA) fibre upon application of stress is one such effect which may be obser...

Physical Activity, Sedentary Behaviours, and Cardiovascular Health: When Will Cardiorespiratory Fitness Become a Vital Sign?

Science.gov (United States)

Després, Jean-Pierre

2016-04-01

Although it is generally agreed upon that a physically active lifestyle and regular exercise are good for heart health, it is much less appreciated by the public that the prolonged hours of sedentary time resulting from sitting at work or screen time are also risk factors for cardiovascular outcomes and other cardiometabolic diseases. In this short narrative review, evidence is discussed and prudent recommendations are made in the context of the sedentary, affluent lifestyle that characterizes a large proportion of our population. It has become overwhelmingly clear that a sedentary lifestyle is a powerful risk factor for cardiovascular and other chronic diseases. In addition, vigorous physical activity and exercise is also associated with metabolic and cardiovascular adaptations that are compatible with cardiovascular health. In that regard, cardiorespiratory fitness, a reliable metric to assess the ability of the cardiovascular system to sustain prolonged physical work, has been shown to be the most powerful predictor of mortality and morbidity, way beyond classical cardiovascular disease (CVD) risk factors such as smoking, cholesterol, hypertension, and diabetes. On the basis of the evidence available, it is proposed that both dimensions of overall physical activity level (reducing sedentary time and performing regular physical activity or endurance type exercise) should be targeted to reduce CVD risk. Finally, because of the robust evidence that poor cardiorespiratory fitness is an independent risk factor for CVD and related mortality, it is proposed that this simple physiological metric should be incorporated as a vital sign in CVD risk factor evaluation and management. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Seasonal variation in objectively measured physical activity, sedentary time, cardio-respiratory fitness and sleep duration among 8–11 year-old Danish children: a repeated-measures study

DEFF Research Database (Denmark)

Hjorth, Mads F.; Chaput, Jean-Philippe; Michaelsen, Kim

2013-01-01

BACKGROUND: Understanding fluctuations in lifestyle indicators is important to identify relevant time periods to intervene in order to promote a healthy lifestyle; however, objective assessment of multiple lifestyle indicators has never been done using a repeated-measures design. The primary aim...... was, therefore, to examine between-season and within-week variation in physical activity, sedentary behaviour, cardio-respiratory fitness and sleep duration among 8–11 year-old children. METHODS: A total of 1021 children from nine Danish schools were invited to participate and 834 accepted. Due...... to missing data, 730 children were included in the current analytical sample. An accelerometer was worn for 7 days and 8 nights during autumn, winter and spring, from which physical activity, sedentary time and sleep duration were measured. Cardio-respiratory fitness was assessed using a 10-min intermittent...

Manual Development and Pilot Testing of a Mindfulness- and Acceptance-Based Intervention for Increasing Cardiorespiratory Fitness in Sedentary Adults

OpenAIRE

Martin, Emily Cecile

2012-01-01

The aim of this research project was to conduct a manual development study and an open clinical trial in order to demonstrate the feasibility and efficacy of a mindfulness and acceptance based intervention for increasing cardiorespiratory fitness (CRF) in sedentary adults through adherence to a fitness walking program. Development of the treatment manual followed a 3-phase process (literature review and initial draft preparation, expert review, draft revision) based on expert systems analysis...

Dealing Collectively with Critical Incident Stress Reactions in High Risk Work Environments

DEFF Research Database (Denmark)

Müller-Leonhardt, Alice; Strøbæk, Pernille Solveig; Vogt, joachim

2015-01-01

organisations. Indeed, we found that the CISM programme once integrated within the socio-cultural patterns of this specific working environment enhanced not only individual feelings of being supported but also organisational safety culture. Keywords: coping; safety culture; critical incident stress management......aim of this paper is to shift the representation of coping patterns within high risk occupations to an existential part of cultural pattern and social structure, which characterises high reliability organisations. Drawing upon the specific peer model of critical incident stress management (CISM......), in which qualified operational peers support colleagues who experienced critical incident stress, the paper discusses critical incident stress management in air traffic control. Our study revealed coping patterns that co-vary with the culture that the CISM programme fostered within this specific high...

Effects of High Mean Stress on High-cycle Fatigue Behavior of PWA 1480

Science.gov (United States)

Majumdar, S.; Antolovich, S. D.; Milligan, W. W.

1985-01-01

PWA 1480 is a potential candidate material for use in the high-pressure fuel turbine blade of the space shuttle main engine. As an engine material it will be subjected to high-cycle fatigue loading superimposed on a high mean stress due to combined centrifugal and thermal loadings. The present paper describes the results obtained in an ongoing program at the Argonne National Laboratory, sponsored by NASA Lewis, to determine the effects of a high mean stress on the high-cycle fatigue behavior of this material. Straight-gauge high-cycle fatigue specimens, 0.2 inch in diameter and with the specimen axis in the 001 direction, were supplied by NASA Lewis. The nominal room temperature yield and ultimate strength of the material were 146 and 154 ksi, respectively. Each specimen was polished with 1-micron diamond paste prior to testing. However, the surface of each specimen contained many pores, some of which were as large as 50 micron. In the initial tests, specimens were subjected to axial-strain-controlled cycles. However, very little cyclic plasticity was observed.

Analysis of the Residual Stresses in Helical Cylindrical Springs at High Temperature

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H. Sun

2015-01-01

Full Text Available Creep is one of the basic properties of materials, its speed significantly depends on the temperature. Helical cylindrical springs are widely used in the elements of heating systems. This results in necessity of taking into account the effect of temperature on the stress-strain state of the spring. The object of research is a helical cylindrical spring used at high temperatures. Under this condition the spring state stability should be ensured.The paper studies relaxation of stress state and generation of residual stresses. Calculations are carried out in ABAQUS environment. The purpose of this work is to discuss the law of relaxation and residual stress in the spring.This paper describes the basic creep theories of helical cylindrical spring material. The calculation formulas of shear stress relaxation for a fixed compression ratio are obtained. Distribution and character of stress contour lines in the cross section of spring are presented. The stress relaxation – time relationships are discussed. The approximate formula for calculating relaxation shear stresses in the cross section of helical springs is obtained.The paper investigates creep ratio and law of residual stress variation in the cross-section of spring at 650℃. Computer simulation in ABAQUS environment was used. Research presents a finite element model of the spring creep in the cross-section.The paper conducts analysis of the stress changes for the creep under constant load. Under constant load stresses are quickly decreased in the around area of cross-section and are increased in the centre, i.e. the maximum and minimum stresses come close with time. Research work shows the possibility for using the approximate formula to calculate the relaxation shear stress in the cross section of spring and can provide a theoretical basis for predicting the service life of spring at high temperatures.In research relaxation processes of stress state are studied. Finite element model is cre

Cardiorespiratory Fitness and Cognitive Function are Positively Related Among Participants with Mild and Subjective Cognitive Impairment.

Science.gov (United States)

Stuckenschneider, Tim; Askew, Christopher David; Rüdiger, Stefanie; Cristina Polidori, Maria; Abeln, Vera; Vogt, Tobias; Krome, Andreas; Olde Rikkert, Marcel; Lawlor, Brian; Schneider, Stefan

2018-01-01

By 2030, about 74 million people will be diagnosed with dementia, and many more will experience subjective (SCI) or mild cognitive impairment (MCI). As physical inactivity has been identified to be a strong modifiable risk factor for dementia, exercise and physical activity (PA) may be important parameters to predict the progression from MCI to dementia, but might also represent disease trajectory modifying strategies for SCI and MCI. A better understanding of the relationship between activity, fitness, and cognitive function across the spectrum of MCI and SCI would provide an insight into the potential utility of PA and fitness as early markers, and treatment targets to prevent cognitive decline. 121 participants were stratified into three groups, late MCI (LMCI), early MCI (EMCI), and SCI based on the Montreal Cognitive Assessment (MoCA). Cognitive function assessments also included the Trail Making Test A+B, and a verbal fluency test. PA levels were evaluated with an interviewer-administered questionnaire (LAPAQ) and an activity monitor. An incremental exercise test was performed to estimate cardiorespiratory fitness and to determine exercise capacity relative to population normative data. ANCOVA revealed that LMCI subjects had the lowest PA levels (LAPAQ, p = 0.018; activity monitor, p = 0.041), and the lowest exercise capacity in relation to normative values (p = 0.041). Moreover, a modest correlation between MoCA and cardiorespiratory fitness (r = 0.25; p cognitive impairment PA and exercise capacity might present a marker for the risk of further cognitive decline. This finding warrants further investigation using longitudinal cohort studies.

Prediction of cardiorespiratory fitness from self-reported data in elderly

Directory of Open Access Journals (Sweden)

Geraldo A Maranhao Neto

2017-12-01

Full Text Available Cardiorespiratory fitness (CRF is associated with several health outcomes. Some non-exercise equations are available for CRF estimation. However, little is known about the validation of these equations among elderly. The aim of this study was to exam the validity of non-exercise equations with self-reported information in elderly. Participants (n= 93 aged 60 to 91 years measured CRF using maximal cardiopulmonary exercise test. Five non-exercise equations were selected. Data included in the equations (age, sex, weight, height, body mass index, physical activity and smoking were self-reported. Coefficient of determination (R2 of linear regressions with laboratory-measured VO2 peak ranged from 0.04 to 0.64. The Bland-Altman plots showed higher agreement between achieved and predicted CRF obtained by Jackson and colleagues, and Wier and colleagues equations. On the other hand, the other equations showed lower agreement and overestimation. Our findings provide evidences that two non-exercise equations, previously developed, could be used on the prediction of CRF among elderly.

Low Cardiorespiratory Fitness in African Americans: A Health Disparity Risk Factor?

Science.gov (United States)

Swift, Damon L.; Staiano, Amanda E.; Johannsen, Neil M.; Lavie, Carl J.; Earnest, Conrad P.; Katzmarzyk, Peter T.; Blair, Steven N.; Newton, Robert L.; Church, Timothy S.

2013-01-01

Low cardiorespiratory fitness (CRF) is a well-established risk factor for all-cause and cardiovascular disease mortality. African Americans have higher rates of cardiovascular disease compared to their Caucasian counterparts. However, the extent to which lower CRF levels contribute to the excess risk in African Americans has not been fully explored. The purpose of this review is to: 1) explore the literature evaluating the relationship between CRF and mortality specifically in African American populations; and 2) critically evaluate the studies which have compared CRF between African American and Caucasians in epidemiological studies and clinical trials. We have further discussed several potential mechanisms that may contribute to the observation of lower CRF levels in African American compared to Caucasian adults including potential racial differences in physical activity levels, muscle fiber type distribution, and hemoglobin levels. If lower CRF is generally present in African Americans compared to Caucasians, and is of a clinically meaningful difference, this may represent an important public health concern. PMID:23982718

Dietary Fat, Sugar Consumption, and Cardiorespiratory Fitness in Patients With Heart Failure With Preserved Ejection Fraction

Directory of Open Access Journals (Sweden)

Salvatore Carbone, MS

2017-10-01

Full Text Available Heart failure with preserved ejection fraction (HFpEF is associated with obesity and, indirectly, with unhealthy diet. The role of dietary components in HFpEF is, however, largely unknown. In this study, the authors showed that in obese HFpEF patients, consumption of unsaturated fatty acids (UFA, was associated with better cardiorespiratory fitness, and UFA consumption correlated with better diastolic function and with greater fat-free mass. Similarly, mice fed with a high-fat diet rich in UFA and low in sugars had preserved myocardial function and reduced weight gain. Randomized clinical trials increasing dietary UFA consumption and reducing sugar consumption are warranted to confirm and expand our findings.

Persistent high job demands and reactivity to mental stress predict future ambulatory blood pressure.

Science.gov (United States)

Steptoe, A; Cropley, M

2000-05-01

To test the hypothesis that work stress (persistent high job demands over 1 year) in combination with high reactivity to mental stress predict ambulatory blood pressure. Assessment of cardiovascular responses to standardized behavioural tasks, job demands, and ambulatory blood pressure over a working day and evening after 12 months. We studied 81 school teachers (26 men, 55 women), 36 of whom experienced persistent high job demands over 1 year, while 45 reported lower job demands. Participants were divided on the basis of high and low job demands, and high and low systolic pressure reactions to an uncontrollable stress task. Blood pressure and concurrent physical activity were monitored using ambulatory apparatus from 0900 to 2230 h on a working day. Cardiovascular stress reactivity was associated with waist/hip ratio. Systolic and diastolic pressure during the working day were greater in high job demand participants who were stress reactive than in other groups, after adjustment for age, baseline blood pressure, body mass index and negative affectivity. The difference was not accounted for by variations in physical activity. Cardiovascular stress reactivity and sustained psychosocial stress may act in concert to increase cardiovascular risk in susceptible individuals.

Parenting stress and parent support among mothers with high and low education

OpenAIRE

Parkes, Alison; Sweeting, Helen; Wight, Daniel

2015-01-01

Current theorizing and evidence suggest that parenting stress might be greater among parents from both low and high socioeconomic positions (SEP) compared with those from intermediate levels because of material hardship among parents of low SEP and employment demands among parents of high SEP. However, little is known about how this socioeconomic variation in stress relates to the support that parents receive. This study explored whether variation in maternal parenting stress in a population ...

Response surface modeling of remifentanil-propofol interaction on cardiorespiratory control and bispectral index.

Science.gov (United States)

Nieuwenhuijs, Diederik J F; Olofsen, Erik; Romberg, Raymonda R; Sarton, Elise; Ward, Denham; Engbers, Frank; Vuyk, Jaap; Mooren, Rene; Teppema, Luc J; Dahan, Albert

2003-02-01

Since propofol and remifentanil are frequently combined for monitored anesthesia care, we examined the influence of the separate and combined administration of these agents on cardiorespiratory control and bispectral index in humans. The effect of steady-state concentrations of remifentanil and propofol was assessed in 22 healthy male volunteer subjects. For each subject, measurements were obtained from experiments using remifentanil alone, propofol alone, and remifentanil plus propofol (measured arterial blood concentration range: propofol studies, 0-2.6 microg/ml; remifentanil studies, 0-2.0 ng/ml). Respiratory experiments consisted of ventilatory responses to three to eight increases in end-tidal Pco2 (Petco2). Invasive blood pressure, heart rate, and bispectral index were monitored concurrently. The nature of interaction was assessed by response surface modeling using a population approach with NONMEM. Values are population estimate plus or minus standard error. A total of 94 responses were obtained at various drug combinations. When given separately, remifentanil and propofol depressed cardiorespiratory variables in a dose-dependent fashion (resting V(i) : 12.6 +/- 3.3% and 27.7 +/- 3.5% depression at 1 microg/ml propofol and 1 ng/ml remifentanil, respectively; V(i) at fixed Petco of 55 mmHg: 44.3 +/- 3.9% and 57.7 +/- 3.5% depression at 1 microg/ml propofol and 1 ng/ml remifentanil, respectively; blood pressure: 9.9 +/- 1.8% and 3.7 +/- 1.1% depression at 1 microg/ml propofol and 1 ng/ml remifentanil, respectively). When given in combination, their effect on respiration was synergistic (greatest synergy observed for resting V(i)). The effects of both drugs on heart rate and blood pressure were modest, with additive interactions when combined. Over the dose range studied, remifentanil had no effect on bispectral index even when combined with propofol (inert interaction). These data show dose-dependent effects on respiration at relatively low concentrations of

Academic stress levels were positively associated with sweet food consumption among Korean high-school students.

