Maximal power output during incremental exercise by resistance and endurance trained athletes.

Science.gov (United States)

Sakthivelavan, D S; Sumathilatha, S

2010-01-01

This study was aimed at comparing the maximal power output by resistance trained and endurance trained athletes during incremental exercise. Thirty male athletes who received resistance training (Group I) and thirty male athletes of similar age group who received endurance training (Group II) for a period of more than 1 year were chosen for the study. Physical parameters were measured and exercise stress testing was done on a cycle ergometer with a portable gas analyzing system. The maximal progressive incremental cycle ergometer power output at peak exercise and carbon dioxide production at VO2max were measured. Highly significant (P biofeedback and perk up the athlete's performance.

Pharmacokinetics of detomidine administered to horses at rest and after maximal exercise.

Science.gov (United States)

Hubbell, J A E; Sams, R A; Schmall, L M; Robertson, J T; Hinchcliff, K W; Muir, W W

2009-05-01

Increased doses of detomidine are required to produce sedation in horses after maximal exercise compared to calm or resting horses. To determine if the pharmacokinetics of detomidine in Thoroughbred horses are different when the drug is given during recuperation from a brief period of maximal exercise compared to administration at rest. Six Thoroughbred horses were preconditioned by exercising them on a treadmill. Each horse ran a simulated race at a treadmill speed that caused it to exercise at 120% of its maximal oxygen consumption. One minute after the end of exercise, horses were treated with detomidine. Each horse was treated with the same dose of detomidine on a second occasion a minimum of 14 days later while standing in a stocks. Samples of heparinised blood were obtained at various time points on both occasions. Plasma detomidine concentrations were determined by liquid chromatography-mass spectrometry. The plasma concentration vs. time data were analysed by nonlinear regression analysis. Median back-extrapolated time zero plasma concentration was significantly lower and median plasma half-life and median mean residence time were significantly longer when detomidine was administered after exercise compared to administration at rest. Median volume of distribution was significantly higher after exercise but median plasma clearance was not different between the 2 administrations. Detomidine i.v. is more widely distributed when administered to horses immediately after exercise compared to administration at rest resulting in lower peak plasma concentrations and a slower rate of elimination. The dose requirement to produce an equivalent effect may be higher in horses after exercise than in resting horses and less frequent subsequent doses may be required to produce a sustained effect.

Thermoregulatory Responses to Graded Exercise Differ among Sasang Types

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Duong Duc Pham

2015-01-01

Full Text Available We compared sweat rate and variables such as workload (We, metabolic heat production (Hprod, and temperature increment load (Tinc across Sasang types. 304 apparently healthy participants aged 20–49 years with their Sasang type determined were enrolled. Local sweat rates on the chest (LSRchest and back (LSRback were measured using a perspiration meter during a maximum treadmill exercise test. Oxygen uptake was measured continuously using a breath-by-breath mode indirect calorimeter. The TaeEum (TE type had a larger body size, a higher percent body fat, and a lower body area surface area (BSA to body mass compared with the other Sasang types, particularly the SoEum (SE type. The TE type tended to have a shorter exercise time to exhaustion and lower maximal oxygen uptake (mL·kg−1·min−1 than the other types. LSRchest in TE types was greater than that of the SE and SoYang (SY types in men, whereas LSRback was higher in the TE type than that of the other types in women. After normalizing LSR for We, Hprod, Tinc, and BSA, this tendency still remained. Our findings suggest that the thermoregulatory response to graded exercise may differ across Sasang types such that the TE type was the most susceptible to heat stress.

Thermoregulatory Responses to Graded Exercise Differ among Sasang Types.

Science.gov (United States)

Pham, Duong Duc; Lee, Jeong Hoon; Park, Eun Seok; Baek, Hyun Sung; Kim, Ga Yul; Lee, Young Boum; Ku, BonCho; Kim, Jong Yeol; Leem, Chae Hun

2015-01-01

We compared sweat rate and variables such as workload (W e ), metabolic heat production (H prod), and temperature increment load (T inc) across Sasang types. 304 apparently healthy participants aged 20-49 years with their Sasang type determined were enrolled. Local sweat rates on the chest (LSRchest) and back (LSRback) were measured using a perspiration meter during a maximum treadmill exercise test. Oxygen uptake was measured continuously using a breath-by-breath mode indirect calorimeter. The TaeEum (TE) type had a larger body size, a higher percent body fat, and a lower body area surface area (BSA) to body mass compared with the other Sasang types, particularly the SoEum (SE) type. The TE type tended to have a shorter exercise time to exhaustion and lower maximal oxygen uptake (mL·kg(-1)·min(-1)) than the other types. LSRchest in TE types was greater than that of the SE and SoYang (SY) types in men, whereas LSRback was higher in the TE type than that of the other types in women. After normalizing LSR for W e , H prod, T inc, and BSA, this tendency still remained. Our findings suggest that the thermoregulatory response to graded exercise may differ across Sasang types such that the TE type was the most susceptible to heat stress.

CFTR Genotype and Maximal Exercise Capacity in Cystic Fibrosis: A Cross-sectional Study.

Science.gov (United States)

Radtke, Thomas; Hebestreit, Helge; Gallati, Sabina; Schneiderman, Jane E; Braun, Julia; Stevens, Daniel; Hulzebos, Erik Hj; Takken, Tim; Boas, Steven R; Urquhart, Don S; Lands, Larry C; Tejero, Sergio; Sovtic, Aleksandar; Dwyer, Tiffany; Petrovic, Milos; Harris, Ryan A; Karila, Chantal; Savi, Daniela; Usemann, Jakob; Mei-Zahav, Meir; Hatziagorou, Elpis; Ratjen, Felix; Kriemler, Susi

2018-02-01

Cystic fibrosis transmembrane conductance regulator (CFTR) is expressed in human skeletal muscle cells. Variations of CFTR dysfunction among patients with cystic fibrosis may be an important determinant of maximal exercise capacity in cystic fibrosis. Previous studies on the relationship between CFTR genotype and maximal exercise capacity are scarce and contradictory. This study was designed to explore factors influencing maximal exercise capacity, expressed as peak oxygen uptake (V.O2peak), with a specific focus on CFTR genotype in children and adults with cystic fibrosis. In an international, multicenter, cross-sectional study, we collected data on CFTR genotype and cardiopulmonary exercise tests in patients with cystic fibrosis who were ages 8 years and older. CFTR mutations were classified into functional classes I–V. The final analysis included 726 patients (45% females; age range, 8–61 yr; forced expiratory volume in 1 s, 16 to 123% predicted) from 17 cystic fibrosis centers in North America, Europe, Australia, and Asia, all of whom had both valid maximal cardiopulmonary exercise tests and complete CFTR genotype data. Overall, patients exhibited exercise intolerance (V.O2peak, 77.3 ± 19.1% predicted), but values were comparable among different CFTR classes. We did not detect an association between CFTR genotype functional classes I–III and either V.O2peak (percent predicted) (adjusted β = −0.95; 95% CI, −4.18 to 2.29; P = 0.57) or maximum work rate (Wattmax) (adjusted β = −1.38; 95% CI, −5.04 to 2.27; P = 0.46) compared with classes IV–V. Those with at least one copy of a F508del-CFTR mutation and one copy of a class V mutation had a significantly lower V.O2peak (β = −8.24%; 95% CI, −14.53 to −2.99; P = 0.003) and lower Wattmax (adjusted β = −7.59%; 95% CI, −14.21 to −0.95; P = 0.025) than those with two copies of a class II mutation. On the basis of linear regression analysis adjusted for

Persistent low-grade inflammation and regular exercise

DEFF Research Database (Denmark)

Astrom, Maj-Briit; Feigh, Michael; Pedersen, Bente Klarlund

2010-01-01

Persistent low-grade systemic inflammation is a feature of chronic diseases such as cardiovascular disease (CVD), type 2 diabetes and dementia and evidence exists that inflammation is a causal factor in the development of insulin resistance and atherosclerosis. Regular exercise offers protection ...... diabetes and dementia. We suggest that the anti-inflammatory effects of exercise may be mediated via a long-term effect of exercise leading to a reduction in visceral fat mass and/or by induction of anti-inflammatory cytokines with each bout of exercise....

Bicarbonate attenuates arterial desaturation during maximal exercise in humans

DEFF Research Database (Denmark)

Nielsen, Henning B; Bredmose, Per P; Strømstad, Morten

2002-01-01

The contribution of pH to exercise-induced arterial O2 desaturation was evaluated by intravenous infusion of sodium bicarbonate (Bic, 1 M; 200-350 ml) or an equal volume of saline (Sal; 1 M) at a constant infusion rate during a "2,000-m" maximal ergometer row in five male oarsmen. Blood...

A comparison of maximal exercise and dipyridamole thallium-201 planar gated scintigraphy

International Nuclear Information System (INIS)

Martin, W.; Tweddel, A.C.; Main, G.; Hutton, I.

1992-01-01

Both symptom-limited maximal exercise and intravenously given dipyridamole stress (0.56 mg/kg over 4 min with a 2 min walk) gated thallium scans were performed in 22 patients undergoing coronary arteriography for the assessment of chest pain. All scans were acquired gated to the electrocardiogram in 3 projections and were reported for the presence and extent of defects in 5 myocardial segments in each view. In addition, left and right ventricular myocardial uptake and estimates of right and left lung and liver to left ventricular uptake were assessed relative to the injected dose of thallium-201. Overall, 190/310 segments were abnormal with exercise compared with 169/310 with dipyridamole. Segments were scored greater in extent in 90/310 cases with exercise, compared with 46/310 in which the defect was more extensive with dipyridamole. Non-attenuation corrected percentage myocardial thallium uptakes were similar for both stresses. Left and right lung and liver to left ventricle ratios were all significantly higher with dipyridamole than with exercise. High right and left lung uptakes with dipyridamole were strongly correlated with high exercise values. The liver uptake was weakly correlated between the 2 different stress tests. These results demonstrate that dipyridamole induces fewer and less extensive thallium perfusion defects than maximal exercise, and that liver and lung to myocardial ratios are higher with dipyridamole than with exercise. (orig./MG)

Submaximal exercise capacity and maximal power output in polio subjects

NARCIS (Netherlands)

Nollet, F.; Beelen, A.; Sargeant, A. J.; de Visser, M.; Lankhorst, G. J.; de Jong, B. A.

2001-01-01

OBJECTIVES: To compare the submaximal exercise capacity of polio subjects with postpoliomyelitis syndrome (PPS) and without (non-PPS) with that of healthy control subjects, to investigate the relationship of this capacity with maximal short-term power and quadriceps strength, and to evaluate

Persistent low-grade inflammation and regular exercise

DEFF Research Database (Denmark)

Åström, Maj-brit; Feigh, Michael; Pedersen, Bente Klarlund

2010-01-01

against all of these diseases and recent evidence suggests that the protective effect of exercise may to some extent be ascribed to an anti-inflammatory effect of regular exercise. Visceral adiposity contributes to systemic inflammation and is independently associated with the occurrence of CVD, type 2...... diabetes and dementia. We suggest that the anti-inflammatory effects of exercise may be mediated via a long-term effect of exercise leading to a reduction in visceral fat mass and/or by induction of anti-inflammatory cytokines with each bout of exercise.......Persistent low-grade systemic inflammation is a feature of chronic diseases such as cardiovascular disease (CVD), type 2 diabetes and dementia and evidence exists that inflammation is a causal factor in the development of insulin resistance and atherosclerosis. Regular exercise offers protection...

Maximal exercise testing of men with prostate cancer being treated with androgen deprivation therapy.

Science.gov (United States)

Wall, Bradley A; Galvão, Daniel A; Fatehee, Naeem; Taaffe, Dennis R; Spry, Nigel; Joseph, David; Newton, Robert U

2014-12-01

Exercise is being increasingly established as a key adjuvant therapy in clinical oncology. As research has demonstrated the beneficial effect of exercise for cancer management, a growing number of patients with cancer are undertaking structured exercise programs. This study aimed to determine the safety and feasibility of formal exercise testing in clinical settings as it is becoming increasingly used as a screening tool and for exercise prescription purposes. One hundred and twelve patients with prostate cancer undergoing androgen deprivation therapy (ADT) took part in a physician-supervised multistage maximal stress test (Bruce protocol). Sixty patients had been on ADT for 3 months (chronic). Of these men, 85% were able to meet the criteria for the attainment of V˙O2max, whereas three positive tests (3.2%) were observed. The three participants who recorded a positive stress test underwent further medical examination and were subsequently cleared of clinically significant cardiovascular disease. Apart from the relatively low V˙O2max (24.7 ± 6.0 mL·kg·min, 10th-15th percentile), compared with normative data in healthy age-matched controls, the cardiovascular response to exercise was similar in this cancer population. Moreover, treatment duration did not seem to influence cardiovascular responses to exercise. This early evidence suggests that risk of adverse events during maximal exercise testing is relatively low in this population and certainly no higher than that in ages-matched, apparently healthy individuals. Maximal exercise testing was demonstrated to be feasible and safe, providing a direct assessment of V˙O2max. The relatively low number of positive tests in this study suggests that the risk of adverse events is relatively low in this population and certainly no higher than that in age-matched, apparently healthy individuals.

Relationship between traditional and ballistic squat exercise with vertical jumping and maximal sprinting.

Science.gov (United States)

Requena, Bernardo; García, Inmaculada; Requena, Francisco; de Villarreal, Eduardo Sáez-Sáez; Cronin, John B

2011-08-01

The purpose of this study was to quantify the magnitude of the relationship between vertical jumping and maximal sprinting at different distances with performance in the traditional and ballistic concentric squat exercise in well-trained sprinters. Twenty-one men performed 2 types of barbell squats (ballistic and traditional) across different loads with the aim of determining the maximal peak and average power outputs and 1 repetition maximum (1RM) values. Moreover, vertical jumping (countermovement jump test [CMJ]) and maximal sprints over 10, 20, 30, 40, 60, and 80 m were also assessed. In respect to 1RM in traditional squat, (a) no significant correlation was found with CMJ performance; (b) positive strong relationships (p ballistic and traditional squat exercises (r = 0.53-0.90); (c) negative significant correlations (r = -0.49 to -0.59, p ballistic or traditional squat exercises. Sprint time at 20 m was only related to ballistic and traditional squat performance when power values were expressed in relative terms. Moderate significant correlations (r = -0.39 to -0.56, p ballistic and traditional squat exercises. Sprint times at 60 and 80 m were mainly related to ballistic squat power outputs. Although correlations can only give insights into associations and not into cause and effect, from this investigation, it can be seen that traditional squat strength has little in common with CMJ performance and that relative 1RM and power outputs for both squat exercises are statistically correlated to most sprint distances underlying the importance of strength and power to sprinting.

The effect of acute maximal exercise on postexercise hemodynamics and central arterial stiffness in obese and normal-weight individuals.

Science.gov (United States)

Bunsawat, Kanokwan; Ranadive, Sushant M; Lane-Cordova, Abbi D; Yan, Huimin; Kappus, Rebecca M; Fernhall, Bo; Baynard, Tracy

2017-04-01

Central arterial stiffness is associated with incident hypertension and negative cardiovascular outcomes. Obese individuals have higher central blood pressure (BP) and central arterial stiffness than their normal-weight counterparts, but it is unclear whether obesity also affects hemodynamics and central arterial stiffness after maximal exercise. We evaluated central hemodynamics and arterial stiffness during recovery from acute maximal aerobic exercise in obese and normal-weight individuals. Forty-six normal-weight and twenty-one obese individuals underwent measurements of central BP and central arterial stiffness at rest and 15 and 30 min following acute maximal exercise. Central BP and normalized augmentation index (AIx@75) were derived from radial artery applanation tonometry, and central arterial stiffness was obtained via carotid-femoral pulse wave velocity (cPWV) and corrected for central mean arterial pressure (cPWV/cMAP). Central arterial stiffness increased in obese individuals but decreased in normal-weight individuals following acute maximal exercise, after adjusting for fitness. Obese individuals also exhibited an overall higher central BP ( P  <   0.05), with no exercise effect. The increase in heart rate was greater in obese versus normal-weight individuals following exercise ( P  <   0.05), but there was no group differences or exercise effect for AIx@75 In conclusion, obese (but not normal-weight) individuals increased central arterial stiffness following acute maximal exercise. An assessment of arterial stiffness response to acute exercise may serve as a useful detection tool for subclinical vascular dysfunction. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Maximal muscular vascular conductances during whole body upright exercise in humans

DEFF Research Database (Denmark)

Calbet, J A L; Jensen-Urstad, M; Van Hall, Gerrit

2004-01-01

76% of VO(2,max) and at VO(2,max) with different techniques: diagonal stride (combined arm and leg exercise), double poling (predominantly arm exercise) and leg skiing (predominantly leg exercise). During submaximal exercise cardiac output (26-27 l min(-1)), mean blood pressure (MAP) (approximately......That muscular blood flow may reach 2.5 l kg(-1) min(-1) in the quadriceps muscle has led to the suggestion that muscular vascular conductance must be restrained during whole body exercise to avoid hypotension. The main aim of this study was to determine the maximal arm and leg muscle vascular...... (VO(2,max)) 5.1 +/- 0.1 l min(-1) participated in the study. Femoral and subclavian vein blood flows, intra-arterial blood pressure, cardiac output, as well as blood gases in the femoral and subclavian vein, right atrium and femoral artery were determined during skiing (roller skis) at approximately...

Hypertension, and blood pressure response to graded exercise in ...

African Journals Online (AJOL)

Hypertension, and blood pressure response to graded exercise in young obese and non- athletic Nigerian university students. ... onset of hypertension and thus other cardiovascular diseases and less tolerant to physical exercises. Our results add to the evidence that hypertension is common among obese young adults.

Cardiac function and myocardial perfusion immediately following maximal treadmill exercise inside the MRI room

Directory of Open Access Journals (Sweden)

Ballinger Michelle R

2008-01-01

Full Text Available Abstract Treadmill exercise stress testing is an essential tool in the prevention, detection, and treatment of a broad spectrum of cardiovascular disease. After maximal exercise, cardiac images at peak stress are typically acquired using nuclear scintigraphy or echocardiography, both of which have inherent limitations. Although CMR offers superior image quality, the lack of MRI-compatible exercise and monitoring equipment has prevented the realization of treadmill exercise CMR. It is critical to commence imaging as quickly as possible after exercise to capture exercise-induced cardiac wall motion abnormalities. We modified a commercial treadmill such that it could be safely positioned inside the MRI room to minimize the distance between the treadmill and the scan table. We optimized the treadmill exercise CMR protocol in 20 healthy volunteers and successfully imaged cardiac function and myocardial perfusion at peak stress, followed by viability imaging at rest. Imaging commenced an average of 30 seconds after maximal exercise. Real-time cine of seven slices with no breath-hold and no ECG-gating was completed within 45 seconds of exercise, immediately followed by stress perfusion imaging of three short-axis slices which showed an average time to peak enhancement within 57 seconds of exercise. We observed a 3.1-fold increase in cardiac output and a myocardial perfusion reserve index of 1.9, which agree with reported values for healthy subjects at peak stress. This study successfully demonstrates in-room treadmill exercise CMR in healthy volunteers, but confirmation of feasibility in patients with heart disease is still needed.

Exercise Training at Maximal Fat Oxidation Intensity for Older Women with Type 2 Diabetes.

Science.gov (United States)

Tan, Sijie; Du, Ping; Zhao, Wanting; Pang, Jiaqi; Wang, Jianxiong

2018-05-01

The purpose of this study was to investigate the pleiotropic effects of 12 weeks of supervised exercise training at maximal fat oxidation (FATmax) intensity on body composition, lipid profile, glycemic control, insulin sensitivity and serum adipokine levels in older women with type 2 diabetes. Thirty-one women with type 2 diabetes, aged 60 to 69 years, were randomly allocated into exercise and control groups. Body composition, lipid profile, blood glucose, insulin resistance and serum leptin and adiponectin concentrations were measured before and after the intervention. Exercise group (n=16) walked at individualized FATmax intensities for 1 h/day for 3 days/week over 12 weeks. No dietary intervention was introduced during the experimental period. Maximal fat oxidation rate was 0.37±0.10 g/min, and occurred at 37.3±7.3% of the estimated VO 2 max. Within the exercise group, significant improvements were observed for most of the measured variables compared to non-exercising controls; in particular, the FATmax program reduced body fat% (presistance (pchange in daily energy intake for all participants during the intervention period. These results suggest that individualized FATmax training is an effective exercise training intensity for managing type 2 diabetes in older women. © Georg Thieme Verlag KG Stuttgart · New York.

Incentive structure in team-based learning: graded versus ungraded Group Application exercises.

Science.gov (United States)

Deardorff, Adam S; Moore, Jeremy A; McCormick, Colleen; Koles, Paul G; Borges, Nicole J

2014-04-21

Previous studies on team-based learning (TBL) in medical education demonstrated improved learner engagement, learner satisfaction, and academic performance; however, a paucity of information exists on modifications of the incentive structure of "traditional" TBL practices. The current study investigates the impact of modification to conventional Group Application exercises by examining student preference and student perceptions of TBL outcomes when Group Application exercises are excluded from TBL grades. During the 2009-2010 and 2010-2011 academic years, 175 students (95.6% response rate) completed a 22-item multiple choice survey followed by 3 open response questions at the end of their second year of medical school. These students had participated in a TBL supplemented preclinical curriculum with graded Group Application exercises during year one and ungraded Group Application exercises during year two of medical school. Chi-square analyses showed significant differences between grading categories for general assessment of TBL, participation and communication, intra-team discussion, inter-team discussion, student perceptions of their own effort and development of teamwork skills. Furthermore, 83.8% of students polled prefer ungraded Group Application exercises with only 7.2% preferring graded and 9.0% indicating no preference. The use of ungraded Group Application exercises appears to be a successful modification of TBL, making it more "student-friendly" while maintaining the goals of active learning and development of teamwork skills.

Modeling of Teaching 5th-7th-Grade Boys Physical Exercises

Directory of Open Access Journals (Sweden)

Т. Г. Абдулхалікова

2017-09-01

Full Text Available The research objective is to determine the effectiveness of orthogonal variants of teaching 5th-7th graders physical exercises. Materials and methods. The participants in the research were boys of the 5th grade (n = 32, 6th grade (n = 40, 7th grade (n = 52. To achieve the tasks set, the research used the following methods: analysis of scientific and methodological literature; pedagogical testing, pedagogical observation, timing of educational tasks; pedagogical experiment, medical and biological research methods; methods of mathematical statistics, methods of mathematical experiment planning. In order to achieve the objective set, the research has studied the effect of different variants of the educational process structure, namely: the number of repetitions (х1 and rest intervals (х2 when learning the technique of performing physical exercises. The research has conducted a complete factor experiment of type 22. According to the experiment plan, the 5th-7th graders were divided into training groups. In total, there were 12 experimental groups organized. Research results. The analysis of the regression equations shows that the teaching of physical exercises to the 5th-7th-grade boys is mostly influenced by rest intervals between repetitions (х2. The number of repetitions (х1 has somewhat less influence. The interaction of these factors is insignificant when teaching physical exercises and becomes much more influential only when teaching a switch leg pull-over exercise (х1х2. Conclusions. To increase the effectiveness of teaching 5th-7th graders physical exercises, it is necessary to shorten rest intervals between repetition to 60 s and to reduce the number of repetitions to six. When teaching boys the switch leg pull-over exercise, rest intervals should be increased to 120 s and the number of repetitions — to twelve.

Low-Grade Inflammation and Spinal Cord Injury: Exercise as Therapy?

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Eduardo da Silva Alves

2013-01-01

Full Text Available An increase in the prevalence of obesity in people with spinal cord injury can contribute to low-grade chronic inflammation and increase the risk of infection in this population. A decrease in sympathetic activity contributes to immunosuppression due to the lower activation of immune cells in the blood. The effects of physical exercise on inflammatory parameters in individuals with spinal cord injury have not been well described. We conducted a review of the literature published from 1974 to 2012. This review explored the relationships between low-grade inflammation, spinal cord injury, and exercise to discuss a novel mechanism that might explain the beneficial effects of exercise involving an increase in catecholamines and cytokines in people with spinal cord injury.

Low-Grade Inflammation and Spinal Cord Injury: Exercise as Therapy?

Science.gov (United States)

da Silva Alves, Eduardo; de Aquino Lemos, Valdir; Ruiz da Silva, Francieli; Lira, Fabio Santos; dos Santos, Ronaldo Vagner Thomathieli; Rosa, João Paulo Pereira; Caperuto, Erico; Tufik, Sergio; de Mello, Marco Tulio

2013-01-01

An increase in the prevalence of obesity in people with spinal cord injury can contribute to low-grade chronic inflammation and increase the risk of infection in this population. A decrease in sympathetic activity contributes to immunosuppression due to the lower activation of immune cells in the blood. The effects of physical exercise on inflammatory parameters in individuals with spinal cord injury have not been well described. We conducted a review of the literature published from 1974 to 2012. This review explored the relationships between low-grade inflammation, spinal cord injury, and exercise to discuss a novel mechanism that might explain the beneficial effects of exercise involving an increase in catecholamines and cytokines in people with spinal cord injury. PMID:23533315

Effects of cluster vs. traditional plyometric training sets on maximal-intensity exercise performance

Directory of Open Access Journals (Sweden)

Abbas Asadi

2016-01-01

Conclusions: Although both plyometric training methods improved lower body maximal-intensity exercise performance, the traditional sets methods resulted in greater adaptations in sprint performance, while the cluster sets method resulted in greater jump and agility adaptations.

Maximal exercise electrocardiography responses and coronary heart disease mortality among men with diabetes mellitus.

Science.gov (United States)

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

2008-05-27

An abnormal ECG during maximal exercise testing has been shown to be a powerful predictor of future coronary heart disease (CHD) mortality in asymptomatic men. However, little is known about the relationship between exercise ECG responses and CHD risk in men with diabetes mellitus. We examined the association between exercise ECG responses and mortality in 2854 men with documented diabetes mellitus (mean age 49.5 years) who completed a maximal treadmill exercise test during the period from 1974 to 2001 and who were without a previous cardiovascular disease (CVD) event at baseline. Mortality due to all causes, CHD, and CVD were the main outcome measures across categories of exercise ECG responses, with stratification by cardiorespiratory fitness, quantified as treadmill test duration. During an average follow-up of 16 years, 441 deaths (210 CVD and 133 CHD) were identified. Across normal, equivocal, and abnormal exercise ECG groups, age- and examination year-adjusted CHD mortality rates per 10 000 person-years were 23.0, 48.6, and 69.0, respectively (P(trend)<0.001). After further adjustment for fasting plasma glucose level, smoking, body mass index, hypercholesterolemia, hypertension, family history of CVD or diabetes mellitus, abnormal resting ECG responses, and cardiorespiratory fitness, hazard ratios (95% confidence intervals) were 1.00 (referent), 1.68 (1.01 to 2.77), and 2.21 (1.41 to 3.46; P(trend)<0.001). Similar patterns of associations were noted between exercise ECG testing and both CVD and all-cause mortality risk. Among men with diabetes mellitus, equivocal and abnormal exercise ECG responses were associated with higher risk of all-cause, CVD, and CHD mortality.

Effect of maturation on hemodynamic and autonomic control recovery following maximal running exercise in highly-trained young soccer players

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Martin eBuchheit

2011-10-01

Full Text Available The purpose of this study was to examine the effect of maturation on post-exercise hemodynamic and autonomic responses. Fifty-five highly-trained young male soccer players (12-18 yr classified as pre-, circum- or post-peak height velocity (PHV performed a graded running test to exhaustion on a treadmill. Before (Pre and after (5th-10th min, Post exercise, heart rate (HR, stroke volume (SV, cardiac ouput (CO, arterial pressure (AP and total peripheral resistance (TPR were monitored. Parasympathetic (high-frequency [HFRR] of HR variability (HRV and baroreflex sensitivity [Ln BRS] and sympathetic activity (low-frequency [LFSAP] of systolic AP variability were estimated. Post-exercise blood lactate [La]b, the HR recovery (HRR time constant and parasympathetic reactivation (time varying HRV analysis were assessed. In all three groups, exercise resulted in increased HR, CO, AP and LFSAP (P<0.001, decreased SV, HFRR and Ln BRS (all P<0.001, and no change in TPRI (P=0.98. There was no ‘maturation x time’ interaction for any of the hemodynamic or autonomic variables (all P>0.22. After exercise, pre-PHV players displayed lower SV, CO and [La]b, faster HRR and greater parasympathetic reactivation compared with circum- and post-PHV players. Multiple regression analysis showed that lean muscle mass, [La]b and Pre parasympathetic activity were the strongest predictors of HRR (r2=0.62, P<0.001. While pre-PHV players displayed a faster HRR and greater post-exercise parasympathetic reactivation, maturation had little influence on the hemodynamic and autonomic responses following maximal running exercise. HRR relates to lean muscle mass, blood acidosis and intrinsic parasympathetic function, with less evident impact of post-exercise autonomic function.

CHANGES IN EEG DURING GRADED EXERCISE ON A RECUMBENT CYCLE ERGOMETER

Directory of Open Access Journals (Sweden)

Stephen P. Bailey

2008-12-01

Full Text Available Previous studies have shown changes in brain activity as a result of exercise; however, few studies have examined changes during exercise. The purpose of this study was to examine brain activity during a graded exercise test. Twenty male participants performed a graded exercise test on a recumbent cycle ergometer. Exercise intensity was set initially at 50W and was increased by 50W every 2 minutes until volitional fatigue was reached. Electroencephalography (EEG was measured prior to the onset of exercise, during the last minute of each stage of exercise, immediately post-exercise, and 10 minutes into recovery. EEG was recorded from 8 scalp sites leading to analysis of alpha 1, alpha 2, beta 1, beta 2, and theta activities. Expired air was collected and analyzed for ventilation rate (VE, VO2, % of peak VO2, and Respiratory Exchange Ratio (RER. No differences were seen in EEG between the hemispheres of the brain. There was, however, a significant increase in brain activity across the spectrum occurring at 200 W through immediately post-exercise. Brain activity returned to pre- exercise levels by 10 minutes post. VO2, % of peak VO2 and RER increased linearly with exercise intensity. VE increased linearly through 200 W; however, a disproportionate increase was seen in VE from 200 W to peak exercise. The results of this investigation demonstrate that brain activity may be related to exercise intensity. Future research will want to examine how these changes in brain activity influence affective, perceptual and cognitive changes often associated with exercise. Efforts will also need to be made to determine if changes in brain activity during exercise are mediated by central (within the brain or peripheral mechanisms

Maximal exercise and muscle oxygen extraction in acclimatizing lowlanders and high altitude natives

DEFF Research Database (Denmark)

Lundby, Carsten; Sander, Mikael; van Hall, Gerrit

2006-01-01

, and is the focus of the present study. We have studied six lowlanders during maximal exercise at sea level (SL) and with acute (AH) exposure to 4,100 m altitude, and again after 2 (W2) and 8 weeks (W8) of altitude sojourn, where also eight high altitude native (Nat) Aymaras were studied. Fractional arterial muscle...... O(2) extraction at maximal exercise was 90.0+/-1.0% in the Danish lowlanders at sea level, and remained close to this value in all situations. In contrast to this, fractional arterial O(2) extraction was 83.2+/-2.8% in the high altitude natives, and did not change with the induction of normoxia....... The capillary oxygen conductance of the lower extremity, a measure of oxygen diffusing capacity, was decreased in the Danish lowlanders after 8 weeks of acclimatization, but was still higher than the value obtained from the high altitude natives. The values were (in ml min(-1) mmHg(-1)) 55.2+/-3.7 (SL), 48...

Changes in EEG during graded exercise on a recumbent cycle ergometer.

Science.gov (United States)

Bailey, Stephen P; Hall, Eric E; Folger, Stephen E; Miller, Paul C

2008-01-01

Previous studies have shown changes in brain activity as a result of exercise; however, few studies have examined changes during exercise. The purpose of this study was to examine brain activity during a graded exercise test. Twenty male participants performed a graded exercise test on a recumbent cycle ergometer. Exercise intensity was set initially at 50W and was increased by 50W every 2 minutes until volitional fatigue was reached. Electroencephalography (EEG) was measured prior to the onset of exercise, during the last minute of each stage of exercise, immediately post-exercise, and 10 minutes into recovery. EEG was recorded from 8 scalp sites leading to analysis of alpha 1, alpha 2, beta 1, beta 2, and theta activities. Expired air was collected and analyzed for ventilation rate (VE), VO2, % of peak VO2, and Respiratory Exchange Ratio (RER). No differences were seen in EEG between the hemispheres of the brain. There was, however, a significant increase in brain activity across the spectrum occurring at 200 W through immediately post-exercise. Brain activity returned to pre- exercise levels by 10 minutes post. VO2, % of peak VO2 and RER increased linearly with exercise intensity. VE increased linearly through 200 W; however, a disproportionate increase was seen in VE from 200 W to peak exercise. The results of this investigation demonstrate that brain activity may be related to exercise intensity. Future research will want to examine how these changes in brain activity influence affective, perceptual and cognitive changes often associated with exercise. Efforts will also need to be made to determine if changes in brain activity during exercise are mediated by central (within the brain) or peripheral mechanisms. Key pointsEEG can be recorded during exercise.Brain EEG activity increases during exercise and may be related to exercise intensity.Brain EEG activity returns to resting levels quickly after the cessation of exercise.

Hydrogen peroxide release and acid-base status in exhaled breath condensate at rest and after maximal exercise in young, healthy subjects.