Science.gov (United States)

Kim, Yeonsoo; Yang, Hye Young; Kim, Ae-Jung; Lim, Yunsook

2013-01-01

The objectives of the present study were to identify the association among levels of persistent academic stress, appetite, and dietary habits and to determine the specific types of sweet foods consumed by Korean high-school students according to their academic stress levels. The study participants included 333 high-school students in the 10th to 12th grades in Kyunggi Province, Korea. The level of academic stress was scored with a 75-item academic stress scale and was categorized as high, medium, or low. A food-frequency questionnaire was used to measure the sugar intake from sweet foods. Korean high-school students with a high academic stress level had larger meals than the other students. Compared with students with low academic stress, the students with high academic stress had a higher frequency of sugar intake from the following food types: confectionaries, candies and chocolates, breads, and flavored milk. Moreover, compared with students with low academic stress, the students with high academic stress had a higher total intake of sugar from the following food types: confectionaries, candies, chocolates, flavored milk, traditional Korean beverages, and spicy, sweet, and fried rice cakes. Unhealthy stress-related food choices may compromise high-school students' health and contribute to their morbidity. The findings of the present study could be used to help nutritionists develop effective strategies for nutritional education and counseling to improve adolescent health. Copyright © 2013 Elsevier Inc. All rights reserved.

Associations between sports participation, levels of moderate to vigorous physical activity and cardiorespiratory fitness in childrenand adolescents

DEFF Research Database (Denmark)

Silva, Gustavo; Andersen, Lars Bo; Aires, Luisa

2013-01-01

Abstract The purpose of this study was to analyse the associations between sports participation, levels of moderate to vigorous physical activity (MVPA) and cardiorespiratory fitness (CRF). The study comprised 310 participants (183 girls and 127 boys) aged 11-18 years. Sports participation...... was assessed by questionnaire and habitual physical activity (PA) was measured objectively with accelerometers. The 20-m shuttle-run test was used to estimate CRF. Logistic regression analyses were carried out with CRF as the outcome. The odds ratio (OR) for being fit was greater for those who comply with60min...

Effects of cardiorespiratory fitness and weight status on knowledge of physical activity and fitness, attitude toward physical education, and physical activity.

Science.gov (United States)

Chen, Senlin; Gu, Xiangli

2018-02-20

The purpose of this study was to examine the effects of cardiorespiratory fitness and weight status on knowledge of physical activity and fitness (PAF knowledge), attitude toward physical education (PE), and physical activity. A total of 343 middle school students participated in the study (Age: M/SD = 12.76/.94, ranging from 11 to 14 years old). PE Metrics™ was used to measure PAF knowledge, and Attitude toward Physical Education Questionnaire and Youth Activity Profile were used to measure attitude, physical activity and sedentary behavior. Fitness and weight status were assessed using FitnessGram and converted to in Healthy Fitness Zone (HFZ) or Not in HFZ. Two-way multivariate analyses of covariance (MANCOVA; gender and grade as covariates) showed a significant group effect for cardiorespiratory fitness (Λ Pilla  = .07, F 4,255  = 5.03, p = .001, [Formula: see text] = .07) but not for weight status (p = .57). PAF knowledge (F 1,258  = 9.49, p fitness in middle school PE as students acquire attitude, knowledge, and behaviors needed for active-living.

Cardiorespiratory fitness and physical function in children with cancer from diagnosis throughout treatment

DEFF Research Database (Denmark)

Thorsteinsson, Troels; Larsen, Hanne Bækgaard; Schmiegelow, Kjeld

2017-01-01

Background: Children with cancer experience severe reductions in physical fitness and functionality during and following intensive treatment. This may negatively impact their quality of life. Purpose: To describe the physical capacity and functionality of children with cancer during and after...... treatment as well as the feasibility of physical activity intervention in the Rehabilitation including Social and Physical activity and Education in Children and Teenagers with Cancer study. Patients and methods: The study included children diagnosed from January 2013 to April 2016 with paediatric cancer...... or Langerhans cell histiocytosis, all treated with chemotherapy. Seventy-five of 78 consecutively eligible children (96.2%) were included. Median age was 11 years (range 6‒18). The physical capacity and function were assessed based on testing of physical strength, balance and cardiorespiratory fitness. Children...

Investigation of smooth specimen scc test procedures; variations in environment, specimen size, stressing frame, and stress state. [for high strength aluminum alloys

Science.gov (United States)

Lifka, B. W.; Sprowls, D. O.; Kelsey, R. A.

1975-01-01

The variables studied in the stress-corrosion cracking performance of high strength aluminum alloys were: (1) corrosiveness of the environment, (2) specimen size and stiffness of the stressing system, (3) interpretation of transgranular cracking, and (4) interaction of the state of stress and specimen orientation in a product with an anisotropic grain structure. It was shown that the probability of failure and time to fracture for a specimen loaded in direct tension are influenced by corrosion pattern, the stressing assembly stiffness, and the notch tensile strength of the alloy. Results demonstrate that the combination of a normal tension stress and a shear stress acting on the plane of maximum susceptibility in a product with a highly directional grain cause the greatest tendency for stress-corrosion cracking.

A comparative study of a new wireless continuous cardiorespiratory monitor for the diagnosis and management of patients with congestive heart failure at home.

Science.gov (United States)

Andrews, D; Gouda, M S; Higgins, S; Johnson, P; Williams, A; Vandenburg, M

2002-01-01

Congestive heart failure (CHF) is a major and increasing chronic disease in Western society, with a high mortality, morbidity and cost for unplanned hospital admissions. Continuous cardiorespiratory monitoring is required to detect Cheyne-Stokes respiration (CSR). We have tested a new wireless monitoring system and compared it with polysomnography (PSG) and respiratory inductance plethysmography (RIP) in six CHF patients with CSR in a sleep laboratory. The wireless system compared well with RIP for the detection of CSR but less well with PSG, which had unexpected but significant respiratory sensing errors that led to misclassification of the respiratory disorder present. The wireless system could be used to select CHF patients for better-customized treatment at home as part of a specialist-supported community telemedicine programme.

Validity of a Newly-Designed Rectilinear Stepping Ergometer Submaximal Exercise Test to Assess Cardiorespiratory Fitness.

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Zhang, Rubin; Zhan, Likui; Sun, Shaoming; Peng, Wei; Sun, Yining

2017-09-01

The maximum oxygen uptake (V̇O 2 max), determined from graded maximal or submaximal exercise tests, is used to classify the cardiorespiratory fitness level of individuals. The purpose of this study was to examine the validity and reliability of the YMCA submaximal exercise test protocol performed on a newly-designed rectilinear stepping ergometer (RSE) that used up and down reciprocating vertical motion in place of conventional circular motion and giving precise measurement of workload, to determine V̇O 2 max in young healthy male adults. Thirty-two young healthy male adults (32 males; age range: 20-35 years; height: 1.75 ± 0.05 m; weight: 67.5 ± 8.6 kg) firstly participated in a maximal-effort graded exercise test using a cycle ergometer (CE) to directly obtain measured V̇O 2 max. Subjects then completed the progressive multistage test on the RSE beginning at 50W and including additional stages of 70, 90, 110, 130, and 150W, and the RSE YMCA submaximal test consisting of a workload increase every 3 minutes until the termination criterion was reached. A metabolic equation was derived from the RSE multistage exercise test to predict oxygen consumption (V̇O 2 ) from power output (W) during the submaximal exercise test (V̇O 2 (mL·min -1 )=12.4 ×W(watts)+3.5 mL·kg -1 ·min -1 ×M+160mL·min -1 , R 2 = 0.91, standard error of the estimate (SEE) = 134.8mL·min -1 ). A high correlation was observed between the RSE YMCA estimated V̇O 2 max and the CE measured V̇O 2 max (r=0.87). The mean difference between estimated and measured V̇O 2 max was 2.5 mL·kg -1 ·min -1 , with an SEE of 3.55 mL·kg -1 ·min -1 . The data suggest that the RSE YMCA submaximal exercise test is valid for predicting V̇O 2 max in young healthy male adults. The findings show that the rectilinear stepping exercise is an effective submaximal exercise for predicting V̇O 2 max. The newly-designed RSE may be potentially further developed as an alternative ergometer for assessing

Caffeine prevents cognitive impairment induced by chronic psychosocial stress and/or high fat-high carbohydrate diet.

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Alzoubi, K H; Abdul-Razzak, K K; Khabour, O F; Al-Tuweiq, G M; Alzubi, M A; Alkadhi, K A

2013-01-15

Caffeine alleviates cognitive impairment associated with a variety of health conditions. In this study, we examined the effect of caffeine treatment on chronic stress- and/or high fat-high carbohydrate Western diet (WD)-induced impairment of learning and memory in rats. Chronic psychosocial stress, WD and caffeine (0.3 g/L in drinking water) were simultaneously administered for 3 months to adult male Wistar rats. At the conclusion of the 3 months, and while the previous treatments continued, rats were tested in the radial arm water maze (RAWM) for learning, short-term and long-term memory. This procedure was applied on a daily basis to all animals for 5 consecutive days or until the animal reaches days to criterion (DTC) in the 12th learning trial and memory tests. DTC is the number of days that the animal takes to make zero error in two consecutive days. Chronic stress and/or WD groups caused impaired learning, which was prevented by chronic caffeine administration. In the memory tests, chronic caffeine administration also prevented memory impairment during chronic stress conditions and/or WD. Furthermore, DTC value for caffeine treated stress, WD, and stress/WD groups indicated that caffeine normalizes memory impairment in these groups. These results showed that chronic caffeine administration prevented stress and/or WD-induced impairment of spatial learning and memory. Copyright © 2012 Elsevier B.V. All rights reserved.

Control of breathing and the circulation in high-altitude mammals and birds.

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Ivy, Catherine M; Scott, Graham R

2015-08-01

Hypoxia is an unremitting stressor at high altitudes that places a premium on oxygen transport by the respiratory and cardiovascular systems. Phenotypic plasticity and genotypic adaptation at various steps in the O2 cascade could help offset the effects of hypoxia on cellular O2 supply in high-altitude natives. In this review, we will discuss the unique mechanisms by which ventilation, cardiac output, and blood flow are controlled in high-altitude mammals and birds. Acclimatization to high altitudes leads to some changes in respiratory and cardiovascular control that increase O2 transport in hypoxia (e.g., ventilatory acclimatization to hypoxia). However, acclimatization or development in hypoxia can also modify cardiorespiratory control in ways that are maladaptive for O2 transport. Hypoxia responses that arose as short-term solutions to O2 deprivation (e.g., peripheral vasoconstriction) or regional variation in O2 levels in the lungs (i.e., hypoxic pulmonary vasoconstriction) are detrimental at in chronic high-altitude hypoxia. Evolved changes in cardiorespiratory control have arisen in many high-altitude taxa, including increases in effective ventilation, attenuation of hypoxic pulmonary vasoconstriction, and changes in catecholamine sensitivity of the heart and systemic vasculature. Parallel evolution of some of these changes in independent highland lineages supports their adaptive significance. Much less is known about the genomic bases and potential interactive effects of adaptation, acclimatization, developmental plasticity, and trans-generational epigenetic transfer on cardiorespiratory control. Future work to understand these various influences on breathing and circulation in high-altitude natives will help elucidate how complex physiological systems can be pushed to their limits to maintain cellular function in hypoxia. Copyright © 2014 Elsevier Inc. All rights reserved.

High Dose Ascorbate Causes Both Genotoxic and Metabolic Stress in Glioma Cells

Science.gov (United States)

Castro, Maria Leticia; Carson, Georgia M.; McConnell, Melanie J.; Herst, Patries M.

2017-01-01

We have previously shown that exposure to high dose ascorbate causes double stranded breaks (DSBs) and a build-up in S-phase in glioblastoma (GBM) cell lines. Here we investigated whether or not this was due to genotoxic stress as well as metabolic stress generated by exposure to high dose ascorbate, radiation, ascorbate plus radiation and H2O2 in established and primary GBM cell lines. Genotoxic stress was measured as phosphorylation of the variant histone protein, H2AX, 8-oxo-7,8-dihydroguanine (8OH-dG) positive cells and cells with comet tails. Metabolic stress was measured as a decrease in NADH flux, mitochondrial membrane potential (by CMXRos), ATP levels (by ATP luminescence) and mitochondrial superoxide production (by mitoSOX). High dose ascorbate, ascorbate plus radiation, and H2O2 treatments induced both genotoxic and metabolic stress. Exposure to high dose ascorbate blocked DNA synthesis in both DNA damaged and undamaged cell of ascorbate sensitive GBM cell lines. H2O2 treatment blocked DNA synthesis in all cell lines with and without DNA damage. DNA synthesis arrest in cells with damaged DNA is likely due to both genotoxic and metabolic stress. However, arrest in DNA synthesis in cells with undamaged DNA is likely due to oxidative damage to components of the mitochondrial energy metabolism pathway. PMID:28737676

The role of the vagus nerve in the generation of cardiorespiratory interactions in a neotropical fish, the pacu, Piaractus mesopotamicus.

Science.gov (United States)

Leite, Cleo Alcantara Costa; Taylor, E W; Guerra, C D R; Florindo, L H; Belão, T; Rantin, F T

2009-08-01

The role of the vagus nerve in determining heart rate (f(H)) and cardiorespiratory interactions was investigated in a neotropical fish, Piaractus mesopotamicus. During progressive hypoxia f(H) initially increased, establishing a 1:1 ratio with ventilation rate (f(R)). Subsequently there was a hypoxic bradycardia. Injection of atropine abolished a normoxic inhibitory tonus on the heart and the f(H) adjustments during progressive hypoxia, confirming that they are imposed by efferent parasympathetic inputs via the vagus nerve. Efferent activity recorded from the cardiac vagus in lightly anesthetized normoxic fish included occasional bursts of activity related to spontaneous changes in ventilation amplitude, which increased the cardiac interval. Restricting the flow of aerated water irrigating the gills resulted in increased respiratory effort and bursts of respiration-related activity in the cardiac vagus that seemed to cause f(H) to couple with f(R). Cell bodies of cardiac vagal pre-ganglionic neurons were located in two distinct groups within the dorsal vagal motor column having an overlapping distribution with respiratory motor-neurons. A small proportion of cardiac vagal pre-ganglionic neurons (2%) was in scattered positions in the ventrolateral medulla. This division of cardiac vagal pre-ganglionic neurons into distinct motor groups may relate to their functional roles in determining cardiorespiratory interactions.

The stress-strain relationship for multilayers of the high Tc superconducting oxides

International Nuclear Information System (INIS)

Hidaka, H.; Yamamura, H.

1988-01-01

This paper reports the calculation of the stress-strain relationship for multilayers of the high Tc superconducting oxides. The elucidation of this relationship is expected quite helpful for the preparation of high-quality multilayers of these materials. This calculation is possible to do in the same way of Timoshenko's bi-metal treatment. The authors did computation of the residual stress and strain, and the state of stress and strain for these multilayers has been acquired in detail by this calculation

Application of a Full Reynolds Stress Model to High Lift Flows

Science.gov (United States)

Lee-Rausch, E. M.; Rumsey, C. L.; Eisfeld, B.

2016-01-01

A recently developed second-moment Reynolds stress model was applied to two challenging high-lift flows: (1) transonic flow over the ONERA M6 wing, and (2) subsonic flow over the DLR-F11 wing-body configuration from the second AIAA High Lift Prediction Workshop. In this study, the Reynolds stress model results were contrasted with those obtained from one- and two{equation turbulence models, and were found to be competitive in terms of the prediction of shock location and separation. For an ONERA M6 case, results from multiple codes, grids, and models were compared, with the Reynolds stress model tending to yield a slightly smaller shock-induced separation bubble near the wing tip than the simpler models, but all models were fairly close to the limited experimental surface pressure data. For a series of high-lift DLR{F11 cases, the range of results was more limited, but there was indication that the Reynolds stress model yielded less-separated results than the one-equation model near maximum lift. These less-separated results were similar to results from the one-equation model with a quadratic constitutive relation. Additional computations need to be performed before a more definitive assessment of the Reynolds stress model can be made.

[Cardiorespiratory arrest of the adult patient in a hospital environment: nursing contributions].

Science.gov (United States)

Luzia, Melissa de Freitas; Lucena, Amália de Fátima

2009-06-01

The objective of this study was to analyse the scientific production regarding cardiorespiratory arrest (CA) in adult patients in a hospital environment, as to support nursing knowledge. This is a systematic review, which were used SciELO, LILACS and MEDLINE databases from 1997 to 2007. Most of the articles used in the analysis referred to the survival prognostic factors of patients submitted to cardiopulmonary ressucitation (CPR) and to the results of this intervention. The prospective studies were methodologically prevalent. The nursing scientific production was numerically small when compared to the medical area. The importance of a nursing team trained and apt for CA treatment and prevention was pointed out; continual education programs were stimulated. The conclusion is that there are few nursing studies about CPR, and continual incentive to the scientific production regarding its acting both in CA prevention and RCP management is imperative.

The challenge of preserving cardiorespiratory fitness in physically inactive patients with colon or breast cancer during adjuvant chemotherapy: a randomised feasibility study

DEFF Research Database (Denmark)

Møller, Tom; Lillelund, Christian; Andersen, Christina

2015-01-01

Introduction Anti-neoplastic treatment is synonymous with an inactive daily life for a substantial number of patients. It remains unclear what is the optimal setting, dosage and combination of exercise and health promoting components that best facilitate patient adherence and symptom management...... in order to support cardio-respiratory fitness and lifestyle changes in an at-risk population of pre-illness physically inactive cancer patients.Methods Patients with breast or colon cancer referred to adjuvant chemotherapy and by the oncologists pre-screening verified as physically inactive were eligible...... to enter a randomised three-armed feasibility study comparing a 12-week supervised hospital-based moderate to high intensity exercise intervention or alternate an instructive home-based12-week pedometer intervention, with usual care.Results Using a recommendation based physical activity screening...

Fatigue crack closure behavior at high stress ratios

Science.gov (United States)

Turner, C. Christopher; Carman, C. Davis; Hillberry, Ben M.

1988-01-01

Fatigue crack delay behavior at high stress ratio caused by single peak overloads was investigated in two thicknesses of 7475-T731 aluminum alloy. Closure measurements indicated no closure occurred before or throughout the overload plastic zones following the overload. This was further substantiated by comparing the specimen compliance following the overload with the compliance of a low R ratio test when the crack was fully open. Scanning electron microscope studies revealed that crack tunneling and possibly reinitiation of the crack occurred, most likely a result of crack-tip blunting. The number of delay cycles was greater for the thinner mixed mode stress state specimen than for the thicker plane strain stress state specimen, which is similar to low R ratio test results and may be due to a larger plastic zone for the mixed mode cased.

Acute stress induces hyperacusis in women with high levels of emotional exhaustion.

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Dan Hasson

Full Text Available BACKGROUND: Hearing problems is one of the top ten public health disorders in the general population and there is a well-established relationship between stress and hearing problems. The aim of the present study was to explore if an acute stress will increase auditory sensitivity (hyperacusis in individuals with high levels of emotional exhaustion (EE. METHODS: Hyperacusis was assessed using uncomfortable loudness levels (ULL in 348 individuals (140 men; 208 women; age 23-71 years. Multivariate analyses (ordered logistic regression, were used to calculate odds ratios, including interacting or confounding effects of age, gender, ear wax and hearing loss (PTA. Two-way ANCOVAs were used to assess possible differences in mean ULLs between EE groups pre- and post-acute stress task (a combination of cold pressor, emotional Stroop and Social stress/video recording. RESULTS: There were no baseline differences in mean ULLs between the three EE groups (one-way ANOVA. However, after the acute stress exposure there were significant differences in ULL means between the EE-groups in women. Post-hoc analyses showed that the differences in mean ULLs were between those with high vs. low EE (range 5.5-6.5 dB. Similar results were found for frequencies 0.5 and 1 kHz. The results demonstrate that women with high EE-levels display hyperacusis after an acute stress task. The odds of having hyperacusis were 2.5 (2 kHz, right ear; left ns and 2.2 (4 kHz, right ear; left ns times higher among those with high EE compared to those with low levels. All these results are adjusted for age, hearing loss and ear wax. CONCLUSION: Women with high levels of emotional exhaustion become more sensitive to sound after an acute stress task. This novel finding highlights the importance of including emotional exhaustion in the diagnosis and treatment of hearing problems.

Acute stress induces hyperacusis in women with high levels of emotional exhaustion.

Science.gov (United States)

Hasson, Dan; Theorell, Töres; Bergquist, Jonas; Canlon, Barbara

2013-01-01

Hearing problems is one of the top ten public health disorders in the general population and there is a well-established relationship between stress and hearing problems. The aim of the present study was to explore if an acute stress will increase auditory sensitivity (hyperacusis) in individuals with high levels of emotional exhaustion (EE). Hyperacusis was assessed using uncomfortable loudness levels (ULL) in 348 individuals (140 men; 208 women; age 23-71 years). Multivariate analyses (ordered logistic regression), were used to calculate odds ratios, including interacting or confounding effects of age, gender, ear wax and hearing loss (PTA). Two-way ANCOVAs were used to assess possible differences in mean ULLs between EE groups pre- and post-acute stress task (a combination of cold pressor, emotional Stroop and Social stress/video recording). There were no baseline differences in mean ULLs between the three EE groups (one-way ANOVA). However, after the acute stress exposure there were significant differences in ULL means between the EE-groups in women. Post-hoc analyses showed that the differences in mean ULLs were between those with high vs. low EE (range 5.5-6.5 dB). Similar results were found for frequencies 0.5 and 1 kHz. The results demonstrate that women with high EE-levels display hyperacusis after an acute stress task. The odds of having hyperacusis were 2.5 (2 kHz, right ear; left ns) and 2.2 (4 kHz, right ear; left ns) times higher among those with high EE compared to those with low levels. All these results are adjusted for age, hearing loss and ear wax. Women with high levels of emotional exhaustion become more sensitive to sound after an acute stress task. This novel finding highlights the importance of including emotional exhaustion in the diagnosis and treatment of hearing problems.

Deciphering Stress State of Seismogenic Faults in Oklahoma and Kansas Based on High-resolution Stress Maps

Science.gov (United States)

Qin, Y.; Chen, X.; Haffener, J.; Trugman, D. T.; Carpenter, B.; Reches, Z.

2017-12-01

Induced seismicity in Oklahoma and Kansas delineates clear fault trends. It is assumed that fluid injection reactivates faults which are optimally oriented relative to the regional tectonic stress field. We utilized recently improved earthquake locations and more complete focal mechanism catalogs to quantitatively analyze the stress state of seismogenic faults with high-resolution stress maps. The steps of analysis are: (1) Mapping the faults by clustering seismicity using a nearest-neighbor approach, manually picking the fault in each cluster and calculating the fault geometry using principal component analysis. (2) Running a stress inversion with 0.2° grid spacing to produce an in-situ stress map. (3) The fault stress state is determined from fault geometry and a 3D Mohr circle. The parameter `understress' is calculated to quantify the criticalness of these faults. If it approaches 0, the fault is critically stressed; while understress=1 means there is no shear stress on the fault. Our results indicate that most of the active faults have a planar shape (planarity>0.8), and dip steeply (dip>70°). The fault trends are distributed mainly in conjugate set ranges of [50°,70°] and [100°,120°]. More importantly, these conjugate trends are consistent with mapped basement fractures in southern Oklahoma, suggesting similar basement features from regional tectonics. The fault length data shows a loglinear relationship with the maximum earthquake magnitude with an expected maximum magnitude range from 3.2 to 4.4 for most seismogenic faults. Based on 3D local Mohr circle, we find that 61% of the faults have low understress (0.5) are located within highest-rate injection zones and therefore are likely to be influenced by high pore pressure. The faults that hosted the largest earthquakes, M5.7 Prague and M5.8 Pawnee are critically stressed (understress 0.2). These differences may help in understanding earthquake sequences, for example, the predominantly aftershock

High occupational stress and low career satisfaction of Korean surgeons.

Science.gov (United States)

Kang, Sang Hee; Boo, Yoon Jung; Lee, Ji Sung; Han, Hyung Joon; Jung, Cheol Woong; Kim, Chong Suk

2015-02-01

Surgery is a demanding and stressful field in Korea. Occupational stress can adversely affect the quality of care, decrease job satisfaction, and potentially increase medical errors. The aim of this study was to investigate the occupational stress and career satisfaction of Korean surgeons. We have conducted an electronic survey of 621 Korean surgeons for the occupational stress. Sixty-five questions were used to assess practical and personal characteristics and occupational stress using the Korean occupational stress scale (KOSS). The mean KOSS score was 49.31, which was higher than the average of Korean occupational stress (45.86) or that of other specialized professions (46.03). Young age, female gender, long working hours, and frequent night duties were significantly related to the higher KOSS score. Having spouse, having hobby and regular exercise decreased the KOSS score. Multiple linear regression analysis showed that long working hours and regular exercise were the independent factors associated with the KOSS score. Less than 50% of surgeons answered that they would become a surgeon again. Most surgeons (82.5%) did not want to recommend their child follow their career. Korean Surgeons have high occupational stress and low level of career satisfaction.

Respostas cardio-respiratórias em pacientes com traumatismo raquimedular Cardiorespiratory responses of patients with spinal cord injuries

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Fernanda Rossi Paolillo

2005-01-01

Full Text Available O objetivo desta pesquisa foi investigar as variáveis cardio-respiratórias (Pa, FC, VO2, VCO2 e Ve durante a Estimulação Elétrica Neuromuscular (EENM do quadríceps em portadores de lesão medular. Participaram da pesquisa dez pacientes (cinco paraplégicos e cinco tetraplégicos. O protocolo do teste consistiu em 10 minutos de repouso, 20 minutos de EENM dos quadriceps e 10 minutos de recuperação. Durante a EENM foram constatados baixos valores de VO2 e VCO2. Os paraplégicos apresentaram rápida cinética dos gases e os tetraplégicos lenta cinética dos gases. Houve o aumento da Pa sistólica e da FC. Ainda, os valores das variáveis cardio-respiratórias foram inversamente relatadas para o nível de lesão, ou seja, quanto maior o nível de lesão, menor os valores. Portanto, a maioria dos pacientes apresentaram algumas limitações nas respostas cardio-respiratórias, indicando realização de exercício exaustivo, mas apresentaram capacidade de realização de exercício induzido artificialmente, possivelmente devido aos benefícios da EENM.The objective of this study was to investigate cardiorespiratory responses (Heart Rate, Blood Pressure, VO2, VCO2 e Ve to Neuromuscular Electrical Stimulation (NMES of the quadriceps in patients with spinal cord injury. Ten patients (five paraplegics and five tetraplegics participated in this study. The protocol of the test consisted of ten minutes of rest, twenty minutes of NMES of the quadriceps and ten minutes of recovery. The findings in this study indicated that, during NMES, the patients demonstrated low levels of VO2 and VCO2 and slow gas kinetics for tetraplegic individuals, and a fast gas kinetics for paraplegic individuals. Moreover, there were increases in blood pressure and heart rate. Cardiorespiratory responses increased with descending spinal cord injury level, meaning that the more severe the lesion, the lower the values. Therefore, most of the patients presented some limitations

White matter microstructure mediates the relationship between cardiorespiratory fitness and spatial working memory in older adults.

Science.gov (United States)

Oberlin, Lauren E; Verstynen, Timothy D; Burzynska, Agnieszka Z; Voss, Michelle W; Prakash, Ruchika Shaurya; Chaddock-Heyman, Laura; Wong, Chelsea; Fanning, Jason; Awick, Elizabeth; Gothe, Neha; Phillips, Siobhan M; Mailey, Emily; Ehlers, Diane; Olson, Erin; Wojcicki, Thomas; McAuley, Edward; Kramer, Arthur F; Erickson, Kirk I

2016-05-01

White matter structure declines with advancing age and has been associated with a decline in memory and executive processes in older adulthood. Yet, recent research suggests that higher physical activity and fitness levels may be associated with less white matter degeneration in late life, although the tract-specificity of this relationship is not well understood. In addition, these prior studies infrequently associate measures of white matter microstructure to cognitive outcomes, so the behavioral importance of higher levels of white matter microstructural organization with greater fitness levels remains a matter of speculation. Here we tested whether cardiorespiratory fitness (VO2max) levels were associated with white matter microstructure and whether this relationship constituted an indirect pathway between cardiorespiratory fitness and spatial working memory in two large, cognitively and neurologically healthy older adult samples. Diffusion tensor imaging was used to determine white matter microstructure in two separate groups: Experiment 1, N=113 (mean age=66.61) and Experiment 2, N=154 (mean age=65.66). Using a voxel-based regression approach, we found that higher VO2max was associated with higher fractional anisotropy (FA), a measure of white matter microstructure, in a diverse network of white matter tracts, including the anterior corona radiata, anterior internal capsule, fornix, cingulum, and corpus callosum (PFDR-correctedmicrostructure within these regions, among others, constituted a significant indirect path between VO2max and spatial working memory performance. These results suggest that greater aerobic fitness levels are associated with higher levels of white matter microstructural organization, which may, in turn, preserve spatial memory performance in older adulthood. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of acute supplementation of caffeine on cardiorespiratory responses during endurance running in a hot & humid climate.

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Ping, Wong Chee; Keong, Chen Chee; Bandyopadhyay, Amit

2010-07-01

Athletes in Malaysia need to perform in a hot and humid climate. Chronic supplementation of caffeine on endurance performance have been studied extensively in different populations. However, concurrent research on the effects of acute supplementation of caffeine on cardiorespiratory responses during endurance exercise in the Malaysian context especially in a hot and humid environment is unavailable. Nine heat adapted recreational Malaysian male runners (aged: 25.4+/-6.9 yr) who were nonusers of caffeine (23.7+/-12.6 mg per day) were recruited in this placebo--controlled double--blind randomized study. Caffeine (5 mg per kg of body weight) or placebo was ingested in the form of a capsule one hour prior to the running exercise trial at 70 per cent of VO2max on a motorised treadmill in a heat-controlled laboratory (31 degrees C, 70% relative humidity). Subjects drank 3 ml of cool water per kg of body weight every 20 min during the running trials to avoid the adverse effects of dehydration. Heart rate, core body temperature and rate of perceived exertion (RPE) were recorded at intervals of 10 min, while oxygen consumption was measured at intervals of 20 min. Running time to exhaustion was significantly (Pexercise from their respective resting values in both trials (P<0.001). Our study showed that ingestion of 5 mg of caffeine per kg of body weight improved the endurance running performance but did not impose any significant effect on other individual cardiorespiratory parameters of heat-acclimated recreational runners in hot and humid conditions.