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Marek, E; Platen, P; Volke, J; Mückenhoff, K; Marek, W

2009-12-07

Exhaled breath condensate (EBC) contains among a large number of mediators hydrogen peroxide (H2O2) as a marker of airway inflammation and oxidative stress. Similarly EBC pH also changes in respiratory diseases. It was the aim of our investigation to prove if hydrogen peroxide release and changes in pH of EBC changes with exercise. EBC was collected from 100 litres exhaled air along with samples of arterialized blood of 16 healthy subjects (9 males, 7 females, age 23 +/- 1 years). EBC hydrogen peroxide was analyzed with EcoCheck amperometer (FILT, Berlin). The rate of H(2)O(2) release was calculated from the concentration and collection time. pH and PCO(2) in blood and in EBC were measured with the Radiometer blood gas analyzer, EBC was equilibrated with a gas mixture (5% CO(2) in O(2)). The bicarbonate concentration was calculated according to the law of mass action for CO(2) and HCO(3)(-) (pK = 6.1). H(2)O(2) concentration in EBC was 190 +/- 109 nmol/l, and H (2)O(2) release at rest was 31.0 +/- 18.3 pmol/min. At maximal exercise, the H(2)O(2) concentration in EBC increased to 250 +/- 120 nmol/l, and H(2)O(2) release significantly increased at maximal exercise to 84.4 +/- 39.9 pmol/min (Pexercise, pH 6.18 +/- 0.17 and [HCO(3)(-)] 1.23 +/- 0.30 mmol/l remained almost unaltered. The rate of H(2)O(2) release in EBC increased during exhausting exercise (external load: 300 Watt) by a factor of 2, whereas the pH and the bicarbonate concentration of the EBC, equilibrated with 5% CO(2) at 37 degrees C were not significantly altered. It has to be proven by further experiments whether there is a linear relationship between the rates of H(2)O(2) release in EBC in graded submaximal exercise.

Glucose clearance in aged trained skeletal muscle during maximal insulin with superimposed exercise

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Dela, Flemming; Mikines, K J; Larsen, J J

1999-01-01

Insulin and muscle contractions are major stimuli for glucose uptake in skeletal muscle and have in young healthy people been shown to be additive. We studied the effect of superimposed exercise during a maximal insulin stimulus on glucose uptake and clearance in trained (T) (1-legged bicycle tra...

Validity and reliability of grade scoring in the diagnosis of exercise-induced laryngeal obstruction

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Walsted, Emil Schwarz; Hull, James H; Hvedstrup, Jeppe

2017-01-01

The current gold-standard method for diagnosing exercise-induced laryngeal obstruction (EILO) is continuous laryngoscopy during exercise (CLE), with severity classified by a visual grade scoring system. We evaluated the precision of this approach, by evaluating test-retest reliability of CLE...... grade scoring system does not appear to be a robust means for reliably classifying severity of EILO....

Pump speed modulations and sub-maximal exercise tolerance in left ventricular assist device recipients

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Jung, Mette Holme; Houston, Brian; Russell, Stuart D

2017-01-01

of the 2 sub-maximal tests was determined by randomization. Both patient and physician were blinded to the sequence. Exercise duration, oxygen consumption (VO2) and rate of perceived exertion (RPE), using the Borg scale (score 6 to 20), were recorded. RESULTS: Nineteen patients (all with a HeartMate II...... ventricular assist device) completed 57 exercise tests. Baseline pump speed was 9,326 ± 378 rpm. At AT, workload was 63 ± 26 W (25 to 115 W) and VO2 was 79 ± 14% of maximum. Exercise duration improved by 106 ± 217 seconds (~13%) in Speedinc compared with Speedbase (837 ± 358 vs 942 ± 359 seconds; p = 0...

Biochemical changes in relation to a maximal exercise test in patients with fibromyalgia

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Nørregaard, J; Bülow, P M; Mehlsen, J

1994-01-01

Patients with fibromyalgia often complain of fatigue and pain during exercise and of worsening of pain days after exercise. The aim of the study described here was to determine if abnormal changes in potassium or lactate could be observed during an exercise test in fibromyalgia. Whether an abnormal...... incline in plasma creatine kinase or myoglobin could be observed days after the test was studied also. Fifteen female fibromyalgia patients and 15 age- and sex-matched controls performed a stepwise incremental maximal bicycle-ergometer test. Blood samples were collected from a catheter in a cubital vein......-1 was reached at a heart rate of 124 min-1 in the patients with fibromyalgia as compared to 140 min-1 in the controls (P = 0.02). In relation to workload, the patients scored higher on a Borg scale for perceived exertion during exercise, but if the Borg score was related to lactate no significant...

Determinants of time trial performance and maximal incremental exercise in highly trained endurance athletes

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Jacobs, Robert Acton; Rasmussen, Peter; Siebenmann, Christoph

2011-01-01

Human endurance performance can be predicted from maximal oxygen consumption (VO(2max)), lactate threshold, and exercise efficiency. These physiologic parameters, however, are not wholly exclusive from one another and their interplay is complex. Accordingly, we sought to identify more specific me...

Hydrogen peroxide release and acid-base status in exhaled breath condensate at rest and after maximal exercise in young, healthy subjects

Directory of Open Access Journals (Sweden)

Marek E

2009-12-01

Full Text Available Abstract Objective Exhaled breath condensate (EBC contains among a large number of mediators hydrogen peroxide (H2O2 as a marker of airway inflammation and oxidative stress. Similarly EBC pH also changes in respiratory diseases. It was the aim of our investigation to prove if hydrogen peroxide release and changes in pH of EBC changes with exercise. Methods EBC was collected from 100 litres exhaled air along with samples of arterialized blood of 16 healthy subjects (9 males, 7 females, age 23 ± 1 years. EBC hydrogen peroxide was analyzed with EcoCheck amperometer (FILT, Berlin. The rate of H2O2 release was calculated from the concentration and collection time. pH and PCO2 in blood and in EBC were measured with the Radiometer blood gas analyzer, EBC was equilibrated with a gas mixture (5% CO2 in O2. The bicarbonate concentration was calculated according to the law of mass action for CO2 and HCO3- (pK = 6.1. Results H2O2 concentration in EBC was 190 ± 109 nmol/l, and H2O2 release at rest was 31.0 ± 18.3 pmol/min. At maximal exercise, the H2O = concentration in EBC increased to 250 ± 120 nmol/l, and H2O2 release significantly increased at maximal exercise to 84.4 ± 39.9 pmol/min (P 2 equilibrated EBC was at 6.08 ± 0.23 and the [HCO3 -] was 1.03 ± 0.40 mmol/l. At maximum exercise, pH 6.18 ± 0.17 and [HCO3-] 1.23 ± 0.30 mmol/l remained almost unaltered. Conclusions The rate of H2O2 release in EBC increased during exhausting exercise (external load: 300 Watt by a factor of 2, whereas the pH and the bicarbonate concentration of the EBC, equilibrated with 5% CO2 at 37°C were not significantly altered. It has to be proven by further experiments whether there is a linear relationship between the rates of H2O2 release in EBC in graded submaximal exercise.

Comparison of myocardial 201Tl clearance after maximal and submaximal exercise: implications for diagnosis of coronary disease: concise communication

International Nuclear Information System (INIS)

Massie, B.M.; Wisneski, J.; Kramer, B.; Hollenberg, M.; Gertz, E.; Stern, D.

1982-01-01

Recently the quantitation of regional 201 Tl clearance has been shown to increase the sensitivity of the scintigraphic detection of coronary disease. Although 201 Tl clearance rates might be expected to vary with the degree of exercise, this relationship has not been explored. We therefore evaluated the rate of decrease in myocardial 201 Tl activity following maximal and submaximal stress in seven normal subjects and 21 patients with chest pain, using the seven-pinhole tomographic reconstruction technique. In normals, the mean 201 Tl clearance rate declined from 41% +/- 7 over a 3-hr period with maximal exercise to 25% +/- 5 after 3 hr at a submaximal level (p less than 0.001). Similar differences in clearance rates were found in the normally perfused regions of the left ventricle in patients with chest pain, depending on whether or not a maximal end point (defined as either the appearance of ischemia or reaching 85% of age-predicted heart rate) was achieved. In five patients who did not reach these end points, 3-hr clearance rates in uninvolved regions averaged 25% +/- 2, in contrast to a mean of 38% +/- 5 for such regions in 15 patients who exercised to ischemia or an adequate heart rate. These findings indicate that clearance criteria derived from normals can be applied to patients who are stressed maximally, even if the duration of exercise is limited, but that caution must be used in interpreting clearance rates in those who do not exercise to an accepted end point

Effects of volume-based overload plyometric training on maximal-intensity exercise adaptations in young basketball players.

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Asadi, Abbas; Ramirez-Campillo, Rodrigo; Meylan, Cesar; Nakamura, Fabio Y; Cañas-Jamett, Rodrigo; Izquierdo, Mikel

2017-12-01

The aim of the present study was to compare maximal-intensity exercise adaptations in young basketball players (who were strong individuals at baseline) participating in regular basketball training versus regular plus a volume-based plyometric training program in the pre-season period. Young basketball players were recruited and assigned either to a plyometric with regular basketball training group (experimental group [EG]; N.=8), or a basketball training only group (control group [CG]; N.=8). The athletes in EG performed periodized (i.e., from 117 to 183 jumps per session) plyometric training for eight weeks. Before and after the intervention, players were assessed in vertical and broad jump, change of direction, maximal strength and a 60-meter sprint test. No significant improvements were found in the CG, while the EG improved vertical jump (effect size [ES] 2.8), broad jump (ES=2.4), agility T test (ES=2.2), Illinois agility test (ES=1.4), maximal strength (ES=1.8), and 60-m sprint (ES=1.6) (Ptraining in addition to regular basketball practice can lead to meaningful improvements in maximal-intensity exercise adaptations among young basketball players during the pre-season.

Pilot study of a graded exercise program for the treatment of anorexia nervosa.

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Thien, V; Thomas, A; Markin, D; Birmingham, C L

2000-07-01

To determine whether a graded exercise program used in the treatment of anorexia nervosa improves quality of life and does not decrease the rate of gain of body fat. A randomized controlled trial with outcome measures: change in percent body fat, body mass index (BMI), and Medical Outcomes Survey Short Form 36-item Quality of Life questionnaire. Fifteen females and one male meeting the DSM-IV criteria for the diagnosis of anorexia nervosa were randomized. There was no difference in change in BMI or percent body fat at 3 months. Quality of life outcomes improved from baseline in the experimental group compared with the control group. However, this difference was not statistically significant. Incorporation of a graded exercise program may increase compliance with treatment, but it did not reduce the short-term rate of gain of body fat or BMI. Longer studies with more subjects are necessary to determine the usefulness of a graded exercise program in anorexia nervosa. Copyright 2000 by John Wiley & Sons, Inc.

Do Nondomestic Undergraduates Choose a Major Field in Order to Maximize Grade Point Averages?

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Bergman, Matthew E.; Fass-Holmes, Barry

2016-01-01

The authors investigated whether undergraduates attending an American West Coast public university who were not U.S. citizens (nondomestic) maximized their grade point averages (GPA) through their choice of major field. Multiple regression hierarchical linear modeling analyses showed that major field's effect size was small for these…

Small RNA-seq during acute maximal exercise reveal RNAs involved in vascular inflammation and cardiometabolic health: brief report.

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Shah, Ravi; Yeri, Ashish; Das, Avash; Courtright-Lim, Amanda; Ziegler, Olivia; Gervino, Ernest; Ocel, Jeffrey; Quintero-Pinzon, Pablo; Wooster, Luke; Bailey, Cole Shields; Tanriverdi, Kahraman; Beaulieu, Lea M; Freedman, Jane E; Ghiran, Ionita; Lewis, Gregory D; Van Keuren-Jensen, Kendall; Das, Saumya

2017-12-01

Exercise improves cardiometabolic and vascular function, although the mechanisms remain unclear. Our objective was to demonstrate the diversity of circulating extracellular RNA (ex-RNA) release during acute exercise in humans and its relevance to exercise-mediated benefits on vascular inflammation. We performed plasma small RNA sequencing in 26 individuals undergoing symptom-limited maximal treadmill exercise, with replication of our top candidate miRNA in a separate cohort of 59 individuals undergoing bicycle ergometry. We found changes in miRNAs and other ex-RNAs with exercise (e.g., Y RNAs and tRNAs) implicated in cardiovascular disease. In two independent cohorts of acute maximal exercise, we identified miR-181b-5p as a key ex-RNA increased in plasma after exercise, with validation in a separate cohort. In a mouse model of acute exercise, we found significant increases in miR-181b-5p expression in skeletal muscle after acute exercise in young (but not older) mice. Previous work revealed a strong role for miR-181b-5p in vascular inflammation in obesity, insulin resistance, sepsis, and cardiovascular disease. We conclude that circulating ex-RNAs were altered in plasma after acute exercise target pathways involved in inflammation, including miR-181b-5p. Further investigation into the role of known (e.g., miRNA) and novel (e.g., Y RNAs) RNAs is warranted to uncover new mechanisms of vascular inflammation on exercise-mediated benefits on health. NEW & NOTEWORTHY How exercise provides benefits to cardiometabolic health remains unclear. We performed RNA sequencing in plasma during exercise to identify the landscape of small noncoding circulating transcriptional changes. Our results suggest a link between inflammation and exercise, providing rich data on circulating noncoding RNAs for future studies by the scientific community. Copyright © 2017 the American Physiological Society.

Genomic predictors of the maximal O2 uptake response to standardized exercise training programs

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Sarzynski, Mark A.; Rice, Treva K.; Kraus, William E.; Church, Timothy S.; Sung, Yun Ju; Rao, D. C.; Rankinen, Tuomo

2011-01-01

Low cardiorespiratory fitness is a powerful predictor of morbidity and cardiovascular mortality. In 473 sedentary adults, all whites, from 99 families of the Health, Risk Factors, Exercise Training, and Genetics (HERITAGE) Family Study, the heritability of gains in maximal O2 uptake (V̇o2max) after exposure to a standardized 20-wk exercise program was estimated at 47%. A genome-wide association study based on 324,611 single-nucleotide polymorphisms (SNPs) was undertaken to identify SNPs associated with improvements in V̇o2max Based on single-SNP analysis, 39 SNPs were associated with the gains with P HERITAGE whites were replicated in HERITAGE blacks (n = 247). These genomic predictors of the response of V̇o2max to regular exercise provide new targets for the study of the biology of fitness and its adaptation to regular exercise. Large-scale replication studies are warranted. PMID:21183627

Plasma volume, osmolality, vasopressin, and renin activity during graded exercise in man

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Convertino, V. A.; Keil, L. C.; Bernauer, E. M.; Greenleaf, J. E.

1981-01-01

The influence of work intensity on plasma volume, osmolality, vasopressin and renin activity and the interrelationships between these responses are investigated. Plasma volume, renin activity and osmotic, sodium and arginine vasopressin concentrations were measured in venous blood samples taken from 15 healthy male subjects before and after six minutes of bicycle ergometer exercise at 100, 175 and 225 W. Plasma volume is found to decrease significantly with increasing work intensity, while increases in Na(+) concentration, osmolality and vasopressin are only observed to be significant when the work intensity exceeds 40% maximal aerobic capacity and plasma resin activity increased linearly at all work levels. In addition, significant correlations are observed between plasma volume and osmolality and sodium changes, and between vasopressin and osmolality and sodium content changes. Data thus support the hypotheses that (1) vasopressin may be the primary controlling endocrine for fluid and electrolyte levels following exercise; (2) an exercise intensity greater than 40% maximal aerobic capacity is required to stimulate vasopressin release through changes in plasma osmolality; and (3) the stimulation of the renin-angiotensin system is a more general stress response.

Effect of short-term heat acclimation training on kinetics of lactate removal following maximal exercise.

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Dileo, Tsavis D; Powell, Jeffrey B; Kang, Hyoung K; Roberge, Raymond J; Coca, Aitor; Kim, Jung-Hyun

2016-01-01

Heat acclimation (HA) evokes numerous physiological adaptations, improves heat tolerance and has also been shown to enhance lactate (LA) responses during exercise, similar to that seen with endurance training. The purpose of this study was to examine whether HA improves the body's ability to remove LA during recovery following maximal exercise. Ten healthy men completed two trials of maximal treadmill exercise (pre- and post-HA) separated by 5 days of HA. Each day of HA consisted of two 45 minute periods of cycling at ~50% VO2max separated by a 15min rest period in an environmental chamber (T(db) 45° C, RH 20%). In pre-/post-HA trials, venous blood was collected during 60 minutes of recovery to determine LA concentrations and removal kinetics (A2: amplitude and y2: velocity constant) using bi-exponential curve fitting. Physiological adaptation to heat was significantly developed during HA, as evidenced by end-exercise T(re) (DAY1 vs. 5) (38.89±0.56 vs. 38.66±0.44° C), T(sk) (38.07±0.51 vs. 37.66±0.48° C), HR (175.0±9.9 vs. 165.0±18.5 beats·min(-1)), and sweat rate (1.24 ±.26 vs. 1.47 ±0.27 L·min(-1)) (PLA concentrations (LA(0min): 8.78±1.08 vs. 8.69±1.23; LA(peak): 10.97±1.77 vs. 10.95±1.46; and La(60min); 2.88±0.82 vs. 2.96±0.93 mmol·L(-1)) or removal kinetics (A2: -13.05±7.05 vs -15.59±7.90 mmol.L(-1) and y2: 0.02±0.01 vs. 0.03±.01 min(-1)). The present study concluded that, while effective in inducing thermo-physiological adaptations to heat stress, short-term HA does not improve the body's ability to remove LA following maximal exercise. Therefore, athletes and workers seeking faster LA recovery from intense physical activity may not benefit from short-term HA.

Plasma pH does not influence the cerebral metabolic ratio during maximal whole body exercise

DEFF Research Database (Denmark)

Volianitis, Stefanos; Rasmussen, Peter; Seifert, Thomas

2011-01-01

.05) following the Sal and Bicarb trials, respectively. Accordingly, the cerebral metabolic ratio decreased equally during the Sal and Bicarb trials: from 5.8 ± 0.6 at rest to 1.7 ± 0.1 and 1.8 ± 0.2, respectively. The enlarged blood-buffering capacity after infusion of Bicarb eliminated metabolic acidosis......Exercise lowers the cerebral metabolic ratio of O2 to carbohydrate (glucose + 1/2 lactate) and metabolic acidosis appears to promote cerebral lactate uptake. However, the influence of pH on cerebral lactate uptake and, in turn, on the cerebral metabolic ratio during exercise is not known. Sodium...... during maximal exercise but that did not affect the cerebral lactate uptake and, therefore, the decrease in the cerebral metabolic ratio....

Developing maximal neuromuscular power: part 2 - training considerations for improving maximal power production.

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Cormie, Prue; McGuigan, Michael R; Newton, Robert U

2011-02-01

This series of reviews focuses on the most important neuromuscular function in many sport performances: the ability to generate maximal muscular power. Part 1, published in an earlier issue of Sports Medicine, focused on the factors that affect maximal power production while part 2 explores the practical application of these findings by reviewing the scientific literature relevant to the development of training programmes that most effectively enhance maximal power production. The ability to generate maximal power during complex motor skills is of paramount importance to successful athletic performance across many sports. A crucial issue faced by scientists and coaches is the development of effective and efficient training programmes that improve maximal power production in dynamic, multi-joint movements. Such training is referred to as 'power training' for the purposes of this review. Although further research is required in order to gain a deeper understanding of the optimal training techniques for maximizing power in complex, sports-specific movements and the precise mechanisms underlying adaptation, several key conclusions can be drawn from this review. First, a fundamental relationship exists between strength and power, which dictates that an individual cannot possess a high level of power without first being relatively strong. Thus, enhancing and maintaining maximal strength is essential when considering the long-term development of power. Second, consideration of movement pattern, load and velocity specificity is essential when designing power training programmes. Ballistic, plyometric and weightlifting exercises can be used effectively as primary exercises within a power training programme that enhances maximal power. The loads applied to these exercises will depend on the specific requirements of each particular sport and the type of movement being trained. The use of ballistic exercises with loads ranging from 0% to 50% of one-repetition maximum (1RM) and

The role of exercise testing in heart failure.

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Swedberg, K; Gundersen, T

1993-01-01

The objectives of exercise testing in congestive heart failure (CHF) may be summarized as follows: (a) detect impaired cardiac performance, (b) grade severity of cardiac failure and classify functional capability, and (c) assess effects of interventions. Several different methods are available to make these assessments, and we have to ask ourselves how well exercise testing achieves these objectives. It has to be kept in mind that the power generated by the exercising muscles is dependent on the oxygen delivery to the skeletal muscles. Oxygen uptake is the result of an integrated performance of the lungs, heart, and peripheral circulation. In patients, as well as in normal subjects, oxygen uptake is related to hemodynamic indices such as cardiac output, stroke volume, or exercise duration when a stepwise regulated maximal exercise protocol is used. However, there are major differences in the concept of a true maximum in normal subjects versus heart failure patients. Fit-normal subjects will achieve a real maximal oxygen uptake, whereas patients may stop testing before a maximum is reached because of symptoms such as dyspnea or leg fatigue. Therefore, it is better if the actual oxygen uptake can be measured. "Peak" rather than true maximal oxygen uptake has been suggested for the classification of the severity of heart failure. Peripheral factors modify the cardiac output through such factors as vascular resistance, organ function, and hormonal release. Maximal exercise will stress the cardiovascular system to a point where the weakest chain will impose a limiting effect.(ABSTRACT TRUNCATED AT 250 WORDS)

[Maximal exercise in spinal cord injured subjects: effects of an antigravity suit].

Science.gov (United States)

Bazzi-Grossin, C; Bonnin, P; Bailliart, O; Bazzi, H; Kedra, A W; Martineaud, J P

1996-01-01

Paraplegics have low aerobic capacity because of the spinal cord injury. Their functional muscle mass is reduced and usually untrained. They have to use upperbody muscles for displacements and daily activities. Sympathic nervous system injury is responsible of vasomotricity disturbances in leg vessels and possible abdominal vessels, proportionally to level injury. If cord injury level is higher than T5, then sympathic cardiac efferences may be damaged. Underbody muscles atrophy and vasomotricity disturbances contribute to phlebostasis. This stasis may decrease venous return, preload and stroke volume (Starling). To maintain appropriate cardiac output, tachycardia is necessary, especially during exercise. Low stroke volume, all the more since it is associated with cardio-acceleration disturbances, may reduce cardiac output reserve, and so constitutes a limiting factor for adaptation to exercise. The aim of this study was to verify if use of an underlesional pressure suit may increase cardiac output reserve because of lower venous stasis, and increase performance. We studied 10 able-bodied and 14 traumatic paraplegic subjects. Able-bodied subjects were 37 +/- 6 years old, wellbeing, not especially trained with upperbody muscles: there were 2 women and 8 men. Paraplegics were 27 +/- 7 years old, wellbeing except paraplegia, five of them practiced sport regularly (athletism or basket for disabled), and the others just daily propelled their wheelchair; there were 5 women and 9 men. For 8 of them, cord injury levels were located below T7, between T1 and T6 for the others. The age disability varied from 6 months to 2 years for 9 of them, it was approximately five years for 4 of them, and 20 years for one. We used a maximal triangular arm crank exercise with an electro-magnetic ergocycle Gauthier frame. After five minutes warm up, it was proceeded in one minute successive stages until maximal oxygen consumption is raised. VO2, VCO2, RER were measured by direct method with

Hemodynamic mechanisms of the attenuated blood pressure response to mental stress after a single bout of maximal dynamic exercise in healthy subjects

Directory of Open Access Journals (Sweden)

F.J. Neves

2012-07-01

Full Text Available To determine the hemodynamic mechanisms responsible for the attenuated blood pressure response to mental stress after exercise, 26 healthy sedentary individuals (age 29 ± 8 years underwent the Stroop color-word test before and 60 min after a bout of maximal dynamic exercise on a treadmill. A subgroup (N = 11 underwent a time-control experiment without exercise. Blood pressure was continuously and noninvasively recorded by infrared finger photoplethysmography. Stroke volume was derived from pressure signals, and cardiac output and peripheral vascular resistance were calculated. Perceived mental stress scores were comparable between mental stress tests both in the exercise (P = 0.96 and control (P = 0.24 experiments. After exercise, the blood pressure response to mental stress was attenuated (pre: 10 ± 13 vs post: 6 ± 7 mmHg; P 0.05. In conclusion, a single bout of maximal dynamic exercise attenuates the blood pressure response to mental stress in healthy subjects, along with lower stroke volume and cardiac output, denoting an acute modulatory action of exercise on the central hemodynamic response to mental stress.

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

Positive exercise thallium-201 test responses in patients with less than 50% maximal coronary stenosis: angiographic and clinical predictors

International Nuclear Information System (INIS)

Brown, K.A.; Osbakken, M.; Boucher, C.A.; Strauss, H.W.; Pohost, G.M.; Okada, R.D.

1985-01-01

The incidence and causes of abnormal thallium-201 (TI-201) myocardial perfusion studies in the absence of significant coronary artery disease were examined. The study group consisted of 100 consecutive patients undergoing exercise TI-201 testing and coronary angiography who were found to have maximal coronary artery diameter narrowing of less than 50%. Maximal coronary stenosis ranged from 0 to 40%. The independent and relative influences of patient clinical, exercise and angiographic data were assessed by logistic regression analysis. Significant predictors of a positive stress TI-201 test result were: (1) percent maximal coronary stenosis (p less than 0.0005), (2) propranolol use (p less than 0.01), (3) interaction of propranolol use and percent maximal stenosis (p less than 0.005), and (4) stress-induced chest pain (p . 0.05). No other patient variable had a significant influence. Positive TI-201 test results were more common in patients with 21 to 40% maximal stenosis (59%) than in patients with 0 to 20% maximal stenosis (27%) (p less than 0.01). Among patients with 21 to 40% stenosis, a positive test response was more common when 85% of maximal predicted heart rate was achieved (75%) than when it was not (40%) (p less than 0.05). Of 16 nonapical perfusion defects seen in patients with 21 to 40% maximal stenosis, 14 were in the territory that corresponded with such a coronary stenosis. Patients taking propranolol were more likely to have a positive TI-201 test result (45%) than patients not taking propranolol (22%) (p less than 0.05)

Myocardial functional responses do not contribute to maximal exercise performance in the heat.

Science.gov (United States)

Smith, Denise L; DeBlois, Jacob P; Wharton, Margaret; Rowland, Thomas

2015-01-01

Both the extent and means by which maximal oxygen uptake ([Formula: see text]) is depressed by elevated ambient temperature are uncertain. Particularly, information is currently unavailable regarding the possible influence of alterations in myocardial function on [Formula: see text] and performance during exercise in the heat. This study investigated the effects of environmental heat on [Formula: see text], peak work capacity, and myocardial function during a standard, progressive cycle test to exhaustion. Twelve euhydrated men (aged 20.7 ± 1.7 years) performed a maximal cycle test in an environmental chamber in both heat stress [35°C, 30% relative humidity (RH)] and temperate (20°C, 30% RH) conditions with measurement of standard gas exchange variables, core temperature, and echocardiographic measures of cardiac function. A small but statistically significant reduction of peak work capacity was observed in the heat stress versus temperate conditions (253 ± 30 and 259 ± 30 W, respectively, p = 0.02). Mean [Formula: see text] was not statistically different in the two conditions (p = 0.16) but values were 3.4% lower in the heat, and 9 of 12 participants demonstrated lower values in the heat stress trial. No differences in responses of heart rate, cardiac output, stroke volume, core temperature, hydration status, or myocardial systolic or diastolic function were observed between the two conditions, but perceived body temperature was higher in the heat. The small, negative impact of heat on exercise performance and [Formula: see text] could not be explained by disturbances in myocardial functional responses to exercise in young adult males.

Motor control or graded activity exercises for chronic low back pain? A randomised controlled trial

Science.gov (United States)

Macedo, Luciana G; Latimer, Jane; Maher, Chris G; Hodges, Paul W; Nicholas, Michael; Tonkin, Lois; McAuley, James H; Stafford, Ryan

2008-01-01

Background Chronic low back pain remains a major health problem in Australia and around the world. Unfortunately the majority of treatments for this condition produce small effects because not all patients respond to each treatment. It appears that only 25–50% of patients respond to exercise. The two most popular types of exercise for low back pain are graded activity and motor control exercises. At present however, there are no guidelines to help clinicians select the best treatment for a patient. As a result, time and money are wasted on treatments which ultimately fail to help the patient. Methods This paper describes the protocol of a randomised clinical trial comparing the effects of motor control exercises with a graded activity program in the treatment of chronic non specific low back pain. Further analysis will identify clinical features that may predict a patient's response to each treatment. One hundred and seventy two participants will be randomly allocated to receive either a program of motor control exercises or graded activity. Measures of outcome will be obtained at 2, 6 and 12 months after randomisation. The primary outcomes are: pain (average pain intensity over the last week) and function (patient-specific functional scale) at 2 and 6 months. Potential treatment effect modifiers will be measured at baseline. Discussion This trial will not only evaluate which exercise approach is more effective in general for patients will chronic low back pain, but will also determine which exercise approach is best for an individual patient. Trial registration number ACTRN12607000432415 PMID:18454877

Motor control or graded activity exercises for chronic low back pain? A randomised controlled trial

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McAuley James H

2008-05-01

Full Text Available Abstract Background Chronic low back pain remains a major health problem in Australia and around the world. Unfortunately the majority of treatments for this condition produce small effects because not all patients respond to each treatment. It appears that only 25–50% of patients respond to exercise. The two most popular types of exercise for low back pain are graded activity and motor control exercises. At present however, there are no guidelines to help clinicians select the best treatment for a patient. As a result, time and money are wasted on treatments which ultimately fail to help the patient. Methods This paper describes the protocol of a randomised clinical trial comparing the effects of motor control exercises with a graded activity program in the treatment of chronic non specific low back pain. Further analysis will identify clinical features that may predict a patient's response to each treatment. One hundred and seventy two participants will be randomly allocated to receive either a program of motor control exercises or graded activity. Measures of outcome will be obtained at 2, 6 and 12 months after randomisation. The primary outcomes are: pain (average pain intensity over the last week and function (patient-specific functional scale at 2 and 6 months. Potential treatment effect modifiers will be measured at baseline. Discussion This trial will not only evaluate which exercise approach is more effective in general for patients will chronic low back pain, but will also determine which exercise approach is best for an individual patient. Trial registration number ACTRN12607000432415

Using molecular classification to predict gains in maximal aerobic capacity following endurance exercise training in humans

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Timmons, James A; Knudsen, Steen; Rankinen, Tuomo

2010-01-01

A low maximal oxygen consumption (VO2max) is a strong risk factor for premature mortality. Supervised endurance exercise training increases VO2max with a very wide range of effectiveness in humans. Discovering the DNA variants that contribute to this heterogeneity typically requires substantial s...

Effect of sonic driving on maximal aerobic performance.

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Brilla, L.R.; Hatcher, Stefanie

2000-07-01

The study purpose was to evaluate antecedent binaural stimulation (ABS) on maximal aerobic physical performance. Twenty-two healthy, physically active subjects, 21-34 years, randomly received one of two preparations for each session: 15 min of quiet (BLANK) or percussive sonic driving at 200+ beats per minute (bpm) using a recorded compact disc (FSS, Mill Valley, CA) with headphones (ABS). Baseline HR, blood pressure (BP), and breathing frequency (f(br)) were obtained. During each condition, HR and f(br) were recorded at 3-min intervals. The graded maximal treadmill testing was administered immediately postpreparation session on separate days, with at least 48 h rest between sessions. There were significant differences in the antecedent period means between the two conditions, ABS (HR: 70.2 +/- 10.7 bpm; f(br): 18.5 +/- 3.3 br min(-1); BP: 134.5/87.9 +/- 13.6/9.2 mm Hg) and BLANK (HR: 64.6 +/- 7.9; f(br): 14.3 +/- 2.9; BP: 126.7/80.3 +/- 12.1/8.6). Differences were noted for each 3-min interval and pre- postantecedent period. The maximal graded exercise test (GXT) results showed that there was a small but significant (P 0.05). There may be a latency to ABS related to entrainment or imagery-enhanced warm-up. Am. J. Hum. Biol. 12:558-565, 2000. Copyright 2000 Wiley-Liss, Inc.

The Higher the Insulin Resistance the Lower the Cardiac Output in Men with Type 1 Diabetes During the Maximal Exercise Test.

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Niedzwiecki, Pawel; Naskret, Dariusz; Pilacinski, Stanislaw; Pempera, Maciej; Uruska, Aleksandra; Adamska, Anna; Zozulinska-Ziolkiewicz, Dorota

2017-06-01

The aim of this study was to assess the hemodynamic parameters analyzed in bioimpedance cardiography during maximal exercise in patients with type 1 diabetes differing in insulin resistance. The study group consisted of 40 men with type 1 diabetes. Tissue sensitivity to insulin was assessed on the basis of the glucose disposal rate (GDR) analyzed during hyperinsulinemic-euglycemic clamp. Patients were divided into groups with GDR insulin sensitivity) and GDR ≥4.5 mg/kg/min (G2 group-higher insulin sensitivity). During the exercise test, the heart rate, systolic volume, cardiac output, cardiac index were measured by the impedance meter (PhysioFlow). Compared with the G2 group, the G1 group had a lower cardiac output (CO): during exercise 8.6 (IQR 7.7-10.0) versus 12.8 (IQR 10.8-13.7) L/min; P insulin resistance is associated with cardiac hemodynamic parameters assessed during and after exercise. The higher the insulin resistance the lower the cardiac output during maximal exercise in men with type 1 diabetes.

Effectiveness of Motor Skills Development in 5th-7th Grade Girls at Different Modes of Physical Exercises

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Olga Ivashchenko

2017-12-01

Full Text Available The objective is to determine the influence of the physical exercises modes on effectiveness of motor skills development in 5th-7th grade girls.  Materials and methods. The study involved 5th grade girls (n = 28, 6th grade girls (n = 28 and 7th grade girls (n = 24. To solve the tasks set, the study relied on general scientific and special research methods, methods of mathematical experiment-planning. Studying the influence of different variants of the educational process structure, namely: the number of repetitions (x1 and the rest intervals (x2 on acquisition of the technique of physical exercises performance, provided for achieving the objective. A full 22 type factorial experiment was conducted. The 5th-7th graders were divided into training groups according to the experiment plan. In total, there were twelve experimental groups organized, four in each class. Results. The analysis of the regression equations shows that the rest interval between repetitions (x2 has the greatest influence on teaching 5th-7th grade girls physical exercises, with the number of repetitions (x1 being of somewhat less significant influence. The relation between these factors (x1x2 has a considerable weight in teaching to “rope climb in two or three sets” and to do a “pullover mount with a swing of one and a push-off with the other leg”. Conclusions. To increase the effectiveness of teaching 5th-7th grade girls physical exercises, the number of repetitions in throwing exercises should be increased to twelve times, and the rest interval reduced to 60 seconds. In the 7th grade, the number of repetitions should be reduced to six times, and the rest interval – to 60 seconds. The rest intervals in the exercises: “pullover mount with a swing of one and a push-off with the other leg” and “rope climbing in two or three sets”, should be reduced to 60 seconds and the number of repetitions – to six.