High-resolution axial MR imaging of tibial stress injuries

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Mammoto Takeo

2012-05-01

Full Text Available Abstract Purpose To evaluate the relative involvement of tibial stress injuries using high-resolution axial MR imaging and the correlation with MR and radiographic images. Methods A total of 33 patients with exercise-induced tibial pain were evaluated. All patients underwent radiograph and high-resolution axial MR imaging. Radiographs were taken at initial presentation and 4 weeks later. High-resolution MR axial images were obtained using a microscopy surface coil with 60 × 60 mm field of view on a 1.5T MR unit. All images were evaluated for abnormal signals of the periosteum, cortex and bone marrow. Results Nineteen patients showed no periosteal reaction at initial and follow-up radiographs. MR imaging showed abnormal signals in the periosteal tissue and partially abnormal signals in the bone marrow. In 7 patients, periosteal reaction was not seen at initial radiograph, but was detected at follow-up radiograph. MR imaging showed abnormal signals in the periosteal tissue and entire bone marrow. Abnormal signals in the cortex were found in 6 patients. The remaining 7 showed periosteal reactions at initial radiograph. MR imaging showed abnormal signals in the periosteal tissue in 6 patients. Abnormal signals were seen in the partial and entire bone marrow in 4 and 3 patients, respectively. Conclusions Bone marrow abnormalities in high-resolution axial MR imaging were related to periosteal reactions at follow-up radiograph. Bone marrow abnormalities might predict later periosteal reactions, suggesting shin splints or stress fractures. High-resolution axial MR imaging is useful in early discrimination of tibial stress injuries.

High-resolution axial MR imaging of tibial stress injuries

Science.gov (United States)

2012-01-01

Purpose To evaluate the relative involvement of tibial stress injuries using high-resolution axial MR imaging and the correlation with MR and radiographic images. Methods A total of 33 patients with exercise-induced tibial pain were evaluated. All patients underwent radiograph and high-resolution axial MR imaging. Radiographs were taken at initial presentation and 4 weeks later. High-resolution MR axial images were obtained using a microscopy surface coil with 60 × 60 mm field of view on a 1.5T MR unit. All images were evaluated for abnormal signals of the periosteum, cortex and bone marrow. Results Nineteen patients showed no periosteal reaction at initial and follow-up radiographs. MR imaging showed abnormal signals in the periosteal tissue and partially abnormal signals in the bone marrow. In 7 patients, periosteal reaction was not seen at initial radiograph, but was detected at follow-up radiograph. MR imaging showed abnormal signals in the periosteal tissue and entire bone marrow. Abnormal signals in the cortex were found in 6 patients. The remaining 7 showed periosteal reactions at initial radiograph. MR imaging showed abnormal signals in the periosteal tissue in 6 patients. Abnormal signals were seen in the partial and entire bone marrow in 4 and 3 patients, respectively. Conclusions Bone marrow abnormalities in high-resolution axial MR imaging were related to periosteal reactions at follow-up radiograph. Bone marrow abnormalities might predict later periosteal reactions, suggesting shin splints or stress fractures. High-resolution axial MR imaging is useful in early discrimination of tibial stress injuries. PMID:22574840

Soil mechanical stresses in high wheel load agricultural field traffic: a case study

DEFF Research Database (Denmark)

Lamandé, Mathieu; Schjønning, Per

2017-01-01

highly skewed. Across tyres, the maximum stress in the contact area correlated linearly with, but was much higher than, the mean ground pressure. For each of the three soil depths, the maximum stresses under the tyres were significantly correlated with the wheel load, but not with other loading......Subsoil compaction is a serious long-term threat to soil functions. Only a few studies have quantified the mechanical stresses reaching deep subsoil layers for modern high wheel load machinery. In the present study we measured the vertical stresses in the tyre–soil contact area and at 0.3, 0...

Muscle-like high-stress dielectric elastomer actuators with oil capsules

International Nuclear Information System (INIS)

La, Thanh-Giang; Lau, Gih-Keong; Shiau, Li-Lynn; Wei-Yee Tan, Adrian

2014-01-01

Despite being capable of generating large strains, dielectric elastomer actuators (DEAs) are short of strength. Often, they cannot produce enough stress or as much work as that achievable by human elbow muscles. Their maximum actuation capacity is limited by the electrical breakdown of dielectric elastomers. Often, failures of these soft actuators are pre-mature and localized at the weakest spot under high field and high stress. Localized breakdowns, such as electrical arcing, thermal runaway and punctures, could spread to ultimately cause rupture if they were not stopped. This work shows that dielectric oil immersion and self-clearable electrodes nibbed the buds of localized breakdowns from DEAs. Dielectric oil encapsulation in soft-membrane capsules was found to help the DEA sustain an ultra-high electrical breakdown field of 835 MVm −1 , which is 46% higher than the electrical breakdown strength of the dry DEA in air at 570 MV m −1 . Because of the increased apparent dielectric strength, this oil-capsuled DEA realizes a higher maximum isotonic work density of up to 31.51Jkg −1 , which is 43.8% higher than that realized by the DEA in air. Meanwhile, it produces higher maximum isometric stress of up to 1.05 MPa, which is 75% higher than that produced by the DEA in air. Such improved actuator performances are comparable to those achieved by human flexor muscles, which can exert up to 1.2 MPa during elbow flexion. This muscle-like, high-stress dielectric elastomeric actuation is very promising to drive future human-like robots. (paper)

Heat priming induces trans-generational tolerance to high temperature stress in wheat

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Xiao eWang

2016-04-01

Full Text Available Wheat plants are very sensitive to high temperature stress during grain filling. Effects of heat priming applied to the first generation on tolerance of the successive generation to post-anthesis high temperature stress were investigated. Compared with the progeny of non-heat primed plants (NH, the progeny of heat-primed plants (PH possessed higher grain yield, leaf photosynthesis and activities of antioxidant enzymes and lower cell membrane damage under high temperature stress. In the transcriptome profile, 1430 probes showed obvious difference in expression between PH and NH. These genes were related to signal transduction, transcription, energy, defense, and protein destination and storage, respectively. The gene encoding the lysine-specific histone demethylase 1 (LSD1 which was involved in histone demethylation related to epigenetic modification was up-regulated in the PH compared with NH. The proteome analysis indicated that the proteins involved in photosynthesis, energy production and protein destination and storage were up-regulated in the PH compared with NH. In short, thermos-tolerance was induced through heritable epigenetic alternation and signaling transduction, both processes further triggered prompt modifications of defense related responses in anti-oxidation, transcription, energy production, and protein destination and storage in the progeny of the primed plants under high temperature stress. It was concluded that trans-generation thermo-tolerance was induced by heat priming in the first generation, and this might be an effective measure to cope with severe high-temperature stresses during key growth stages in wheat production.

Occupational stress and cardiovascular risk factors in high-ranking government officials and office workers.

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Mirmohammadi, Seyyed Jalil; Taheri, Mahmoud; Mehrparvar, Amir Houshang; Heydari, Mohammad; Saadati Kanafi, Ali; Mostaghaci, Mehrdad

2014-08-01

Cardiovascular diseases are among the most important sources of mortality and morbidity, and have a high disease burden. There are some major well-known risk factors, which contribute to the development of these diseases. Occupational stress is caused due to imbalance between job demands and individual's ability, and it has been implicated as an etiology for cardiovascular diseases. This study was conducted to evaluate the cardiovascular risk factors and different dimensions of occupational stress in high-ranking government officials, comparing an age and sex-matched group of office workers with them. We invited 90 high-ranking officials who managed the main governmental offices in a city, and 90 age and sex-matched office workers. The subjects were required to fill the occupational role questionnaire (Osipow) which evaluated their personal and medical history as well as occupational stress. Then, we performed physical examination and laboratory tests to check for cardiovascular risk factors. Finally, the frequency of cardiovascular risk factors and occupational stress of two groups were compared. High-ranking officials in our study had less work experience in their current jobs and smoked fewer pack-years of cigarette, but they had higher waist and hip circumference, higher triglyceride level, more stress from role overload and responsibility, and higher total stress score. Our group of office workers had more occupational stress because of role ambiguity and insufficiency, but their overall job stress was less than officials. The officials have higher scores in some dimensions of occupational stress and higher overall stress score. Some cardiovascular risk factors were also more frequent in managers.

Psychophysiological effects of music on acute recovery from high-intensity interval training.

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Jones, Leighton; Tiller, Nicholas B; Karageorghis, Costas I

2017-03-01

Numerous studies have examined the multifarious effects of music applied during exercise but few have assessed the efficacy of music as an aid to recovery. Music might facilitate physiological recovery via the entrainment of respiratory rhythms with music tempo. High-intensity exercise training is not typically associated with positive affective responses, and thus ways of assuaging negative affect warrant further exploration. This study assessed the psychophysiological effects of music on acute recovery and prevalence of entrainment in between bouts of high-intensity exercise. Thirteen male runners (M age =20.2±1.9years; BMI=21.7±1.7; V̇O 2 max=61.6±6.1mL·kg·min -1 ) completed three exercise sessions comprising 5×5-min bouts of high-intensity intervals interspersed with 3-min periods of passive recovery. During recovery, participants were administered positively-valenced music of a slow-tempo (55-65bpm), fast-tempo (125-135bpm), or a no-music control. A range of measures including affective responses, RPE, cardiorespiratory indices (gas exchange and pulmonary ventilation), and music tempo-respiratory entrainment were recorded during exercise and recovery. Fast-tempo, positively-valenced music resulted in higher Feeling Scale scores throughout recovery periods (pmusic-moderated differences in cardiorespiratory responses. In conclusion, fast-tempo, positively-valenced music applied during recovery periods engenders a more pleasant experience. However, there is limited evidence that music expedites cardiorespiratory recovery in between bouts of high-intensity exercise. These findings have implications for athletic training strategies and individuals seeking to make high-intensity exercise sessions more pleasant. Copyright © 2016 Elsevier Inc. All rights reserved.

High novelty-seeking rats are resilient to negative physiological effects of the early life stress.

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Clinton, Sarah M; Watson, Stanley J; Akil, Huda

2014-01-01

Exposure to early life stress dramatically impacts adult behavior, physiology, and neuroendocrine function. Using rats bred for novelty-seeking differences and known to display divergent anxiety, depression, and stress vulnerability, we examined the interaction between early life adversity and genetic predisposition for high- versus low-emotional reactivity. Thus, bred Low Novelty Responder (bLR) rats, which naturally exhibit high anxiety- and depression-like behavior, and bred High Novelty Responder (bHR) rats, which show low anxiety/depression together with elevated aggression, impulsivity, and addictive behavior, were subjected to daily 3 h maternal separation (MS) stress postnatal days 1-14. We hypothesized that MS stress would differentially impact adult bHR/bLR behavior, physiology (stress-induced defecation), and neuroendocrine reactivity. While MS stress did not impact bHR and bLR anxiety-like behavior in the open field test and elevated plus maze, it exacerbated bLRs' already high physiological response to stress - stress-induced defecation. In both tests, MS bLR adult offspring showed exaggerated stress-induced defecation compared to bLR controls while bHR offspring were unaffected. MS also selectively impacted bLRs' (but not bHRs') neuroendocrine stress reactivity, producing an exaggerated corticosterone acute stress response in MS bLR versus control bLR rats. These findings highlight how genetic predisposition shapes individuals' response to early life stress. Future work will explore neural mechanisms underlying the distinct behavioral and neuroendocrine consequences of MS in bHR/bLR animals.

Limitations in Using Chemical Oxidative Potential to Understand Oxidative Stress from Particulate Matter

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Chan, A. W. H.; Wang, S.; Wang, X.; Kohl, L.; Chow, C. W.

2017-12-01

Particulate matter (PM) in the atmosphere is known to cause adverse cardiorespiratory health effects. It has been suggested that the ability of PM to generate oxidative stress leads to a proinflammatory response. In this work, we study the biological relevance of using a chemical oxidative potential (OP) assay to evaluate proinflammatory response in airway epithelial cells. Here we study the OPs of laboratory secondary organic aerosol (SOA) and metal mixtures, ambient PM from India, ash from the 2016 Alberta wildfires, and diesel exhaust particles. We use SOA derived from naphthalene and from monoterpenes as model systems for SOA. We measure OP using the dithiothreitol (DTT) assay, and cytosolic reactive oxygen species (ROS) production in BEAS-2B cell culture was measured using CellROX assay. We found that both SOA and copper show high OPs individually, but the OP of the combined SOA/copper mixture, which is more atmospherically relevant, was lower than either of the individual OPs. The reduced activity is attributed to chelation between metals and organic compounds using proton nuclear magnetic resonance. There is reasonable association between DTT activity and cellular ROS production within each particle type, but weak association across different particle types, suggesting that particle composition plays an important role in distinguishing between antioxidant consumption and ROS production. Our results highlight that while oxidative potential is a useful metric of PM's ability to generate oxidative stress, the chemical composition and cellular environment should be considered in understanding health impacts of PM.

The phylogeny and ontogeny of autonomic control of the heart and cardiorespiratory interactions in vertebrates.

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Taylor, Edwin W; Leite, Cleo A C; Sartori, Marina R; Wang, Tobias; Abe, Augusto S; Crossley, Dane A

2014-03-01

Heart rate in vertebrates is controlled by activity in the autonomic nervous system. In spontaneously active or experimentally prepared animals, inhibitory parasympathetic control is predominant and is responsible for instantaneous changes in heart rate, such as occur at the first air breath following a period of apnoea in discontinuous breathers like inactive reptiles or species that surface to air breathe after a period of submersion. Parasympathetic control, exerted via fast-conducting, myelinated efferent fibres in the vagus nerve, is also responsible for beat-to-beat changes in heart rate such as the high frequency components observed in spectral analysis of heart rate variability. These include respiratory modulation of the heartbeat that can generate cardiorespiratory synchrony in fish and respiratory sinus arrhythmia in mammals. Both may increase the effectiveness of respiratory gas exchange. Although the central interactions generating respiratory modulation of the heartbeat seem to be highly conserved through vertebrate phylogeny, they are different in kind and location, and in most species are as yet little understood. The heart in vertebrate embryos possesses both muscarinic cholinergic and β-adrenergic receptors very early in development. Adrenergic control by circulating catecholamines seems important throughout development. However, innervation of the cardiac receptors is delayed and first evidence of a functional cholinergic tonus on the heart, exerted via the vagus nerve, is often seen shortly before or immediately after hatching or birth, suggesting that it may be coordinated with the onset of central respiratory rhythmicity and subsequent breathing.

High-risk diagnosis, social stress, and parent-child relationships: A moderation model.

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Bentley, Eryn; Millman, Zachary B; Thompson, Elizabeth; Demro, Caroline; Kline, Emily; Pitts, Steven C; DeVylder, Jordan E; Smith, Melissa Edmondson; Reeves, Gloria; Schiffman, Jason

2016-07-01

Stress is related to symptom severity among youth at clinical high-risk (CHR) for psychosis, although this relation may be influenced by protective factors. We explored whether the association of CHR diagnosis with social stress is moderated by the quality of parent-child relationships in a sample of 96 (36 CHR; 60 help-seeking controls) adolescents and young adults receiving mental health services. We examined self-reported social stress and parent-child relationships as measured by the Behavior Assessment System for Children, Second Edition (BASC-2), and determined CHR status from the clinician-administered Structured Interview for Psychosis-Risk Syndrome (SIPS). The social stress subscale, part of the clinical domain of the BASC-2, assesses feelings of stress and tension in personal relationships and the relations with parents subscale, part of the adaptive domain of the BASC-2, assesses perceptions of importance in family and quality of parent-child relationship. There was a modest direct relation between risk diagnosis and social stress. Among those at CHR, however, there was a significant relation between parent-child relationships and social stress (b=-0.73, t[92]=-3.77, psocial stress for those at risk for psychosis. Findings provide additional evidence to suggest that interventions that simultaneously target both social stress and parent-child relationships might be relevant for adolescents and young adults at clinical high-risk for psychosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Stress-Dilatancy of Cambria Sand for Triaxial Tests at High Pressures

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Szypcio, Zenon

2017-12-01

In this paper, the stress-dilatancy relationship of Cambria sand for drained triaxial compression and extension tests at high stress level is investigated. The stress dilatancy relationship is obtained by use of frictional state theory and experimental tests data published in literature. It is shown that stress-dilatancy relationship is bilinear, described by three parameters of frictional state theory: critical frictional angle and two other parameters. It is accepted that critical friction angle is independent of confining pressure. The two additional parameters are strongly dependent on confining pressure and different for initial and advanced stages. The point at which the values of these parameters change is termed as Transformation Shear Point. This point is not simply visible either in stress ratio-strain or the volume strain-shear strain relationship which are traditionally shown in soil mechanics papers. Transformation Shear Point is very characteristic in stress ratio-plastic dilatancy plane. Thus, stress ratio- plastic dilatancy is very important for describing stress-strain behaviour of soils. The relationship shown in the paper can be used in soil modelling in the future.