Effect of Acute Maximal Exercise on Circulating Levels of Interleukin-12 during Ramadan Fasting.

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Abedelmalek, Salma; Souissi, Nizar; Takayuki, Akimoto; Hadouk, Sami; Tabka, Zouhair

2011-09-01

The purpose of this study was to examine the effects of Ramadan fasting on circulating levels of interleukin-12 (IL-12) after a brief maximal exercise. NINE SUBJECTS PERFORMED A WINGATE TEST ON THREE DIFFERENT OCCASIONS: (i) the first week of Ramadan (1WR), (ii) the fourth week of Ramadan (4WR), and (iii) three weeks after Ramadan (AR). Blood samples were taken before, immediately and 60 min after the exercise. Plasma concentrations of IL-12 were measured using enzyme-linked immunosorbent assay. Variance analysis revealed no significant effect of Ramadan on P(peak) and P(mean) during the three testing periods. Considering the effect of Ramadan on plasma concentrations of IL-12, analysis of the variance revealed a significant Ramadan effect (F((2,) (16))=66.27; P effect (F((2,) (16))= 120.66; P Ramadan × time) of test interaction (F((4,) (32))=2.40; P>0.05). For all measures, IL-12 levels were lower during 1WR and 4WR in comparison with AR (P effects, IL-12 levels measured immediately after the exercise were significantly higher than those measured before and at 60 minutes after the exercise (P Ramadan.

Relations of morphological characteristics and maximal oxygen consumption of fourth grade pupils based on gender

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Jakovljević Vladimir

2014-01-01

Full Text Available On a sample of 71 respondents, 37 boys and 34 girls, age of fourth grade elementary school, accordingly 9 years +/- 6 months, it is assessed correlation and prediction of maximal oxygen consumption based measures of morphological range. Maximum oxygen consumption was measured by indirect method, using a field test of maximal multiple load of feedback running at 20 meters. Range of morphology was analyzed based on 5 measures of longitudinal dimensionality, 4 measures of volume and body mass and 3 measures of transversal dimensionality. Results of correlation analysis showed that in both sexes there was no statistically significant correlation between results of maximal oxygen consumption and measures of longitudinal dimensionality, while regression analysis confirmed that there was no statistically significant prediction of maximum oxygen consumption based on measures of longitudinal dimensionality. While the correlation analysis deduced that part of volume measures and body mass and transversal dimensionality have statistically significant correlation only with female respondents with results of maximal oxygen consumption. Regression analysis showed statistically significant prediction of maximal oxygen consumption based on part of volume measures and body mass and transversal dimensionality. It is determined that female respondents with larger volumes of the thigh and lower leg, accordingly with smaller diameters of knee joint and ankle joint most likely will achieve better results in applied test, and therefore higher maximal oxygen consumption.

Change in the level of strength and endurance development of 5-6 grades pupils under cheerleading exercises influence

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Tetyana Bala

2015-06-01

Full Text Available Purpose: determine the degree of change in the level of strength and endurance development of 5-6 grades pupils under cheerleading exercises influence. Material and Methods: theoretical analysis and generalization of scientific and methodical literature, pedagogical testing, pedagogical experiment and mathematical statistics methods. Results: parameters of strength and endurance development level are presented with their degree of change under cheerleading exercises influence for 5-6 grades pupils of secondary school. Conclusions: cheerleading exercises usage has positive influence on demonstrated strength and endurance degree of secondary school children by all investigated parameters.

The effects of Pilates exercise on cardiopulmonary function in the chronic stroke patients: a randomized controlled trials.

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Lim, Hee Sung; Yoon, Sukhoon

2017-05-01

[Purpose] The purpose of this study was to examine the effect of modified Pilates exercise on cardiopulmonary function in chronic stroke patients. [Subjects and Methods] Twenty participants (age, 62.7 ± 7.3 years; height, 163.3 ± 8.5 cm; weight, 68.8 ± 10.3 kg) were recruited for this study, and randomly allocated to the modified Pilates exercise group (n=10) or the control group (n=10). Graded submaximal treadmill exercise test was used to examine the status of patients' cardiopulmonary function, based on maximal oxygen intake, at the end of a patient's exercise tolerance limit. [Results] The resting heart rates, maximal oxygen intake, and maximal oxygen intake per kilogram were significantly different after 8 weeks of modified Pilates exercise. In addition, these variables were also significantly different between the Pilates and control groups after 8 weeks. [Conclusion] This study has demonstrated that 8 weeks of modified Pilates exercise program can have a positive influence on patients with chronic stroke, potentially by enhancing the cardiopulmonary function, which may have positive implications for increasing their functional ability.

Cigarette smoking decreases dynamic inspiratory capacity during maximal exercise in patients with type 2 diabetes.

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Kitahara, Yoshihiro; Hattori, Noboru; Yokoyama, Akihito; Yamane, Kiminori; Sekikawa, Kiyokazu; Inamizu, Tsutomu; Kohno, Nobuoki

2012-06-01

To investigate the influence of cigarette smoking on exercise capacity, respiratory responses and dynamic changes in lung volume during exercise in patients with type 2 diabetes. Forty-one men with type, 2 diabetes without cardiopulmonary disease were recruited and divided into 28 non-current smokers and 13 current smokers. All subjects received lung function tests and cardiopulmonary exercise testing using tracings of the flow-volume loop. Exercise capacity was compared using the percentage of predicted oxygen uptake at maximal workload (%VO2max). Respiratory variables and inspiratory capacity (IC) were compared between the two groups at rest and at 20%, 40%, 60%, 80% and 100% of maximum workload. Although there was no significant difference in lung function tests between the two groups, venous carboxyhemoglobin (CO-Hb) levels were significantly higher in current smokers. %VO2max was inversely correlated with CO-Hb levels. Changing patterns in respiratory rate, respiratory equivalent and IC were significantly different between the two groups. Current smokers had rapid breathing, a greater respiratory equivalent and a limited increase in IC during exercise. Cigarette smoking diminishes the increase in dynamic IC in patients with type 2 diabetes. As this effect of smoking on dynamic changes in lung volume will exacerbate dynamic hyperinflation in cases complicated by chronic obstructive pulmonary disease, physicians should consider smoking habits and lung function when evaluating exercise capacity in patients with type 2 diabetes.

A Comparison of Exercise-Induced Muscle Damage Following Maximal Eccentric Contractions in Men and Boys.

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Deli, Chariklia K; Fatouros, Ioannis G; Paschalis, Vassilis; Georgakouli, Kalliopi; Zalavras, Athanasios; Avloniti, Alexandra; Koutedakis, Yiannis; Jamurtas, Athanasios Z

2017-08-01

Research regarding exercise-induced muscle-damage mainly focuses on adults. The present study examined exercise-induced muscle-damage responses in adults compared with children. Eleven healthy boys (10-12 y) and 15 healthy men (18-45 y) performed 5 sets of 15 maximal eccentric contractions of the knee extensors. Range of motion (ROM), delayed onset muscle soreness (DOMS) during squat and walking, and peak isometric, concentric and eccentric torque were assessed before, post, 24, 48, 72, and 96 hr postexercise. Creatine kinase (CK) activity was assessed before and 72 hr postexercise. Eccentric exercise resulted in DOMS during squat that persisted for up to 96h in men, and 48 hr in boys (p < .05), and DOMS during walking that persisted for up to 72 hr in men, and 48 hr in boys (p < .01). The ROM was lower in both age groups 48 hr postexercise (p < .001). Isometric (p < .001), concentric (p < .01) and eccentric (p < .01) force decreased post, and up to 48 hr postexercise in men. Except for a reduction in isometric force immediately after exercise, no other changes occurred in boys' isokinetic force. CK activity increased in men at 72 hr postexercise compared with pre exercise levels (p = .05). Our data provide further confirmation that children are less susceptible to exercise-induced muscle damage compared with adults.

Local depletion of glycogen with supra-maximal exercise in human skeletal muscle fibres

DEFF Research Database (Denmark)

Gejl, Kasper Degn; Ørtenblad, Niels; Andersson, Erik

2017-01-01

importance to muscle function. The present study was designed to investigate the depletion of these three sub-cellular glycogen compartments during repeated supra-maximal exercise in elite athletes. Ten elite cross-country skiers (age: 25 ± 4 yrs., VO2 max : 65 ± 4 ml kg(-1) min(-1) , mean ± SD) performed...... four ∼4-minute supra-maximal sprint time trials (STT 1-4) with 45 min recovery. The sub-cellular glycogen volumes in m. triceps brachii were quantified from electron microscopy images before and after both STT 1 and STT 4. During STT 1, the depletion of intramyofibrillar glycogen was higher in type I...... fibres (-52% [-89:-15%]) than type 2 fibres (-15% [-52:22%]) (P = 0.02), while the depletion of intermyofibrillar glycogen (main effect: -19% [-33:0], P = 0.006) and subsarcolemmal glycogen (main effect: -35% [-66:0%], P = 0.03) was similar between fibre types. In contrast, only intermyofibrillar...

Oral Consumption of Vitamin K2 for 8 Weeks Associated With Increased Maximal Cardiac Output During Exercise.

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McFarlin, Brian K; Henning, Andrea L; Venable, Adam S

2017-07-01

Background • Vitamin K1 and K2 are not typically common in a Western diet because they are found in a variety of fermented foods. Vitamin K2 in particular has been demonstrated to restore mitochondrial function and has a key role in production of mitochondrial adenosine triphosphate. Thus, it is reasonable to speculate that dietary supplementation with vitamin K2 could increase the function of muscle with high mitochondrial content (ie, skeletal and cardiac muscle). Objective • The purpose of this study was to determine if 8 wk of dietary supplementation with Vitamin K2 could alter cardiovascular responses to a graded cycle ergometer test. Design • The study was a randomized controlled trial. Setting • The study took place in the Applied Physiology Laboratory of the Department of Biological Sciences at the University of North Texas (Denton, TX, USA). Participants • Participants were aerobically trained males and female athletes (N = 26). Intervention • Participants were randomly assigned either to a control group that received a rice flour placebo or to an intervention group that received vitamin K2. For weeks 1 to 4, participants received 300 mg/d; for weeks 5 to 8, they received 150 mg/d. Subjects assigned to the control group received similar doses to mirror the intervention group. Subjects consumed the supplements during an 8-wk period while they maintained their typical exercise habits. Outcome Measures • At baseline and postintervention, participants completed a standard, graded exercise test on an electronically braked cycle ergometer. Before the test, participants were fitted with a mouth piece, and their oxygen consumption, carbon dioxide production, respiratory rate, and respiratory exchange ratio were measured. In addition, participants were fitted with skin-mounted electrodes that measured noninvasive cardiac output, stroke volume, and heart rate. To assess the cumulative exercise change, an area-under-the-curve (AUC) value was calculated

Perceptual and cerebro-spinal responses to graded innocuous and noxious stimuli following aerobic exercise.

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Micalos, P S; Harris, J; Drinkwater, E J; Cannon, J; Marino, F E

2015-11-01

The aim of this study was to evaluate the effect of aerobic exercise on perceptual and cerebro-spinal responses to graded electrocutaneous stimuli. The design comprised 2 x 30 min of cycling exercise at 30% and 70% of peak oxygen consumption (VO2 peak) on separate occasions in a counter-balanced order in 10 healthy participants. Assessment of nociceptive withdrawal reflex threshold (NWR-T), pain threshold (PT), and somatosensory evoked potentials (SEPs) to graded electrocutaneous stimuli were performed before and after exercise. Perceptual magnitude ratings and SEPs were compared at 30%PT, 60%PT, 100%PT before (Pre), 5 min after (Post1), and 15 min after (Post2) aerobic exercise. There was no difference in the NWR-T and the PT following exercise at 30% and 70% of VO2 peak. ANOVA for the perceptual response within pooled electrocutaneous stimuli show a significant main effect for time (F2,18=5.41, P=0.01) but no difference for exercise intensity (F1,9=0.02, P=0.88). Within-subject contrasts reveal trend differences between 30%PT and 100%PT for Pre-Post1 (P=0.09) and Pre-Post2 (P=0.02). ANOVA for the SEPs peak-to-peak signal amplitude (N1-P1) show significant main effect for time (F2,18=4.04, P=0.04) but no difference for exercise intensity (F1,9=1.83, P=0.21). Pairwise comparisons for time reveal differences between Pre-Post1 (P=0.06) and Pre-Post2 (P=0.01). There was a significant interaction for SEPs N1-P1 between exercise intensity and stimulus intensity (F2,18=3.56, P=0.05). These results indicate that aerobic exercise did not increase the electrocutaneous threshold for pain and the NWR-T. Aerobic exercise attenuated perceptual responses to innocuous stimuli and SEPs N1-P1 response to noxious stimuli.

Comparison of changes in the mobility of the pelvic floor muscle on during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction.

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Jung, Halim; Jung, Sangwoo; Joo, Sunghee; Song, Changho

2016-01-01

[Purpose] The purpose of this study was to compare changes in the mobility of the pelvic floor muscle during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction. [Subjects] Thirty healthy adults participated in this study (15 men and 15 women). [Methods] All participants performed a bridge exercise and abdominal curl-up during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction. Pelvic floor mobility was evaluated as the distance from the bladder base using ultrasound. [Results] According to exercise method, bridge exercise and abdominal curl-ups led to significantly different pelvic floor mobility. The pelvic floor muscle was elevated during the abdominal drawing-in maneuver and descended during maximal expiration. Finally, pelvic floor muscle mobility was greater during abdominal curl-up than during the bridge exercise. [Conclusion] According to these results, the abdominal drawing-in maneuver induced pelvic floor muscle contraction, and pelvic floor muscle contraction was greater during the abdominal curl-up than during the bridge exercise.

Effects of a 6-month exercise program pilot study on walking economy, peak physiological characteristics, and walking performance in patients with peripheral arterial disease

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Crowther RG

2012-04-01

Full Text Available Robert G Crowther1, Anthony S Leicht1, Warwick L Spinks1, Kunwarjit Sangla2, Frank Quigley2, Jonathan Golledge2,31Institute of Sport and Exercise Science, James Cook University, Townsville, Queensland, Australia; 2Townsville Hospital, Townsville, Queensland, Australia; 3The Vascular Biology Unit, James Cook University, Townsville, Queensland, AustraliaAbstract : The purpose of this study was to examine the effects of a 6-month exercise program on submaximal walking economy in individuals with peripheral arterial disease and intermittent claudication (PAD-IC. Participants (n = 16 were randomly allocated to either a control PAD-IC group (CPAD-IC, n = 6 which received standard medical therapy, or a treatment PAD-IC group (TPAD-IC; n = 10 which took part in a supervised exercise program. During a graded treadmill test, physiological responses, including oxygen consumption, were assessed to calculate walking economy during submaximal and maximal walking performance. Differences between groups at baseline and post-intervention were analyzed via Kruskal–Wallis tests. At baseline, CPAD-IC and TPAD-IC groups demonstrated similar walking performance and physiological responses. Postintervention, TPAD-IC patients demonstrated significantly lower oxygen consumption during the graded exercise test, and greater maximal walking performance compared to CPAD-IC. These preliminary results indicate that 6 months of regular exercise improves both submaximal walking economy and maximal walking performance, without significant changes in maximal walking economy. Enhanced walking economy may contribute to physiological efficiency, which in turn may improve walking performance as demonstrated by PAD-IC patients following regular exercise programs.Keywords: vascular disease, peripheral vascular disease, walking economy

Low-Grade Inflammation and Spinal Cord Injury: Exercise as Therapy?

OpenAIRE

da Silva Alves, Eduardo; de Aquino Lemos, Valdir; Ruiz da Silva, Francieli; Lira, Fabio Santos; dos Santos, Ronaldo Vagner Thomathieli; Rosa, Jo?o Paulo Pereira; Caperuto, Erico; Tufik, Sergio; de Mello, Marco Tulio

2013-01-01

An increase in the prevalence of obesity in people with spinal cord injury can contribute to low-grade chronic inflammation and increase the risk of infection in this population. A decrease in sympathetic activity contributes to immunosuppression due to the lower activation of immune cells in the blood. The effects of physical exercise on inflammatory parameters in individuals with spinal cord injury have not been well described. We conducted a review of the literature published from 1974 to ...

Compliance and safety of a novel home exercise program for patients with high-grade brain tumors, a prospective observational study.

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Baima, Jennifer; Omer, Zehra B; Varlotto, John; Yunus, Shakeeb

2017-09-01

The purpose of this study is to evaluate compliance with and safety of a novel independent home exercise program for patients with high-grade brain tumors. We designed this program around the preferences and individual capabilities of this population as well as the potential barriers to exercise in cancer patients. Demographics were collected to better understand those that persisted with exercise. Subjects with high-grade brain tumor received one-time training that included watching an exercise video and live demonstration of resistance band exercises, a balance exercise, and recommendations for walking. Subjects were instructed to do the exercises every day for 1 month. Main outcome measures were percentage of subjects who exercised throughout the month, frequency of exercising, demographic factors, quality of life scores (assessed by FACT-BR), and self report of adverse events. Fourteen of the 15 (93%) subjects started the exercises during the course of the month. Nine of the fifteen (60%) continued the exercises throughout the month. Three additional subjects would have continued to exercise if formal or supervised rehabilitation had been offered. Among the subjects who continued the exercises regularly, higher frequency of exercising was significantly associated with living as married (p = 0.033), annual income >$50,000 (p = 0.047), scores of physical well-being (p = 0.047), and brain cancer specific well-being (p = 0.054) subscales. Among those who exercised frequently, there was also a trend towards increase in total FACT-BR scores (p = 0.059). The subjects who scored higher on the social well-being subscale of the FACT-BR at baseline self-reported a higher likelihood to continue the exercises after 1 month of participation in the study (p = 0.018). No adverse events were reported. Our small group of subjects with high-grade brain tumors demonstrated compliance with and safety of a novel independent strength and balance exercise program in the

Effects of plyometric training on maximal-intensity exercise and endurance in male and female soccer players.

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Ramírez-Campillo, Rodrigo; Vergara-Pedreros, Marcelo; Henríquez-Olguín, Carlos; Martínez-Salazar, Cristian; Alvarez, Cristian; Nakamura, Fábio Yuzo; De La Fuente, Carlos I; Caniuqueo, Alexis; Alonso-Martinez, Alicia M; Izquierdo, Mikel

2016-01-01

In a randomised controlled trial design, effects of 6 weeks of plyometric training on maximal-intensity exercise and endurance performance were compared in male and female soccer players. Young (age 21.1 ± 2.7 years) players with similar training load and competitive background were assigned to training (women, n = 19; men, n = 21) and control (women, n = 19; men, n = 21) groups. Players were evaluated for lower- and upper-body maximal-intensity exercise, 30 m sprint, change of direction speed and endurance performance before and after 6 weeks of training. After intervention, the control groups did not change, whereas both training groups improved jumps (effect size (ES) = 0.35-1.76), throwing (ES = 0.62-0.78), sprint (ES = 0.86-1.44), change of direction speed (ES = 0.46-0.85) and endurance performance (ES = 0.42-0.62). There were no differences in performance improvements between the plyometric training groups. Both plyometric groups improved more in all performance tests than the controls. The results suggest that adaptations to plyometric training do not differ between men and women.

Repeated Excessive Exercise Attenuates the Anti-Inflammatory Effects of Exercise in Older Men

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Ronni E. Sahl

2017-06-01

Full Text Available Introduction/Purpose: A number of studies have investigated the effect of training with a moderate exercise dose (3–6 h/weekly on the inflammatory profile in blood, and the data are inconsistent. Cross-sectional studies indicate a positive effect of physical activity level on inflammation levels and risk of metabolic disease. However, it is not clear whether this may be dose dependent and if very prolonged repeated exercise therefore may be beneficial for low-grade inflammation. Based on this we studied how excessive repeated prolonged exercise influenced low-grade inflammation and adipose tissue anti-inflammatory macrophage content in six older male recreationally trained cyclists. Low-grade inflammation and adipose tissue macrophage content were investigated in six older trained men (age: 61 ± 4 years; VO2peak: 48 ± 2 mL kg−1 min−1 following repeated prolonged exercise.Methods: Cycling was performed daily for 14 days covering in total 2,706 km (1,681 miles. Maximal oxygen uptake (VO2peak was measured before and after the cycling. Duration and intensity of the exercise were determined from heart rates sampled during cycling. An adipose tissue biopsy from subcutaneous abdominal fat and a blood sample were obtained at rest in the overnight fasted state before and after the cycling. Anti-inflammatory adipose tissue macrophages (ATM were immunohistochemically stained in cross sectional sections using a CD163 binding antibody. The ATM and adipocyte sizes were analyzed blindly.Results: The cyclists exercised daily for 10 h and 31 ± 37 min and average intensity was 53 ± 1% of VO2peak. Body weight remained unchanged and VO2peak decreased by 6 ± 2% (P = 0.04. Plasma inflammatory cytokines, TNFα and IL-18 remained unchanged, as did hsCRP, but plasma IL-6 increased significantly. CD163 macrophage content remained unchanged, as did adipocyte cell size. The HbA1c was not significantly decreased, but there was a trend (P < 0.07 toward an

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...

Iodophenylpentadecanoic acid-myocardial blood flow relationship during maximal exercise with coronary occlusion

Energy Technology Data Exchange (ETDEWEB)

Caldwell, J.H.; Martin, G.V.; Link, J.M.; Krohn, K.A.; Bassingthwaighte, J.B. (Seattle VA Medical Center, WA (USA))

1990-01-01

Imaging {sup 123}I-labeled iodophenylpentadecanoic acid (IPPA) uptake and clearance from the myocardium following exercise has been advocated as a means of detecting myocardial ischemia because fatty acid deposition is enhanced and clearance prolonged in regions of low flow. However, normal regional myocardial blood flows are markedly heterogeneous, and it is not known how this heterogeneity affects regional metabolism or substrate uptake and thus image interpretation. In five instrumented dogs running at near maximal workload on a treadmill, {sup 131}I-labeled IPPA and 15-micron 46Sc microspheres were injected into the left atrium after 30 sec of circumflex coronary artery occlusion. Microsphere and IPPA activity were determined in 250 mapped pieces of myocardium of approximately 400 mg. Myocardial blood flows (from microspheres) ranged from 0.05 to 7.6 ml/min/g. Deposition of IPPA was proportional to regional flows (r = 0.83) with an average retention of 25%. The mean endocardial-epicardial ratio for IPPA (0.90 {plus minus} 0.43) was similar to that for microspheres (0.94 {plus minus} 0.47; p = 0.08). Thus, initial IPPA deposition during treadmill exercise increases in proportion to regional myocardial blood flow over a range of flows from very low to five times normal.

Iodophenylpentadecanoic acid-myocardial blood flow relationship during maximal exercise with coronary occlusion

International Nuclear Information System (INIS)

Caldwell, J.H.; Martin, G.V.; Link, J.M.; Krohn, K.A.; Bassingthwaighte, J.B.

1990-01-01

Imaging 123 I-labeled iodophenylpentadecanoic acid (IPPA) uptake and clearance from the myocardium following exercise has been advocated as a means of detecting myocardial ischemia because fatty acid deposition is enhanced and clearance prolonged in regions of low flow. However, normal regional myocardial blood flows are markedly heterogeneous, and it is not known how this heterogeneity affects regional metabolism or substrate uptake and thus image interpretation. In five instrumented dogs running at near maximal workload on a treadmill, 131 I-labeled IPPA and 15-micron 46Sc microspheres were injected into the left atrium after 30 sec of circumflex coronary artery occlusion. Microsphere and IPPA activity were determined in 250 mapped pieces of myocardium of approximately 400 mg. Myocardial blood flows (from microspheres) ranged from 0.05 to 7.6 ml/min/g. Deposition of IPPA was proportional to regional flows (r = 0.83) with an average retention of 25%. The mean endocardial-epicardial ratio for IPPA (0.90 ± 0.43) was similar to that for microspheres (0.94 ± 0.47; p = 0.08). Thus, initial IPPA deposition during treadmill exercise increases in proportion to regional myocardial blood flow over a range of flows from very low to five times normal

Iodophenylpentadecanoic acid-myocardial blood flow relationship during maximal exercise with coronary occlusion.

Science.gov (United States)

Caldwell, J H; Martin, G V; Link, J M; Krohn, K A; Bassingthwaighte, J B

1990-01-01

Imaging 123I-labeled iodophenylpentadecanoic acid (IPPA) uptake and clearance from the myocardium following exercise has been advocated as a means of detecting myocardial ischemia because fatty acid deposition is enhanced and clearance prolonged in regions of low flow. However, normal regional myocardial blood flows are markedly heterogeneous, and it is not known how this heterogeneity affects regional metabolism or substrate uptake and thus image interpretation. In five instrumented dogs running at near maximal workload on a treadmill, 131I-labeled IPPA and 15-micron 46Sc microspheres were injected into the left atrium after 30 sec of circumflex coronary artery occlusion. Microsphere and IPPA activity were determined in 250 mapped pieces of myocardium of approximately 400 mg. Myocardial blood flows (from microspheres) ranged from 0.05 to 7.6 ml/min/g. Deposition of IPPA was proportional to regional flows (r = 0.83) with an average retention of 25%. The mean endocardial-epicardial ratio for IPPA (0.90 +/- 0.43) was similar to that for microspheres (0.94 +/- 0.47; p = 0.08). Thus, initial IPPA deposition during treadmill exercise increases in proportion to regional myocardial blood flow over a range of flows from very low to five times normal.

N-Acetylcysteine Supplementation Controls Total Antioxidant Capacity, Creatine Kinase, Lactate, and Tumor Necrotic Factor-Alpha against Oxidative Stress Induced by Graded Exercise in Sedentary Men

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Donrawee Leelarungrayub

2011-01-01

Full Text Available Aim of this study was to evaluate the effects of short-term (7 days N-acetylcysteine (NAC at 1,200 mg daily supplementation on muscle fatigue, maximal oxygen uptake (VO2max, total antioxidant capacity (TAC, lactate, creatine kinase (CK, and tumor necrotic factor-alpha (TNF-α. Twenty-nine sedentary men (13 controls; 16 in the supplement group from a randomized control were included. At before and after supplementation, fatigue index (FI was evaluated in the quadriceps muscle, and performed a graded exercise treadmill test to induce oxidative stress, and as a measure of VO2max. Blood samples were taken before exercise and 20 minutes after it at before and after supplementation, to determine TAC, CK, lactate, and TNF-α levels. Results showed that FI and VO2max increased significantly in the supplement group. After exercise decreased the levels of TAC and increased lactate, CK, and TNF-α of both groups at before supplementation. After supplementation, lactate, CK, and TNF-α levels significantly increased and TAC decreased after exercise in the control group. Whereas the TAC and lactate levels did not change significantly, but CK and TNF-α increased significantly in the supplement group. Therefore, this results showed that NAC improved the muscle fatigue, VO2max, maintained TAC, controlled lactate production, but had no influence on CK and TNF-α.

Cost-effectiveness of a graded exercise therapy program for patients with chronic shoulder complaints.

NARCIS (Netherlands)

Geraets, J.J.; Goossens, M.E.J.B.; Bruijn, C.P. de; Groot, I.J.M. de; Koke, A.J.; Pelt, R.A.; Heijden, G. van der; Dinant, G.J.; Heuvel, W.J.A. van den

2006-01-01

OBJECTIVES: The present study evaluated the cost-effectiveness of a behavioral graded exercise therapy (GET) program compared with usual care (UC) in terms of the performance of daily activities by patients with chronic shoulder complaints in primary care. METHODS: A total of 176 patients were

Effects of hypobaric Endurance Training on Graded Exercise Induced Lymphocyte Mobilization, Senescence and Their Surface Thiol Levels in Elite Male Athletes

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Karim - Azali Alamdari

2018-03-01

Full Text Available The effects of each hypoxemic exercise session or overall training period still remains to be more elucidated in elite athletes. Therefore, we investigated the effects of hypobaric endurance training on lymphocytes mobilization and senescence and also their surface Thiol levels following to graded exercise test (GXT in elite male athletes. Fourty six volunteer subjects were randomized into normobaric control (NC, hypobaric control (HC, normobaric exercise (NE and hypobaric exercise (HE groups. The NE and HE groups were exposed to homeland (700 mmHg and 2800 meters above sea level (570 mmHg simulated barometric pressures respectively, while HC and NC groups were remained sedentary at the same conditions. The training was included on treadmill running for four weeks, five sessions/week, 45 min/ session. Each session was consisted of three-min warmed up period, three cycles of 10-min running at 65% maximal heart rate reserve (HRRmax interspersed with a three-min active recovery and three-min cool-down running period. Two GXTs were performed before (baseline and after the interventions and blood samples were collected three times at both occasions. In all groups, mobilization of CD8+lymphocytes and senescent phenotype population of their both CD4+ and CD8+ subsets were increased after both GXTs, however; these changes were reversed following to recovery period(P<0.05. Moreover, HE were decreased lymphocytes surface thiol levels before and after the second GXT (P<0.05.it can be concluded that HE has no additional benefits for elite athletes regarded to lymphocytes mobilization and senescence, however; it may render them to oxidative stress.  

Inverse relationship between changes of maximal aerobic capacity and changes in walking economy after weight loss.

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Borges, Juliano H; Carter, Stephen J; Singh, Harshvardhan; Hunter, Gary R

2018-05-16

The aims of this study were to: (1) determine the relationships between maximum oxygen uptake ([Formula: see text]O 2max ) and walking economy during non-graded and graded walking among overweight women and (2) examine potential differences in [Formula: see text]O 2max and walking economy before and after weight loss. One-hundred and twenty-four premenopausal women with a body mass index (BMI) between 27 and 30 kg/m 2 were randomly assigned to one of three groups: (a) diet only; (b) diet and aerobic exercise training; and (c) diet and resistance exercise training. All were furnished with standard, very-low calorie diet to reduce BMI to < 25 kg/m 2 . [Formula: see text]O 2max was measured using a modified-Bruce protocol while walking economy (1-net [Formula: see text]O 2 ) was obtained during fixed-speed (4.8 k·h -1 ), steady-state treadmill walking at 0% grade and 2.5% grade. Assessments were conducted before and after achieving target BMI. Prior to weight loss, [Formula: see text]O 2max was inversely related (P < 0.05) with non-graded and graded walking economy (r = - 0.28 to - 0.35). Similar results were also observed following weight loss (r = - 0.22 to - 0.28). Additionally, we also detected a significant inverse relationship (P < 0.05) between the changes (∆, after weight loss) in ∆[Formula: see text]O 2max , adjusted for fat-free mass, with non-graded and graded ∆walking economy (r = - 0.37 to - 0.41). Our results demonstrate [Formula: see text]O 2max and walking economy are inversely related (cross-sectional) before and after weight loss. Importantly though, ∆[Formula: see text]O 2max and ∆walking economy were also found to be inversely related, suggesting a strong synchrony between maximal aerobic capacity and metabolic cost of exercise.

INFLUENCE OF GRADED AEROBIC EXERCISE ON QUALITY OF LIFE IN POST SURGICAL MITRAL VALVE DISEASE INDIVIDUAL A PROSPECTIVE RANDOMIZED OPEN LABEL STUDY

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Shanthi C

2016-10-01

Full Text Available Background: Post surgical mitral valve disease individual focus their cardiac rehabilitation training on two major goal that is to improve cardiac output response exercises and place an important role in determining exercise tolerance and to improve quality of life. Cardiac rehabilitation programs involve prescribed exercise and education however various other method are being used to improve quality of life. But our study to find out the effectiveness of graded aerobic exercise protocol on ejection fraction and quality of life in post surgical mitral valve disease individuals. Methods: The study design was open label studies total of 100 post surgical mitral valve disease individuals patients from the age group of 20-60 years were recruited from SVIMS hospital. They were randomly divided into two groups. Group I underwent a twelve week structured graded individually tailored exercises. The group II received only none graded (not individualized exercise training. The ejection fraction and quality of life was measured before and after 12 weeks of exercise training for two groups. Results: Repeated measures ANOVA was used to compare mean values of continuous variables between baseline and at the time of discharge and three months after surgery for each parameter. Comparison of means between groups was done by the unpaired student t test. Mean age of the subjects was 40.18±10.29. There was a significant increase in the ejection fraction in the group I(61.34±2.49 to 64.4±3.31 compared to with the group II (61.06±2.51. to 61.62 ±2.37. QOL had improved in group I than group II at p<0.05. Conclusion: A 12 week structured graded aerobic exercise training significantly improved ejection fraction and quality of life in post surgical mitral valve disease individuals.

Residual myocardial ischaemia in first non-Q versus Q wave infarction: maximal exercise testing and ambulatory ST-segment monitoring

DEFF Research Database (Denmark)

Mickley, H; Pless, P; Nielsen, J R

1993-01-01

the infarction. The prevalence of exercise-induced ischaemic manifestations in the infarct types was similar: chest pain 14% vs 16% and ST-segment depression 54% vs 54%. The ischaemic threshold did not differ either (heart rate at 1 mm of ST-segment depression 120 +/- 27 vs 119 +/- 25 beats.min-1). During early...... in non-Q wave infarction (51%) as compared to Q wave infarction (31%) (P depression on ambulatory recording and exercise testing significantly predicted the development of future angina pectoris, whereas patients at increased risk for subsequent......In a prospective study of 123 consecutive survivors of a first myocardial infarction (43 non-Q wave, 80 Q wave), we determined the total residual ischaemic burden by use of pre-discharge maximal exercise testing and post-discharge 36 h ambulatory ST-segment monitoring initiated 11 +/- 5 days after...

Effects of Increased Respiratory Resistance on Maximal O2 Uptake and Anaerobic Threshold during Incremental Exercise Tests

OpenAIRE

ÖZÇELİK, Oğuz

2014-01-01

This study was undertaken to assess whether maximal O2 uptake (VO2max) can be used as an index of measuring aerobic capacity under the condition of increased respiratory resistance. Seven male subjects performed two incremental exercise tests on a cycle ergometer on different days: one control (C) and one breathing through an 8 mm bore diameter respiratory resistance (R). Ventilatory and gas exchange responses were measured with a turbine volume transducer and mass spectrometry, and processed...

Effectiveness of resistance exercise compared to aerobic exercise without insulin therapy in patients with type 2 diabetes mellitus: a meta-analysis.

Science.gov (United States)

Nery, Cybelle; Moraes, Silvia Regina Arruda De; Novaes, Karyne Albino; Bezerra, Márcio Almeida; Silveira, Patrícia Verçoza De Castro; Lemos, Andrea

Physical exercise has been used to mitigate the metabolic effects of diabetes mellitus. To evaluate the effect of resistance exercise when compared to aerobic exercise without insulin therapy on metabolic and clinical outcomes in patients with type 2 diabetes mellitus. Papers were searched on the databases MEDLINE/PubMed, CINAHL, SPORTDiscus, LILACS, and SCIELO, without language or date of publication limits. Clinical trials that compared resistance exercise to aerobic exercise in adults with type 2 diabetes mellitus who did not use insulin therapy were included. The quality of evidence and risk of bias were assessed using the GRADE system and the Cochrane Risk of Bias tool, respectively. Meta-analysis was also used, whenever possible. Two reviewers extracted the data independently. Eight eligible articles were included in this study, with a total of 336 individuals, with a mean age of 48-58 years. The protocols of aerobic and resistance exercise varied in duration from eight to 22 weeks, 30-60min/day, three to five times/week. Overall the available evidence came from a very low quality of evidence and there was an increase in Maximal oxygen consumption (mean difference: -2.86; 95% CI: -3.90 to -1.81; random effect) for the resistance exercise and no difference was found in Glycated hemoglobin, Body mass index, High-density lipoprotein cholesterol, Low-density lipoprotein cholesterol, triglycerides, and total cholesterol. Resistance exercise appears to be more effective in promoting an increase in Maximal oxygen consumption in protocols longer than 12 weeks and there is no difference in the control of glycemic and lipid levels between the two types of exercise. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

High Intensity Interval Training for Maximizing Health Outcomes.

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Karlsen, Trine; Aamot, Inger-Lise; Haykowsky, Mark; Rognmo, Øivind

Regular physical activity and exercise training are important actions to improve cardiorespiratory fitness and maintain health throughout life. There is solid evidence that exercise is an effective preventative strategy against at least 25 medical conditions, including cardiovascular disease, stroke, hypertension, colon and breast cancer, and type 2 diabetes. Traditionally, endurance exercise training (ET) to improve health related outcomes has consisted of low- to moderate ET intensity. However, a growing body of evidence suggests that higher exercise intensities may be superior to moderate intensity for maximizing health outcomes. The primary objective of this review is to discuss how aerobic high-intensity interval training (HIIT) as compared to moderate continuous training may maximize outcomes, and to provide practical advices for successful clinical and home-based HIIT. Copyright © 2017. Published by Elsevier Inc.

Cardiac rehabilitation: impact of graded exercise in the recovery period following myocardial infarction

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White S

2013-07-01

Full Text Available Simon WhiteSchool of Pharmacy, Keele University, Staffordshire, UKAbstract: This paper reviews the impact of graded exercise undertaken as part of a cardiac rehabilitation (CR program in the recovery period following a myocardial infarction, focusing on how CR may be best provided and the evidence-base relating to exercise-based CR. Essential components of CR are considered here to include education about healthy behavior, lifestyle modification where necessary (especially in relation to smoking, diet, and physical exercise, medical risk factor management, use of cardioprotective medicines and implantable devices, and psychosocial health management. It is argued that the totality of the evidence continues to demonstrate benefits of exercise-based CR in terms of mortality and morbidity, despite the debate about the magnitude of that benefit. However, given the wide variance in the quality and nature of CR service provision, there is no guarantee that patients eligible for CR will benefit fully. In line with national and international standards, CR should be tailored to the patient's individual needs, but structured exercise is recommended for most patients. Exercise sessions, whether based in hospital, in the community, or at home, should be designed to vary the frequency, intensity, duration, and type of exercise. They must include an initial warm-up period, before a conditioning period, and finish with a cool-down period. Patients should be taught to self-monitor so that they can exercise safely on their own. In designing interventions to support patients to change health behavior, health professionals should recognize that patients may only make lifestyle modifications to aspects of lifestyle perceived as causes of their cardiovascular disease and so, for example, may not do the recommended amount of exercise if they do not perceive lack of exercise to be a cause of their cardiovascular disease.Keywords: cardiovascular disease, public health

Coping with an exogenous glucose overload: glucose kinetics of rainbow trout during graded swimming.

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Choi, Kevin; Weber, Jean-Michel

2016-03-15

This study examines how chronically hyperglycemic rainbow trout modulate glucose kinetics in response to graded exercise up to critical swimming speed (Ucrit), with or without exogenous glucose supply. Our goals were 1) to quantify the rates of hepatic glucose production (Ra glucose) and disposal (Rd glucose) during graded swimming, 2) to determine how exogenous glucose affects the changes in glucose fluxes caused by exercise, and 3) to establish whether exogenous glucose modifies Ucrit or the cost of transport. Results show that graded swimming causes no change in Ra and Rd glucose at speeds below 2.5 body lengths per second (BL/s), but that glucose fluxes may be stimulated at the highest speeds. Excellent glucoregulation is also achieved at all exercise intensities. When exogenous glucose is supplied during exercise, trout suppress hepatic production from 16.4 ± 1.6 to 4.1 ± 1.7 μmol·kg(-1)·min(-1) and boost glucose disposal to 40.1 ± 13 μmol·kg(-1)·min(-1). These responses limit the effects of exogenous glucose to a 2.5-fold increase in glycemia, whereas fish showing no modulation of fluxes would reach dangerous levels of 114 mM of blood glucose. Exogenous glucose reduces metabolic rate by 16% and, therefore, causes total cost of transport to decrease accordingly. High glucose availability does not improve Ucrit because the fish are unable to take advantage of this extra fuel during maximal exercise and rely on tissue glycogen instead. In conclusion, trout have a remarkable ability to adjust glucose fluxes that allows them to cope with the cumulative stresses of a glucose overload and graded exercise. Copyright © 2016 the American Physiological Society.

Normobaric hypoxia increases the growth hormone response to maximal resistance exercise in trained men.

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Filopoulos, Dean; Cormack, Stuart J; Whyte, Douglas G

2017-08-01

This study examined the effect of hypoxia on growth hormone (GH) release during an acute bout of high-intensity, low-volume resistance exercise. Using a single-blinded, randomised crossover design, 16 resistance-trained males completed two resistance exercise sessions in normobaric hypoxia (HYP; inspiratory oxygen fraction, (FiO 2 ) 0.12, arterial oxygen saturation (SpO 2 ) 82 ± 2%) and normoxia (NOR; FiO 2 0.21, SpO 2 98 ± 0%). Each session consisted of five sets of three repetitions of 45° leg press and bench press at 85% of one repetition maximum. Heart rate, SpO 2 , and electromyographic activity (EMG) of the vastus lateralis muscle were measured throughout the protocol. Serum lactate and GH levels were determined pre-exposure, and at 5, 15, 30 and 60 min post-exercise. Differences in mean and integrated EMG between HYP and NOR treatments were unclear. However, there was an important increase in the peak levels and area under the curve of both lactate (HYP 5.8 ± 1.8 v NOR 3.9 ± 1.1 mmol.L -1 and HYP 138.7 ± 33.1 v NOR 105.8 ± 20.8 min.mmol.L -1 ) and GH (HYP 4.4 ± 3.1 v NOR 2.1 ± 2.5 ng.mL -1 and HYP 117.7 ± 86.9 v NOR 72.9 ± 85.3 min.ng.mL -1 ) in response to HYP. These results suggest that performing high-intensity resistance exercise in a hypoxic environment may provide a beneficial endocrine response without compromising the neuromuscular activation required for maximal strength development.

Maximal heart rate does not limit cardiovascular capacity in healthy humans

DEFF Research Database (Denmark)

Munch, G D W; Svendsen, J H; Damsgaard, R

2014-01-01

In humans, maximal aerobic power (VO2 max ) is associated with a plateau in cardiac output (Q), but the mechanisms regulating the interplay between maximal heart rate (HRmax) and stroke volume (SV) are unclear. To evaluate the effect of tachycardia and elevations in HRmax on cardiovascular function...... and capacity during maximal exercise in healthy humans, 12 young male cyclists performed incremental cycling and one-legged knee-extensor exercise (KEE) to exhaustion with and without right atrial pacing to increase HR. During control cycling, Q and leg blood flow increased up to 85% of maximal workload (WLmax...... and RAP (P healthy...

Dance-Based ExerGaming: User Experience Design Implications for Maximizing Health Benefits Based on Exercise Intensity and Perceived Enjoyment

Science.gov (United States)

Thin, Alasdair G.; Poole, Nicola

Dance is a form of exercise that is considered to have widespread popular appeal and in particular to adolescent females. Dance-based body-movement controlled video games are a popular form of ExerGaming that is being adopted for use in school-based physical activity health promotion programs. The results of this study indicate that the game play mechanics and skill demands of the dance-based ExerGames would appear to have limited the subjects' level of physical exertion over the period of study. After training there was an increase in enjoyment rating for the Step Aerobics game which appears related to a perceptible improvement in game performance. It is therefore recommended that ExerGames should be designed with very low initial skill demands in order to maximize the user's level of exertion and to realize and reward progress, thereby helping to promote an enjoyable exercise experience and counterbalance any sense of exertional discomfort. Keywords: exercise; health promotion; exergaming; user experience; design; video game; enjoyment.

Phlebotomy eliminates the maximal cardiac output response to six weeks of exercise training

DEFF Research Database (Denmark)

Bonne, Thomas Christian; Doucende, Gregory; Flück, Daniela

2014-01-01

With this study we tested the hypothesis that six weeks of endurance training increases maximal cardiac output (Qmax) relatively more by elevating blood volume (BV) than by inducing structural and functional changes within the heart. Nine healthy but untrained volunteers (VO2max 47 ± 5 ml.min(-1......).kg(-1)) underwent supervised training (60 min; 4 times weekly at 65% VO2max for six weeks) and Qmax was determined by inert gas re-breathing during cycle ergometer exercise before and after the training period. After the training period, blood volume (determined in duplicates by CO re......-breathing) was re-established to pre-training values by phlebotomy and Qmax was quantified again. Resting echography revealed no structural heart adaptations as a consequence of the training intervention. Following the training period, plasma volume (PV), red blood cell volume (RBCV) and BV increased (p...

Effects of acute hypoxia on renal and endocrine function at rest and during graded exercise in hydrated subjects

DEFF Research Database (Denmark)

Olsen, Niels Vidiendal; Kanstrup, I L; Richalet, J P

1992-01-01

Renal effects of altitude hypoxia are unclear. Renal and hormonal function was investigated in eight males at rest and during graded exercise at sea level (SL) and 48 h after rapid ascent to 4,350 m (HA). HA did not change resting values of effective renal plasma flow (ERPF), glomerular filtration...... rate (GFR), sodium clearance (CNa), urine flow, or lithium clearance (CLi), which was used as an index of proximal tubular outflow. At rest, HA increased plasma norepinephrine concentration and decreased plasma concentrations of renin and aldosterone. Exercise decreased ERPF similarly in both...... environments. Normoxic exercise progressively reduced GFR, but at HA GFR only decreased during heavy exercise. This resulted in a higher filtration fraction during light and moderate hypoxic exercise. However, calculated absolute proximal reabsorption rate (GFR-CLi) at HA was higher during low...

Maximal exercise capacity in patients with obstructive sleep apnoea syndrome: A systematic review and meta-analysis.

Science.gov (United States)

Mendelson, Monique; Marillier, Mathieu; Bailly, Sébastien; Flore, Patrice; Borel, Jean-Christian; Vivodtzev, Isabelle; Doutreleau, Stéphane; Tamisier, Renaud; Pépin, Jean-Louis; Verges, Samuel

2018-04-26

Maximal aerobic capacity is a strong health predictor and peak oxygen consumption (VO 2peak ) is considered a reflection of total body health. No systematic reviews or meta-analysis' to date have synthesised the existing data regarding VO 2peak in patients with obstructive sleep apnoea (OSA).A systematic review of English and French articles using Pubmed/Medline and Embase included studies assessing VO 2peak of OSA patients in mL·kg -1 ·min -1 compared with controls or in % predicted. Two independent reviewers analysed the studies, extracted the data and assessed the quality of evidence.Mean VO 2peak expressed in mL·kg -1 ·min -1 was significantly lower in patients with OSA when compared with controls (mean difference=-2.7 mL·kg -1 ·min -1 ; p<0.001; n=850). This reduction in VO 2peak was found to be larger in non-obese patients (BMI<30 kg·m -2 ). Mean VO 2peak in % predicted was 90.7±21.0% in OSA patients (n=643).OSA patients present reduced maximal aerobic capacity, which can be associated with increased cardiovascular risks and reduced survival in certain patient subgroups. Maximal exercise testing can be useful to characterise functional limitation and to evaluate health status in OSA patients. Registration # CRD42017057319. Copyright ©ERS 2018.

Multicomponent Exercise Improves Hemodynamic Parameters and Mobility, but Not Maximal Walking Speed, Transfer Capacity, and Executive Function of Older Type II Diabetic Patients

Directory of Open Access Journals (Sweden)

Hélio José Coelho Junior

2018-01-01

Full Text Available The present study aimed to investigate the effects of a 6-month multicomponent exercise program (MCEP on functional, cognitive, and hemodynamic parameters of older Type 2 diabetes mellitus (T2DM patients. Moreover, additional analyses were performed to evaluate if T2DM patients present impaired adaptability in response to physical exercise when compared to nondiabetic volunteers. A total of 72 T2DM patients and 72 age-matched healthy volunteers (CG were recruited and submitted to functional, cognitive, and hemodynamic evaluations before and after six months of a MCEP. The program of exercise was performed twice a week at moderate intensity. Results indicate T2DM and nondiabetic patients present an increase in mobility (i.e., usual walking speed after the MCEP. However, improvements in maximal walking speed, transfer capacity, and executive function were only observed in the CG. On the other hand, only T2DM group reveals a marked decline in blood pressure. In conclusion, data of the current study indicate that a 6-month MCEP improves mobility and reduce blood pressure in T2DM patients. However, maximal walking speed, transfer capacity, and executive function were only improved in CG, indicating that T2DM may present impaired adaptability in response to physical stimulus.

Crossover and maximal fat-oxidation points in sedentary healthy subjects: methodological issues.

Science.gov (United States)

Gmada, N; Marzouki, H; Haboubi, M; Tabka, Z; Shephard, R J; Bouhlel, E

2012-02-01

Our study aimed to assess the influence of protocol on the crossover point and maximal fat-oxidation (LIPOX(max)) values in sedentary, but otherwise healthy, young men. Maximal oxygen intake was assessed in 23 subjects, using a progressive maximal cycle ergometer test. Twelve sedentary males (aged 20.5±1.0 years) whose directly measured maximal aerobic power (MAP) values were lower than their theoretical maximal values (tMAP) were selected from this group. These individuals performed, in random sequence, three submaximal graded exercise tests, separated by three-day intervals; work rates were based on the tMAP in one test and on MAP in the remaining two. The third test was used to assess the reliability of data. Heart rate, respiratory parameters, blood lactate, the crossover point and LIPOX(max) values were measured during each of these tests. The crossover point and LIPOX(max) values were significantly lower when the testing protocol was based on tMAP rather than on MAP (PtMAP at 30, 40, 50 and 60% of maximal aerobic power (PtMAP rather than MAP (P<0.001). During the first 5 min of recovery, EPOC(5 min) and blood lactate were significantly correlated (r=0.89; P<0.001). Our data show that, to assess the crossover point and LIPOX(max) values for research purposes, the protocol must be based on the measured MAP rather than on a theoretical value. Such a determination should improve individualization of training for initially sedentary subjects. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Heart rate response to hypoxic exercise

DEFF Research Database (Denmark)

Lundby, C; Møller, P; Kanstrup, I L

2001-01-01

progressively decreased the maximal heart rate from day 1 and onwards; also, hypoxia by itself increased plasma noradrenaline levels after maximal exercise. Domperidone further increased maximal noradrenaline concentrations, but had no effect on maximal heart rate. On each study day at altitude, oxygen......This study examined the effects of dopamine D(2)-receptor blockade on the early decrease in maximal heart rate at high altitude (4559 m). We also attempted to clarify the time-dependent component of this reduction and the extent to which it is reversed by oxygen breathing. Twelve subjects performed...... two consecutive maximal exercise tests, without and with oxygen supplementation respectively, at sea level and after 1, 3 and 5 days at altitude. On each study day, domperidone (30 mg; n=6) or no medication (n=6) was given 1 h before the first exercise session. Compared with sea level, hypoxia...

Effects of a short-term personalized Intermittent Work Exercise Program (IWEP) on maximal cardio-respiratory function and endurance parameters among healthy young and older seniors.

Science.gov (United States)

Vogel, T; Leprêtre, P-M; Brechat, P-H; Lonsdorfer, E; Benetos, A; Kaltenbach, G; Lonsdorfer, J

2011-12-01

The aim of this study was to evaluate the efficiency of a short-term Intermittent Work Exercise Program (IWEP) among healthy elderly subjects. This longitudinal prospective study took place at the Strasbourg University Hospital geriatric department. One hundred and fifty older volunteers, previously determined as being free from cardiac and pulmonary disease, were separated into two age groups: the "young senior" (60.2 ± 3.1 yr) and the "older senior" groups (70.8 ± 5.2 yr). These groups were then subdivided by gender into the "young female senior", "young male senior" "older female senior" and "older male senior" groups. Before and after the IWEP, all subjects were asked to perform an incremental cycle exercise to obtain their first ventilatory threshold (VT1), maximal tolerated power (MTP), peak oxygen uptake (VO2peak) and maximal minute ventilation (MMV). The IWEP consisted of a 30-min cycling exercise which took place twice a week, and was divided into six 5-min stages consisting of 4 min at VT1 intensity and 1 min at 90% MTP. An assessment was made of the effects of the IWEP on maximal cardio-respiratory function (MTP, VO2peak, MMV) and endurance parameters (VT1, heart rate [HR] measured at pretraining VT1 and lactate concentrations at pre-training MTP). This short-term training program resulted in a significant increase of MTP (from 13.2% to 20.6%), VO2peak (from 8.9% to 16.6%) and MMV (from 11.1% to 21.8%) in all groups (pseniors" were not significantly different (p>0.05) from the "young seniors" pre-training values for the same parameters. The most striking finding in this study is that after only 9 weeks, our short-term "individually-tailored" IWEP significantly improved both maximal cardio-respiratory function and endurance parameters in healthy, previously untrained seniors.

Oxygen uptake during peak graded exercise and single-stage fatigue tests of wheelchair propulsion in manual wheelchair users and the able-bodied.

Science.gov (United States)

Keyser, R E; Rodgers, M M; Gardner, E R; Russell, P J

1999-10-01

To determine if a single-stage, submaximal fatigue test on a wheelchair ergometer would result in higher than expected energy expenditure. An experimental survey design contrasting physiologic responses during peak graded exercise tests and fatigue tests. A rehabilitation science laboratory that included a prototypical wheelchair ergometer, open-circuit spirometry system, and heart rate monitor. Nine able-bodied non-wheelchair users (the NWC group: 6 men and 3 women, mean +/- SD age 30 +/- 7yrs) and 15 manual wheelchair users (the WC group: 12 men and 3 women, age 40 +/- 9yrs, time in wheelchair 16 +/- 9yrs). No subject had any disease, medication regimen, or upper body neurologic, orthopedic, or other condition that would limit wheelchair exercise. Peak oxygen uptake (VO2) for graded exercise testing and during fatigue testing, using a power output corresponding to 75% peak aerobic capacity on graded exercise test. In the WC group, VO2 at 6 minutes of fatigue testing was not significantly different from peak VO2. In the NWC group, VO2 was similar to the expected level throughout fatigue testing. Energy expenditure was higher than expected in the WC group but not in the NWC group. Fatigue testing may provide a useful evaluation of cardiorespiratory status in manual wheelchair users.

Peak torque and rate of torque development influence on repeated maximal exercise performance: contractile and neural contributions.

Science.gov (United States)

Morel, Baptiste; Rouffet, David M; Saboul, Damien; Rota, Samuel; Clémençon, Michel; Hautier, Christophe A

2015-01-01

Rapid force production is critical to improve performance and prevent injuries. However, changes in rate of force/torque development caused by the repetition of maximal contractions have received little attention. The aim of this study was to determine the relative influence of rate of torque development (RTD) and peak torque (T(peak)) on the overall performance (i.e. mean torque, T(mean)) decrease during repeated maximal contractions and to investigate the contribution of contractile and neural mechanisms to the alteration of the various mechanical variables. Eleven well-trained men performed 20 sets of 6-s isokinetic maximal knee extensions at 240° · s(-1), beginning every 30 seconds. RTD, T(peak) and T(mean) as well as the Rate of EMG Rise (RER), peak EMG (EMG(peak)) and mean EMG (EMG(mean)) of the vastus lateralis were monitored for each contraction. A wavelet transform was also performed on raw EMG signal for instant mean frequency (if(mean)) calculation. A neuromuscular testing procedure was carried out before and immediately after the fatiguing protocol including evoked RTD (eRTD) and maximal evoked torque (eT(peak)) induced by high frequency doublet (100 Hz). T(mean) decrease was correlated to RTD and T(peak) decrease (R(²) = 0.62; p<0.001; respectively β=0.62 and β=0.19). RER, eRTD and initial if(mean) (0-225 ms) decreased after 20 sets (respectively -21.1 ± 14.1, -25 ± 13%, and ~20%). RTD decrease was correlated to RER decrease (R(²) = 0.36; p<0.05). The eT(peak) decreased significantly after 20 sets (24 ± 5%; p<0.05) contrary to EMG(peak) (-3.2 ± 19.5 %; p=0.71). Our results show that reductions of RTD explained part of the alterations of the overall performance during repeated moderate velocity maximal exercise. The reductions of RTD were associated to an impairment of the ability of the central nervous system to maximally activate the muscle in the first milliseconds of the contraction.

Gastroenteropancreatic hormonal changes during exercise

DEFF Research Database (Denmark)

Hilsted, J; Galbo, H; Sonne, B

1980-01-01

Peripheral plasma concentrations of gastroenteropancreatic peptides were measured during a 3-h period of bicycle exercise at 40% of maximal oxygen uptake in six normal men. Marked increases (P......Peripheral plasma concentrations of gastroenteropancreatic peptides were measured during a 3-h period of bicycle exercise at 40% of maximal oxygen uptake in six normal men. Marked increases (P...

Lifestyle change diminishes a hypertensive response to exercise in type 2 diabetes.

Science.gov (United States)

Schultz, Martin G; Hordern, Matthew D; Leano, Rodel; Coombes, Jeffrey S; Marwick, Thomas H; Sharman, James E

2011-05-01

A hypertensive response to exercise (HRE) is common in patients with type 2 diabetes and is associated with increased left ventricular (LV) mass and mortality. This study aimed to determine whether lifestyle modification would improve exercise blood pressure (BP) and reduce LV mass in patients with type 2 diabetes. One hundred and eighty-five patients with type 2 diabetes were randomized to 1 yr of lifestyle intervention (n=97, mean ± SD age=54.7 ± 11.3 yr, 51% men) or usual care (control; n=88, age=53.8 ± 8.1 yr, 61% men). Brachial BP was measured at rest and during a graded maximal exercise test at baseline and 1 yr. Patients also underwent two-dimensional echocardiography to determine LV dimensions. A subgroup of 61 patients had resting and exercise central BP estimated from radial tonometry. An HRE was defined as a maximal exercise systolic BP of ≥210 mm Hg for men and ≥190 mm Hg for women. At study entry, there were 101 patients (55%) with an HRE (n=51 controls). Compared with controls, lifestyle intervention significantly reduced the propensity to develop an HRE in those participants who did not have HRE at baseline (29.8% vs 59.5%, P=0.006). However, absolute values of exercise and resting (brachial and central) BP and LV mass were not significantly changed (all P values >0.05). There were significant (all P values HRE but does not reduce cardiac size after 1 yr in patients with type 2 diabetes. © 2011 by the American College of Sports Medicine

Altered gas-exchange at peak exercise in obese adolescents: implications for verification of effort during cardiopulmonary exercise testing.

Science.gov (United States)

Marinus, Nastasia; Bervoets, Liene; Massa, Guy; Verboven, Kenneth; Stevens, An; Takken, Tim; Hansen, Dominique

2017-12-01

Cardiopulmonary exercise testing is advised ahead of exercise intervention in obese adolescents to assess medical safety of exercise and physical fitness. Optimal validity and reliability of test results are required to identify maximal exercise effort. As fat oxidation during exercise is disturbed in obese individuals, it remains an unresolved methodological issue whether the respiratory gas exchange ratio (RER) is a valid marker for maximal effort during exercise testing in this population. RER during maximal exercise testing (RERpeak), and RER trajectories, was compared between obese and lean adolescents and relationships between RERpeak, RER slope and subject characteristics (age, gender, Body Mass Index [BMI], Tanner stage, physical activity level) were explored. Thirty-four obese (BMI: 35.1±5.1 kg/m²) and 18 lean (BMI: 18.8±1.9 kg/m²) adolescents (aged 12-18 years) performed a maximal cardiopulmonary exercise test on bike, with comparison of oxygen uptake (VO2), heart rate (HR), expiratory volume (VE), carbon dioxide output (VCO2), and cycling power output (W). RERpeak (1.09±0.06 vs. 1.14±0.06 in obese vs. lean adolescents, respectively) and RER slope (0.03±0.01 vs. 0.05±0.01 per 10% increase in VO2, in obese vs. lean adolescents, respectively) was significantly lower in obese adolescents, and independently related to BMI (Pexercise testing in this population.

With age a lower individual breathing reserve is associated with a higher maximal heart rate.

Science.gov (United States)

Burtscher, Martin; Gatterer, Hannes; Faulhaber, Martin; Burtscher, Johannes

2018-01-01

Maximal heart rate (HRmax) is linearly declining with increasing age. Regular exercise training is supposed to partly prevent this decline, whereas sex and habitual physical activity do not. High exercise capacity is associated with a high cardiac output (HR x stroke volume) and high ventilatory requirements. Due to the close cardiorespiratory coupling, we hypothesized that the individual ventilatory response to maximal exercise might be associated with the age-related HRmax. Retrospective analyses have been conducted on the results of 129 consecutively performed routine cardiopulmonary exercise tests. The study sample comprised healthy subjects of both sexes of a broad range of age (20-86 years). Maximal values of power output, minute ventilation, oxygen uptake and heart rate were assessed by the use of incremental cycle spiroergometry. Linear multivariate regression analysis revealed that in addition to age the individual breathing reserve at maximal exercise was independently predictive for HRmax. A lower breathing reserve due to a high ventilatory demand and/or a low ventilatory capacity, which is more pronounced at a higher age, was associated with higher HRmax. Age explained the observed variance in HRmax by 72% and was improved to 83% when the variable "breathing reserve" was entered. The presented findings indicate an independent association between the breathing reserve at maximal exercise and maximal heart rate, i.e. a low individual breathing reserve is associated with a higher age-related HRmax. A deeper understanding of this association has to be investigated in a more physiological scenario. Copyright © 2017 Elsevier B.V. All rights reserved.

Muscle glycogen metabolism changes in rats fed early postnatal a fructose-rich diet after maternal protein malnutrition: effects of acute physical exercise at the maximal lactate steady-state intensity.

Science.gov (United States)

Cambri, Lucieli T; Ribeiro, Carla; Botezelli, José D; Ghezzi, Ana C; Mello, Maria Ar

2014-01-01

The objective was to evaluate the muscle glucose metabolism in rats fed a fructose-rich diet after fetal protein malnutrition, at rest and after acute physical exercise at maximal lactate steady-state intensity. The male offspring born of mothers fed on a balanced or low-protein diet were split in four groups until 60 days: Balanced (B): balanced diet during the whole period; Balanced/Fructose (BF): balanced diet in utero and fructose-rich diet after birth; Low protein/Balanced (LB): low-protein diet in utero and balanced diet after birth; Low protein/Fructose (LF): low protein diet in utero and fructose-rich diet after birth. Acute physical exercise reduced the muscle glycogen concentrations in all groups, although the LF group showed higher concentrations at rest. There was no difference among the groups in the glucose uptake and oxidation rates in the isolated soleus muscle neither at rest nor after acute exercise. However, glycogen synthesis was higher in the LF muscle than in the others at rest. Acute physical exercise increased glycogen synthesis in all groups, and the LF group showed the highest values. The fructose-rich diet administered in rats after fetal protein malnutrition alters muscle glycogen concentrations and glycogen synthesis in the rest and after acute exercise at maximal lactate steady-state intensity.

Acute Postexercise Time Course Responses of Hypertrophic vs. Power-Endurance Squat Exercise Protocols on Maximal and Rapid Torque of the Knee Extensors.

Science.gov (United States)

Conchola, Eric C; Thiele, Ryan M; Palmer, Ty B; Smith, Doug B; Thompson, Brennan J

2015-05-01

The aim of this study was to examine the effects of a medium-intensity high-volume vs. explosive squat protocol on the postexercise time course responses of maximal and rapid strength of the knee extensors. Seventeen resistance-trained men (mean ± SD: age = 22.0 ± 2.6 years) performed maximal voluntary contractions (MVCs) of the knee extensors before and after performing a squat workout using either a low-intensity fast velocity (LIFV) (5 × 16 at 40% 1 repetition maximum) or a traditional high-intensity slow velocity (TISV) (5 × 8 at 80% 1RM) exercise protocol. For each MVC, peak torque (PT), peak rate of torque development (RTDpeak), absolute (RTDabs), and relative RTD (RTDnorm) at early (0-50 milliseconds) and late (100-200 milliseconds) phases of muscle contraction were examined at pre- (Pre) and post-exercise at 0, 7, 15, and 30 (Post0...30) minutes. There were no intensity × time interactions for any variables (p = 0.098-0.832). Peak torque was greater at Pre than Post0 and Post7 (p = 0.001-0.016) but was not greater than Post15 and Post30 (p = 0.010-0.189). RTDpeak and early absolute RTD (RTD50abs) were greater at Pre than all postexercise time phases (p = 0.001-0.050); however, later absolute RTD (RTD100-200abs) was only greater at Pre than Post0 and Post30 (p = 0.013-0.048). Early relative RTD (RTD50norm) was only higher at Pre compared with Post0 (p = 0.023), whereas no differences were observed for later relative RTD (RTD100-200norm) (p = 0.920-0.990). Low-intensity fast velocity and TISV squat protocols both yielded acute decreases in maximal and rapid strength capacities following free-weight squats, with rapid strength showing slower recovery characteristics than maximal strength.

Aerobic Exercise Training Improves Orthostatic Tolerance in Aging Humans.

Science.gov (United States)

Xu, Diqun; Wang, Hong; Chen, Shande; Ross, Sarah; Liu, Howe; Olivencia-Yurvati, Albert; Raven, Peter B; Shi, Xiangrong

2017-04-01

This study was designed to test the hypothesis that aerobic exercise training of the elderly will increase aerobic fitness without compromising orthostatic tolerance (OT). Eight healthy sedentary volunteers (67.0 ± 1.7 yr old, four women) participated in 1 yr of endurance exercise training (stationary bicycle and/or treadmill) program at the individuals' 65%-75% of HRpeak. Peak O2 uptake (V˙O2peak) and HRpeak were determined by a maximal exercise stress test using a bicycle ergometer. Carotid baroreceptor reflex (CBR) control of HR and mean arterial pressure (MAP) were assessed by a neck pressure-neck suction protocol. Each subject's maximal gain (Gmax), or sensitivity, of the CBR function curves were derived from fitting their reflex HR and MAP responses to the corresponding neck pressure-neck suction stimuli using a logistic function curve. The subjects' OT was assessed using lower-body negative pressure (LBNP) graded to -50 mm Hg; the sum of the product of LBNP intensity and time (mm Hg·min) was calculated as the cumulative stress index. Training increased V˙O2peak (before vs after: 22.8 ± 0.92 vs 27.9 ± 1.33 mL·min·kg, P stress index was increased from 767 ± 68 mm Hg·min pretraining to 946 ± 44 mm Hg·min posttraining (P Aerobic exercise training improved the aerobic fitness and OT in elderly subjects. An improved OT is likely associated with an enhanced CBR function that has been reset to better maintain cerebral perfusion and cerebral tissue oxygenation during LBNP.

Effects of exercise training on calf muscle oxygen extraction and blood flow in patients with peripheral artery disease.

Science.gov (United States)

Baker, Wesley B; Li, Zhe; Schenkel, Steven S; Chandra, Malavika; Busch, David R; Englund, Erin K; Schmitz, Kathryn H; Yodh, Arjun G; Floyd, Thomas F; Mohler, Emile R

2017-12-01

We employed near-infrared optical techniques, diffuse correlation spectroscopy (DCS), and frequency-domain near-infrared spectroscopy (FD-NIRS) to test the hypothesis that supervised exercise training increases skeletal muscle microvascular blood flow and oxygen extraction in patients with peripheral artery disease (PAD) who experience claudication. PAD patients ( n = 64) were randomly assigned to exercise and control groups. Patients in the exercise group received 3 mo of supervised exercise training. Calf muscle blood flow and oxygen extraction were optically monitored before, during, and after performance of a graded treadmill protocol at baseline and at 3 mo in both groups. Additionally, measurements of the ankle-brachial index (ABI) and peak walking time (PWT) to maximal claudication were made during each patient visit. Supervised exercise training was found to increase the maximal calf muscle blood flow and oxygen extraction levels during treadmill exercise by 29% (13%, 50%) and 8% (1%, 12%), respectively [ P group population were significantly higher than corresponding changes in the control group ( P training also increased PWT by 49% (18%, 101%) ( P = 0.01). However, within statistical error, the ABI, resting calf muscle blood flow and oxygen extraction, and the recovery half-time for hemoglobin\\myoglobin desaturation following cessation of maximal exercise were not altered by exercise training. The concurrent monitoring of both blood flow and oxygen extraction with the hybrid DCS/FD-NIRS instrument revealed enhanced muscle oxidative metabolism during physical activity from exercise training, which could be an underlying mechanism for the observed improvement in PWT. NEW & NOTEWORTHY We report on noninvasive optical measurements of skeletal muscle blood flow and oxygen extraction dynamics before/during/after treadmill exercise in peripheral artery disease patients who experience claudication. The measurements tracked the effects of a 3-mo supervised

Mechanisms underlying enhancements in muscle force and power output during maximal cycle ergometer exercise induced by chronic β2-adrenergic stimulation in men

DEFF Research Database (Denmark)

Hostrup, Morten; Kalsen, Anders; Onslev, Johan

2015-01-01

The study was a randomized placebo-controlled trial investigating mechanisms by which chronic β2-adrenergic stimulation enhances muscle force and power output during maximal cycle ergometer exercise in young men. Eighteen trained men were assigned to an experimental group (oral terbutaline 5 mg∙30...... of muscle proteins involved in growth, ion handling, lactate production and clearance increased (P≤0.05) with the intervention in TER compared to PLA, with no change in oxidative enzymes. Our observations suggest that muscle hypertrophy is the primary mechanism underlying enhancements in muscle force...... and peak power during maximal cycling induced by chronic β2-adrenergic stimulation in humans....