High carotenoids content can enhance resistance of selected Pinctada fucata families to high temperature stress.

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Meng, Zihao; Zhang, Bo; Liu, Baosuo; Li, Haimei; Fan, Sigang; Yu, Dahui

2017-02-01

Carotenoids are a class of natural antioxidants widely found in aquatic, and they have significant effects on the growth, survival, and immunity of these organisms. To investigate the mechanisms of carotenoids in high temperature resistance, we observed the immune response of selected pearl oyster Pinctada fucata (Akoya pearl oyster) families with different carotenoids contents to high temperature stress. The results indicated that the survival rate (SR) of P. fucata decreased significantly with increase in temperature from 26 °C to 34 °C and with the decrease of total carotenoids content (TCC); when the TCC was higher, the SR tended to be higher. TCC and total antioxidant capacity (TAC) decreased significantly at 30 °C with increasing stress time. Correlation analysis indicated that TAC was positively and linearly correlated with TCC, and SR was S-type correlated with TCC and TAC. Immune analysis indicated that levels of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) in selected families (with higher TCC) under temperature stress (at 30 °C) were generally significantly lower than in the control group (with lowest TCC) and from 0 to 96 h, the levels of each of these substances varied significantly. Levels of SOD, CAT, and MDA within each family first rose from 0 to 3 h, then decreased to their lowest point after 24 h, and then rose again to their highest levels at 96 h. When TCC was higher, the levels of SOD, CAT, and MDA tended to be lower. These findings indicated that carotenoids play an important role in improving survival rates of P. fucata under high temperature stress by enhancing animals' antioxidant system, and could serve as an index for breeding stress-resistant lines in selective breeding practices. Copyright © 2016 Elsevier Ltd. All rights reserved.

Associations Between Cardiorespiratory Fitness and Overweight With Academic Performance in 12-Year-Old Brazilian Children.

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de Almeida Santana, Carla Caroliny; Farah, Breno Quintella; de Azevedo, Liane Beretta; Hill, James O; Gunnarsdottir, Thrudur; Botero, João Paulo; do Prado, Edna Cristina; do Prado, Wagner Luiz

2017-05-01

Obesity has been associated with poor academic achievement, while cardiorespiratory fitness (CRF) has been linked to academic success. To investigate whether CRF is associated with academic performance in Brazilian students, independently of body mass index (BMI), fatness and socioeconomic status (SES). 392 5th and 6th grade students (193 girls) (12.11 ± 0.75 years old) were evaluated in 2012. Skinfold thickness measures were performed, and students were classified according to BMI-percentile. CRF was estimated by a 20-meter shuttle run test, and academic achievement by standardized math and Portuguese tests. Multiple linear regression analyses were conducted to explore the association between academic performance and CRF, adjusted for SES, skinfold thickness or BMI-percentile. Among girls CRF was associated with higher academic achievement in math (β = 0.146;p = .003) and Portuguese (β = 0.129;p = .004) in crude and adjusted analyses. No significant association was found among boys. BMI was not associated with overall academic performance. There was a weak negative association between skinfold thickness and performance in mathematics in boys (β =- 0.030;p = .04), but not in girls. The results highlight the importance of maintaining high fitness levels in girls throughout adolescence a period commonly associated with reductions in physical activity levels and CRF.

Maternal high-fat diet intensifies the metabolic response to stress in male rat offspring.

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Karbaschi, Roxana; Zardooz, Homeira; Khodagholi, Fariba; Dargahi, Leila; Salimi, Mina; Rashidi, FatemehSadat

2017-01-01

The mother's consumption of high-fat food can affect glucose metabolism and the hypothalamic-pituitary-adrenal axis responsiveness in the offspring and potentially affect the metabolic responses to stress as well. This study examines the effect of maternal high-fat diet on the expression of pancreatic glucose transporter 2 and the secretion of insulin in response to stress in offspring. Female rats were randomly divided into normal and high-fat diet groups and were fed in accordance with their given diets from pre-pregnancy to the end of lactation. The offspring were divided into control (NC and HFC) and stress (NS and HFS) groups based on their mothers' diet and exposure to stress in adulthood. After the two-week stress induction period was over, an intraperitoneal glucose tolerance test (IPGTT) was performed and plasma glucose and insulin levels were assessed. The pancreas was then removed for measuring insulin secretion from the isolated islets as well as glucose transporter 2 mRNA expression and protein levels. According to the results obtained, plasma corticosterone concentrations increased significantly on days 1 and 14 of the stress induction period and were lower on the last day compared to on the first day. In both the NS and HFS groups, stress reduced plasma insulin concentration in the IPGTT without changing the plasma glucose concentration, suggesting an increased insulin sensitivity in the NS and HFS groups, although more markedly in the latter. Stress reduced insulin secretion (at high glucose concentrations) and increased glucose transporter 2 mRNA and protein expression, especially in the HFS group. Mothers' high-fat diet appears to intensify the stress response by changing the programming of the neuroendocrine system in the offspring.

Effects of a 12-month exercise program on cardiorespiratory health indicators of Vietnam War veterans resident in the tropics.

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Kerr, Rebecca M; Leicht, Anthony S; Spinks, Warwick L

2008-06-01

To measure the effect of a combined aerobic and resistance exercise program on key cardiovascular disease risk factors (i.e. body composition or anthropometry and cardiorespiratory function) of Australian male, Vietnam War veterans living in the tropics. Twelve-month exercise program with assessments at commencement, 3, 6 and 12 months. North Queensland regional centre. Australian male, Vietnam War veterans (n = 164) resident in north Queensland. Measurement of heart rate, blood pressure, skinfold and girth measurements, exercise heart rate response and estimated aerobic capacity to determine whether the implementation of a simple aerobic and resistance exercise program could positively change selected cardiovascular disease risk factors in Vietnam Veterans. Significant improvements were reported for systolic blood pressure (131.1 (SD 15.7) reduced to 122.7 (12.4) mmHg), diastolic blood pressure (82.7 (9.1) reduced to 76.3 (10.3) mmHg), resting heart rate (73 (11) reduced to 69 (11) bpm), sum of skinfolds (127.5 (40.3) reduced to 99.5 (32.1) mm), waist girth (103.2 (12.0) reduced to 100.5 (12.1) cm), hip girth (105.3 (9.6) reduced to 103.7 (10.4) cm) and aerobic capacity (2.17 (0.39) increased to 2.36 (0.34) L min(-1)). Participation in a combined aerobic and resistance training program elicited significant anthropometric and cardiorespiratory benefits that might lead to a decreased risk of developing cardiovascular disease for male Vietnam War veterans resident in rural and regional areas.

High precision stress measurements in semiconductor structures by Raman microscopy

Energy Technology Data Exchange (ETDEWEB)

Uhlig, Benjamin

2009-07-01

Stress in silicon structures plays an essential role in modern semiconductor technology. This stress has to be measured and due to the ongoing miniaturization in today's semiconductor industry, the measuring method has to meet certain requirements. The present thesis deals with the question how Raman spectroscopy can be used to measure the state of stress in semiconductor structures. In the first chapter the relation between Raman peakshift and stress in the material is explained. It is shown that detailed stress maps with a spatial resolution close to the diffraction limit can be obtained in structured semiconductor samples. Furthermore a novel procedure, the so called Stokes-AntiStokes-Difference method is introduced. With this method, topography, tool or drift effects can be distinguished from stress related influences in the sample. In the next chapter Tip-enhanced Raman Scattering (TERS) and its application for an improvement in lateral resolution is discussed. For this, a study is presented, which shows the influence of metal particles on the intensity and localization of the Raman signal. A method to attach metal particles to scannable tips is successfully applied. First TERS scans are shown and their impact on and challenges for high resolution stress measurements on semiconductor structures is explained. (orig.)

Can high social capital at the workplace buffer against stress and musculoskeletal pain?

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Jay, Kenneth; Andersen, Lars L.

2018-01-01

Abstract Work-related musculoskeletal pain and stress are both highly prevalent in the working environment and relate well to the biopsychosocial model. While the onset of musculoskeletal pain is often dependent on the biological element of the biopsychosocial model, chronic pain is often influenced by psychological and social factors. Similarly, stress is also influenced by biological, psychological, and social factors. This study investigates the possibility of social capital being a buffer for stress and musculoskeletal pain in a group of female laboratory technicians. Female laboratory technicians (n = 500) replied to questions about stress (Cohens Perceived Stress Scale-10), musculoskeletal pain (0–10 visual analog scale), and social capital at the workplace (bonding [in teams], bridging [between teams], and linking [between teams and leaders]). Outcome variables were stress and musculoskeletal pain and the predictor variable was social capital. General linear models tested the association of the 3 types of social capital (predictor variables) with stress and pain (mutually adjusted outcome variables). Analyses were controlled for age, lifestyle (body mass index, smoking), seniority, and working hours per week. For stress as outcome, moderate and high bonding social capital were different from low social capital with −2.04 (95% confidence interval [CI] −3.33 to −0.76) and −4.56 (95% CI −5.84 to −3.28) points on the Perceived Stress Scale of 0 to 42, respectively. Similarly, moderate and high bridging social capital were different from low social capital with −1.50 (95% CI −2.76 to −0.24) and −4.39 (95% CI −5.75 to −3.03), respectively. For linking, only high social was significantly different from low with −2.94 (95% CI −4.28 to −1.60). None of the 3 types of social capital was associated with musculoskeletal pain. Higher levels of social capital at the workplace appear to buffer against stress, but not against

Stress and sleep quality in high school brazilian adolescents

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Gema Mesquita

2010-06-01

Full Text Available OBJECTIVE: The objective of the present study is to analyze the effect of stress on sleep quality in a group of adolescents. METHOD: Two high schools in Alfenas, southern Minas Gerais State, Brazil, were chosen to participate in the study. The sample consisted of both genders (n=160 with 65.63% females. The age range of participants was 15 to18 years. The Pittsburgh Sleep Quality Index (PSQI was applied for collection of data to quantify sleep quality. The Lipp Inventory of Stress Symptoms that objectively identifies symptoms of stress was applied. RESULTS: It was observed that 23.53% of stressed students and 45.33% of unstressed ones sleep well; 76.47% of stressed pupils and 54.67% of those unstressed do not sleep well. With regard to school performance, a mean of 0.65 was found for stressed students and 0.60 for those without stress, Mann-Whitney (p=0.0596. CONCLUSION: Stress contributed to raising the percentage of poor sleepers, as ell as increasing ean school performance.OBJETIVO: O objetivo do presente estudo foi analisar a influência do stress sobre a qualidade do sono em um grupo de adolescentes. MÉTODO: Foram escolhidas duas instituições educacionais do ensino médio, na cidade de Alfenas, sul de Minas Gerais, Brasil. A amostra foi composta por ambos os sexos (n=160, com 65,63% do sexo feminino. A faixa etária dos participantes foi de 15 a 18 anos. Para a coleta de dados aplicou-se: Índice de Qualidade de Sono de Pittsburgh (IQSP utilizado para quantificar a qualidade do sono; o Inventário de Sintomas de Stress para Adultos de Lipp (ISSL que identifica de modo objetivo a sintomatologia de stress foi aplicado. RESULTADOS: Observou-se que 23,53% dos estressados dormem bem e 45,33% dos não estressados dormem bem; 76,47% dos estressados não dormem bem e 54,67% dos não estressados não dormem bem. Quanto ao rendimento escolar têm-se as médias 0,65 para os alunos estressados e 0,60 para aqueles que não sofrem de stress, Mann

Exercise increases blood flow to locomotor, vestibular, cardiorespiratory and visual regions of the brain in miniature swine

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Delp, M. D.; Armstrong, R. B.; Godfrey, D. A.; Laughlin, M. H.; Ross, C. D.; Wilkerson, M. K.

2001-01-01

1. The purpose of these experiments was to use radiolabelled microspheres to measure blood flow distribution within the brain, and in particular to areas associated with motor function, maintenance of equilibrium, cardiorespiratory control, vision, hearing and smell, at rest and during exercise in miniature swine. Exercise consisted of steady-state treadmill running at intensities eliciting 70 and 100 % maximal oxygen consumption (V(O(2),max)). 2. Mean arterial pressure was elevated by 17 and 26 % above that at rest during exercise at 70 and 100 % V(O(2),max), respectively. 3. Mean brain blood flow increased 24 and 25 % at 70 and 100 % V(O(2),max), respectively. Blood flow was not locally elevated to cortical regions associated with motor and somatosensory functions during exercise, but was increased to several subcortical areas that are involved in the control of locomotion. 4. Exercise elevated perfusion and diminished vascular resistance in several regions of the brain related to the maintenance of equilibrium (vestibular nuclear area, cerebellar ventral vermis and floccular lobe), cardiorespiratory control (medulla and pons), and vision (dorsal occipital cortex, superior colliculi and lateral geniculate body). Conversely, blood flow to regions related to hearing (cochlear nuclei, inferior colliculi and temporal cortex) and smell (olfactory bulbs and rhinencephalon) were unaltered by exercise and associated with increases in vascular resistance. 5. The data indicate that blood flow increases as a function of exercise intensity to several areas of the brain associated with integrating sensory input and motor output (anterior and dorsal cerebellar vermis) and the maintenance of equilibrium (vestibular nuclei). Additionally, there was an intensity-dependent decrease of vascular resistance in the dorsal cerebellar vermis.

Does the MTHFR A1298C Polymorphism Modulate the Cardiorespiratory Response to Training?

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Cięszczyk, Paweł; Zarębska, Aleksandra; Jastrzębski, Zbigniew; Sawczyn, Michał; Kozakiewicz-Drobnik, Izabela; Leońska-Duniec, Agata; Kaczmarczyk, Mariusz; Maciejewska-Skrendo, Agnieszka; Żmijewski, Piotr; Trybek, Grzegorz; Smółka, Wojciech; Pilch, Jan; Leźnicka, Katarzyna; Lulińska-Kuklik, Ewelina; Sawczuk, Marek; Massidda, Myosotis

2016-12-01

The 5,10-methylenetetrahydrofolate reductase gene (MTHFR) A1298C polymorphic variant is a candidate to explain the individual differences in trainability and response to exercise training. Therefore, the aim of the study was to verify whether the A1298C polymorphism influenced the aerobic and anaerobic performance as well as body and mass composition in young Polish women following low-high impact aerobic exercise training. Two hundred and one women aged 21 ± 1 years (range 19-24) were included in the study. All of them completed a 12-week exercise training program and were measured for selected somatic features, aerobic capacity and cardiorespiratory fitness indices as well as peak anaerobic power and anaerobic capacity, before and after the intervention. A mixed 2 x 2 ANOVA for 20 dependent variables grouped in three categories was conducted. No significant interaction of the genotype with training for body mass and body composition variables was observed. Although, there were three significant genotype x training interactions for maximal oxygen uptake variables, regardless of body mass i.e.: for VO2max (p < 0.05), HRmax (p < 0.0001) and HRAT/HRmax (p < 0.0001). Significantly greater improvement in VO2max was gained by the CC+AC group compared to the AA genotype group. The present results support the hypothesis that individual differences in trainability are at least in part determined by the genetic component and MTHFR A1298C seems to be one of the many polymorphisms involved.

Role of high-fat diet in stress response of Drosophila.

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Erilynn T Heinrichsen

Full Text Available Obesity is associated with many diseases, one of the most common being obstructive sleep apnea (OSA, which in turn leads to blood gas disturbances, including intermittent hypoxia (IH. Obesity, OSA and IH are associated with metabolic changes, and while much mammalian work has been done, mechanisms underlying the response to IH, the role of obesity and the interaction of obesity and hypoxia remain unknown. As a model organism, Drosophila offers tremendous power to study a specific phenotype and, at a subsequent stage, to uncover and study fundamental mechanisms, given the conservation of molecular pathways. Herein, we characterize the phenotype of Drosophila on a high-fat diet in normoxia, IH and constant hypoxia (CH using triglyceride and glucose levels, response to stress and lifespan. We found that female flies on a high-fat diet show increased triglyceride levels (p<0.001 and a shortened lifespan in normoxia, IH and CH. Furthermore, flies on a high-fat diet in normoxia and CH show diminished tolerance to stress, with decreased survival after exposure to extreme cold or anoxia (p<0.001. Of interest, IH seems to rescue this decreased cold tolerance, as flies on a high-fat diet almost completely recovered from cold stress following IH. We conclude that the cross talk between hypoxia and a high-fat diet can be either deleterious or compensatory, depending on the nature of the hypoxic treatment.

Effect of classic massage in quality of life of university students

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Nuno Miguel Lopes de Oliveira

Full Text Available Abstract Introduction : Due to often excessive academic activities, some university students are affected by stress, anxiety and depression, which can negatively influence quality of life. The classical massage was tested as a strategy for improving quality of life, since it presents psychogenic effects that contribute to this. Objective : To evaluate the effects of classical massage on quality of life, in stress, anxiety, depression and cardiorespiratory variables of university students. Methods : The sample consisted of an intervention group and a control group. While the intervention group (n = 10 received ten massage sessions, twice a week, for 30 minutes in the region of the cervical and thoracic spine, the control group (n = 12 received no intervention. For evaluating psychological variables, the Quality of Life Scale, the Lipp Inventory of Stress Symptoms for Adults, and the Hospital Anxiety and Depression Scale were used. To assess cardiorespiratory variables, blood pressure, heart and respiratory rate were measured. Results : There was a significant improvement in quality of life and significant decrease in cardiorespiratory variables. Conclusion : The classic massage can be a strategy for the improvement of quality of life in university students who present symptoms of stress, anxiety, elevation of blood pressure, heart and respiratory rate.

Modelling Of Residual Stresses Induced By High Speed Milling Process

International Nuclear Information System (INIS)

Desmaison, Olivier; Mocellin, Katia; Jardin, Nicolas

2011-01-01

Maintenance processes used in heavy industries often include high speed milling operations. The reliability of the post-process material state has to be studied. Numerical simulation appears to be a very interesting way to supply an efficient residual stresses (RS) distribution prediction.Because the adiabatic shear band and the serrated chip shaping are features of the austenitic stainless steel high speed machining, a 2D high speed orthogonal cutting model is briefly presented. This finite element model, developed on Forge registered software, is based on data taken from Outeiro and al.'s paper [1]. A new behaviour law fully coupling Johnson-Cook's constitutive law and Latham and Cockcroft's damage model is detailed in this paper. It ensures results that fit those found in literature.Then, the numerical tools used on the 2D model are integrated to a 3D high speed milling model. Residual stresses distribution is analysed, on the surface and into the depth of the material. Various revolutions and passes of the two teeth hemispheric mill on the workpiece are simulated. Thus the sensitivity of the residual stresses generation to the cutting conditions can be discussed. In order to validate the 3D model, a comparison of the cutting forces measured by EDF R and D to those given by numerical simulations is achieved.

Stress Recovery Effects of High- and Low-Frequency Amplified Music on Heart Rate Variability.

Science.gov (United States)

Nakajima, Yoshie; Tanaka, Naofumi; Mima, Tatsuya; Izumi, Shin-Ichi

Sounds can induce autonomic responses in listeners. However, the modulatory effect of specific frequency components of music is not fully understood. Here, we examined the role of the frequency component of music on autonomic responses. Specifically, we presented music that had been amplified in the high- or low-frequency domains. Twelve healthy women listened to white noise, a stress-inducing noise, and then one of three versions of a piece of music: original, low-, or high-frequency amplified. To measure autonomic response, we calculated the high-frequency normalized unit (HFnu), low-frequency normalized unit, and the LF/HF ratio from the heart rate using electrocardiography. We defined the stress recovery ratio as the value obtained after participants listened to music following scratching noise, normalized by the value obtained after participants listened to white noise after the stress noise, in terms of the HFnu, low-frequency normalized unit, LF/HF ratio, and heart rate. Results indicated that high-frequency amplified music had the highest HFnu of the three versions. The stress recovery ratio of HFnu under the high-frequency amplified stimulus was significantly larger than that under the low-frequency stimulus. Our results suggest that the high-frequency component of music plays a greater role in stress relief than low-frequency components.

Cardiorespiratory responses and reduced apneic time to cold-water face immersion after high intensity exercise.

Science.gov (United States)

Konstantinidou, Sylvia; Soultanakis, Helen

2016-01-01

Apnea after exercise may evoke a neurally mediated conflict that may affect apneic time and create a cardiovascular strain. The physiological responses, induced by apnea with face immersion in cold water (10 °C), after a 3-min exercise bout, at 85% of VO2max,were examined in 10 swimmers. A pre-selected 40-s apnea, completed after rest (AAR), could not be met after exercise (AAE), and was terminated with an agonal gasp reflex, and a reduction of apneic time, by 75%. Bradycardia was evident with immersion after both, 40-s of AAR and after AAE (P<0.05). The dramatic elevation of, systolic pressure and pulse pressure, after AAE, were indicative of cardiovascular stress. Blood pressure after exercise without apnea was not equally elevated. The activation of neurally opposing functions as those elicited by the diving reflex after high intensity exercise may create an autonomic conflict possibly related to oxygen-conserving reflexes stimulated by the trigeminal nerve, and those elicited by exercise. Copyright © 2015. Published by Elsevier B.V.

Notch size effects on high cycle fatigue limit stress of Udimet 720

International Nuclear Information System (INIS)

Ren Weiju; Nicholas, Theodore

2003-01-01

Notch size effects on the high cycle fatigue (HCF) limit stress of Ni-base superalloy Udimet 720 were investigated on cylindrical specimens with three notch sizes of the same stress concentration factor K t =2.74. The HCF limit stress corresponding to a life of 10 6 cycles was experimentally determined at a stress ratio of 0.1 and a frequency of 25 Hz at room temperature. The stresses were calculated using finite element analysis (FEA) and the specimens analyzed using scanning electron microscopy (SEM). Test results show that at the same K t value, notch size can slightly affect the HCF limit stress of U720 when notch root plasticity occurs. FEA and SEM results reveal that the notch size effects are influenced by a complicated combination of the stress and plastic strain fields at the notch tip, the nominal stress, and the effects of prior plastic deformation on fatigue crack initiation

Epidemiology of stress fracture injuries among US high school athletes, 2005-2006 through 2012-2013.

Science.gov (United States)

Changstrom, Bradley G; Brou, Lina; Khodaee, Morteza; Braund, Cortney; Comstock, R Dawn

2015-01-01

High school athletes in the United States sustain millions of injuries annually, approximately 10% of which are fractures. However, there is no clear estimate of the number of stress fractures sustained by high school athletes annually despite reports that stress fractures account for 0.7% to 20% of injuries seen in sports medicine clinics. This suggests a high utilization of resources for a potentially preventable injury. In addition, stress fractures have been associated with low energy availability and disordered eating in young athletes, highlighting the importance of early recognition and intervention. To investigate stress fracture rates and patterns in a large national sample of US high school athletes. Descriptive epidemiologic study. Data from High School RIO (Reporting Information Online), a national sports injury surveillance study, were analyzed to describe rates and patterns of stress fracture injury sustained from 2005-2006 through 2012-2013, across sports and by sex. From 2005-2006 through 2012-2013, a total of 51,773 injuries were sustained during 25,268,873 athlete-exposures, of which 389 (0.8%) were stress fractures, resulting in an overall stress fracture rate of 1.54 per 100,000 athlete-exposures. Rates per 100,000 athlete-exposures were highest in girls' cross country (10.62), girls' gymnastics (7.43), and boys' cross country (5.42). In sex-comparable sports, girls sustained more stress fractures (63.3%) than did boys (36.7%) and had higher rates of stress fracture (2.22 vs 1.27; rate ratio, 1.75; 95% CI, 1.38-2.23). The most commonly injured sites were the lower leg (40.3% of all stress fractures), foot (34.9%), and lower back/lumbar spine/pelvis (15.2%). Management was nonsurgical in 98.7% of the cases, and 65.3% of injuries resulted in ≥3 weeks of time loss, medical disqualification, or an end to the season before athletes could return to play. Although a rare injury, stress fractures cause considerable morbidity for high school athletes

High Compressive Stresses Near the Surface of the Sierra Nevada, California

Science.gov (United States)

Martel, S. J.; Logan, J. M.; Stock, G. M.

2012-12-01

Observations and stress measurements in granitic rocks of the Sierra Nevada, California reveal strong compressive stresses parallel to the surface of the range at shallow depths. New overcoring measurements show high compressive stresses at three locations along an east-west transect through Yosemite National Park. At the westernmost site (west end of Tenaya Lake), the mean compressive stress is 1.9. At the middle site (north shore of Tenaya Lake) the mean compressive stress is 6.8 MPa. At the easternmost site (south side of Lembert Dome) the mean compressive stress is 3.0 MPa. The trend of the most compressive stress at these sites is within ~30° of the strike of the local topographic surface. Previously published hydraulic fracturing measurements by others elsewhere in the Sierra Nevada indicate surface-parallel compressive stresses of several MPa within several tens of meters of the surface, with the stress magnitudes generally diminishing to the west. Both the new and the previously published compressive stress magnitudes are consistent with the presence of sheeting joints (i.e., "exfoliation joints") in the Sierra Nevada, which require lateral compressive stresses of several MPa to form. These fractures are widespread: they are distributed in granitic rocks from the north end of the range to its southern tip and across the width of the range. Uplift along the normal faults of the eastern escarpment, recently measured by others at ~1-2 mm/yr, probably contributes to these stresses substantially. Geodetic surveys reveal that normal faulting flexes a range concave upwards in response to fault slip, and this flexure is predicted by elastic dislocation models. The topographic relief of the eastern escarpment of the Sierra Nevada is 2-4 km, and since alluvial fill generally buries the bedrock east of the faults, the offset of granitic rocks is at least that much. Compressive stresses of several MPa are predicted by elastic dislocation models of the range front

What characterizes persons with high levels of perceived stress in Denmark? A national representative study.

Science.gov (United States)

Nielsen, Line; Curtis, Tine; Kristensen, Tage S; Rod Nielsen, Naja

2008-06-01

Stress is a growing public health problem, but there are only a few studies with national representative samples on the occurrence of stress. The aim of this study was to assess the level of stress, measured by the Perceived Stress Scale, in Denmark, and to identify and characterize the group with high levels of stress by factors measured at both the individual and neighbourhood levels in a national representative sample of the Danish population. The 10,022 participants in the National Health Interview Survey 2005 were asked about perceived stress and individual factors in a cross-sectional design. Information on neighbourhood factors was derived from a national registry. Data were analysed by means of logistic regression models. Low education, heavy smoking, physical inactivity, lack of social network and poor working conditions were associated with perceived stress. For women, living in a neighbourhood with low average education, and for men, living in a neighbourhood with a high rate of crime and a low degree of ethnic diversity, were associated with higher perceived stress. Perceived stress was also related to indicators of morbidity. The group with high perceived stress is characterized by individual and neighbourhood factors with negative impacts on quality of life and risk of illness. This knowledge can guide future stress prevention efforts. Additionally, the results suggest a negative social component where perceived stress, unhealthy lifestyle and low social status are accumulated, and perceived stress might be used as a measure to identify groups characterized by accumulation of risk factors.

A Comparison between Alpine Skiing, Cross-Country Skiing and Indoor Cycling on Cardiorespiratory and Metabolic Response

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Thomas Stöggl, Christoph Schwarzl, Edith E. Müller, Masaru Nagasaki, Julia Stöggl, Peter Scheiber, Martin Schönfelder, Josef Niebauer

2016-03-01

Full Text Available Since physical inactivity especially prevails during winter months, we set out to identify outdoor alternatives to indoor cycling (IC by comparing the metabolic and cardiorespiratory responses during alpine skiing (AS, cross-country skiing (XCS and IC and analyse the effects of sex, age and fitness level in this comparison. Twenty one healthy subjects performed alpine skiing (AS, cross-country skiing (XCS, and IC. Oxygen uptake (VO2, total energy expenditure (EE, heart rate (HR, lactate, blood glucose and rate of perceived exertion (RPE were determined during three 4-min stages of low, moderate and high intensity. During XCS and IC VO2max and EE were higher than during AS. At least 2½ hours of AS are necessary to reach the same EE as during one hour of XCS or IC. HR, VO2, lactate, and RPEarms were highest during XCS, whereas RPEwhole-body was similar and RPElegs lower than during AS and IC, respectively. Weight adjusted VO2 and EE were higher in men than in women while fitness level had no effect. Male, fit and young participants were able to increase their EE and VO2 values more pronounced. Both AS and XCS can be individually tailored to serve as alternatives to IC and may thus help to overcome the winter activity deficit. XCS was found to be the most effective activity for generating a high EE and VO2 while AS was the most demanding activity for the legs.

STRESS FRACTURE OF THE FIRST RIB IN A HIGH SCHOOL WEIGHT LIFTER

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Hiroyuki Fujioka

2009-06-01

Full Text Available A 17-year-old boy, who played a weight lifting in high school, sustained stress fracture of the first rib without any causes. We successfully treated first rib stress fracture with limitation of using the upper extremity and with using low-intensity pulsed ultrasound

A novel land use approach for assessment of human health: The relationship between urban structure types and cardiorespiratory disease risk.

Science.gov (United States)

Réquia Júnior, Weeberb João; Roig, Henrique Llacer; Koutrakis, Petros

2015-12-01

Extensive evidence shows that in addition to lifestyle factors, environmental aspects are an important risk factor for human health. Numerous approaches have been used to estimate the relationship between environment and health. For example, the urban characteristics, especially the types of land use, are considered a potential proxy indicator to evaluate risk of disease. Although several studies have used land use variables to assess human health, none of them has used the concept of Urban Morphology by Urban Structure Types (USTs) as indicators of land use. The aim of this study was to assess the relationship between USTs and cardiorespiratory disease risks in the Federal District, Brazil. Toward this end, we used a quantile regression model to estimate risk. We used 21 types of UST. Income and population density were used as covariates in our sensitivity analysis. Our analysis showed an association between cardiorespiratory diseases risk and 10 UST variables (1 related to rural area, 6 related to residential area, 1 recreational area, 1 public area and 1 commercial area). Our findings suggest that the conventional land use method may be missing important information about the effect of land use on human health. The use of USTs can be an approach to complement the conventional method. This should be of interest to policy makers in order to enhance public health policies and to create future strategies in terms of urban planning, land use and environmental health. Copyright © 2015 Elsevier Ltd. All rights reserved.