Exercise Responses after Inactivity

Science.gov (United States)

Convertino, Victor A.

1986-01-01

The exercise response after bed rest inactivity is a reduction in the physical work capacity and is manifested by significant decreases in oxygen uptake. The magnitude of decrease in maximal oxygen intake V(dot)O2max is related to the duration of confinement and the pre-bed-rest level of aerobic fitness; these relationships are relatively independent of age and gender. The reduced exercise performance and V(dot)O2max following bed rest are associated with various physiological adaptations including reductions in blood volume, submaximal and maximal stroke volume, maximal cardiac output, sceletal muscle tone and strength, and aerobic enzyme capacities, as well as increases in venous compliance and submaximal and maximal heart rate. This reduction in physiological capacity can be partially restored by specific countermeasures that provide regular muscular activity or orhtostatic stress or both during the bed rest exposure. The understanding of these physiological and physical responses to exercise following bed rest inactivity has important implications for the solution to safety and health problems that arise in clinical medicine, aerospace medicine, sedentary living, and aging.

Time perception, pacing and exercise intensity: maximal exercise distorts the perception of time

OpenAIRE

Edwards, A. M.; McCormick, A.

2017-01-01

Introduction\\ud \\ud Currently there are no data examining the impact of exercise on the perception of time, which is surprising as optimal competitive performance is dependent on accurate pacing using knowledge of time elapsed.\\ud \\ud \\ud Methods\\ud \\ud With institutional ethics approval, 12 recreationally active adult participants (f = 7, m = 5) undertook both 30 s Wingate cycles and 20 min (1200 s) rowing ergometer bouts as short and long duration self-paced exercise trials, in each of thre...

Construct validation of a non-exercise measure of cardiorespiratory fitness in older adults

Directory of Open Access Journals (Sweden)

Kramer Arthur F

2010-02-01

Full Text Available Abstract Background Cardiorespiratory fitness (CRF is associated with a decreased risk of all-cause mortality but is rarely assessed in medical settings due to burdens of time, cost, risk, and resources. The purpose of this study was to test the construct validity of a regression equation developed by Jurca and colleagues (2005 to estimate CRF without exercise testing in community dwelling older adults. Methods Participants (n = 172 aged 60 to 80 years with no contraindications to submaximal or maximal exercise testing completed a maximal graded exercise test (GXT and the submaximal Rockport 1-mile walk test on separate occasions. Data included in the regression equation (age, sex, body mass index, resting heart rate, and physical activity were obtained via measurement or self-report. Participants also reported presence of cardiovascular conditions. Results The multiple R for the regression equation was .72, p and CRF estimated from this equation was significantly correlated with the MET value from the GXT (r = 0.66 and with CRF estimated from submaximal field testing (r = 0.67. All three CRF indices were significantly and inversely associated with reporting more cardiovascular conditions. Conclusions This research provides preliminary evidence that a non-exercise estimate of CRF is at least as valid as field test estimates of CRF and represents a low-risk, low-cost, and expedient method for estimating fitness in older adults.

Insulin resistance and maximal oxygen uptake

DEFF Research Database (Denmark)

Seibaek, Marie; Vestergaard, Henrik; Burchardt, Hans

2003-01-01

BACKGROUND: Type 2 diabetes, coronary atherosclerosis, and physical fitness all correlate with insulin resistance, but the relative importance of each component is unknown. HYPOTHESIS: This study was undertaken to determine the relationship between insulin resistance, maximal oxygen uptake......, and the presence of either diabetes or ischemic heart disease. METHODS: The study population comprised 33 patients with and without diabetes and ischemic heart disease. Insulin resistance was measured by a hyperinsulinemic euglycemic clamp; maximal oxygen uptake was measured during a bicycle exercise test. RESULTS......: There was a strong correlation between maximal oxygen uptake and insulin-stimulated glucose uptake (r = 0.7, p = 0.001), and maximal oxygen uptake was the only factor of importance for determining insulin sensitivity in a model, which also included the presence of diabetes and ischemic heart disease. CONCLUSION...

Hemodynamic causes of exercise intolerance in Fontan patients

DEFF Research Database (Denmark)

Hebert, Anders; Jensen, Annette S; Mikkelsen, Ulla Ramer

2014-01-01

BACKGROUND: Exercise intolerance is frequent among Fontan patients and an important determinant for quality of life. This study investigated the hemodynamic causes of impaired exercise capacity in Fontan patients with particular focus on the influence of stroke volume index (SVI) and heart rate (HR...... patients and controls respectively. CONCLUSION: SVI decreased significantly in Fontan patients near the end of maximal effort exercise. The low SVI at maximal exercise was the most important hemodynamic factor limiting exercise capacity in Fontan patients, whereas chronotropic impairment had a smaller...

Improving the Accuracy of Predicting Maximal Oxygen Consumption (VO2pk)

Science.gov (United States)

Downs, Meghan E.; Lee, Stuart M. C.; Ploutz-Snyder, Lori; Feiveson, Alan

2016-01-01

Maximal oxygen (VO2pk) is the maximum amount of oxygen that the body can use during intense exercise and is used for benchmarking endurance exercise capacity. The most accurate method to determineVO2pk requires continuous measurements of ventilation and gas exchange during an exercise test to maximal effort, which necessitates expensive equipment, a trained staff, and time to set-up the equipment. For astronauts, accurate VO2pk measures are important to assess mission critical task performance capabilities and to prescribe exercise intensities to optimize performance. Currently, astronauts perform submaximal exercise tests during flight to predict VO2pk; however, while submaximal VO2pk prediction equations provide reliable estimates of mean VO2pk for populations, they can be unacceptably inaccurate for a given individual. The error in current predictions and logistical limitations of measuring VO2pk, particularly during spaceflight, highlights the need for improved estimation methods.

Comparison of changes in the mobility of the pelvic floor muscle on during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction

OpenAIRE

Jung, Halim; Jung, Sangwoo; Joo, Sunghee; Song, Changho

2016-01-01

[Purpose] The purpose of this study was to compare changes in the mobility of the pelvic floor muscle during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction. [Subjects] Thirty healthy adults participated in this study (15 men and 15 women). [Methods] All participants performed a bridge exercise and abdominal curl-up during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction. Pelvic floor mobility...

Rest and exercise ventricular function in adults with congenital ventricular septal defects

International Nuclear Information System (INIS)

Jablonsky, G.; Hilton, J.D.; Liu, P.P.; Morch, J.E.; Druck, M.N.; Bar-Shlomo, B.Z.; McLaughlin, P.R.

1983-01-01

Rest and exercise right and left ventricular function were compared using equilibrium gated radionuclide angiography in 19 normal sedentary control subjects and 34 patients with hemodynamically documented congenital ventricular septal defect (VSD). Gated radionuclide angiography was performed at rest and during each level of graded supine bicycle exercise to fatigue. Heart rate, blood pressure, maximal work load achieved, and right and left ventricular ejection fractions were assessed. The control subjects demonstrated an increase in both the left and right ventricular ejection fractions with exercise. All study groups failed to demonstrate an increase in ejection fraction in either ventricle with exercise. Furthermore, resting left ventricular ejection fraction in Groups 2 and 3 was lower than that in the control subjects and resting right ventricular ejection fraction was lower in Group 3 versus control subjects. Thus left and right ventricular function on exercise were abnormal in patients with residual VSD as compared with control subjects; rest and exercise left ventricular ejection fractions remained abnormal despite surgical closure of VSD in the remote past; resting left and right ventricular function was abnormal in patients with Eisenmenger's complex; lifelong volume overload may be detrimental to myocardial function

Exercise at the Extremes: The Amount of Exercise to Reduce Cardiovascular Events.

NARCIS (Netherlands)

Eijsvogels, T.M.H.; Molossi, S.; Lee, D.C.; Emery, M.S.; Thompson, P.D.

2016-01-01

Habitual physical activity and regular exercise training improve cardiovascular health and longevity. A physically active lifestyle is, therefore, a key aspect of primary and secondary prevention strategies. An appropriate volume and intensity are essential to maximally benefit from exercise

Age-Predicted Maximal Heart Rate in Recreational Marathon Runners: A Cross-Sectional Study on Fox's and Tanaka's Equations

Science.gov (United States)

Nikolaidis, Pantelis T.; Rosemann, Thomas; Knechtle, Beat

2018-01-01

Age-based prediction equations of maximal heart rate (HRmax), such as the popular formulas Fox's 220-age, or Tanaka's 208-0.7 × age, have been widely used in various populations. Surprisingly, so far these equations have not been validated in marathon runners, despite the importance of the role of HRmax for training purposes in endurance running. The aim of the present study was to examine the validity of Fox and Tanaka equations in a large sample of women and men recreational marathon runners. Participants (n = 180, age 43.2 ± 8.5 years, VO2max 46.8 mL/min/kg, finishers in at least one marathon during the last year) performed a graded exercise test on a treadmill, where HRmax was measured. Measured HRmax correlated largely with age in the total sample (r = −0.50, p marathon runners. In addition, exercise physiologists and sport scientists should consider the observed differences among various assessment methods when performing exercise testing or prescribing training program relying on HR. PMID:29599724

Age-Predicted Maximal Heart Rate in Recreational Marathon Runners: A Cross-Sectional Study on Fox's and Tanaka's Equations.

Science.gov (United States)

Nikolaidis, Pantelis T; Rosemann, Thomas; Knechtle, Beat

2018-01-01

Age-based prediction equations of maximal heart rate (HR max ), such as the popular formulas Fox's 220-age, or Tanaka's 208-0.7 × age, have been widely used in various populations. Surprisingly, so far these equations have not been validated in marathon runners, despite the importance of the role of HR max for training purposes in endurance running. The aim of the present study was to examine the validity of Fox and Tanaka equations in a large sample of women and men recreational marathon runners. Participants ( n = 180, age 43.2 ± 8.5 years, VO 2max 46.8 mL/min/kg, finishers in at least one marathon during the last year) performed a graded exercise test on a treadmill, where HR max was measured. Measured HR max correlated largely with age in the total sample ( r = -0.50, p marathon runners. In addition, exercise physiologists and sport scientists should consider the observed differences among various assessment methods when performing exercise testing or prescribing training program relying on HR.

Segmental wall-motion analysis in the right anterior oblique projection: comparison of exercise equilibrium radionuclide ventriculography and exercise contrast ventriculography

International Nuclear Information System (INIS)

Brady, T.J.; Thrall, J.H.; Keyes, J.W. Jr.; Brymer, J.F.; Walton, J.A.; Pitt, B.

1980-01-01

Thirty-nine patients with known or suspected coronary artery disease were studied at rest and during supine bicycle exercise with radionuclide and contrast left ventriculography. Analysis of regional wall motion was made by visual evaluation of the five standard 30 0 right anterior oblique (RAO) wall segments in the contrast images and the corresponding 10 0 RAO radionuclide segments. The radionuclide studies were evaluated independently by three observers using a five-point grading system. The interobserver wall-motion grading agreed completely in more than 80% of segments at rest and exercise, and agreed within one wall-motion grade in more than 95% of segments. The comparison of wall-motion grades between radionuclide and contrast ventriculograms showed complete agreement in 86% of segments at rest and in 78% during exercise, and agreement within one wall-motion grade in 97% of rest and 96% of exercise segments. Visual evaluation of 10 0 RAO rest and exercise radionuclide ventriculograms compares favorably with rest and exercise 30 0 RAO contrast ventriculograms and demonstrates satisfactory interobserver agreement

Non-invasive haemodynamic assessments using Innocor during standard graded exercise tests.

Science.gov (United States)

Fontana, Piero; Boutellier, Urs; Toigo, Marco

2010-02-01

Cardiac output (Q) and stroke volume (V(S)) represent primary determinants of cardiovascular performance and should therefore be determined for performance diagnostics purposes. Since it is unknown, whether measurements of Q and V(S) can be performed by means of Innocor during standard graded exercise tests (GXTs), and whether current GXT stages are sufficiently long for the measurements to take place, we determined Q and V(S) at an early and late point in time on submaximal 2 min GXT stages. 16 male cyclists (age 25.4 +/- 2.9 years, body mass 71.2 +/- 5.0 kg) performed three GXTs and we determined Q and V(S) after 46 and 103 s at 69, 77, and 85% peak power. We found that the rebreathings could easily be incorporated into the GXTs and that Q and V(S) remained unchanged between the two points in time on the same GXT stage (69% peak power, Q: 18.1 +/- 2.1 vs. 18.2 +/- 2.3 l min(-1), V(S): 126 +/- 18 vs. 123 +/- 21 ml; 77% peak power, Q: 20.7 +/- 2.6 vs. 21.0 +/- 2.3 l min(-1), V(S): 132 +/- 18 vs. 131 +/- 18 ml; 85% peak power, Q: 21.6 +/- 2.4 vs. 21.8 +/- 2.7 l min(-1), V(S): 131 +/- 17 vs. 131 +/- 22 ml). We conclude that Innocor may be a useful device for assessing Q and V(S) during GXTs, and that the adaptation of Q and V(S) to exercise-to-exercise transitions at moderate to high submaximal power outputs is fast enough for 1 and 2 min GXT stage durations.

An Exercise in Using the U.S. Environmental Protection Agency's Hazard Ranking System: A Simulation. Grades 8-12.

Science.gov (United States)

HAZWRAP, The Hazardous Waste Remedial Actions Program.

The educational objective of this exercise is for students to use a risk assessment tool to evaluate a hazardous release site and for students in grades 8-12 to increase their experience with geology, aquifers, soils, land use, pollution, data analysis, and map concepts. Students use background information on hazardous materials, the Environmental…

Responses of catecholestrogen metabolism to acute graded exercise in normal menstruating women before and after training.

Science.gov (United States)

De Crée, C; Ball, P; Seidlitz, B; Van Kranenburg, G; Geurten, P; Keizer, H A

1997-10-01

It has been hypothesized that exercise-related hypo-estrogenemia occurs as a consequence of increased competition of catecholestrogens (CE) for catechol-O-methyltransferase (COMT). This may result in higher norepinephrine (NE) concentrations, which could interfere with normal gonadotropin pulsatility. The present study investigates the effects of training on CE responses to acute exercise stress. Nine untrained eumenorrheic women (mean percentage of body fat +/-SD: 24.8 +/- 3.1%) volunteered for an intensive 5-day training program. Resting, submaximal, and maximal (tmax) exercise plasma CE, estrogen, and catecholamine responses were determined pre- and post training in both the follicular (FPh) and luteal phase (LPh). Acute exercise stress increased total primary estrogens (E) but had little effect on total 2-hydroxyestrogens (2-OHE) and 2-hydroxyestrogen-monomethylethers (2-MeOE) (= O-methylated CE after competition for catechol-O-methyltransferase). This pattern was not significantly changed by training. However, posttraining LPh mean (+/-SE) plasma E, 2-OHE, and 2-MeOE concentrations were significantly lower (P Training produced opposite effects on 2-OHE:E ratios (an estimation of CE formation) during acute exercise in the FPh (reduction) and LPh (increase). The 2-MeOE:2-OHE ratio (an estimation of CE activity) showed significantly higher values at tmax in both menstrual phases after training (FPh: +11%; LPh: +23%; P training, NE values were significantly higher (P training lowers absolute concentrations of plasma estrogens and CE; the acute exercise challenge altered plasma estrogens but had little effect on CE; estimation of the formation and activity of CE suggests that formation and O-methylation of CE proportionately increases. These findings may be of importance for NE-mediated effects on gonadotropin release.

Using Maximal Isometric Force to Determine the Optimal Load for Measuring Dynamic Muscle Power

Science.gov (United States)

Spiering, Barry A.; Lee, Stuart M. C.; Mulavara, Ajitkumar P.; Bentley, Jason R.; Nash, Roxanne E.; Sinka, Joseph; Bloomberg, Jacob J.

2009-01-01

Maximal power output occurs when subjects perform ballistic exercises using loads of 30-50% of one-repetition maximum (1-RM). However, performing 1-RM testing prior to power measurement requires considerable time, especially when testing involves multiple exercises. Maximal isometric force (MIF), which requires substantially less time to measure than 1-RM, might be an acceptable alternative for determining the optimal load for power testing. PURPOSE: To determine the optimal load based on MIF for maximizing dynamic power output during leg press and bench press exercises. METHODS: Twenty healthy volunteers (12 men and 8 women; mean +/- SD age: 31+/-6 y; body mass: 72 +/- 15 kg) performed isometric leg press and bench press movements, during which MIF was measured using force plates. Subsequently, subjects performed ballistic leg press and bench press exercises using loads corresponding to 20%, 30%, 40%, 50%, and 60% of MIF presented in randomized order. Maximal instantaneous power was calculated during the ballistic exercise tests using force plates and position transducers. Repeated-measures ANOVA and Fisher LSD post hoc tests were used to determine the load(s) that elicited maximal power output. RESULTS: For the leg press power test, six subjects were unable to be tested at 20% and 30% MIF because these loads were less than the lightest possible load (i.e., the weight of the unloaded leg press sled assembly [31.4 kg]). For the bench press power test, five subjects were unable to be tested at 20% MIF because these loads were less than the weight of the unloaded aluminum bar (i.e., 11.4 kg). Therefore, these loads were excluded from analysis. A trend (p = 0.07) for a main effect of load existed for the leg press exercise, indicating that the 40% MIF load tended to elicit greater power output than the 60% MIF load (effect size = 0.38). A significant (p . 0.05) main effect of load existed for the bench press exercise; post hoc analysis indicated that the effect of

Exercise intensities during a ballet lesson in female adolescents with different technical ability.

Science.gov (United States)

Guidetti, L; Gallotta, M C; Emerenziani, G P; Baldari, C

2007-09-01

To investigate the exercise intensity during a typical grade five ballet lesson, thirty-nine dancers (13 - 16 yrs) were divided into three different technical proficiency groups: low level (n = 13), intermediate level (n = 14), and high level (n = 12). A progressively incremented treadmill test was administered to determine VO(2max), individual ventilatory threshold (IVT), and the individual anaerobic threshold (IAT). Oxygen uptake (VO(2)), heart rate (HR) and blood lactate (La) were then evaluated during a grade five ballet lesson. Oxygen uptake at IVT, IAT and maximal oxygen uptake were greater (p ballet lesson were similar among groups. During the ballet lesson, low technical level dancers had more V.O (2) and La values above (p < 0.05) the IAT than the other groups. Correlation analysis revealed that the number of exercises performed above IAT was positively related to anthropometric characteristics (BMI, %FM; r = 0.36, p < 0.05; r = 0.46, p < 0.01), negatively related to fitness parameters (VO(2IVT), VO(2IAT), VO(2max); r between - 0.43 and - 0.69; p < 0.001) and to technical level (r = - 0.70; p < 0.001). The subjects classified as having low technical abilities had lower fitness levels and performed more exercises above IAT than the more skilled dancers.

Maximal exercise capacity is related to cardiovascular structure in patients with longstanding hypertension. A LIFE substudy. Losartan Intervention For Endpoint-Reduction in Hypertension

DEFF Research Database (Denmark)

Olsen, M H; Wachtell, K; Hermann, K L

2001-01-01

BACKGROUND: Cardiovascular hypertrophy and remodeling in patients with never-treated hypertension has been associated with impaired exercise capacity, but whether this relationship remains in patients with longstanding hypertension and target organ damage is less elucidated. METHODS: In 43...... unmedicated patients with essential hypertension and electrocardiographic left ventricular (LV) hypertrophy, we measured maximal workload and oxygen reserve by bicycle test, 24-h ambulatory blood pressure (BP), LV mass index by magnetic resonance imaging (LVMI(MRI), n = 31), LVMI(echo) and systemic vascular...... compliance by echocardiography, minimal forearm vascular resistance (MFVR) by plethysmography, and intima media thickness and distensibility in the common carotid arteries by ultrasound. RESULTS: The patients did not achieve the maximal workload as predicted by age, gender and body composition (146...

Cordyceps militaris improves tolerance to high intensity exercise after acute and chronic supplementation

Science.gov (United States)

Hirsch, Katie R.; Smith-Ryan, Abbie E.; Roelofs, Erica J.; Trexler, Eric T.; Mock, Meredith G.

2016-01-01

To determine the effects of a mushroom blend containing cordyceps militaris on high intensity exercise after 1- and 3-weeks of supplementation. Twenty-eight individuals (Mean ± SD; Age=22.7 ± 4.1 yrs; Height=175.4 ± 8.7 cm; Weight=71.6 ± 12.0 kg) participated in this randomized, repeated measures, double-blind, placebo-controlled design. Maximal oxygen consumption (VO2max), time to exhaustion (TTE), and ventilatory threshold (VT) were measured during a maximal graded exercise test on a cycle ergometer. Relative peak power output (RPP), average power output (AvgP), and percent drop (%drop) were recorded during a 3-minute maximal cycle test with resistance at 4.5% body weight. Subjects consumed 4 g·d−1 mushroom blend (MR) or maltodextrin (PL) for 1 week. Ten volunteers supplemented for an additional 2 weeks. Exercise tests were separated by at least 48-hours and repeated following supplementation periods. One week of supplementation elicited no significant time × treatment interaction for VO2max (p=0.364), VT (p=0.514), TTE (p=0.540), RPP (p=0.134), AvgP (p=0.398), or %drop (p=0.823). After 3-weeks, VO2max significantly improved (p=0.042) in MR (+4.8 ml·kg−1·min−1), but not PL (+0.9 ml·kg−1·min−1). Analysis of 95% confidence intervals revealed significant improvements in TTE after 1- (+28.1 s) and 3-weeks (+69.8 s) in MR, but not PL, with additional improvements in VO2max (+4.8 ml·kg−1·min−1) and VT (+0.7 l·min−1) after 3-weeks. Acute supplementation with a cordyceps militaris containing mushroom blend may improve tolerance to high intensity exercise; greater benefits may be elicited with consistent chronic supplementation. PMID:27408987

Repeated Excessive Exercise Attenuates the Anti-Inflammatory Effects of Exercise in Older Men

DEFF Research Database (Denmark)

Sahl, Ronni E.; Andersen, Peter R.; Gronbaek, Katja

2017-01-01

Introduction/Purpose: A number of studies have investigated the effect of training with a moderate exercise dose (3–6 h/weekly) on the inflammatory profile in blood, and the data are inconsistent. Cross-sectional studies indicate a positive effect of physical activity level on inflammation levels...... inflammation, but the higher plasma IL-6 concentration concurrent with a trend toward higher insulin resistance and decreased VO2peak implies that the excessive amount of exercise probably attenuated the possible potential anti-inflammatory effects of exercise....... and risk of metabolic disease. However, it is not clear whether this may be dose dependent and if very prolonged repeated exercise therefore may be beneficial for low-grade inflammation. Based on this we studied how excessive repeated prolonged exercise influenced low-grade inflammation and adipose tissue...

Effects on muscle strength, maximal jump height, flexibility and postural sway after soccer and Zumba exercise among female hospital employees: a 9-month randomised controlled trial.

Science.gov (United States)

Barene, Svein; Holtermann, Andreas; Oseland, Harald; Brekke, Ole-Lars; Krustrup, Peter

2016-10-01

This 9-month randomised controlled workplace physical activity trial investigated the effects of soccer and Zumba exercise, respectively, on muscle strength, maximal jump height, sit-and-reach flexibility and postural sway among female workers. A total of 107 female hospital employees aged 25-63 were cluster-randomised to a soccer group, a Zumba group or a control group. Training was conducted outside working hours as two to three 1-h weekly sessions the first 3 months and once a week the last 6 months. Tests were conducted at baseline, after 3 and 9 months. The soccer group improved maximal neck extension strength both after 3 (1.2 kg; P flexibility. The present study indicates that workplace-initiated soccer and Zumba exercise may be beneficial for improvement of the neck and trunk strength, which may have preventive effects with regard to future perceived muscle pain in the respective body regions. Furthermore, the Zumba group revealed positive effects on lower limb lean mass and postural sway compared to the control group.

Cross-training in birds: cold and exercise training produce similar changes in maximal metabolic output, muscle masses and myostatin expression in house sparrows (Passer domesticus)

Science.gov (United States)

Zhang, Yufeng; Eyster, Kathleen; Liu, Jin-Song; Swanson, David L.

2015-01-01

ABSTRACT Maximal metabolic outputs for exercise and thermogenesis in birds presumably influence fitness through effects on flight and shivering performance. Because both summit (Msum, maximum thermoregulatory metabolic rate) and maximum (MMR, maximum exercise metabolic rate) metabolic rates are functions of skeletal muscle activity, correlations between these measurements and their mechanistic underpinnings might occur. To examine whether such correlations occur, we measured the effects of experimental cold and exercise training protocols for 3 weeks on body (Mb) and muscle (Mpec) masses, basal metabolic rate (BMR), Msum, MMR, pectoralis mRNA and protein expression for myostatin, and mRNA expression of TLL-1 and TLL-2 (metalloproteinase activators of myostatin) in house sparrows (Passer domesticus). Both training protocols increased Msum, MMR, Mb and Mpec, but BMR increased with cold training and decreased with exercise training. No significant differences occurred for pectoralis myostatin mRNA expression, but cold and exercise increased the expression of TLL-1 and TLL-2. Pectoralis myostatin protein levels were generally reduced for both training groups. These data clearly demonstrate cross-training effects of cold and exercise in birds, and are consistent with a role for myostatin in increasing pectoralis muscle mass and driving organismal increases in metabolic capacities. PMID:25987736

Cross-training in birds: cold and exercise training produce similar changes in maximal metabolic output, muscle masses and myostatin expression in house sparrows (Passer domesticus).

Science.gov (United States)

Zhang, Yufeng; Eyster, Kathleen; Liu, Jin-Song; Swanson, David L

2015-07-01

Maximal metabolic outputs for exercise and thermogenesis in birds presumably influence fitness through effects on flight and shivering performance. Because both summit (Msum, maximum thermoregulatory metabolic rate) and maximum (MMR, maximum exercise metabolic rate) metabolic rates are functions of skeletal muscle activity, correlations between these measurements and their mechanistic underpinnings might occur. To examine whether such correlations occur, we measured the effects of experimental cold and exercise training protocols for 3 weeks on body (Mb) and muscle (Mpec) masses, basal metabolic rate (BMR), Msum, MMR, pectoralis mRNA and protein expression for myostatin, and mRNA expression of TLL-1 and TLL-2 (metalloproteinase activators of myostatin) in house sparrows (Passer domesticus). Both training protocols increased Msum, MMR, Mb and Mpec, but BMR increased with cold training and decreased with exercise training. No significant differences occurred for pectoralis myostatin mRNA expression, but cold and exercise increased the expression of TLL-1 and TLL-2. Pectoralis myostatin protein levels were generally reduced for both training groups. These data clearly demonstrate cross-training effects of cold and exercise in birds, and are consistent with a role for myostatin in increasing pectoralis muscle mass and driving organismal increases in metabolic capacities. © 2015. Published by The Company of Biologists Ltd.

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

Science.gov (United States)

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

Serum Tumor Necrosis Factor-alpha associates with Myocardial Oxygen Demand and Exercise Tolerance in Postmenopausal Women.

Science.gov (United States)

Carter, Stephen J; Bryan, David R; Neumeier, William H; Glasser, Stephen P; Hunter, Gary R

2018-01-01

The functional implications of serum tumor necrosis factor-alpha (TNF-α), a marker of oxidative stress, on hemodynamic parameters at rest and during physical exertion are unclear. The aims of this investigation were to examine the independent associations of TNF-α on myocardial oxygen demand at rest and during submaximal exercise, while also evaluating the association of TNF-α on exercise tolerance. Forty, postmenopausal women, provided blood samples and completed a modified-Balke protocol to measure maximal oxygen uptake (VO 2max ). Large artery compliance was measured by pulse contour analyses while rate-pressure product (RPP), an index of myocardial oxygen demand, was measured at rest and during two submaximal workloads (i.e., ≈55% and ≈75% VO 2max ). RPP was calculated by dividing the product of heart rate and systolic blood pressure (via auscultation) by 100. Exercise tolerance corresponded with the cessation of the graded exercise test. During higher-intensity exertion, ≈75% VO 2max , multiple linear regression revealed a positive association ( r = 0.43; p = 0.015) between TNF-α and RPP while adjusting for maximal heart rate, VO 2max , large artery compliance, and percent body fat. Path analyses revealed a significant indirect effect of large artery compliance on exercise tolerance through TNF-α, β = 0.13, CI [0.03, 0.35], indicating greater levels of TNF-α associated with poorer exercise tolerance. These data suggest TNF-α independently associates with myocardial oxygen demand during physical exertion, thus highlighting the utility of higher-intensity efforts to expose important phenomena not apparent at rest. TNF-α also appears to be indirectly associated with the link between large artery compliance and exercise tolerance.

Psychophysiological Responses to Group Exercise Training Sessions: Does Exercise Intensity Matter?

Science.gov (United States)

Vandoni, Matteo; Codrons, Erwan; Marin, Luca; Correale, Luca; Bigliassi, Marcelo; Buzzachera, Cosme Franklim

2016-01-01

Group exercise training programs were introduced as a strategy for improving health and fitness and potentially reducing dropout rates. This study examined the psychophysiological responses to group exercise training sessions. Twenty-seven adults completed two group exercise training sessions of moderate and vigorous exercise intensities in a random and counterbalanced order. The %HRR and the exertional and arousal responses to vigorous session were higher than those during the moderate session (psession were less pleasant than those during moderate session (ptraining sessions are intensity-dependent. From an adherence perspective, interventionists are encouraged to emphasize group exercise training sessions at a moderate intensity to maximize affective responses and to minimize exertional responses, which in turn may positively affect future exercise behavior.

The effect of caffeine on maximal oxygen uptake and vertical jump performance in male basketball players.

Science.gov (United States)

Tucker, Matthew A; Hargreaves, Jill M; Clarke, Jenny C; Dale, Darren L; Blackwell, Gavin J

2013-02-01

This study investigated whether performance enhancement from caffeine described by other researchers transfers to male basketball players. The effects of caffeine ingestion were studied in a maximal-effort test on a treadmill that was followed by a vertical-jump test. Five elite-level male basketball players completed a graded treadmill test that measured maximal oxygen uptake, blood lactate profiles, respiratory exchange ratio, and rating of perceived exertion at each 3-minute stage. After a 15-minute warm-down, the subjects performed 10 vertical rebound jumps. Each subject completed the test twice--once with a 3 mg·kg(-1) of body weight dose of caffeine and once with a placebo, with the dosage administered 60 minutes before commencement of exercise. The test was thus administered according to a double-blind protocol. No substantial trends were found between caffeine and control trials, regardless of trial order. The study showed that the specified dosage had negligible effects on the players' power and endurance performance and had no efficacy as an ergogenic aid for male basketball players.

Factors in Maximal Power Production and in Exercise Endurance Relative to Maximal Power

Science.gov (United States)

1988-10-13

Mechanical efficiency of fast -and slow - twitch muscle fibers in mnan during cycling. J. ADLi Physiol.:Reespirat. Environ. Exercise Physiol. 47: 263- 267...R.S. Hikida, and F.C. Hagerman. Myofibrillar ATPase activity in hu-man muscle fast - twitch subtypes. Histochem. 78: 405-408, 1983. 31. Suzuki, Y...capacity and muscle fibre composition in mnan. J. Physiol (London) 354: 73P, 1984. 21. Margaria, R., P. Aghemo, and E. Rovelli. Measurement of muscular

Exercise addiction in CrossFit: Prevalence and psychometric properties of the Exercise Addiction Inventory

OpenAIRE

Lichtenstein, Mia Beck; Jensen, Tanja Tang

2016-01-01

Introduction: CrossFit is a mix of aerobic and anaerobic exercise regimes with the stated goal of improving fitness and physical performance. It is growing in popularity and has a strong community known to motivate and push the participants to maximal performance. The negative consequences of these extreme exercise patterns have rarely been described. The prevalence of injuries in CrossFit is high but exercise addiction and harmful exercise attitudes have not yet been assessed. The aim of thi...

Diurnal variation and reliability of the urine lactate concentration after maximal exercise.

Science.gov (United States)

Nikolaidis, Stefanos; Kosmidis, Ioannis; Sougioultzis, Michail; Kabasakalis, Athanasios; Mougios, Vassilis

2018-01-01

The postexercise urine lactate concentration is a novel valid exercise biomarker, which has exhibited satisfactory reliability in the morning hours under controlled water intake. The aim of the present study was to investigate the diurnal variation of the postexercise urine lactate concentration and its reliability in the afternoon hours. Thirty-two healthy children (11 boys and 21 girls) and 23 adults (13 men and 10 women) participated in the study. All participants performed two identical sessions of eight 25 m bouts of maximal freestyle swimming executed every 2 min with passive recovery in between. These sessions were performed in the morning and afternoon and were separated by 3-4 days. Adults performed an additional afternoon session that was also separated by 3-4 days. All swimmers drank 500 mL of water before and another 500 mL after each test. Capillary blood and urine samples were collected before and after each test for lactate determination. Urine creatinine, urine density and body water content were also measured. The intraclass correlation coefficient was used as a reliability index between the morning and afternoon tests, as well as between the afternoon test and retest. Swimming performance and body water content exhibited excellent reliability in both children and adults. The postexercise blood lactate concentration did not show diurnal variation, showing a good reliability between the morning and afternoon tests, as well as high reliability between the afternoon test and retest. The postexercise urine density and lactate concentration were affected by time of day. However, when lactate was normalized to creatinine, it exhibited excellent reliability in children and good-to-high reliability in adults. The postexercise urine lactate concentration showed high reliability between the afternoon test and retest, independent of creatinine normalization. The postexercise blood and urine lactate concentrations were significantly correlated in all

[Status of exercise and sedentary activities in the leisure time among third and fourth grade pupils in three cities of Shandong province].

Science.gov (United States)

Song, Chao; Yu Xinping; Ding, Caicui; Zhen, Baojie; Chen, Jian; Wang, Yanyong; Li, Li; Liu, Ailing

2015-05-01

To analyze the status and the influence factors of exercise and sedentary activities in the leisure time among third and fourth grade pupils in Qingdao, Tai' an and Yantai city of Shandong province. With random cluster sampling, a total of 2283 primary students were selected from three cities of Shandong province. Questionnaires were used to collect the information on their exercise, sedentary activities. In the past week the participation rate of exercise in the leisure time among the pupils was 65.9%. Among the pupils who participated exercise, the average days of moderate and high-intensity exercise was four, and the average daily exercise time was 30 minutes. The average time of sedentary activities in the leisure time was 0.9 h/d, and the rate of 2 hours and over per day of sedentary activities was 13.6%. Pupils participating the exercise was related to their area, gender, their satisfaction of their body image and their parents' exercise. Their sedentary patterns was related to their understanding of their own body weight and their parents' sedentary behavior. Intervention related to physical activity should be strengthened among pupils and their parents to promote their physical activity level.

Effects of a short-term exercise training program on aerobic fitness, fatigue, health perception and activity level of subjects with multiple sclerosis.

Science.gov (United States)

Mostert, S; Kesselring, J

2002-04-01

Multiple sclerosis (MS) patients of an inpatient rehabilitation program have been randomly assigned to an exercise training (MS-ET) or nontraining group (MS-NI). Before and after 4 weeks of aerobic exercise training, a graded maximal exercise test with measurement of gas exchange and a lung function test was administered to all 26 patients fulfilling the inclusion criteria. Activity level, fatigue and health perception were measured by means of questionnaires. Twenty-six healthy persons served as control group and were matched in respect of age, gender and activity level. Training intervention consisted of 5x30 min sessions per week of bicycle exercise with individualised intensity. Compared with baseline, the MS training group demonstrated a significant rightward placement of the aerobic threshold (AT) (VO2+13%; work rate [WR])+11%), an improvement of health perception (vitality+46%; social interaction+36%), an increase of activity level (+17%) and a tendency to less fatigue. No changes were observed for the MS-NI group and the control groups. Maximal aerobic capacity and lung function were not changed by either training or nontraining in all four groups. Overall compliance to the training program was quite low (65%), whereas incidence of symptom exacerbation by physical activity has been lower than expected (6%).

Children and Exercise: Appropriate Practices for Grades K-6

Science.gov (United States)

Fisher, Michele

2009-01-01

Growth and development have a profound effect on physical fitness, response to exercise, and exercise programming in children. This article reviews the essential pediatric exercise physiology concepts relevant to physical education programs for K-6 children. Indices of physical fitness such as cardiorespiratory endurance, muscular strength, and…

Effect of a 1-hour single bout of moderate-intensity exercise on fat oxidation kinetics.

Science.gov (United States)

Chenevière, Xavier; Borrani, Fabio; Ebenegger, Vincent; Gojanovic, Boris; Malatesta, Davide

2009-12-01

The present study aimed to examine the effects of a prior 1-hour continuous exercise bout (CONT) at an intensity (Fat(max)) that elicits the maximal fat oxidation (MFO) on the fat oxidation kinetics during a subsequent submaximal incremental test (IncrC). Twenty moderately trained subjects (9 men and 11 women) performed a graded test on a treadmill (Incr), with 3-minute stages and 1-km.h(-1) increments. Fat oxidation was measured using indirect calorimetry and plotted as a function of exercise intensity. A mathematical model (SIN) including 3 independent variables (dilatation, symmetry, and translation) was used to characterize the shape of fat oxidation kinetics and to determine Fat(max) and MFO. On a second visit, the subjects performed CONT at Fat(max) followed by IncrC. After CONT performed at 57% +/- 3% (means +/- SE) maximal oxygen uptake (Vo(2max)), the respiratory exchange ratio during IncrC was lower at every stage compared with Incr (P rates from 35% to 70% Vo(2max) (P .05), whereas symmetry tended to be greater in IncrC (P = .096). This study showed that the prior 1-hour continuous moderate-intensity exercise bout increased Fat(max), MFO, and fat oxidation rates over a wide range of intensities during the postexercise incremental test. Moreover, the shape of the postexercise fat oxidation kinetics tended to have a rightward asymmetry.

Effect of Maximal Versus Supra-Maximal Exhausting Race on Lipid Peroxidation, Antioxidant Activity and Muscle-Damage Biomarkers in Long-Distance and Middle-Distance Runners.

Science.gov (United States)

Mohamed, Said; Lamya, Ncir; Hamda, Mansour

2016-03-01

Exhausting physical exercise increases lipid peroxidation and causes important muscle damages. The human body tries to mitigate these adverse effects by mobilizing its antioxidant defenses. This study aims to investigate the effect of a maximal versus supra-maximal race sustained until exhaustion on lipid peroxidation, antioxidant activity and muscle-damage biomarkers in trained (i.e. long-distance and middle-distance runners) and sedentary subjects. The study has been carried out on 8 middle-distance runners (MDR), 9 long-distance runners (LDR), and 8 sedentary subjects (SS). Each subject has undergone two exhaustive running tests, the first one is an incremental event (VAMEVAL test), the second one is a constant supra-maximal intensity test (limited-time test). Blood samples were collected at rest and immediately after each test. A significant increase in malondialdehyde (MDA) concentrations was observed in SS and MDR after the VAMEVAL test and in LDR after the Limited-Time test. A significant difference was also observed between LDR and the other two groups after the VAMEVAL test, and between LDR and MDR after the Limited-Time test. Significant modifications, notably, in myoglobin, CK, LDH, IL-6, TNF-α, and TAS were likewise noted but depending on the race-type and the sportive specialty. Maximal and supra-maximal races induce a significant increase in lipid peroxidation and cause non-negligible inflammation and muscle damage. These effects were relatively related to the physical exercise type and the sportive specialty.

NASA Exercise Physiology and Countermeasures Project Overview

Science.gov (United States)

Loerch, Linda; Ploutz-Snyder, Lori

2009-01-01

Efficient exercise countermeasures are necessary to offset or minimize spaceflight-induced deconditioning and to maximize crew performance of mission tasks. These countermeasure protocols should use the fewest crew and vehicle resources. NASA s Exercise Physiology and Countermeasures (ExPC) Project works to identify, collect, interpret, and summarize evidence that results in effective exercise countermeasure protocols which protect crew health and performance during International Space Station (ISS) and future exploration-class missions. The ExPC and NASA s Human Research Program are sponsoring multiple studies to evaluate and improve the efficacy of spaceflight exercise countermeasures. First, the Project will measure maximal aerobic capacity (VO2max) during cycle ergometry before, during, and after ISS missions. Second, the Project is sponsoring an evaluation of a new prototype harness that offers improved comfort and increased loading during treadmill operations. Third, the Functional Tasks Test protocol will map performance of anticipated lunar mission tasks with physiologic systems before and after short and long-duration spaceflight, to target system contributions and the tailoring of exercise protocols to maximize performance. In addition to these studies that are actively enrolling crewmember participants, the ExPC is planning new studies that include an evaluation of a higher-intensity/lower-volume exercise countermeasure protocol aboard the ISS using the Advanced Resistive Exercise Device and second-generation treadmill, studies that evaluate bone loading during spaceflight exercise, and ground-based studies that focus on fitness for duty standards required to complete lunar mission tasks and for which exercise protocols need to protect. Summaries of these current and future studies and strategies will be provided to international colleagues for knowledge sharing and possible collaboration.

Social facilitation in virtual reality-enhanced exercise: competitiveness moderates exercise effort of older adults.

Science.gov (United States)

Anderson-Hanley, Cay; Snyder, Amanda L; Nimon, Joseph P; Arciero, Paul J

2011-01-01

This study examined the effect of virtual social facilitation and competitiveness on exercise effort in exergaming older adults. Fourteen exergaming older adults participated. Competitiveness was assessed prior to the start of exercise. Participants were trained to ride a "cybercycle;" a virtual reality-enhanced stationary bike with interactive competition. After establishing a cybercycling baseline, competitive avatars were introduced. Pedaling effort (watts) was assessed. Repeated measures ANOVA revealed a significant group (high vs low competitiveness) × time (pre- to post-avatar) interaction (F[1,12] = 13.1, P = 0.003). Virtual social facilitation increased exercise effort among more competitive exercisers. Exercise programs that match competitiveness may maximize exercise effort.

Whole-body fat oxidation determined by graded exercise and indirect calorimetry: a role for muscle oxidative capacity?

DEFF Research Database (Denmark)

Nordby, P; Saltin, B; Helge, J W

2006-01-01

During whole-body exercise, peak fat oxidation occurs at a moderate intensity. This study investigated whole-body peak fat oxidation in untrained and trained subjects, and the presence of a relation between skeletal muscle oxidative enzyme activity and whole-body peak fat oxidation. Healthy male...... subjects were recruited and categorized into an untrained (N=8, VO(2max) 3.5+/-0.1 L/min) and a trained (N=8, VO(2max) 4.6+/-0.2 L/min) group. Subjects performed a graded exercise test commencing at 60 W for 8 min followed by 35 W increments every 3 min. On a separate day, muscle biopsies were obtained...... oxidation was determined. The body composition was determined by DEXA. Whole-body peak fat oxidation (250+/-25 and 462+/-33 mg/min) was higher (Ptrained compared with untrained subjects, respectively. Muscle...

The Ottawa panel clinical practice guidelines for the management of knee osteoarthritis. Part two: strengthening exercise programs.

Science.gov (United States)

Brosseau, Lucie; Taki, Jade; Desjardins, Brigit; Thevenot, Odette; Fransen, Marlene; Wells, George A; Mizusaki Imoto, Aline; Toupin-April, Karine; Westby, Marie; Álvarez Gallardo, Inmaculada C; Gifford, Wendy; Laferrière, Lucie; Rahman, Prinon; Loew, Laurianne; De Angelis, Gino; Cavallo, Sabrina; Shallwani, Shirin Mehdi; Aburub, Ala'; Bennell, Kim L; Van der Esch, Martin; Simic, Milena; McConnell, Sara; Harmer, Alison; Kenny, Glen P; Paterson, Gail; Regnaux, Jean-Philippe; Lefevre-Colau, Marie-Martine; McLean, Linda

2017-05-01

To identify effective strengthening exercise programs and provide rehabilitation teams and patients with updated, high-quality recommendations concerning traditional land-based exercises for knee osteoarthritis. A systematic search and adapted selection criteria included comparative controlled trials with strengthening exercise programs for patients with knee osteoarthritis. A panel of experts reached consensus on the recommendations using a Delphi survey. A hierarchical alphabetical grading system (A, B, C+, C, D, D+ or D-) was based on statistical significance ( p osteoarthritis management within a six-month period. Strengthening exercise programs demonstrated a significant improvement for pain relief (four Grade A, ten Grade B, two Grade C+), physical function (four Grade A, eight Grade B) and quality of life (three Grade B). Strengthening in combination with other types of exercises (coordination, balance, functional) showed a significant improvement in pain relief (three Grade A, 11 Grade B, eight Grade C+), physical function (two Grade A, four Grade B, three Grade C+) and quality of life (one Grade A, one Grade C+). There are a variety of choices for strengthening exercise programs with positive recommendations for healthcare professionals and knee osteoarthritis patients. There is a need to develop combined behavioral and muscle-strengthening strategies to improve long-term maintenance of regular strengthening exercise programs.

Automatic Evaluations and Exercising: Systematic Review and Implications for Future Research.

Science.gov (United States)

Schinkoeth, Michaela; Antoniewicz, Franziska

2017-01-01

The general purpose of this systematic review was to summarize, structure and evaluate the findings on automatic evaluations of exercising. Studies were eligible for inclusion if they reported measuring automatic evaluations of exercising with an implicit measure and assessed some kind of exercise variable. Fourteen nonexperimental and six experimental studies (out of a total N = 1,928) were identified and rated by two independent reviewers. The main study characteristics were extracted and the grade of evidence for each study evaluated. First, results revealed a large heterogeneity in the applied measures to assess automatic evaluations of exercising and the exercise variables. Generally, small to large-sized significant relations between automatic evaluations of exercising and exercise variables were identified in the vast majority of studies. The review offers a systematization of the various examined exercise variables and prompts to differentiate more carefully between actually observed exercise behavior (proximal exercise indicator) and associated physiological or psychological variables (distal exercise indicator). Second, a lack of transparent reported reflections on the differing theoretical basis leading to the use of specific implicit measures was observed. Implicit measures should be applied purposefully, taking into consideration the individual advantages or disadvantages of the measures. Third, 12 studies were rated as providing first-grade evidence (lowest grade of evidence), five represent second-grade and three were rated as third-grade evidence. There is a dramatic lack of experimental studies, which are essential for illustrating the cause-effect relation between automatic evaluations of exercising and exercise and investigating under which conditions automatic evaluations of exercising influence behavior. Conclusions about the necessity of exercise interventions targeted at the alteration of automatic evaluations of exercising should therefore

Graded activity: legacy of the sanatorium.

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Creighton, C

1993-08-01

Occupational therapists in all areas of practice grade therapeutic activities to help patients progress toward their goals. It is proposed in this paper that the concept of graded activity originated in German tuberculosis sanatoria in the late 1800s, when patients were required to walk on graded (sloped) land for exercise. British physician Marcus Paterson included work, as well as walking, in his graduated exercise program for tuberculosis patients and was honored for this innovation at the founding meeting of the National Society for the Promotion of Occupational Therapy (NSPOT). George Barton, Susan Tracy, and Herbert Hall were among the NSPOT members who contributed to the development of graded activity as a principle in occupational therapy intervention. The military rehabilitation programs established during World War I provided additional impetus, and by the mid-1920s, graded activity was recognized as central to the profession.

Short Communication: HIV Patient Systemic Mitochondrial Respiration Improves with Exercise.

Science.gov (United States)

Kocher, Morgan; McDermott, Mindy; Lindsey, Rachel; Shikuma, Cecilia M; Gerschenson, Mariana; Chow, Dominic C; Kohorn, Lindsay B; Hetzler, Ronald K; Kimura, Iris F

2017-10-01

In HIV-infected individuals, impaired mitochondrial function may contribute to cardiometabolic disease as well as to fatigue and frailty. Aerobic exercise improves total body energy reserves; however, its impact at the cellular level is unknown. We assessed alterations in cellular bioenergetics in peripheral blood mononuclear cells (PBMC) before and after a 12-week aerobic exercise study in sedentary HIV-infected subjects on stable antiretroviral therapy who successfully completed a 12-week aerobic exercise program. In this prospective study, participants underwent supervised 20-40 min of light aerobic exercise (walking or jogging) performed three times per week for 12 weeks, gradually increasing to maintain an intensity of 50%-80% of heart rate reserve. Maximal aerobic capacity (VO 2MAX ) was assessed by a graded exercise test on a cycle ergometer before and after completion of the study. PBMC from compliant subjects (attended at least 70% of exercise sessions) were assessed for mitochondrial respiration using the Seahorse XF24 Bio-Analyzer. Seven of 24 enrolled subjects were compliant with the exercise regimen. In these individuals, a significant increase (p = .04) in VO 2MAX over 12 weeks was found with a median increase of 14%. During the same interval, a 2.45-fold increase in PBMC mitochondrial respiratory capacity (p = .04), a 5.65-fold increase in spare respiratory capacity (p = .01), and a 3.15-fold (p = .04) increase in nonmitochondrial respiration was observed. Aerobic exercise improves respiration at the cellular level. The diagnostic and prognostic value of such improved cellular respiration in the setting of chronic HIV warrants further investigation.

Utility of atropine in patients under beta-blocker effect during exercise stress echocardiography

International Nuclear Information System (INIS)

Munera, Ana G; Restrepo, Gustavo; Aristizabal, Dagnovar; Cubides, Carlos A

2006-01-01

The objective is to assess the usefulness of adding atropine 0.5 to 1.0 mg by intravenous injection during peak exercise in patients under beta-blocker effect that are subjected to exercise stress echocardiography. Population: exercise stress echocardiography was performed in 73 patients receiving beta-blocking agents with basal heart rate below 60 beats per minute (BPM). Two groups were established at random: group I (18 patients that did not receive atropine during maximal exercise) and group II (50 patients from whom 28 received 0.5 mg atropine IV 30 seconds to one minute before concluding the exercise and 22 patients who received 1.0 mg atropine IV 30 seconds to one minute before its conclusion). From a demographic point of view, there were no differences between the two groups. Mean age was 59 ± 10.8 years (57% male). Most of the patients received metoprolol (87%) and no significant statistical differences in relation with the doses were found in these two groups. At the end of the exercise, the patients had a mean heart rate of 84% from their maximal heart rate (MHR). The values post-exercise were 76% at 30 seconds, 68% at 60 sec., 62% at 90 sec., and 59% of the maximal heart rate at 120 sec. When comparing the percentage of the maximal heart rate achieved in maximal exercise and the one observed during the first 120 sec. after exercise, no statistically significant difference was observed between the two groups (p > 0.05). Conclusion: during the performance of stress exercise echocardiography, the administration of intravenous atropine was of no use for incrementing the peak heart rate post-exercise in patients with significant beta-blocker effect (basal heart rate < 60 BPM)

Objective and subjective measures of exercise intensity during thermo-neutral and hot yoga.

Science.gov (United States)

Boyd, Corinne N; Lannan, Stephanie M; Zuhl, Micah N; Mora-Rodriguez, Ricardo; Nelson, Rachael K

2018-04-01

While hot yoga has gained enormous popularity in recent years, owing in part to increased environmental challenge associated with exercise in the heat, it is not clear whether hot yoga is more vigorous than thermo-neutral yoga. Therefore, the aim of this study was to determine objective and subjective measures of exercise intensity during constant intensity yoga in a hot and thermo-neutral environment. Using a randomized, crossover design, 14 participants completed 2 identical ∼20-min yoga sessions in a hot (35.3 ± 0.8 °C; humidity: 20.5% ± 1.4%) and thermo-neutral (22.1 ± 0.2 °C; humidity: 27.8% ± 1.6%) environment. Oxygen consumption and heart rate (HR) were recorded as objective measures (percentage of maximal oxygen consumption and percentage of maximal HR (%HRmax)) and rating of perceived exertion (RPE) was recorded as a subjective measure of exercise intensity. There was no difference in exercise intensity based on percentage of maximal oxygen consumption during hot versus thermo-neutral yoga (30.9% ± 2.3% vs. 30.5% ± 1.8%, p = 0.68). However, exercise intensity was significantly higher during hot versus thermo-neutral yoga based on %HRmax (67.0% ± 2.3% vs. 60.8% ± 1.9%, p = 0.01) and RPE (12 ± 1 vs. 11 ± 1, p = 0.04). According to established exercise intensities, hot yoga was classified as light-intensity exercise based on percentage of maximal oxygen consumption but moderate-intensity exercise based on %HRmax and RPE while thermo-neutral yoga was classified as light-intensity exercise based on percentage of maximal oxygen uptake, %HRmax, and RPE. Despite the added hemodynamic stress and perception that yoga is more strenuous in a hot environment, we observed similar oxygen consumption during hot versus thermo-neutral yoga, classifying both exercise modalities as light-intensity exercise.

Ingestion of High Molecular Weight Carbohydrate Enhances Subsequent Repeated Maximal Power: A Randomized Controlled Trial.

Directory of Open Access Journals (Sweden)

Jonathan M Oliver

Full Text Available Athletes in sports demanding repeat maximal work outputs frequently train concurrently utilizing sequential bouts of intense endurance and resistance training sessions. On a daily basis, maximal work within subsequent bouts may be limited by muscle glycogen availability. Recently, the ingestion of a unique high molecular weight (HMW carbohydrate was found to increase glycogen re-synthesis rate and enhance work output during subsequent endurance exercise, relative to low molecular weight (LMW carbohydrate ingestion. The effect of the HMW carbohydrate, however, on the performance of intense resistance exercise following prolonged-intense endurance training is unknown. Sixteen resistance trained men (23±3 years; 176.7±9.8 cm; 88.2±8.6 kg participated in a double-blind, placebo-controlled, randomized 3-way crossover design comprising a muscle-glycogen depleting cycling exercise followed by ingestion of placebo (PLA, or 1.2 g•kg•bw-1 of LMW or HMW carbohydrate solution (10% with blood sampling for 2-h post-ingestion. Thereafter, participants performed 5 sets of 10 maximal explosive repetitions of back squat (75% of 1RM. Compared to PLA, ingestion of HMW (4.9%, 90%CI 3.8%, 5.9% and LMW (1.9%, 90%CI 0.8%, 3.0% carbohydrate solutions substantially increased power output during resistance exercise, with the 3.1% (90% CI 4.3, 2.0% almost certain additional gain in power after HMW-LMW ingestion attributed to higher movement velocity after force kinematic analysis (HMW-LMW 2.5%, 90%CI 1.4, 3.7%. Both carbohydrate solutions increased post-exercise plasma glucose, glucoregulatory and gut hormones compared to PLA, but differences between carbohydrates were unclear; thus, the underlying mechanism remains to be elucidated. Ingestion of a HMW carbohydrate following prolonged intense endurance exercise provides superior benefits to movement velocity and power output during subsequent repeated maximal explosive resistance exercise. This study was registered

Psychophysiological Responses to Group Exercise Training Sessions: Does Exercise Intensity Matter?

Directory of Open Access Journals (Sweden)

Matteo Vandoni

Full Text Available Group exercise training programs were introduced as a strategy for improving health and fitness and potentially reducing dropout rates. This study examined the psychophysiological responses to group exercise training sessions. Twenty-seven adults completed two group exercise training sessions of moderate and vigorous exercise intensities in a random and counterbalanced order. The %HRR and the exertional and arousal responses to vigorous session were higher than those during the moderate session (p<0.05. Consequently, the affective responses to vigorous session were less pleasant than those during moderate session (p<0.05. These results suggest that the psychophysiological responses to group exercise training sessions are intensity-dependent. From an adherence perspective, interventionists are encouraged to emphasize group exercise training sessions at a moderate intensity to maximize affective responses and to minimize exertional responses, which in turn may positively affect future exercise behavior.

The Ottawa panel clinical practice guidelines for the management of knee osteoarthritis. Part three: aerobic exercise programs.

Science.gov (United States)

Brosseau, Lucie; Taki, Jade; Desjardins, Brigit; Thevenot, Odette; Fransen, Marlene; Wells, George A; Mizusaki Imoto, Aline; Toupin-April, Karine; Westby, Marie; Álvarez Gallardo, Inmaculada C; Gifford, Wendy; Laferrière, Lucie; Rahman, Prinon; Loew, Laurianne; De Angelis, Gino; Cavallo, Sabrina; Shallwani, Shirin Mehdi; Aburub, Ala'; Bennell, Kim L; Van der Esch, Martin; Simic, Milena; McConnell, Sara; Harmer, Alison; Kenny, Glen P; Paterson, Gail; Regnaux, Jean-Philippe; Lefevre-Colau, Marie-Martine; McLean, Linda

2017-05-01

To identify effective aerobic exercise programs and provide clinicians and patients with updated, high-quality recommendations concerning traditional land-based exercises for knee osteoarthritis. A systematic search and adapted selection criteria included comparative controlled trials with strengthening exercise programs for patients with knee osteoarthritis. A panel of experts reached consensus on the recommendations using a Delphi survey. A hierarchical alphabetical grading system (A, B, C+, C, D, D+, or D-) was used, based on statistical significance ( P osteoarthritis within a 12-week period. An aerobic exercise program demonstrated significant improvement for pain relief (Grade B), physical function (Grade B) and quality of life (Grade C+). Aerobic exercise in combination with strengthening exercises showed significant improvement for pain relief (3 Grade A) and physical function (2 Grade A, 2 Grade B). A short-term aerobic exercise program with/without muscle strengthening exercises is promising for reducing pain, improving physical function and quality of life for individuals with knee osteoarthritis.

Behavioural graded activity results in better exercise adherence and more physical activity than usual care in people with osteoarthritis: a cluster-randomised trial

NARCIS (Netherlands)

Pisters, M.F.; Veenhof, C.; de Bakker, D.H.; Schellevis, F.G.; Dekker, J.

2010-01-01

Question: Does behavioural graded activity result in better exercise adherence and more physical activity than usual care in people with osteoarthritis of the hip or knee? Design: Analysis of secondary outcomes of a cluster-randomised trial with concealed allocation, assessor blinding, and

Determinants of maximal oxygen uptake in severe acute hypoxia

DEFF Research Database (Denmark)

Calbet, J A L; Boushel, Robert Christopher; Rådegran, G

2003-01-01

To unravel the mechanisms by which maximal oxygen uptake (VO2 max) is reduced with severe acute hypoxia in humans, nine Danish lowlanders performed incremental cycle ergometer exercise to exhaustion, while breathing room air (normoxia) or 10.5% O2 in N2 (hypoxia, approximately 5,300 m above sea......: 1) reduction of PiO2, 2) impairment of pulmonary gas exchange, and 3) reduction of maximal cardiac output and peak leg blood flow, each explaining about one-third of the loss in VO2 max....

Effects of propranolol and pindolol on plasma ANP levels in humans at rest and during exercise.

Science.gov (United States)

Bouissou, P; Galen, F X; Richalet, J P; Lartigue, M; Devaux, F; Dubray, C; Atlan, G

1989-08-01

In attempt to elucidate whether the beta-adrenoceptor is involved in the control of atrial natriuretic peptide (ANP) secretion, plasma immunoreactive ANP level was measured at rest, in recumbent and upright positions, and during graded maximal ergocycle exercise in nine healthy male subjects (23 +/- 0.5 years of age) treated for 3 days with nonselective beta-blockers propranolol (150 mg/day) or pindolol (15 mg/day) or with placebo. The effects of beta-blockers, which differ by their hemodynamic actions at rest because of the intrinsic sympathomimetic activity of pindolol, were compared. Maximal O2 consumption (VO2max) during beta-blockade was not significantly different from the placebo value. Resting heart rate was not affected by pindolol treatment but was decreased with propranolol (-10 beats/min). Both beta-blockers caused a reduction in heart rate at all the exercise intensities. Mean blood pressure was not affected by beta-blockade at rest but was significantly reduced during exercise. During placebo treatment, plasma ANP increased in response to exercise intensities greater than 65% of VO2max. At 100% VO2max plasma ANP was nearly doubled (101.5 +/- 14 pg/ml) compared with the basal value in upright position (56.6 +/- 15 pg/ml). beta-Blockade caused a marked elevation in plasma ANP at all the levels of activity. Despite different hemodynamic responses to pindolol and propranolol, both beta-blockers produced similar increases in the basal level of plasma ANP. These rises were maintained in the course of exercise tests, and no significant difference was found between propranolol and pindolol. We conclude that beta-adrenoceptor mechanisms are not directly responsible for tonic and exercise-induced ANP secretion in humans.(ABSTRACT TRUNCATED AT 250 WORDS)

Maximal Strength Performance and Muscle Activation for the Bench Press and Triceps Extension Exercises Adopting Dumbbell, Barbell, and Machine Modalities Over Multiple Sets.

Science.gov (United States)

Farias, Déborah de Araújo; Willardson, Jeffrey M; Paz, Gabriel A; Bezerra, Ewertton de S; Miranda, Humberto

2017-07-01

Farias, DdA, Willardson, JM, Paz, GA, Bezerra, EdS, and Miranda, H. Maximal strength performance and muscle activation for the bench press and triceps extension exercises adopting dumbbell, barbell and machine modalities over multiple sets. J Strength Cond Res 31(7): 1879-1887, 2017-The purpose of this study was to investigate muscle activation, total repetitions, and training volume for 3 bench press (BP) exercise modes (Smith machine [SMBP], barbell [BBP], and dumbbell [DBP]) that were followed by a triceps extension (TE) exercise. Nineteen trained men performed 3 testing protocols in random order, which included: (P1) SMBP + TE; (P2) BBP + TE; and (P3) DBP + TE. Each protocol involved 4 sets with a 10-repetition maximum (RM) load, immediately followed by a TE exercise that was also performed for 4 sets with a 10RM load. A 2-minute rest interval was adopted between sets and exercises. Surface electromyographic activity was assessed for the pectoralis major (PM), anterior deltoid (AD), biceps brachii (BB), and triceps brachii (TB). The results indicated that significantly higher total repetitions were achieved for the DBP (31.2 ± 3.2) vs. the BBP (27.8 ± 4.8). For the TE, significantly greater volume was achieved when this exercise was performed after the BBP (1,204.4 ± 249.4 kg) and DBP (1,216.8 ± 287.5 kg) vs. the SMBP (1,097.5 ± 193 kg). The DBP elicited significantly greater PM activity vs. the BBP. The SMBP elicited significantly greater AD activity vs. the BBP and DBP. During the different BP modes, the SMBP and BBP elicited significantly greater TB activity vs. the DBP. However, the DBP elicited significantly greater BB activity vs. the SMBP and BBP, respectively. During the succeeding TE exercise, significantly greater activity of the TB was observed when this exercise was performed after the BBP vs. the SMBP and DBP. Therefore, it seems that the variation in BP modes does influence both repetition performance and muscle activation patterns during the

Exercise at the Extremes: The Amount of Exercise to Reduce Cardiovascular Events.

Science.gov (United States)

Eijsvogels, Thijs M H; Molossi, Silvana; Lee, Duck-Chul; Emery, Michael S; Thompson, Paul D

2016-01-26

Habitual physical activity and regular exercise training improve cardiovascular health and longevity. A physically active lifestyle is, therefore, a key aspect of primary and secondary prevention strategies. An appropriate volume and intensity are essential to maximally benefit from exercise interventions. This document summarizes available evidence on the relationship between the exercise volume and risk reductions in cardiovascular morbidity and mortality. Furthermore, the risks and benefits of moderate- versus high-intensity exercise interventions are compared. Findings are presented for the general population and cardiac patients eligible for cardiac rehabilitation. Finally, the controversy of excessive volumes of exercise in the athletic population is discussed. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Developmental Trajectories of Boys’ Driven Exercise and Fasting During the Middle School Years

Science.gov (United States)

Davis, Heather A.; Guller, Leila; Smith, Gregory T.

2016-01-01

Boys appear to engage in eating disorder behavior, particularly nonpurging compensatory behaviors such as driven exercise and fasting, at higher rates than previously thought. Little is known about the development of these behaviors in adolescent boys. In a sample of 631 non-binge eating and non-purging boys studied once in 5th grade and 6 times over the 3 years of middle school (grades 6 through 8), we found that (a) for some youth, driven exercise and fasting were present from grade 6; (b) different boys progressed along different trajectories of engagement in driven exercise and fasting, with some boys engaging in no driven exercise or fasting (65.8% and 83.5%, respectively), some boys engaging in driven exercise and fasting throughout middle school (25.2% and 16.5%, respectively), and other boys discontinuing engagement in driven exercise (9%); (c) 5th grade depression, eating expectancies, and thinness expectancies predicted subsequent trajectory group membership; and (d) boys engaging in driven exercise and fasting in 8th grade remained distressed. Boys’ engagement in driven exercise and fasting behavior merits the attention of researchers and clinicians. PMID:26707543

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

Science.gov (United States)

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.

Oscillation of tissue oxygen index in non-exercising muscle during exercise.

Science.gov (United States)

Yano, T; Afroundeh, R; Shirakawa, K; Lian, C-S; Shibata, K; Xiao, Z; Yunoki, T

2015-09-01

The purpose of the present study was to examine how oscillation of tissue oxygen index (TOI) in non-exercising exercise is affected during high-intensity and low-intensity exercises. Three exercises were performed with exercise intensities of 30% and 70% peak oxygen uptake (Vo(2)peak) for 12 min and with exercise intensity of 70% Vo(2)peak for 30 s. TOI in non-exercising muscle (biceps brachii) during the exercises for 12 min was determined by nearinfrared spectroscopy. TOI in the non-exercising muscle during the exercises was analyzed by fast Fourier transform (FFT) to obtain power spectra density (PSD). The frequency at which maximal PSD appeared (Fmax) during the exercise with 70% Vo(2)peak for 12 min (0.00477 ± 0.00172 Hz) was significantly lower than that during the exercise with 30% Vo2peak for 12 min (0.00781 ± 0.00338 Hz). There were significant differences in blood pH and blood lactate between the exercise with 70% Vo(2)peak and the exercise with 30% Vo(2)peak. It is concluded that TOI in nonexercising muscle oscillates during low-intensity exercise as well as during high-intensity exercise and that the difference in Fmax between the two exercises is associated with the difference in increase in blood lactate derived from the exercise.

Time-dependent effects of cardiovascular exercise on memory

DEFF Research Database (Denmark)

Roig, Marc; Thomas, Richard; Mang, Cameron S

2016-01-01

We present new evidence supporting the hypothesis that the effects of cardiovascular exercise on memory can be regulated in a time-dependent manner. When the exercise stimulus is temporally coupled with specific phases of the memory formation process, a single bout of cardiovascular exercise may...... be sufficient to improve memory. SUMMARY: The timing of exercise in relation to the information to be remembered is critical to maximize the effects of acute cardiovascular exercise on memory....

Influence of Lumber Volume Maximization on Value in Sawing Hardwood Sawlogs

Science.gov (United States)

Philip H. Steele; Francis G. Wagner; Lalit Kumar; Philip A. Araman

1992-01-01

Research based on applying volume-maximizing sawing solutions to idealized hardwood log forms has shown that average lumber yield can be increased by 6 percent. It is possible, however, that a lumber volume-maximizing solution may result in a decrease in lumber grade and a net reduction in total value of sawn lumber. The objective of this study was to determine the...

The intent to exercise influences the cerebral O(2)/carbohydrate uptake ratio in humans

DEFF Research Database (Denmark)

Dalsgaard, Mads K; Ide, Kojiro; Cai, Yan

2002-01-01

During and after maximal exercise there is a 15-30 % decrease in the metabolic uptake ratio (O(2)/[glucose + 1/2 lactate]) and a net lactate uptake by the human brain. This study evaluated if this cerebral metabolic uptake ratio is influenced by the intent to exercise, and whether a change could......, the a-v difference for the amino acids and glycerol did not change significantly, and there was only a minimal increase in the a-v difference for free fatty acids after maximal exercise. After maximal exercise the metabolic uptake ratio of the brain decreased from 6.1 +/- 0.5 (mean +/- S.E.M.) at rest.......2) in the early recovery (n = 10; P brain are increased out of proportion to O(2) when the brain is activated by exhaustive exercise, and that such metabolic changes are influenced by the will to exercise. We speculate that the uptake ratio...