Wind-Induced Fatigue Analysis of High-Rise Steel Structures Using Equivalent Structural Stress Method

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Zhao Fang

2017-01-01

Full Text Available Welded beam-to-column connections of high-rise steel structures are susceptive to fatigue damage under wind loading. However, most fatigue assessments in the field of civil engineering are mainly based on nominal stress or hot spot stress theories, which has the disadvantage of dependence on the meshing styles and massive curves selected. To address this problem, in this paper, the equivalent structural stress method with advantages of mesh-insensitive quality and capability of unifying different stress-life curves (S-N curves into one is introduced to the wind-induced fatigue assessment of a large-scale complicated high-rise steel structure. The multi-scale finite element model is established and the corresponding wind loading is simulated. Fatigue life assessments using equivalent structural stress method, hot spot stress method and nominal stress method are performed, and the results are verified and comparisons are made. The mesh-insensitive quality is also verified. The results show that the lateral weld toe of the butt weld connecting the beam flange plate and the column is the location where fatigue damage most likely happens. Nominal stress method considers fatigue assessment of welds in a more global way by averaging all the stress on the weld section while in equivalent structural stress method and hot spot method local stress concentration can be taken into account more precisely.

[Weight status and cardiorespiratory fitness in school students in the central region of Peru].

Science.gov (United States)

Bustamante, Alcibíades; Maia, José

2013-07-01

To determine the frequency of overweight and obesity in relation to cardiorespiratory fitness (CRF) levels in school students in 4 districts of the central region of Peru, and to analyze the relations among these variables. Weight, height and CRF were evaluated in 7841 school students who reside in four districts located on the coast, in the highlands and in the jungle of the central region of the country. Overweight and obesity were classified according to the criteria proposed by Cole. CRF was evaluated by a 12-minute run/walk test taken from the American Alliance for Health, Physical Education, Recreation and Dance's test battery. ANOVA and logistic regression were used to examine the differences of the averages and the associations among these variables. Both male and female school students have similar frequency of overweight and obesity (20.9% in women and 20.1% in men). Residents of the coast (Barranco) presen thigh frequency of overweight and obesity (37.8%). Age, sex, geographical area and CRF were significant predictors of overweight and obesity. School students who live in Barranco are five times more likely to be obese (OR=4.67; CI95%: 3.55-6.14), while those who reside in the highlands (Junin) are less likely to be obese (OR=0.03; CI95%: 0.01-0.20). Furthermore, in contrast with students with high CRF, those with low CRF are more likely to be obese (OR=11.82; CI95%: 7.25-19.27). There was a high frequency of overweight and obesity among school students who reside in Barranco. Low CRF is associated with overweight and obesity.

Stress relief of ceramic components in high voltage assemblies. Final report

International Nuclear Information System (INIS)

Heinen, R.J.

1979-02-01

Two types of ceramic packages were evaluated to determine the effectiveness of encapsulating the ceramic components in beta eucryptite filled epoxy. The requirements (no high voltage breakdown, no ceramic cracking, and no encapsulant cracking) were met by the spark gap assembly, but the sprytron assembly had cracking in the encapsulant after thermal cycling. The encapsulation of the ceramic component in beta eucryptite filled epoxy with a stress decoupling material selectively applied in the stress concentrated areas were used to prevent cracking in the sprytron encapsulant. This method is proposed as the standard encapsulation process for high voltage ceramic components

Melatonin induction and its role in high light stress tolerance in Arabidopsis thaliana.

Science.gov (United States)

Lee, Hyoung Yool; Back, Kyoungwhan

2018-05-16

In plants, melatonin is a potent bioactive molecule involved in the response against various biotic and abiotic stresses. However, little is known of its defensive role against high light (HL) stress. In this study, we found that melatonin was transiently induced in response to HL stress in Arabidopsis thaliana with a simultaneous increase in the expression of melatonin biosynthetic genes, including serotonin N-acetyltransferase1 (SNAT1). Transient induction of melatonin was also observed in the flu mutant, a singlet oxygen ( 1 O 2 )-producing mutant, upon light exposure, suggestive of melatonin induction by chloroplastidic 1 O 2 against HL stress. An Arabidopsis snat1 mutant was devoid of melatonin induction upon HL stress, resulting in high susceptibility to HL stress. Exogenous melatonin treatment mitigated damage caused by HL stress in the snat1 mutant by reducing O 2 - production and increasing the expression of various ROS-responsive genes. In analogy, an Arabidopsis SNAT1-overexpressing line showed increased tolerance of HL stress concomitant with a reduction in malondialdehyde and ion leakage. A complementation line expressing an Arabidopsis SNAT1 genomic fragment in the snat1 mutant completely restored HL stress susceptibility in the snat1 mutant to levels comparable to that of wild-type Col-0 plants. The results of the analysis of several Arabidopsis genetic lines reveal for the first time at the genetic level that melatonin is involved in conferring HL stress tolerance in plants. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Proteomic analysis of broccoli (Brassica oleracea) under high temperature and waterlogging stresses.

Science.gov (United States)

Lin, Hsin-Hung; Lin, Kuan-Hung; Chen, Su-Ching; Shen, Yu-Hsing; Lo, Hsiao-Feng

2015-12-01

The production of broccoli (Brassica oleracea) is largely reduced by waterlogging and high temperature stresses. Heat-tolerant and heat-susceptible broccoli cultivars TSS-AVRDC-2 and B-75, respectively, were used for physiological and proteomic analyses. The objective of this study was to identify TSS-AVRDC-2 and B-75 proteins differentially regulated at different time periods in response to waterlogging at 40 °C for three days. TSS-AVRDC-2 exhibited significantly higher chlorophyll content, lower stomatal conductance, and better H 2 O 2 scavenging under stress in comparison to B-75. Two-dimensional liquid phase fractionation analyses revealed that Rubisco proteins in both varieties were regulated under stressing treatments, and that TSS-AVRDC-2 had higher levels of both Rubisco large and small subunit transcripts than B-75 when subjected to high temperature and/or waterlogging. This report utilizes physiological and proteomic approaches to discover changes in the protein expression profiles of broccoli in response to heat and waterlogging stresses. Higher levels of Rubisco proteins in TSS-AVRDC-2 could lead to increased carbon fixation efficiency to provide sufficient energy to enable stress tolerance under waterlogging at 40 °C.

Influence of taekwondo as security martial arts training on anaerobic threshold, cardiorespiratory fitness, and blood lactate recovery.

Science.gov (United States)

Kim, Dae-Young; Seo, Byoung-Do; Choi, Pan-Am

2014-04-01

[Purpose] This study was conducted to determine the influence of Taekwondo as security martial arts training on anaerobic threshold, cardiorespiratory fitness, and blood lactate recovery. [Subjects and Methods] Fourteen healthy university students were recruited and divided into an exercise group and a control group (n = 7 in each group). The subjects who participated in the experiment were subjected to an exercise loading test in which anaerobic threshold, value of ventilation, oxygen uptake, maximal oxygen uptake, heart rate, and maximal values of ventilation / heart rate were measured during the exercise, immediately after maximum exercise loading, and at 1, 3, 5, 10, and 15 min of recovery. [Results] At the anaerobic threshold time point, the exercise group showed a significantly longer time to reach anaerobic threshold. The exercise group showed significantly higher values for the time to reach VO2max, maximal values of ventilation, maximal oxygen uptake and maximal values of ventilation / heart rate. Significant changes were observed in the value of ventilation volumes at the 1- and 5-min recovery time points within the exercise group; oxygen uptake and maximal oxygen uptake were significantly different at the 5- and 10-min time points; heart rate was significantly different at the 1- and 3-min time points; and maximal values of ventilation / heart rate was significantly different at the 5-min time point. The exercise group showed significant decreases in blood lactate levels at the 15- and 30-min recovery time points. [Conclusion] The study results revealed that Taekwondo as a security martial arts training increases the maximal oxygen uptake and anaerobic threshold and accelerates an individual's recovery to the normal state of cardiorespiratory fitness and blood lactate level. These results are expected to contribute to the execution of more effective security services in emergencies in which violence can occur.

Increasing age is a major risk factor for susceptibility to heat stress during physical activity.

Science.gov (United States)

McGinn, Ryan; Poirier, Martin P; Louie, Jeffrey C; Sigal, Ronald J; Boulay, Pierre; Flouris, Andreas D; Kenny, Glen P

2017-11-01

We evaluated the extent to which age, cardiorespiratory fitness, and body fat can independently determine whole-body heat loss (WBHL) in 87 otherwise healthy adults. We show that increasing age is a major predictor for decreasing WBHL in otherwise healthy adults (aged 20-70 years), accounting for 40% of the variation in the largest study to date. While greater body fat also had a minor detrimental impact on WBHL, there was no significant role for cardiorespiratory fitness.

Financial stress, parent functioning and adolescent problem behavior: an actor-partner interdependence approach to family stress processes in low-, middle-, and high-income families.

Science.gov (United States)

Ponnet, Koen

2014-10-01

The family stress model proposes that financial stress experienced by parents is associated with problem behavior in adolescents. The present study applied an actor-partner interdependence approach to the family stress model and focused on low-, middle-, and high-income families to broaden our understanding of the pathways by which the financial stress of mothers and fathers are related to adolescent outcomes. The study uses dyadic data (N = 798 heterosexual couples) from the Relationship between Mothers, Fathers and Children study in which two-parent families with an adolescent between 11 and 17 years of age participated. Path-analytic results indicated that in each of the families the association between parents' financial stress and problem behavior in adolescents is mediated through parents' depressive symptoms, interparental conflict, and positive parenting. Family stress processes also appear to operate in different ways for low-, middle-, and high-income families. In addition to a higher absolute level of financial stress in low-income families, financial stress experienced by mothers and fathers in these families had significant direct and indirect effects on problem behavior in adolescents, while in middle- and high-income families only significant indirect effects were found. The financial stress of a low-income mother also had a more detrimental impact on her level of depressive feelings than it had on mothers in middle-income families. Furthermore, the study revealed gender differences in the pathways of mothers and fathers. Implications for research, clinical practice, and policy are also discussed.

Cardiorespiratory fitness attenuates risk for major adverse cardiac events in hyperlipidemic men and women independent of statin therapy: The Henry Ford ExercIse Testing Project.

Science.gov (United States)

Hung, Rupert K; Al-Mallah, Mouaz H; Qadi, Mohamud A; Shaya, Gabriel E; Blumenthal, Roger S; Nasir, Khurram; Brawner, Clinton A; Keteyian, Steven J; Blaha, Michael J

2015-08-01

We sought to evaluate the effect of cardiorespiratory fitness (CRF) in predicting mortality, myocardial infarction (MI), and revascularization in patients with hyperlipidemia after stratification by gender and statin therapy. This retrospective cohort study included 33,204 patients with hyperlipidemia (57 ± 12 years old, 56% men, 25% black) who underwent physician-referred treadmill stress testing at the Henry Ford Health System from 1991 to 2009. Patients were stratified by gender, baseline statin therapy, and estimated metabolic equivalents from stress testing. We computed hazard ratios using Cox regression models after adjusting for demographics, cardiac risk factors, comorbidities, pertinent medications, interaction terms, and indication for stress testing. There were 4,851 deaths, 1,962 MIs, and 2,686 revascularizations over a median follow-up of 10.3 years. In men and women not on statin therapy and men and women on statin therapy, each 1-metabolic equivalent increment in CRF was associated with hazard ratios of 0.86 (95% CI 0.85-0.88), 0.83 (95% CI 0.81-0.85), 0.85 (95% CI 0.83-0.87), and 0.84 (95% CI 0.81-0.87) for mortality; 0.93 (95% CI 0.90-0.96), 0.87 (95% CI 0.83-0.91), 0.89 (95% CI 0.86-0.92), and 0.90 (95% CI 0.86-0.95) for MI; and 0.91 (95% CI 0.88-0.93), 0.87 (95% CI 0.83-0.91), 0.89 (95% CI 0.87-0.92), and 0.90 (95% CI 0.86-0.94) for revascularization, respectively. No significant interactions were observed between CRF and statin therapy (P > .23). Higher CRF attenuated risk for mortality, MI, and revascularization independent of gender and statin therapy in patients with hyperlipidemia. These results reinforce the prognostic value of CRF and support greater promotion of CRF in this patient population. Copyright © 2015 Elsevier Inc. All rights reserved.

High stresses stored in fault zones: example of the Nojima fault (Japan)

Science.gov (United States)

Boullier, Anne-Marie; Robach, Odile; Ildefonse, Benoît; Barou, Fabrice; Mainprice, David; Ohtani, Tomoyuki; Fujimoto, Koichiro

2018-04-01

During the last decade pulverized rocks have been described on outcrops along large active faults and attributed to damage related to a propagating seismic rupture front. Questions remain concerning the maximal lateral distance from the fault plane and maximal depth for dynamic damage to be imprinted in rocks. In order to document these questions, a representative core sample of granodiorite located 51.3 m from the Nojima fault (Japan) that was drilled after the Hyogo-ken Nanbu (Kobe) earthquake is studied by using electron backscattered diffraction (EBSD) and high-resolution X-ray Laue microdiffraction. Although located outside of the Nojima damage fault zone and macroscopically undeformed, the sample shows pervasive microfractures and local fragmentation. These features are attributed to the first stage of seismic activity along the Nojima fault characterized by laumontite as the main sealing mineral. EBSD mapping was used in order to characterize the crystallographic orientation and deformation microstructures in the sample, and X-ray microdiffraction was used to measure elastic strain and residual stresses on each point of the mapped quartz grain. Both methods give consistent results on the crystallographic orientation and show small and short wavelength misorientations associated with laumontite-sealed microfractures and alignments of tiny fluid inclusions. Deformation microstructures in quartz are symptomatic of the semi-brittle faulting regime, in which low-temperature brittle plastic deformation and stress-driven dissolution-deposition processes occur conjointly. This deformation occurred at a 3.7-11.1 km depth interval as indicated by the laumontite stability domain. Residual stresses are calculated from deviatoric elastic strain tensor measured using X-ray Laue microdiffraction using the Hooke's law. The modal value of the von Mises stress distribution is at 100 MPa and the mean at 141 MPa. Such stress values are comparable to the peak strength of a

High stresses stored in fault zones: example of the Nojima fault (Japan

Directory of Open Access Journals (Sweden)

A.-M. Boullier

2018-04-01

Full Text Available During the last decade pulverized rocks have been described on outcrops along large active faults and attributed to damage related to a propagating seismic rupture front. Questions remain concerning the maximal lateral distance from the fault plane and maximal depth for dynamic damage to be imprinted in rocks. In order to document these questions, a representative core sample of granodiorite located 51.3 m from the Nojima fault (Japan that was drilled after the Hyogo-ken Nanbu (Kobe earthquake is studied by using electron backscattered diffraction (EBSD and high-resolution X-ray Laue microdiffraction. Although located outside of the Nojima damage fault zone and macroscopically undeformed, the sample shows pervasive microfractures and local fragmentation. These features are attributed to the first stage of seismic activity along the Nojima fault characterized by laumontite as the main sealing mineral. EBSD mapping was used in order to characterize the crystallographic orientation and deformation microstructures in the sample, and X-ray microdiffraction was used to measure elastic strain and residual stresses on each point of the mapped quartz grain. Both methods give consistent results on the crystallographic orientation and show small and short wavelength misorientations associated with laumontite-sealed microfractures and alignments of tiny fluid inclusions. Deformation microstructures in quartz are symptomatic of the semi-brittle faulting regime, in which low-temperature brittle plastic deformation and stress-driven dissolution-deposition processes occur conjointly. This deformation occurred at a 3.7–11.1 km depth interval as indicated by the laumontite stability domain. Residual stresses are calculated from deviatoric elastic strain tensor measured using X-ray Laue microdiffraction using the Hooke's law. The modal value of the von Mises stress distribution is at 100 MPa and the mean at 141 MPa. Such stress values are comparable to

Effects of a 2-year school-based daily physical activity intervention on cardiorespiratory fitness: the Sogndal school-intervention study

DEFF Research Database (Denmark)

Resaland, G K; Andersen, Lars Bo; Mamen, A

2011-01-01

The aim of this study was to describe changes in children's cardiorespiratory fitness (CRF) following a school-based physical activity (PA) intervention. In total, 259 children (age 9.3+/-0.3 years) were invited to participate, of whom 256 participated. The children from the intervention school (63...... boys, 62 girls) carried out 60-min PA over 2 school years. The children from the control school (62 boys, 69 girls) had the regular curriculum-defined amount of physical education in school, i.e. 45 min twice weekly. One hundred and eighty-eight children (73.4%) successfully completed both the baseline...