Estimation of maximal oxygen uptake via submaximal exercise testing in sports, clinical, and home settings.

Science.gov (United States)

Sartor, Francesco; Vernillo, Gianluca; de Morree, Helma M; Bonomi, Alberto G; La Torre, Antonio; Kubis, Hans-Peter; Veicsteinas, Arsenio

2013-09-01

Assessment of the functional capacity of the cardiovascular system is essential in sports medicine. For athletes, the maximal oxygen uptake [Formula: see text] provides valuable information about their aerobic power. In the clinical setting, the (VO(2max)) provides important diagnostic and prognostic information in several clinical populations, such as patients with coronary artery disease or heart failure. Likewise, VO(2max) assessment can be very important to evaluate fitness in asymptomatic adults. Although direct determination of [VO(2max) is the most accurate method, it requires a maximal level of exertion, which brings a higher risk of adverse events in individuals with an intermediate to high risk of cardiovascular problems. Estimation of VO(2max) during submaximal exercise testing can offer a precious alternative. Over the past decades, many protocols have been developed for this purpose. The present review gives an overview of these submaximal protocols and aims to facilitate appropriate test selection in sports, clinical, and home settings. Several factors must be considered when selecting a protocol: (i) The population being tested and its specific needs in terms of safety, supervision, and accuracy and repeatability of the VO(2max) estimation. (ii) The parameters upon which the prediction is based (e.g. heart rate, power output, rating of perceived exertion [RPE]), as well as the need for additional clinically relevant parameters (e.g. blood pressure, ECG). (iii) The appropriate test modality that should meet the above-mentioned requirements should also be in line with the functional mobility of the target population, and depends on the available equipment. In the sports setting, high repeatability is crucial to track training-induced seasonal changes. In the clinical setting, special attention must be paid to the test modality, because multiple physiological parameters often need to be measured during test execution. When estimating VO(2max), one has

Facing Contrast-Enhancing Gliomas: Perfusion MRI in Grade III and Grade IV Gliomas according to Tumor Area

Directory of Open Access Journals (Sweden)

Anna Luisa Di Stefano

2014-01-01

Full Text Available Tumoral neoangiogenesis characterizes high grade gliomas. Relative Cerebral Blood Volume (rCBV, calculated with Dynamic Susceptibility Contrast (DSC Perfusion-Weighted Imaging (PWI, allows for the estimation of vascular density over the tumor bed. The aim of the study was to characterize putative tumoral neoangiogenesis via the study of maximal rCBV with a Region of Interest (ROI approach in three tumor areas—the contrast-enhancing area, the nonenhancing tumor, and the high perfusion area on CBV map—in patients affected by contrast-enhancing glioma (grades III and IV. Twenty-one patients were included: 15 were affected by grade IV and 6 by grade III glioma. Maximal rCBV values for each patient were averaged according to glioma grade. Although rCBV from contrast-enhancement and from nonenhancing tumor areas was higher in grade IV glioma than in grade III (5.58 and 2.68; 3.01 and 2.2, resp., the differences were not significant. Instead, rCBV recorded in the high perfusion area on CBV map, independently of tumor compartment, was significantly higher in grade IV glioma than in grade III (7.51 versus 3.78, P=0.036. In conclusion, neoangiogenesis encompasses different tumor compartments and CBV maps appear capable of best characterizing the degree of neovascularization. Facing contrast-enhancing brain tumors, areas of high perfusion on CBV maps should be considered as the reference areas to be targeted for glioma grading.

Aerobic exercise deconditioning and countermeasures during bed rest.

Science.gov (United States)

Lee, Stuart M C; Moore, Alan D; Everett, Meghan E; Stenger, Michael B; Platts, Steven H

2010-01-01

Bed rest is a well-accepted model for spaceflight in which the physiologic adaptations, particularly in the cardiovascular system, are studied and potential countermeasures can be tested. Bed rest without countermeasures results in reduced aerobic capacity and altered submaximal exercise responses. Aerobic endurance and factors which may impact prolonged exercise, however, have not been well studied. The initial loss of aerobic capacity is rapid, occurring in parallel with the loss of plasma volume. Thereafter, the reduction in maximal aerobic capacity proceeds more slowly and is influenced by central and peripheral adaptation. Exercise capacity can be maintained during bed rest and may be improved during recovery with appropriate countermeasures. Plasma volume restoration, resistive exercise, orthostatic stress, aerobic exercise, and aerobic exercise plus orthostatic stress all have been tested with varying levels of success. However, the optimal combination of elements-exercise modality, intensity, duration, muscle groups exercised and frequency of aerobic exercise, orthostatic stress, and supplementary resistive or anaerobic exercise training-has not been systematically evaluated. Currently, frequent (at least 3 days per week) bouts of intense exercise (interval-style and near maximal) with orthostatic stress appears to be the most efficacious method to protect aerobic capacity during bed rest. Further refinement of protocols and countermeasure hardware may be necessary to insure the success of countermeasures in the unique environment of space.

Pediatric exercise testing. In health and disease

NARCIS (Netherlands)

Bongers, B.C.

2013-01-01

Measuring peak oxygen uptake (VO2peak) during progressive cardiopulmonary exercise testing (CPET) up to maximal exertion is widely recognized as the best single measure of aerobic exercise capacity. It is an important determinant of health, even in childhood and adolescence. Measuring VO2peak

The survey regarding sports and exercise of Keio University students

OpenAIRE

野口, 和行; 近藤, 明彦; 加藤, 大仁; 山内, 賢

2009-01-01

We conducted a survey of "College Students' Attitude toward Sports and Exercise" using students of all facilities and grades in Keio University. The purpose of this report is 1) to compare the amount of sports and exercise across facilities and grades, 2) to analyze frequencies, amount of time, and attitudes regarding different types of sports and exercise activities, 3) to examine attitudes toward and reasoning of no exercise, and 4) to examine their preference of activities in their free ti...

Skeletal muscle fiber type composition and performance during repeated bouts of maximal, concentric contractions

Science.gov (United States)

Colliander, E. B.; Dudley, G. A.; Tesch, P. A.

1988-01-01

Force output and fatigue and recovery patterns were studied during intermittent short-term exercise. 27 men performed three bouts of 30 maximal unilateral knee extensions on 2 different occasions. Blood flow was maintained or occluded during recovery periods (60 s). Blood flow was restricted by inflating a pneumatic cuff placed around the proximal thigh. Muscle biopsies from vastus lateralis were analyzed for identification of fast twitch (FT) and slow twitch (ST) fibers and relative FT area. Peak torque decreased during each bout of exercise and more when blood flow was restricted during recovery. Initial peak torque (IPT) and average peak torque (APT) decreased over the three exercise bouts. This response was 3 fold greater without than with blood flow during recovery. IPT and APT decreased more in individuals with mainly FT fibers than in those with mainly ST fibers. It is suggested that performance during repeated bouts of maximal concentric contractions differs between individuals with different fiber type composition. Specifically, in high intensity, intermittent exercise with emphasis on anaerobic energy release a high FT composition may not necessarily be advantageous for performance.

Randomized Evaluation of Cognitive-Behavioral Therapy and Graded Exercise Therapy for Post-Cancer Fatigue.

Science.gov (United States)

Sandler, Carolina X; Goldstein, David; Horsfield, Sarah; Bennett, Barbara K; Friedlander, Michael; Bastick, Patricia A; Lewis, Craig R; Segelov, Eva; Boyle, Frances M; Chin, Melvin T M; Webber, Kate; Barry, Benjamin K; Lloyd, Andrew R

2017-07-01

Cancer-related fatigue is prevalent and disabling. When persistent and unexplained, it is termed post-cancer fatigue (PCF). Cognitive behavioral therapy (CBT) and graded exercise therapy (GET) may improve symptoms and functional outcomes. To evaluate the outcomes of a randomized controlled trial, which assigned patients with post-cancer fatigue to education, or 12 weeks of integrated cognitive-behavioral therapy (CBT) and graded exercise therapy (GET). Three months after treatment for breast or colon cancer, eligible patients had clinically significant fatigue, no comorbid medical or psychiatric conditions that explained the fatigue, and no evidence of recurrence. The CBT/GET arm included individually tailored consultations at approximately two weekly intervals. The education arm included a single visit with clinicians describing the principles of CBT/GET and a booklet. The primary outcome was clinically significant improvement in self-reported fatigue (Somatic and Psychological HEalth REport 0-12), designated a priori as greater than one SD of improvement in fatigue score. The secondary outcome was associated improvement in function (role limitation due to physical health problems-36-Item Short Form Health Survey 0-100) comparing baseline, end treatment (12 weeks), and follow-up (24 weeks). There were 46 patients enrolled, including 43 women (94%), with a mean age of 51 years. Fatigue severity improved in all subjects from a mean of 5.2 (±3.1) at baseline to 3.9 (±2.8) at 12 weeks, suggesting a natural history of improvement. Clinically significant improvement was observed in 7 of 22 subjects in the intervention group compared with 2 of 24 in the education group (P < 0.05, χ 2 ). These subjects also had improvement in functional status compared with nonresponders (P < 0.01, t-test). Combined CBT/GET improves fatigue and functional outcomes for a subset of patients with post-cancer fatigue. Further studies to improve the response rate and the magnitude of

Social facilitation in virtual reality-enhanced exercise: competitiveness moderates exercise effort of older adults

Directory of Open Access Journals (Sweden)

Anderson-Hanley C

2011-10-01

Full Text Available Cay Anderson-Hanley1,2, Amanda L Snyder1, Joseph P Nimon1, Paul J Arciero1,21Healthy Aging and Neuropsychology Lab, Department of Psychology, Union College, Schenectady, NY, USA; 2Health and Exercise Sciences Department, Skidmore College, Saratoga Springs, NY, USAAbstract: This study examined the effect of virtual social facilitation and competitiveness on exercise effort in exergaming older adults. Fourteen exergaming older adults participated. Competitiveness was assessed prior to the start of exercise. Participants were trained to ride a “cybercycle;” a virtual reality-enhanced stationary bike with interactive competition. After establishing a cybercycling baseline, competitive avatars were introduced. Pedaling effort (watts was assessed. Repeated measures ANOVA revealed a significant group (high vs low competitiveness X time (pre- to post-avatar interaction (F[1,12] = 13.1, P = 0.003. Virtual social facilitation increased exercise effort among more competitive exercisers. Exercise programs that match competitiveness may maximize exercise effort.Keywords: exercise, aging, virtual reality, competitiveness, social facilitation, exercise intensity

A maximal incremental effort alters tear osmolarity depending on the fitness level in military helicopter pilots.

Science.gov (United States)

Vera, Jesús; Jiménez, Raimundo; Madinabeitia, Iker; Masiulis, Nerijus; Cárdenas, David

2017-10-01

Fitness level modulates the physiological responses to exercise for a variety of indices. While intense bouts of exercise have been demonstrated to increase tear osmolarity (Tosm), it is not known if fitness level can affect the Tosm response to acute exercise. This study aims to compare the effect of a maximal incremental test on Tosm between trained and untrained military helicopter pilots. Nineteen military helicopter pilots (ten trained and nine untrained) performed a maximal incremental test on a treadmill. A tear sample was collected before and after physical effort to determine the exercise-induced changes on Tosm. The Bayesian statistical analysis demonstrated that Tosm significantly increased from 303.72 ± 6.76 to 310.56 ± 8.80 mmol/L after performance of a maximal incremental test. However, while the untrained group showed an acute Tosm rise (12.33 mmol/L of increment), the trained group experienced a stable Tosm physical effort (1.45 mmol/L). There was a significant positive linear association between fat indices and Tosm changes (correlation coefficients [r] range: 0.77-0.89), whereas the Tosm changes displayed a negative relationship with the cardiorespiratory capacity (VO2 max; r = -0.75) and performance parameters (r = -0.75 for velocity, and r = -0.67 for time to exhaustion). The findings from this study provide evidence that fitness level is a major determinant of Tosm response to maximal incremental physical effort, showing a fairly linear association with several indices related to fitness level. High fitness level seems to be beneficial to avoid Tosm changes as consequence of intense exercise. Copyright © 2017 Elsevier Inc. All rights reserved.

Creatine supplementation prevents acute strength loss induced by concurrent exercise.

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de Salles Painelli, Vítor; Alves, Victor Tavares; Ugrinowitsch, Carlos; Benatti, Fabiana Braga; Artioli, Guilherme Giannini; Lancha, Antonio Herbert; Gualano, Bruno; Roschel, Hamilton

2014-08-01

To investigate the effect of creatine (CR) supplementation on the acute interference induced by aerobic exercise on subsequent maximum dynamic strength (1RM) and strength endurance (SE, total number of repetitions) performance. Thirty-two recreationally strength-trained men were submitted to a graded exercise test to determine maximal oxygen consumption (VO2max: 41.56 ± 5.24 ml kg(-1) min(-1)), anaerobic threshold velocity (ATv: 8.3 ± 1.18 km h(-1)), and baseline performance (control) on the 1RM and SE (4 × 80 % 1RM to failure) tests. After the control tests, participants were randomly assigned to either a CR (20 g day(-1) for 7 days followed by 5 g day(-1) throughout the study) or a placebo (PL-dextrose) group, and then completed 4 experimental sessions, consisting of a 5-km run on a treadmill either continuously (90 % ATv) or intermittently (1:1 min at vVO2max) followed by either a leg- or bench-press SE/1RM test. CR was able to maintain the leg-press SE performance after the intermittent aerobic exercise when compared with C (p > 0.05). On the other hand, the PL group showed a significant decrease in leg-press SE (p ≤ 0.05). CR supplementation significantly increased bench-press SE after both aerobic exercise modes, while the bench-press SE was not affected by either mode of aerobic exercise in the PL group. Although small increases in 1RM were observed after either continuous (bench press and leg press) or intermittent (bench press) aerobic exercise in the CR group, they were within the range of variability of the measurement. The PL group only maintained their 1RM. In conclusion, the acute interference effect on strength performance observed in concurrent exercise may be counteracted by CR supplementation.

Gender and developmental differences in exercise beliefs among youth and prediction of their exercise behavior.

Science.gov (United States)

Garcia, A W; Broda, M A; Frenn, M; Coviak, C; Pender, N J; Ronis, D L

1995-08-01

This study examined gender and developmental differences in exercise-related beliefs and exercise behaviors of 286 racially diverse youth and explored factors predictive of exercise. Compared to males, females reported less prior and current exercise, lower self-esteem, poorer health status, and lower exercise self-schema. Adolescents, in contrast to pre-adolescents, reported less social support for exercise and fewer exercise role models. In a path model, gender, the benefits/barriers differential, and access to exercise facilities and programs directly predicted exercise. Effects of grade, perceived health status, exercise self-efficacy, social support for exercise, and social norms for exercise on exercise behavior, were mediated through the benefits/barriers differential. Effect of race on exercise was mediated by access to exercise facilities and programs. Continued exploration of gender and developmental differences in variables influencing physical activity can yield valuable information for tailoring exercise promotion interventions to the unique needs of youth.

Reduced muscle activation during exercise related to brain oxygenation and metabolism in humans

DEFF Research Database (Denmark)

Rasmussen, Peter; Nielsen, Jannie; Overgaard, M

2010-01-01

Maximal exercise may be limited by central fatigue defined as an inability of the central nervous system to fully recruit the involved muscles. This study evaluated whether a reduction in the cerebral oxygen-to-carbohydrate index (OCI) and in the cerebral mitochondrial oxygen tension relate to th...... indicating that reduced cerebral oxygenation may play a role in the development of central fatigue and may be an exercise capacity limiting factor.......Maximal exercise may be limited by central fatigue defined as an inability of the central nervous system to fully recruit the involved muscles. This study evaluated whether a reduction in the cerebral oxygen-to-carbohydrate index (OCI) and in the cerebral mitochondrial oxygen tension relate...... of perceived exertion (RPE), arm maximal voluntary force (MVC), and voluntary activation of elbow flexor muscles assessed with transcranial magnetic stimulation. Low intensity exercise did not produce any indication of central fatigue or marked cerebral metabolic deviations. Exercise in hypoxia (0.10) reduced...

Oxidative stress and nitrite dynamics under maximal load in elite athletes: relation to sport type.

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Cubrilo, Dejan; Djordjevic, Dusica; Zivkovic, Vladimir; Djuric, Dragan; Blagojevic, Dusko; Spasic, Mihajlo; Jakovljevic, Vladimir

2011-09-01

Maximal workload in elite athletes induces increased generation of reactive oxygen/nitrogen species (RONS) and oxidative stress, but the dynamics of RONS production are not fully explored. The aim of our study was to examine the effects of long-term engagement in sports with different energy requirements (aerobic, anaerobic, and aerobic/anaerobic) on oxidative stress parameters during progressive exercise test. Concentrations of lactates, nitric oxide (NO) measured through stabile end product-nitrites (NO(2) (-)), superoxide anion radical (O(2) (•-)), and thiobarbituric reactive substances (TBARS) as index of lipid peroxidation were determined in rest, after maximal workload, and at 4 and 10th min of recovery in blood plasma of top level competitors in rowing, cycling, and taekwondo. Results showed that sportmen had similar concentrations of lactates and O(2) (•-) in rest. Nitrite concentrations in rest were the lowest in taekwondo fighters, while rowers had the highest levels among examined groups. The order of magnitude for TBARS level in the rest was bicycling > taekwondo > rowing. During exercise at maximal intensity, the concentration of lactate significantly elevated to similar levels in all tested sportsmen and they were persistently elevated during recovery period of 4 and 10 min. There were no significant changes in O(2) (•-), nitrite, and TBARS levels neither at the maximum intensity of exercise nor during the recovery period comparing to the rest period in examined individuals. Our results showed that long term different training strategies establish different basal nitrites and lipid peroxidation levels in sportmen. However, progressive exercise does not influence basal nitrite and oxidative stress parameters level neither at maximal load nor during the first 10 min of recovery in sportmen studied.

Plasma volume expansion does not increase maximal cardiac output or VO2 max in lowlanders acclimatized to altitude

DEFF Research Database (Denmark)

Calbet, José A L; Rådegran, Göran; Boushel, Robert Christopher

2004-01-01

liter of 6% dextran 70 (BV = 6.32 +/- 0.34 liters). PV expansion had no effect on Qmax, maximal O2 consumption (VO2), and exercise capacity. Despite maximal systemic O2 transport being reduced 19% due to hemodilution after PV expansion, whole body VO2 was maintained by greater systemic O2 extraction (P...... VO2 during exercise regardless of PV. Pulmonary ventilation, gas exchange, and acid-base balance were essentially unaffected by PV expansion. Sea......With altitude acclimatization, blood hemoglobin concentration increases while plasma volume (PV) and maximal cardiac output (Qmax) decrease. This investigation aimed to determine whether reduction of Qmax at altitude is due to low circulating blood volume (BV). Eight Danish lowlanders (3 females, 5...

Exercise responses in patients with chronically high creatine kinase levels.

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Cooper, Christopher B; Dolezal, Brett A; Neufeld, Eric V; Shieh, Perry; Jenner, John R; Riley, Marshall

2017-08-01

Elevated serum creatine kinase (CK) is often taken to reflect muscle disease, but many individuals have elevated CK without a specific diagnosis. How elevated CK reflects muscle metabolism during exercise is not known. Participants (46 men, 48 women) underwent incremental exercise testing to assess aerobic performance, cardiovascular response, and ventilatory response. Serum lactate, ammonia, and CK were measured at rest, 4 minutes into exercise, and 2 minutes into recovery. High-CK and control subjects demonstrated similar aerobic capacities and cardiovascular responses to incremental exercise. Those with CK ≥ 300 U/L exhibited significantly higher lactate and ammonia levels after maximal exercise, together with increased ventilatory responses, whereas those with CK ≥200 U/L but ≤ 300 U/L did not. We recommend measurement of lactate and ammonia profiles during a maximal incremental exercise protocol to help identify patients who warrant muscle biopsy to rule out myopathy. Muscle Nerve 56: 264-270, 2017. © 2016 Wiley Periodicals, Inc.

[Evaluation of exercise capacity in pulmonary arterial hypertension].

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Demir, Rengin; Küçükoğlu, Mehmet Serdar

2010-12-01

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by increased pulmonary vascular resistance that leads to right ventricular failure. The most common clinical features of PAH are dyspnea and exercise intolerance. Measurement of exercise capacity is of considerable importance for the assessment of disease severity as well as routine monitoring of disease. Maximal, symptom-limited, cardiopulmonary exercise test (CPET) is the gold standard for the evaluation of exercise capacity, whereby functions of several systems involved in exercise can be assessed, including cardiovascular, respiratory, and metabolic systems. However, in order to derive the most useful diagnostic information on physiologic limitations to exercise, CPET requires maximal effort of the patient, which can be difficult and risky for some severely ill patients. Moreover, it requires specific exercise equipment and measurement systems, and experienced and trained personnel. Thus, routine clinical use of CPET to assess exercise capacity in patients with PAH may not always be feasible. A practical and simple alternative to CPET to determine exercise capacity is the 6-minute walk test (6MWT). It is simple to perform, safe, and reproducible. In contrast to CPET, the 6MWT reflects a submaximal level of exertion that is more consistent with the effort required for daily physical activities. This review focuses on the role of CPET and 6MWT in patients with PAH.

Ottawa Panel evidence-based clinical practice guidelines for therapeutic exercise in the management of hip osteoarthritis.

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Brosseau, Lucie; Wells, George A; Pugh, Arlanna G; Smith, Christine Am; Rahman, Prinon; Àlvarez Gallardo, Inmaculada C; Toupin-April, Karine; Loew, Laurianne; De Angelis, Gino; Cavallo, Sabrina; Taki, Jade; Marcotte, Rachel; Fransen, Marlene; Hernandez-Molina, Gabriela; Kenny, Glen P; Regnaux, Jean-Philippe; Lefevre-Colau, Marie-Martine; Brooks, Sydney; Laferriere, Lucie; McLean, Linda; Longchamp, Guy

2016-10-01

The primary objective is to identify effective land-based therapeutic exercise interventions and provide evidence-based recommendations for managing hip osteoarthritis. A secondary objective is to develop an Ottawa Panel evidence-based clinical practice guideline for hip osteoarthritis. The search strategy and modified selection criteria from a Cochrane review were used. Studies included hip osteoarthritis patients in comparative controlled trials with therapeutic exercise interventions. An Expert Panel arrived at a Delphi survey consensus to endorse the recommendations. The Ottawa Panel hierarchical alphabetical grading system (A, B, C+, C, D, D+, or D-) considered the study design (level I: randomized controlled trial and level II: controlled clinical trial), statistical significance (p osteoarthritis. Strength training exercises displayed the greatest improvements for pain (Grade A), disability (Grades A and C+), physical function (Grade A), stiffness (Grade A), and range of motion (Grade A) within a short time period (8-24 weeks). Stretching also greatly improved physical function (Grade A), and flexibility exercises improved pain (Grade A), range of motion (Grade A), physical function (Grade A), and stiffness (Grade C+). The Ottawa Panel recommends land-based therapeutic exercise, notably strength training, for management of hip osteoarthritis in reducing pain, stiffness and self-reported disability, and improving physical function and range of motion. © The Author(s) 2015.

Graded Aerobic Treadmill Testing in Adolescent Traumatic Brain Injury Patients.

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Cordingley, Dean M; Girardin, Richard; Morissette, Marc P; Reimer, Karen; Leiter, Jeff; Russell, Kelly; Ellis, Michael J

2017-11-01

To examine the safety and tolerability of clinical graded aerobic treadmill testing in recovering adolescent moderate and severe traumatic brain injury (TBI) patients referred to a multidisciplinary pediatric concussion program. We completed a retrospective case series of two moderate and five severe TBI patients (mean age, 17.3 years) who underwent initial Buffalo Concussion Treadmill Testing at a mean time of 71.6 days (range, 55-87) postinjury. Six patients completed one graded aerobic treadmill test each and one patient underwent initial and repeat testing. There were no complications. Five initial treadmill tests were completely tolerated and allowed an accurate assessment of exercise tolerance. Two initial tests were terminated early by the treatment team because of neurological and cardiorespiratory limitations. As a result of testing, two patients were cleared for aerobic exercise as tolerated and four patients were treated with individually tailored submaximal aerobic exercise programs resulting in subjective improvement in residual symptoms and/or exercise tolerance. Repeat treadmill testing in one patient performed after 1 month of treatment with submaximal aerobic exercise prescription was suggestive of improved exercise tolerance. One patient was able to tolerate aerobic exercise following surgery for posterior glottic stenosis. Preliminary results suggest that graded aerobic treadmill testing is a safe, well tolerated, and clinically useful tool to assess exercise tolerance in appropriately selected adolescent patients with TBI. Future prospective studies are needed to evaluate the effect of tailored submaximal aerobic exercise prescription on exercise tolerance and patient outcomes in recovering adolescent moderate and severe TBI patients.

CREATINE SUPPLEMENTATION AND EXERCISE PERFORMANCE: A BRIEF REVIEW

Directory of Open Access Journals (Sweden)

Stephen P. Bird

2003-12-01

Full Text Available During the past decade, the nutritional supplement creatine monohydrate has been gaining popularity exponentially. Introduced to the general public in the early 1990s, shortly after the Barcelona Olympic Games, creatine (Cr has become one of the most widely used nutritional supplements or ergogenic aids, with loading doses as high as 20-30 g·day-1 for 5-7 days typical among athletes. This paper reviews the available research that has examined the potential ergogenic value of creatine supplementation (CrS on exercise performance and training adaptations. Short-term CrS has been reported to improve maximal power/strength, work performed during sets of maximal effort muscle contractions, single-effort sprint performance, and work performed during repetitive sprint performance. During training CrS has been reported to promote significantly greater gains in strength, fat free mass, and exercise performance primarily of high intensity tasks. However, not all studies demonstrate a beneficial effect on exercise performance, as CrS does not appear to be effective in improving running and swimming performance. CrS appears to pose no serious health risks when taken at doses described in the literature and may enhance exercise performance in individuals that require maximal single effort and/or repetitive sprint bouts

Effect of Aerobic Exercise Training on Ventilatory Efficiency and Respiratory Drive in Obese Subjects.

Science.gov (United States)

Chlif, Mehdi; Chaouachi, Anis; Ahmaidi, Said

2017-07-01

Obese patients show a decline in exercise capacity and diverse degrees of dyspnea in association with mechanical abnormalities, increased ventilatory requirements secondary to the increased metabolic load, and a greater work of breathing. Consequently, obese patients may be particularly predisposed to the development of respiratory muscle fatigue during exercise. The aim of this study was to assess inspiratory muscle performance during incremental exercise in 19 obese male subjects (body mass index 41 ± 6 kg/m 2 ) after aerobic exercise training using the noninvasive, inspiratory muscle tension-time index (T T0.1 ). Measurements performed included anthropometric parameters, lung function assessed by spirometry, rate of perceived breathlessness with the modified Borg dyspnea scale (0-10), breathing pattern, maximal exercise capacity, and inspiratory muscle performance with a breath-by-breath automated exercise metabolic system during an incremental exercise test. T T0.1 was calculated using the equation, T T0.1 = P 0.1 /P Imax × T I /T tot (where P 0.1 represents mouth occlusion pressure, P Imax is maximal inspiratory pressure, and T I /T tot is the duty cycle). At rest, there was no statistically significant difference for spirometric parameters and cardiorespiratory parameters between pre- and post-training. At maximal exercise, the minute ventilation, the rate of exchange ratio, the rate of perceived breathlessness, and the respiratory muscle performance parameters were not significantly different pre- and post-training; in contrast, tidal volume ( P = .037, effect size = 1.51), breathing frequency ( P = .049, effect size = 0.97), power output ( P = .048, effect size = 0.79), peak oxygen uptake ( P = .02, effect size = 0.92) were significantly higher after training. At comparable work load, training induces lower minute ventilation, mouth occlusion pressure, ratio of occlusion pressure to maximal inspiratory pressure, T T0.1 , and rate of perceived

Maximal strength and cortisol responses to psyching-up during the squat exercise.

Science.gov (United States)

McGuigan, Michael R; Ghiagiarelli, Jamie; Tod, David

2005-07-01

We studied the effect of psyching-up on one-repetition maximum (1-RM) performance and salivary cortisol responses during the squat exercise. Ten men (age 21.6+/-1.4 years; mean+/-s) and ten women (age 22.4+/-2.8 years) with weight training experience of 4.5+/-2.0 years participated in this study. One-repetition maximum squats were performed on a Smith machine during each of two different intervention conditions that were counterbalanced and consisted of a free choice psych-up and a cognitive distraction. Saliva samples were obtained at the beginning of each test session and immediately after the final 1-RM attempt. No significant difference in 1-RM was identified between psyching-up (104+/-50 kg) and cognitive distraction (106+/-52 kg). Performing a 1-RM in the squat exercise significantly increased salivary cortisol concentrations during both conditions (Psquat exercise in strength-trained individuals.

Exercise training improves ambulatory blood pressure but not arterial stiffness in heart transplant recipients.

Science.gov (United States)

Pascoalino, Lucas Nóbilo; Ciolac, Emmanuel Gomes; Tavares, Aline Cristina; Castro, Rafael Ertner; Ayub-Ferreira, Silvia Moreira; Bacal, Fernando; Issa, Victor Sarli; Bocchi, Edimar Alcides; Guimarães, Guilherme Veiga

2015-05-01

Hypertension is the most prevalent comorbidity after heart transplantation (HT). Exercise training (ET) is widely recommended as a key non-pharmacologic intervention for the prevention and management of hypertension, but its effects on ambulatory blood pressure (ABP) and some mechanisms involved in the pathophysiology of hypertension have not been studied in this population. The primary purpose of this study was to investigate the effects of ET on ABP and arterial stiffness of HT recipients. 40 HT patients, randomized to ET (n = 31) or a control group (n = 9) underwent a maximal graded exercise test, 24-hour ABP monitoring, and carotid-femoral pulse wave velocity (PWV) assessment before the intervention and at a 12-week follow-up assessment. The ET program was performed thrice-weekly and consisted primarily of endurance exercise (40 minutes) at ~70% of maximum oxygen uptake (Vo2MAX). The ET group had reduced 24-hour (4.0 ± 1.4 mm Hg, p endurance ET may be a tool to counteract hypertension in this high-risk population. Copyright © 2015 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Exercise starts and ends in the brain.

Science.gov (United States)

Kayser, Bengt

2003-10-01

Classically the limit to endurance of exercise is explained in terms of metabolic capacity. Cardio-respiratory capacity and muscle fatigue are thought to set the limit and the majority of studies on factors limiting endurance exercise discuss issues such as maximal oxygen uptake (VO2max), aerobic enzyme capacity, cardiac output, glycogen stores, etc. However, this paradigm does not explain the limitation to endurance exercise with large muscle groups at altitude, when at exhaustion exercise is ended without limb locomotor muscle fatigue and with sub-maximal cardiac output. A simple fact provides a basis for an explanation. Voluntary exercise starts and ends in the brain. It starts with spatial and temporal recruitment of motor units and ends with their de-recruitment. A conscious decision precedes a voluntary effort. The end of effort is again volitional and a forced conscious decision to stop precedes it, but it is unknown what forces the off-switch of recruitment at exhaustion although sensation of exertion certainly plays a role. An alternative model explaining the limitation of exercise endurance thus proposes that the central nervous system integrates input from various sources all related to the exercise and limits the intensity and duration of recruitment of limb skeletal muscle to prevent jeopardizing the integrity of the organism. This model acknowledges the cardio-respiratory and muscle metabolic capacities as prime actors on the performance scene, while crediting the central nervous system for its pivotal role as the ultimate site where exercise starts and ends.

Exercise-induced maximum metabolic rate scaled to body mass by ...

African Journals Online (AJOL)

Exercise-induced maximum metabolic rate scaled to body mass by the fractal ... rate scaling is that exercise-induced maximum aerobic metabolic rate (MMR) is ... muscle stress limitation, and maximized oxygen delivery and metabolic rates.

Non-Exercise Estimation of VO[subscript 2]max Using the International Physical Activity Questionnaire

Science.gov (United States)

Schembre, Susan M.; Riebe, Deborah A.

2011-01-01

Non-exercise equations developed from self-reported physical activity can estimate maximal oxygen uptake (VO[subscript 2]max) as well as sub-maximal exercise testing. The International Physical Activity Questionnaire is the most widely used and validated self-report measure of physical activity. This study aimed to develop and test a VO[subscript…

The effects of a pilates-aerobic program on maximum exercise capacity of adult women

Directory of Open Access Journals (Sweden)

Milena Mikalački

Full Text Available ABSTRACT Introduction: Physical exercise such as the Pilates method offers clinical benefits on the aging process. Likewise, physiologic parameters may be improved through aerobic exercise. Methods: In order to compare the differences of a Pilates-Aerobic intervention program on physiologic parameters such as the maximum heart rate (HRmax, relative maximal oxygen consumption (relative VO2max and absolute (absolute VOmax, maximum heart rate during maximal oxygen consumption (VO2max-HRmax, maximum minute volume (VE and forced vital capacity (FVC, a total of 64 adult women (active group = 48.1 ± 6.7 years; control group = 47.2 ± 7.4 years participated in the study. The physiological parameters, the maximal speed and total duration of test were measured by maximum exercise capacity testing through Bruce protocol. The HRmax was calculated by a cardio-ergometric software. Pulmonary function tests, maximal speed and total time during the physical test were performed in a treadmill (Medisoft, model 870c. Likewise, the spirometry analyzed the impact on oxygen uptake parameters, including FVC and VE. Results: The VO2max (relative and absolute, VE (all, P<0.001, VO2max-HRmax (P<0.05 and maximal speed of treadmill test (P<0.001 showed significant difference in the active group after a physical exercise interventional program. Conclusion: The present study indicates that the Pilates exercises through a continuous training program might significantly improve the cardiovascular system. Hence, mixing strength and aerobic exercises into a training program is considered the optimal mechanism for healthy aging.

Principles of exercise physiology: responses to acute exercise and long-term adaptations to training.