Growth and Development Temperature Influences Level of Tolerance to High Light Stress 1

Science.gov (United States)

Steffen, Kenneth L.; Palta, Jiwan P.

1989-01-01

The influence of growth and development temperature on the relative tolerance of photosynthetic tissue to high light stress at chilling temperatures was investigated. Two tuber-bearing potato species, Solanum tuberosum L. cv Red Pontiac and Solanum commersonii were grown for 4 weeks, at either 12 or 24°C with 12 hours of about 375 micromoles per second per square meter of photosynthetically active radiation. Paired leaf discs were cut from directly across the midvein of leaflets of comparable developmental stage and light environment from each species at each growth temperature treatment. One disc of each pair was exposed to 1°C and about 1000 micromoles per second per square meter photosynthetically active radiation for 4 hours, and the other disc was held at 1°C in total darkness for the same duration. Photosynthetic tissue of S. tuberosum, developed at 12°C, was much more tolerant to high light and low temperature stress than tissue developed under 24°C conditions. Following the high light treatment, 24°C-grown S. tuberosum tissue demonstrated light-limited and light-saturated rates that were approximately 50% of their paired dark controls. In contrast, the 12°C-grown tissue from S. tuberosum that was subjected to the light stress showed only a 18 and 6% reduction in light-limited and light-saturated rates of photosynthetic oxygen evolution, respectively. Tissue from 24°C-grown S. commersonii was much less sensitive to the light stress than was tissue from S. tuberosum grown under the same conditions. The results presented here demonstrate that: (a) acclimation of S. tuberosum to lower temperature growth conditions with a constant light environment, results in the increased capacity of photosynthetic tissue to tolerate high light stress at chilling temperature and (b) following growth and development at relatively high temperatures S. commersonii, a frost- and heat-tolerant wild species, has a much greater tolerance to the high light stress at chilling

Instantaneous strain measurements during high-temperature stress cycling of a dispersion-strengthened niobium alloy

International Nuclear Information System (INIS)

Farkas, D.M.; Mishra, R.S.; Mukherjee, A.K.

1995-01-01

Experimental results obtained from stress cycling tests performed during high-temperature creep of a dispersion strengthened niobium alloy indicate that the instantaneous strain following the stress change decreases with accumulated strain. The true work-hardening rate was shown to be a small fraction of the elastic modulus which remained fairly constant throughout the strain history. The instantaneous strain change from a stress addition was typically greater than the strain from the corresponding stress reduction. This effect is quite pronounced for small stress changes and diminishes as the magnitude of the stress change increases. This implies that the mobility of dislocations is impeded in the reverse direction unless the magnitude of stress reduction exceeds the value of the internal stress

The study on stress-strain state of the spring at high temperature using ABAQUS

Directory of Open Access Journals (Sweden)

H Sun

2014-01-01

Full Text Available Cylindrical helical springs are widely used in the elements of thermal energy devices. It is necessary to guarantee the stability of the stress state of spring in high temperature. Relaxation phenomenon of stress is studied in this paper. Calculations are carried out in the environment of ABAQUS. The verification is taken out using analytical calculations.This paper describes the distribution and character of stress contour lines on the cross section of spring under the condition of instantaneous load, explicates the relaxation law with time. Research object is cylindrical helical spring, that working at high temperature. The purpose of this work is to get the stress relaxation law of spring, and to guarantee the long-term strength.This article presents the basic theory of helical spring. Establishes spring mathematical model of creep under the loads of compression and torsion. The stress formulas of each component in the cross section of spring are given. The calculation process of relaxation is analyzed in the program ABAQUS.In this paper compare the analytical formulas of spring stress with the simulation results, which are created by program ABAQUS.Finite element model for stress creep analysis in the cross section is created, material of spring – stainless steel 10X18N9T, springs are used at the temperature 650℃.At the beginning, stress-stain of spring is in the elastic state. Analyzes the change law of creep stress under the condition of constant load and a fixed compression.When analyzing under the condition of a fixed compression, the stresses are quickly decreased in most area in the cross section of spring, and the point of minimum shear stress gradually moves to the direction of outer diameter, because of this, stresses in a small area near the center increase slowly at first then decrease gradually with time. When analyzing under the condition of constant load, the stresses are quickly decreased in the around area and in creased

High-intensity interval training versus moderate-intensity continuous training within cardiac rehabilitation: a systematic review and meta-analysis

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Hannan AL

2018-01-01

Full Text Available Amanda L Hannan,1 Wayne Hing,1 Vini Simas,1 Mike Climstein,2,3 Jeff S Coombes,4 Rohan Jayasinghe,5–7 Joshua Byrnes,8 James Furness1 1Faculty of Health Sciences & Medicine, Bond University, Gold Coast, QLD, Australia; 2Exercise Health and Performance Faculty Research Group, Faculty of Health Sciences, The University of Sydney, Sydney, NSW, Australia; 3Water Based Research Unit, Bond University, Gold Coast, QLD, Australia; 4School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, QLD, Australia; 5Cardiology Department, Gold Coast University Hospital, Gold Coast, QLD, Australia; 6Griffith University, Gold Coast, QLD, Australia; 7Macquarie University, Sydney, NSW, Australia; 8Centre for Applied Health Economics, School of Medicine, Griffith University, Logan, QLD, Australia Background: Aerobic capacity has been shown to be inversely proportionate to cardiovascular mortality and morbidity and there is growing evidence that high-intensity interval training (HIIT appears to be more effective than moderate-intensity continuous training (MICT in improving cardiorespiratory fitness within the cardiac population. Previously published systematic reviews in cardiovascular disease have neither investigated the effect that the number of weeks of intervention has on cardiorespiratory fitness changes, nor have adverse events been collated. Objective: We aimed to undertake a systematic review and meta-analysis of randomized controlled trials (RCTs within the cardiac population that investigated cardiorespiratory fitness changes resulting from HIIT versus MICT and to collate adverse events. Methods: A critical narrative synthesis and meta-analysis was conducted after systematically searching relevant databases up to July 2017. We searched for RCTs that compared cardiorespiratory fitness changes resulting from HIIT versus MICT interventions within the cardiac population. Results: Seventeen studies, involving 953 participants (465

Effects of high concentration of chromium stress on physiological ...

African Journals Online (AJOL)

We studied the effects of high concentration of chromium (Cr) stress on physiological and biochemical characters and accumulation of Cr in Pingyang Tezao tea [Camellia sinensis (L) O. Kutze 'Pingyangtezao'] through a pot experiment. The results show that the indicators of photosynthesis were all suppressed with ...

Does the MTHFR A1298C Polymorphism Modulate the Cardiorespiratory Response to Training?

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Cięszczyk Paweł

2016-12-01

Full Text Available The 5,10-methylenetetrahydrofolate reductase gene (MTHFR A1298C polymorphic variant is a candidate to explain the individual differences in trainability and response to exercise training. Therefore, the aim of the study was to verify whether the A1298C polymorphism influenced the aerobic and anaerobic performance as well as body and mass composition in young Polish women following low-high impact aerobic exercise training. Two hundred and one women aged 21 ± 1 years (range 19–24 were included in the study. All of them completed a 12-week exercise training program and were measured for selected somatic features, aerobic capacity and cardiorespiratory fitness indices as well as peak anaerobic power and anaerobic capacity, before and after the intervention. A mixed 2 x 2 ANOVA for 20 dependent variables grouped in three categories was conducted. No significant interaction of the genotype with training for body mass and body composition variables was observed. Although, there were three significant genotype x training interactions for maximal oxygen uptake variables, regardless of body mass i.e.: for VO2max (p < 0.05, HRmax (p < 0.0001 and HRAT/HRmax (p < 0.0001. Significantly greater improvement in VO2max was gained by the CC+AC group compared to the AA genotype group. The present results support the hypothesis that individual differences in trainability are at least in part determined by the genetic component and MTHFR A1298C seems to be one of the many polymorphisms involved.

Cardiorespiratory fitness not sedentary time or physical activity is associated with cardiometabolic risk in active older adults.

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Pollock, R D; Duggal, N A; Lazarus, N R; Lord, J M; Harridge, S D R

2018-02-10

Sedentary time (ST) and moderate-to-vigorous physical activity (MVPA) are associated with cardiometabolic health. Cardiorespiratory fitness (CRF) is also implicated but often overlooked in health recommendations. This study assessed the relationships between ST, MVPA, CRF, and cardiometabolic health in highly active older individuals. 125 healthy amateur cyclists aged 55 to 79 years had their ST and MVPA levels assessed by actigraphy over a 7-day period. CRF was assessed using a maximal effort cycle ergometry test to determine VO 2max with results normalized to both body mass and fat-free mass measured by DXA. Markers of cardiometabolic risk (blood glucose, triglycerides, cholesterol, HDL, LDL, Insulin, HOMA IR, blood pressure, and body fat) were assessed and used to determine cumulative cardiometabolic risk. Multiple linear regression was used to assess ST, MVPA, and CRF associations with cardiometabolic health with the relationship between activity levels and CRF determined. CRF was associated with training volume (P = .003), but not ST or MVPA. A high CRF was associated with lower cumulative cardiometabolic risk, body fat percentage, triglyceride, and HDL levels (P < .05 in all cases). MVPA was negatively associated with body fat percentage, while ST was not associated with any marker of cardiometabolic risk when adjusting for activity levels. An association between CRF and cardiometabolic risk even in a group of older individuals with high fitness levels highlights the importance that CRF may have in maintaining health. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Elite sport is not an additional source of distress for adolescents with high stress levels.

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Gerber, Markus; Holsboer-Trachsler, Edith; Pühse, Uwe; Brand, Serge

2011-04-01

This study examined whether participation in elite sport interacts with stress in decreasing or increasing symptoms of depression and anxiety among adolescents, and further, whether the interplay between participation in high-performance sport and stress is related to the perceived quality of sleep. 434 adolescents (278 girls, 156 boys; age: M = 17.2 yr.) from 15 "Swiss Olympic Sport Classes" and 9 conventional classes answered a questionnaire and completed a 7-day sleep log. Analyses of covariance showed that heightened stress was related to more depressive symptoms and higher scores for trait-anxiety. Moreover, those classified as having poor sleep by a median split cutoff reported higher levels of depressive symptoms. No significant (multivariate) main effects were found for high-performance sport athletes. Similarly, no significant two- or three-way interaction effects were found. These results caution against exaggerated expectations concerning sport participation as a stress buffer. Nevertheless, participation in high-performance sport was not found to be an additional source of distress for adolescents who reported high stress levels despite prior research that has pointed toward such a relationship.

Threading dislocation movement in AlGaN/GaN-on-Si high electron mobility transistors under high temperature reverse bias stressing

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W. A. Sasangka

2016-09-01

Full Text Available Dislocations are known to be associated with both physical and electrical degradation mechanisms of AlGaN/GaN-on-Si high electron mobility transistors (HEMTs. We have observed threading dislocation movement toward the gate-edges in AlGaN/GaN-on-Si HEMT under high reverse bias stressing. Stressed devices have higher threading dislocation densities (i.e. ∼5 × 109/cm2 at the gate-edges, as compared to unstressed devices (i.e. ∼2.5 × 109/cm2. Dislocation movement correlates well with high tensile stress (∼1.6 GPa at the gate-edges, as seen from inverse piezoelectric calculations and x-ray synchrotron diffraction residual stress measurements. Based on Peierls stress calculation, we believe that threading dislocations move via glide in 〈 11 2 ¯ 0 〉 / { 1 1 ¯ 00 } and 〈 11 2 ¯ 0 〉 / { 1 1 ¯ 01 } slip systems. This result illustrates the importance of threading dislocation mobility in controlling the reliability of AlGaN/GaN-on-Si HEMTs.

Effects of Different Exercise Training Programs on Cardiorespiratory Fitness in Overweight/Obese Adults With Hypertension: A Pilot Study.

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Jurio-Iriarte, Borja; Maldonado-Martín, Sara

2018-05-01

The goal of the study was to compare the effects of two supervised aerobic exercise programs (moderate-intensity continuous training [MICT] vs. high-intensity interval training [HIIT]) after 8-, 12-, and 16-week intervention periods on cardiorespiratory fitness (CRF) in overweight/obese adults diagnosed with hypertension. Participants ( N = 64) were divided into three intervention cohorts (control group [CG], MICT, and HIIT) and each of these, in turn, into three intervention length cohorts (8, 12, and 16 weeks). Supervised groups exercised twice a week. There were no statistical changes in postintervention periods in CG ( g HIIT, 4.2 ± 4.7, g = 0.7). The effect of exercise interventions compared with CG was substantial ( p .8) and mostly consequence of HIIT-related effects. The improvements on CRF occurred after 12 and 16 weeks in exercise interventions, rather than in the 8-week group or CG, where Hedges's g index indicated small effect. This study may suggest that both MICT and HIIT exert cardioprotector effects on hypertension in the overweight/obese population. However, short-term training duration (HIIT intervention might generate higher aerobic capacity, which seems to grow as intervention lengthens.

Social Stress and Substance Use Disparities by Sexual Orientation Among High School Students.

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Lowry, Richard; Johns, Michelle M; Robin, Leah E; Kann, Laura K

2017-10-01

Sexual minority youth often experience increased social stress due to prejudice, discrimination, harassment, and victimization. Increased stress may help explain the disproportionate use of substances like tobacco, alcohol, marijuana, and other illicit drug use by sexual minority youth. This study examined the effect of social stress on substance use disparities by sexual orientation among U.S. high school students. In 2016, data from the national 2015 Youth Risk Behavior Survey, conducted among a nationally representative sample of 15,624 U.S. high school students, were analyzed to examine the effect of school-related (threatened/injured at school, bullied at school, bullied electronically, felt unsafe at school) and non-school-related (forced sexual intercourse, early sexual debut) social stress on substance use disparities by sexual orientation, by comparing unadjusted prevalence ratios (PRs) and adjusted (for social stressors, age, sex, and race/ethnicity) prevalence ratios (APRs). Unadjusted PRs reflected significantly (pprevention programs might appropriately include strategies to reduce social stress, including policies and practices designed to provide a safe school environment and improved access to social and mental health services. Published by Elsevier Inc.