Science.gov (United States)

Rivera-Brown, Anita M; Frontera, Walter R

2012-11-01

Physical activity and fitness are associated with a lower prevalence of chronic diseases, such as heart disease, cancer, high blood pressure, and diabetes. This review discusses the body's response to an acute bout of exercise and long-term physiological adaptations to exercise training with an emphasis on endurance exercise. An overview is provided of skeletal muscle actions, muscle fiber types, and the major metabolic pathways involved in energy production. The importance of adequate fluid intake during exercise sessions to prevent impairments induced by dehydration on endurance exercise, muscular power, and strength is discussed. Physiological adaptations that result from regular exercise training such as increases in cardiorespiratory capacity and strength are mentioned. The review emphasizes the cardiovascular and metabolic adaptations that lead to improvements in maximal oxygen capacity. Copyright © 2012 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Martingales and Markov chains solved exercises and elements of theory

CERN Document Server

Baldi, Paolo; Priouret, Pierre

2002-01-01

CONDITIONAL EXPECTATIONSIntroductionDefinition and First PropertiesConditional Expectations and Conditional LawsExercisesSolutionsSTOCHASTIC PROCESSESGeneral FactsStopping TimesExercisesSolutionsMARTINGALESFirst DefinitionsFirst PropertiesThe Stopping TheoremMaximal InequalitiesSquare Integral MartingalesConvergence TheoremsRegular MartingalesExercisesProblemsSolutionsMARKOV CHAINSTransition Matrices, Markov ChainsConstruction and ExistenceComputations on the Canonical ChainPotential OperatorsPassage ProblemsRecurrence, TransienceRecurrent Irreducible ChainsPeriodicityExercisesProblemsSolution

Effects of dynamic hyperinflation on exercise capacity and quality of life in stable COPD patients.

Science.gov (United States)

Zhao, Li; Peng, Liyue; Wu, Baomei; Bu, Xiaoning; Wang, Chen

2016-09-01

Dynamic hyperinflation (DH) is an important pathophysiological characteristic of chronic obstructive pulmonary disease (COPD). There is increasing evidence that DH has negative effects on exercise performance and quality of life. The objective of this study was to explore effects of DH on exercise capacity and quality of life in stable COPD patients. Fifty-eight COPD patients and 20 matched healthy individuals underwent pulmonary function test, 6-min walk test and symptom-limited cardiopulmonary exercise test (CPET). End-expiratory lung volume/total lung capacity ratio (EELVmax/TLC) at peak exercise of CPET was evaluated, and EELVmax/TLC ≥ 75% was defined as 'severe dynamic hyperinflation (SDH)'. Of the 58 patients studied, 29 (50.0%) presented with SDH (SDH+ group, EELVmax/TLC 79.60 ± 3.60%), having worse maximal exercise capacity reflected by lower peakload, maximal oxygen uptake (VO2 max), maximal carbon dioxide output (VCO2 max) and maximal minute ventilation (VEmax) than did those without SDH (SDH- group, EELVmax/TLC 67.44 ± 6.53%). The EELVmax/TLC ratio at peak exercise had no association with variables of pulmonary function and 6-min walk distance (6MWD), but correlated inversely with peakload, VO2 max, VCO2 max and VEmax (r = -0.300~-0.351, P < 0.05). Although no significant differences were observed, patients with EELVmax/TLC ≥ 75% tended to have higher COPD assessment test score (15.07 ± 6.55 vs 13.28 ± 6.59, P = 0.303). DH develops variably during exercise and has a greater impact on maximal exercise capacity than 6MWD, even in those with the same extent of pulmonary function impairment at rest. © 2015 John Wiley & Sons Ltd.

The influence of sodium bicarbonate on maximal force and rates of force development in the triceps surae and brachii during fatiguing exercise.

Science.gov (United States)

Siegler, Jason C; Mudie, Kurt; Marshall, Paul

2016-11-01

What is the central question of this study? Does metabolic alkalosis in humans, induced by sodium bicarbonate, affect rates of skeletal muscle fatigue differentially in muscle groups composed predominately of slow- and fast-twitch fibres? What is the main finding and its importance? Sodium bicarbonate exhibited no effect on the fatigue profile observed between triceps surae and brachii muscle groups during and after 2 min of tetanic stimulation. For the first time in exercising humans, we have profiled the effect of sodium bicarbonate on the voluntary and involuntary contractile characteristics of muscle groups representative of predominately slow- and fast-twitch fibres. The effect of metabolic alkalosis on fibre-specific maximal force production and rates of force development (RFD) has been investigated previously in animal models, with evidence suggesting an improved capacity to develop force rapidly in fast- compared with slow-twitch muscle. We have attempted to model in vivo the fatigue profile of voluntary and involuntary maximal force and RFD in the triceps surae and brachii after sodium bicarbonate (NaHCO 3 ) ingestion. In a double-blind, three-way repeated-measures design, participants (n = 10) ingested either 0.3 g kg -1 NaHCO 3 (ALK) or equivalent calcium carbonate (PLA) prior to 2 min of continuous (1 Hz) supramaximal stimulation (300 ms at 40 Hz) of the triceps surae or brachii, with maximal voluntary efforts (maximal voluntary torque) coupled with direct muscle stimulation also measured at baseline, 1 and 2 min. Metabolic alkalosis was achieved in both ALK trials but was not different between muscle groups. Regardless of the conditions, involuntary torque declined nearly 60% in the triceps brachii (P < 0.001) and ∼30% in the triceps surae (P < 0.001). In all trials, there was a significant decline in normalized involuntary RFD (P < 0.05). Maximal voluntary torque declined nearly 28% but was not different between conditions (P < 0

Making the Grade with Diet and Exercise

Science.gov (United States)

Sibley, Benjamin A.; Ward, Rose Marie; Yazvac, Thomas S.; Zullig, Keith; Potteiger, Jeffrey A.

2008-01-01

Educators are facing increased pressure to improve the academic performance of students. This increased emphasis on student accountability has led many school leaders to implement changes in the school day in order to maximize the time that students spend in academic pursuits. Frequently, this has resulted in the cutting or reducing of time spent…

Predictive Accuracy of Exercise Stress Testing the Healthy Adult.

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Lamont, Linda S.

1981-01-01

Exercise stress testing provides information on the aerobic capacity, heart rate, and blood pressure responses to graded exercises of a healthy adult. The reliability of exercise tests as a diagnostic procedure is discussed in relation to sensitivity and specificity and predictive accuracy. (JN)

Influence of the incremental step size in work rate on exercise response and gas exchange in patients with pulmonary hypertension.

Science.gov (United States)

Gläser, Sven; Lodziewski, Sven; Koch, Beate; Opitz, Christian F; Völzke, Henry; Ewert, Ralf

2008-02-23

Cardiopulmonary exercise testing (CPET) has become increasingly important as a routine procedure in daily clinical work. So far, it is generally accepted that an individualized exercise protocol with exercise duration of 6 to 12 minutes is preferable to assess maximal exercise performance. The aim of this study was to compare an individualized NYHA adapted exercise protocol with a fixed standard protocol in patients with severe pulmonary arterial hypertension. Twenty-two patients (17 female, 5 male; mean age 49 +/- 14 yrs) underwent symptom limited CPET on a bicycle. On two consecutive days each subject performed a stepwise CPET according to a modified Jones protocol (16 Watt per minute stages) as well as an individualized NYHA adapted protocol with 5 or 10 Watt/min stages in a randomized order. Oxygen uptake at peak exercise (peakVO2) and anaerobic threshold (VO2AT), maximal ventilation (VE), breathing reserve (VE/MVV), ventilatory efficiency (VE vs. VCO2 slope), exercise time, maximal power and work rate were assessed and compared between both protocols. Comparing both, adapted NYHA protocol and standardized Jones protocol, we found significant differences in maximal power (56.7 +/- 19 W vs. 74 +/- 18 W; p rate, VE, VE/MVV, peakVO2, VO2AT and VE vs. VCO2 slope. Variations of incremental step size during CPET significantly affect exercise time and maximal power, whereas relevant parameters for clinical judgement and prognosis such as oxygen uptake, ventilation and ventilatory efficiency remain unchanged. These findings have practical implications for the exercise evaluation of patients with pulmonary hypertension. To reach maximal results for ventilation, oxygen uptake and gas exchange an individualization of incremental step size appears not to be mandatory.

High-intensity interval training evokes larger serum BDNF levels compared with intense continuous exercise.

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Saucedo Marquez, Cinthia Maria; Vanaudenaerde, Bart; Troosters, Thierry; Wenderoth, Nicole

2015-12-15

Exercise can have a positive effect on the brain by activating brain-derived neurotrophic factor (BDNF)-related processes. In healthy humans there appears to be a linear relationship between exercise intensity and the positive short-term effect of acute exercise on BDNF levels (i.e., the highest BDNF levels are reported after high-intensity exercise protocols). Here we performed two experiments to test the effectiveness of two high-intensity exercise protocols, both known to improve cardiovascular health, to determine whether they have a similar efficacy in affecting BDNF levels. Participants performed a continuous exercise (CON) protocol at 70% of maximal work rate and a high-intensity interval-training (HIT) protocol at 90% of maximal work rate for periods of 1 min alternating with 1 min of rest (both protocols lasted 20 min). We observed similar BDNF kinetics in both protocols, with maximal BDNF concentrations being reached toward the end of training (experiment 1). We then showed that both exercise protocols significantly increase BDNF levels compared with a rest condition (CON P = 0.04; HIT P exercise are slightly more effective than continuous high-intensity exercise for elevating serum BDNF. Additionally, 73% of the participants preferred the HIT protocol (P = 0.02). Therefore, we suggest that the HIT protocol might represent an effective and preferred intervention for elevating BDNF levels and potentially promoting brain health. Copyright © 2015 the American Physiological Society.

EFFECT OF ENERGY EXPENDITURE AND TRAINING STATUS ON LEPTIN RESPONSE TO SUB-MAXIMAL CYCLING

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Anissa Bouassida

2009-06-01

Full Text Available We examined the leptin response and related hormones during and after two sub-maximal exercise protocols in trained and untrained subjects. During this study, plasma concentrations of leptin [Lep], insulin [I], cortisol [C], growth hormone [GH], glucose [G] and lactate [La] were measured. 7 elite volleyball trained players (TR and 7 untrained (UTR subjects (percent body fat: 13.2 ± 1.8 versus 15.7 ± 1.0, p < 0.01, respectively were examined after short and prolonged sub-maximal cycling exercise protocols (SP and PP. Venous blood samples were collected before each protocol, during, at the end, and after 2 and 24 h of recovery. SP and PP energy expenditures ranged from 470 ± 60 to 740 ± 90 kcal for TR and from 450 ± 60 to 710 ± 90 kcal for UTR, respectively. [Lep] was related to body fat percentage and body fat mass in TR (r = 0. 84, p < 0.05 and r = 0.93, p < 0.01 and in UTR (r = 0.89, p < 0.01 and r = 0.92, p < 0. 01, respectively. [Lep] did not change significantly during both protocols for both groups but was lower (p < 0.05 in all sampling in TR when compared to UTR. Plasma [I] decreased (p < 0.01 and [GH] increased (p < 0.01 significantly during both SP and PP and these hormones remained lower (I: p < 0.01 and higher (GH: p < 0.01 than pre-exercise levels after a 2-h recovery period, returning to base-line at 24-h recovery. Plasma [La] increased (p < 0.01 during both protocols for TR and UTR. There was no significant change in [C] and [G] during and after both protocols for all subjects. It is concluded that 1 leptin is not sensitive to acute short or prolonged sub-maximal exercises (with energy expenditure under 800 kcal in volleyball/ anaerobically trained athletes as in untrained subjects, 2 volleyball athletes showed significantly lower resting and exercise leptin response with respect to untrained subjects and 3 it appears that in these anaerobically trained athletes leptin response to exercise is more sensitive to the level of

Physical Activity Targeted at Maximal Lipid Oxidation: A Meta-Analysis

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A. J. Romain

2012-01-01

Full Text Available Exercise is recognized as a part of the management of obesity and diabetes. Various protocols of exercise are proposed for the management of obesity, diabetes, and other metabolic diseases. One of the strategies proposed by several authors is low intensity endurance training targeted at the level of maximal oxidation. Large series using this technique are lacking. Addressing this issue, we performed a meta-analysis of the studies on anthropometric measurements. From a database of 433 articles, 15 were selected, including 279 subjects with 6 different populations. Studies duration ranged from 2 months to 12 months. Concerning weight loss, in the intervention versus control analysis, five studies with 185 participants were included with a significant effect size favors exercise (P=0.02 without significant heterogeneity (I2=0.0%, P=0.83. Further randomized controlled trials for comparing it with other exercise protocols and defining its dose effectiveness on large samples are needed.

The influence of recovery posture on post-exercise hypotension in normotensive men.

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Raine, N M; Cable, N T; George, K P; Campbell, I G

2001-03-01

Postexercise hypotension may be the result of an impaired vasoconstrictor response. This hypothesis was investigated by examining the central and peripheral hemodynamic responses during supine and seated recovery after maximal upright exercise. After supine or seated baseline measurements, seven normotensive male volunteers completed a graded upright cycling protocol to volitional exhaustion. This was immediately followed by either supine or seated recovery. Measurements of pulsatile arterial blood pressure and central and peripheral hemodynamic variables recorded 30 min before exercise were compared with those taken throughout 60 min of recovery. Compared with baseline, mean arterial pressure (MAP) was reduced after exercise (P different between the supine (-9 +/- 4 mm Hg) and seated positions (-6 +/- 2 mm Hg). This change in MAP was associated with a reduction in diastolic blood pressure (DBP) (P pressure (APP) (P positions, respectively. The reduction in APP during seated recovery was accompanied by a decline in stroke volume (SV) (P position, that limited the contribution of cardiac output (CO) to the maintenance of MAP. This effect of seated recovery was compensated by greater systemic (SVR) and regional vascular resistances in the forearm (FVR) and the forearm skin (SkVRA). There was also evidence of an augmented return of FVR and SkVRA to resting levels in the seated position after exercise. The lower peripheral resistance in the supine compared with seated recovery position suggests there is potential for greater vasoconstriction, although this is not evoked to increase blood pressure. This further suggests that the arterial baroreceptor reflex is reset to a lower operating pressure after exercise.

The Paroxetine Effect on Exercise Performance Depends on the Aerobic Capacity of Exercising Individuals

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Francisco Teixeira-Coelho, João Paulo Uendeles-Pinto, Ana Cláudia Alves Serafim, Samuel Penna Wanner, Márcio de Matos Coelho, Danusa Dias Soares

2014-06-01

Full Text Available This study investigated the influence of aerobic capacity on the activation of the central serotonergic system and exercise fatigue in young men that ingested a selective serotonin reuptake inhibitor and were then subjected to moderate-intensity physical exercise. The maximal oxygen consumption of sixteen volunteers was measured during an incremental test. The volunteers were divided into two groups: subjects with higher (HAC and lower (LAC aerobic capacities. The volunteers were subjected to four experimental trials in which they ingested either placebo or paroxetine (10, 20 or 40 mg and, 4.5 h later, cycled at 60% of their maximal power output until reaching fatigue. None of the three paroxetine doses influenced the total exercise time in the LAC group. However, for the HAC group, the time to fatigue in the 20 mg paroxetine condition was 15% less than that in the placebo condition (76.3 ± 5.1 min vs. 90.0 ± 7.9 min; p < 0.05. The time to fatigue was higher in the HAC group than in the LAC group for all treatments. Our results provide additional evidence that aerobic capacity modulates the activity of the serotonergic system. However, contrary to what would be expected considering previous reports, the activation of the serotonergic system in exercising subjects in the HAC group was not less than that in the LAC group.

Left ventricular atrioventricular plane displacement is preserved with lifelong endurance training and is the main determinant of maximal cardiac output

DEFF Research Database (Denmark)

Steding-Ehrenborg, Katarina; Boushel, Robert C; Calbet, José A

2015-01-01

subjects (29 ± 4 years) underwent cardiac MR. All subjects underwent maximal exercise testing and for elderly subjects maximal cardiac output during cycling was determined using dye dilution technique. RESULTS: Longitudinal and radial contribution to stroke volume did not differ between groups......BACKGROUND: Age-related decline in cardiac function can be prevented or postponed by lifelong endurance training. However, effects of normal ageing as well as of lifelong endurance exercise on longitudinal and radial contribution to stroke volume are unknown. The aim of this study was to determine...... groups for RVAVPD (P = 0.2). LVAVPD was an independent predictor of maximal cardiac output (R(2 = ) 0.61, P groups. However, how longitudinal pumping...

Exercise Capacity and the Obesity Paradox in Heart Failure: The FIT (Henry Ford Exercise Testing) Project.

Science.gov (United States)

McAuley, Paul A; Keteyian, Steven J; Brawner, Clinton A; Dardari, Zeina A; Al Rifai, Mahmoud; Ehrman, Jonathan K; Al-Mallah, Mouaz H; Whelton, Seamus P; Blaha, Michael J

2018-05-03

To assess the influence of exercise capacity and body mass index (BMI) on 10-year mortality in patients with heart failure (HF) and to synthesize these results with those of previous studies. This large biracial sample included 774 men and women (mean age, 60±13 years; 372 [48%] black) with a baseline diagnosis of HF from the Henry Ford Exercise Testing (FIT) Project. All patients completed a symptom-limited maximal treadmill stress test from January 1, 1991, through May 31, 2009. Patients were grouped by World Health Organization BMI categories for Kaplan-Meier survival analyses and stratified by exercise capacity (<4 and ≥4 metabolic equivalents [METs] of task). Associations of BMI and exercise capacity with all-cause mortality were assessed using multivariable-adjusted Cox proportional hazards models. During a mean follow-up of 10.1±4.6 years, 380 patients (49%) died. Kaplan-Meier survival plots revealed a significant positive association between BMI category and survival for exercise capacity less than 4 METs (log-rank, P=.05), but not greater than or equal to 4 METs (P=.76). In the multivariable-adjusted models, exercise capacity (per 1 MET) was inversely associated, but BMI was not associated, with all-cause mortality (hazard ratio, 0.89; 95% CI, 0.85-0.94; P<.001 and hazard ratio, 0.99; 95% CI, 0.97-1.01; P=.16, respectively). Maximal exercise capacity modified the relationship between BMI and long-term survival in patients with HF, upholding the presence of an exercise capacity-obesity paradox dichotomy as observed over the short-term in previous studies. Copyright © 2018 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Increased muscle glucose uptake after exercise

DEFF Research Database (Denmark)

Richter, Erik; Ploug, Thorkil; Galbo, Henrik

1985-01-01

responsiveness of glucose uptake was noted only in controls. Analysis of intracellular glucose-6-phosphate, glucose, glycogen synthesis, and glucose transport suggested that the exercise effect on responsiveness might be due to enhancement of glucose disposal. After electrical stimulation of diabetic...... of glucose. At maximal insulin concentrations, the enhancing effect of exercise on glucose uptake may involve enhancement of glucose disposal, an effect that is probably less in muscle from diabetic rats.(ABSTRACT TRUNCATED AT 250 WORDS)......It has recently been shown that insulin sensitivity of skeletal muscle glucose uptake and glycogen synthesis is increased after a single exercise session. The present study was designed to determine whether insulin is necessary during exercise for development of these changes found after exercise...

Changes in voluntary activation assessed by transcranial magnetic stimulation during prolonged cycling exercise.

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Marc Jubeau

Full Text Available Maximal central motor drive is known to decrease during prolonged exercise although it remains to be determined whether a supraspinal deficit exists, and if so, when it appears. The purpose of this study was to evaluate corticospinal excitability and muscle voluntary activation before, during and after a 4-h cycling exercise. Ten healthy subjects performed three 80-min bouts on an ergocycle at 45% of their maximal aerobic power. Before exercise and immediately after each bout, neuromuscular function was evaluated in the quadriceps femoris muscles under isometric conditions. Transcranial magnetic stimulation was used to assess voluntary activation at the cortical level (VATMS, corticospinal excitability via motor-evoked potential (MEP and intracortical inhibition by cortical silent period (CSP. Electrical stimulation of the femoral nerve was used to measure voluntary activation at the peripheral level (VAFNES and muscle contractile properties. Maximal voluntary force was significantly reduced after the first bout (13 ± 9%, P<0.01 and was further decreased (25 ± 11%, P<0.001 at the end of exercise. CSP remained unchanged throughout the protocol. Rectus femoris and vastus lateralis but not vastus medialis MEP normalized to maximal M-wave amplitude significantly increased during cycling. Finally, significant decreases in both VATMS and VAFNES (∼ 8%, P<0.05 and ∼ 14%, P<0.001 post-exercise, respectively were observed. In conclusion, reductions in VAFNES after a prolonged cycling exercise are partly explained by a deficit at the cortical level accompanied by increased corticospinal excitability and unchanged intracortical inhibition. When comparing the present results with the literature, this study highlights that changes at the cortical and/or motoneuronal levels depend not only on the type of exercise (single-joint vs. whole-body but also on exercise intensity and/or duration.

Guided graded exercise self-help plus specialist medical care versus specialist medical care alone for chronic fatigue syndrome (GETSET): a pragmatic randomised controlled trial.

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Clark, Lucy V; Pesola, Francesca; Thomas, Janice M; Vergara-Williamson, Mario; Beynon, Michelle; White, Peter D

2017-07-22

Graded exercise therapy is an effective and safe treatment for chronic fatigue syndrome, but it is therapist intensive and availability is limited. We aimed to test the efficacy and safety of graded exercise delivered as guided self-help. In this pragmatic randomised controlled trial, we recruited adult patients (18 years and older) who met the UK National Institute for Health and Care Excellence criteria for chronic fatigue syndrome from two secondary-care clinics in the UK. Patients were randomly assigned to receive specialist medical care (SMC) alone (control group) or SMC with additional guided graded exercise self-help (GES). Block randomisation (randomly varying block sizes) was done at the level of the individual with a computer-generated sequence and was stratified by centre, depression score, and severity of physical disability. Patients and physiotherapists were necessarily unmasked from intervention assignment; the statistician was masked from intervention assignment. SMC was delivered by specialist doctors but was not standardised; GES consisted of a self-help booklet describing a six-step graded exercise programme that would take roughly 12 weeks to complete, and up to four guidance sessions with a physiotherapist over 8 weeks (maximum 90 min in total). Primary outcomes were fatigue (measured by the Chalder Fatigue Questionnaire) and physical function (assessed by the Short Form-36 physical function subscale); both were self-rated by patients at 12 weeks after randomisation and analysed in all randomised patients with outcome data at follow-up (ie, by modified intention to treat). We recorded adverse events, including serious adverse reactions to trial interventions. We used multiple linear regression analysis to compare SMC with GES, adjusting for baseline and stratification factors. This trial is registered at ISRCTN, number ISRCTN22975026. Between May 15, 2012, and Dec 24, 2014, we recruited 211 eligible patients, of whom 107 were assigned to the

The Measurement of Maximal (Anaerobic Power Output on a Cycle Ergometer: A Critical Review

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Tarak Driss

2013-01-01

Full Text Available The interests and limits of the different methods and protocols of maximal (anaerobic power ( assessment are reviewed: single all-out tests versus force-velocity tests, isokinetic ergometers versus friction-loaded ergometers, measure of during the acceleration phase or at peak velocity. The effects of training, athletic practice, diet and pharmacological substances upon the production of maximal mechanical power are not discussed in this review mainly focused on the technical (ergometer, crank length, toe clips, methodological (protocols and biological factors (muscle volume, muscle fiber type, age, gender, growth, temperature, chronobiology and fatigue limiting in cycling. Although the validity of the Wingate test is questionable, a large part of the review is dedicated to this test which is currently the all-out cycling test the most often used. The biomechanical characteristics specific of maximal and high speed cycling, the bioenergetics of the all-out cycling exercises and the influence of biochemical factors (acidosis and alkalosis, phosphate ions… are recalled at the beginning of the paper. The basic knowledge concerning the consequences of the force-velocity relationship upon power output, the biomechanics of sub-maximal cycling exercises and the study on the force-velocity relationship in cycling by Dickinson in 1928 are presented in Appendices.

Long-term exercising video-endoscopic examination of the upper airway following laryngoplasty surgery: a prospective cross-sectional study of 41 horses.

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Barnett, T P; O'Leary, J M; Parkin, T D H; Dixon, P M; Barakzai, S Z

2013-09-01

To investigate upper respiratory tract function in horses, previously undergoing laryngoplasty (LP), using exercising video-endoscopy. To evaluate arytenoid abduction and stability, diagnose any concurrent upper airway problems, and correlate these with the owners' perception of success. Horses undergoing LP during a 6-year period at one hospital were initially included. Those available for re-examination were exercised for a duration and intensity considered maximal for their discipline using an over-ground endoscope. Resting and exercising laryngeal and pharyngeal videos were analysed blindly. Multivariable analysis was used to test associations between resting and exercising endoscopic variables, and also between endoscopic variables and owner questionnaire findings. Forty-one horses were included and 78% had a form of upper airway collapse at exercise, with 41% having complex forms, despite 93% of owners reporting the surgery to have been beneficial. Horses with poor abduction (grades 4 or 5/5) were 6 times more likely to make respiratory noise compared with those with good (grades 2 or 3/5) abduction (P = 0.020; 95% confidence interval [CI] 1.3-27.0), and those not having a ventriculectomy were 4.9 times more likely to produce respiratory noise post operatively (P = 0.048; 95% CI 1.0-23.9). Palatal dysfunction was observed in 24% of horses at rest, and 56% at exercise, with the diagnosis at rest and exercise significantly associated (P = 0.001). Increasing severity of pharyngeal lymphoid hyperplasia (prevalence 61%) was significantly associated with increasing arytenoid abduction (P = 0.01). Thirty-four per cent of horses had aryepiglottic fold collapse and 22% of horses had vocal fold collapse. Many horses that had previously had LP were diagnosed with upper airway abnormalities, despite the procedure being considered as beneficial by most owners. When investigating cases of ongoing respiratory noise or poor performance following LP, exercising endoscopy must

Exercise and lifestyle predictors of resting heart rate in healthy young adults

OpenAIRE

Nealen, Paul M.

2016-01-01

Physical exercise is well-understood to provide significant health benefits, through physiological adaptations induced by the repeated exertion stress exercise imposes on our systems. Chief among these are cardiovascular adaptations to exercise, including adjustments of cardiac parameters such as stroke volume, heart rate, and maximal cardiac output. It is commonly assumed that aerobic forms of exercise provide greater cardiovascular benefits than do non-aerobic forms of exercise. To test thi...

Effect of vibration during fatiguing resistance exercise on subsequent muscle activity during maximal voluntary isometric contractions.

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McBride, Jeffrey M; Porcari, John P; Scheunke, Mark D

2004-11-01

This investigation was designed to determine if vibration during fatiguing resistance exercise would alter associated patterns of muscle activity. A cross-over design was employed with 8 subjects completing a resistance exercise bout once with a vibrating dumbbell (V) (44 Hz, 3 mm displacement) and once without vibration (NV). For both exercise bouts, 10 sets were performed with a load that induced concentric muscle failure during the 10th repetition. The appropriate load for each set was determined during a pretest. Each testing session was separated by 1 week. Electromyography (EMG) was obtained from the biceps brachii muscle at 12 different time points during a maximum voluntary contraction (MVC) at a 170 degrees elbow angle after each set of the dumbbell exercise. The time points were as follows: pre (5 minutes before the resistance exercise bout), T1-T10 (immediately following each set of resistance exercise), and post (15 minutes after the resistance exercise bout). EMG was analyzed for median power frequency (MPF) and maximum (mEMG). NV resulted in a significant decrease in MPF at T1-T4 (p recruitment of high threshold motor units during fatiguing contractions. This may indicate the usage of vibration with resistance exercise as an effective tool for strength training athletes.

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

Science.gov (United States)

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

Influence of Lumber Volume Maximization in Sawing Hardwood Sawlogs

Science.gov (United States)

Philip H. Steele; Francis G. Wagner; Lalit Kumar; Philip A. Araman

1993-01-01

The Best Opening Face (BOF) technology for volume maximization during sawing has been rapidly adopted by softwood sawmills. Application of this technology in hardwood sawmills has been limited because of their emphasis on sawing for the highest possible grade of lumber. The reason for this emphasis is that there is a relatively large difference in price between the...

Decreased muscle oxygenation and increased arterial blood flow in the non-exercising limb during leg exercise.

Science.gov (United States)

Shiroishi, Kiyoshi; Kime, Ryotaro; Osada, Takuya; Murase, Norio; Shimomura, Kousuke; Katsumura, Toshihito

2010-01-01

We evaluated arterial blood flow, muscle tissue oxygenation and muscle metabolism in the non-exercising limb during leg cycling exercise. Ten healthy male volunteers performed a graded leg cycling exercise at 0, 40, 80, 120 and 160 watts (W) for 5 min each. Tissue oxygenation index (TOI) of the non-exercising left forearm muscle was measured using a near-infrared spatially resolved spectroscopy (NIR(SRS)), and non-exercising forearm blood flow ((NONEX)FBF) in the brachial artery was also evaluated by a Doppler ultrasound system. We also determined O(2) consumption of the non-exercising forearm muscle (NONEXV(O)(2mus)) by the rate of decrease in O(2)Hb during arterial occlusion at each work rate. TOI was significantly decreased at 160 W (p exercising muscle may be reduced, even though (NONEX)FBF increases at high work rates during leg cycling exercise.

Maximization of the Thermoelectric Cooling of a Graded Peltier Device by Analytical Heat-Equation Resolution

Science.gov (United States)

Thiébaut, E.; Goupil, C.; Pesty, F.; D'Angelo, Y.; Guegan, G.; Lecoeur, P.

2017-12-01

Increasing the maximum cooling effect of a Peltier cooler can be achieved through material and device design. The use of inhomogeneous, functionally graded materials may be adopted in order to increase maximum cooling without improvement of the Z T (figure of merit); however, these systems are usually based on the assumption that the local optimization of the Z T is the suitable criterion to increase thermoelectric performance. We solve the heat equation in a graded material and perform both analytical and numerical analysis of a graded Peltier cooler. We find a local criterion that we use to assess the possible improvement of graded materials for thermoelectric cooling. A fair improvement of the cooling effect (up to 36%) is predicted for semiconductor materials, and the best graded system for cooling is described. The influence of the equation of state of the electronic gas of the material is discussed, and the difference in term of entropy production between the graded and the classical system is also described.

Recruitment of single muscle fibers during submaximal cycling exercise

NARCIS (Netherlands)

Altenburg, T.M.; Degens, H.; van Mechelen, W.; Sargeant, A.J.; de Haan, A.

2007-01-01

In literature, an inconsistency exists in the submaximal exercise intensity at which type II fibers are activated. In the present study, the recruitment of type I and II fibers was investigated from the very beginning and throughout a 45-min cycle exercise at 75% of the maximal oxygen uptake, which

Evaluation of the Virtual Physiology of Exercise Laboratory Program

Science.gov (United States)

Dobson, John L.

2009-01-01

The Virtual Physiology of Exercise Laboratory (VPEL) program was created to simulate the test design, data collection, and analysis phases of selected exercise physiology laboratories. The VPEL program consists of four modules: (1) cardiovascular, (2) maximal O[subscript 2] consumption [Vo[subscript 2max], (3) lactate and ventilatory thresholds,…

Validity of Wearable Activity Monitors during Cycling and Resistance Exercise.

Science.gov (United States)

Boudreaux, Benjamin D; Hebert, Edward P; Hollander, Daniel B; Williams, Brian M; Cormier, Corinne L; Naquin, Mildred R; Gillan, Wynn W; Gusew, Emily E; Kraemer, Robert R

2018-03-01

The use of wearable activity monitors has seen rapid growth; however, the mode and intensity of exercise could affect the validity of heart rate (HR) and caloric (energy) expenditure (EE) readings. There is a lack of data regarding the validity of wearable activity monitors during graded cycling regimen and a standard resistance exercise. The present study determined the validity of eight monitors for HR compared with an ECG and seven monitors for EE compared with a metabolic analyzer during graded cycling and resistance exercise. Fifty subjects (28 women, 22 men) completed separate trials of graded cycling and three sets of four resistance exercises at a 10-repetition-maximum load. Monitors included the following: Apple Watch Series 2, Fitbit Blaze, Fitbit Charge 2, Polar H7, Polar A360, Garmin Vivosmart HR, TomTom Touch, and Bose SoundSport Pulse (BSP) headphones. HR was recorded after each cycling intensity and after each resistance exercise set. EE was recorded after both protocols. Validity was established as having a mean absolute percent error (MAPE) value of ≤10%. The Polar H7 and BSP were valid during both exercise modes (cycling: MAPE = 6.87%, R = 0.79; resistance exercise: MAPE = 6.31%, R = 0.83). During cycling, the Apple Watch Series 2 revealed the greatest HR validity (MAPE = 4.14%, R = 0.80). The BSP revealed the greatest HR accuracy during resistance exercise (MAPE = 6.24%, R = 0.86). Across all devices, as exercise intensity increased, there was greater underestimation of HR. No device was valid for EE during cycling or resistance exercise. HR from wearable devices differed at different exercise intensities; EE estimates from wearable devices were inaccurate. Wearable devices are not medical devices, and users should be cautious when using these devices for monitoring physiological responses to exercise.

Muscle glycogen metabolism changes in rats fed early postnatal a fructose-rich diet after maternal protein malnutrition: effects of acute physical exercise at the maximal lactate steady-state intensity

OpenAIRE

Cambri, Lucieli Teresa [UNESP; Ribeiro, Carla [UNESP; Botezelli, Jose Diego [UNESP; Ghezzi, Ana Carolina [UNESP; Mello, Maria Alice Rostom de [UNESP

2014-01-01

Background: The objective was to evaluate the muscle glucose metabolism in rats fed a fructose-rich diet after fetal protein malnutrition, at rest and after acute physical exercise at maximal lactate steady-state intensity.Methods: The male offspring born of mothers fed on a balanced or low-protein diet were split in four groups until 60 days: Balanced (B): balanced diet during the whole period; Balanced/Fructose (BF): balanced diet in utero and fructose-rich diet after birth; Low protein/Bal...

Measurement properties of maximal cardiopulmonary exercise tests protocols in persons after stroke: A systematic review.

Science.gov (United States)

Wittink, Harriet; Verschuren, Olaf; Terwee, Caroline; de Groot, Janke; Kwakkel, Gert; van de Port, Ingrid

2017-11-21

To systematically review and critically appraise the literature on measurement properties of cardiopulmonary exercise test protocols for measuring aerobic capacity, VO2max, in persons after stroke. PubMed, Embase and Cinahl were searched from inception up to 15 June 2016. A total of 9 studies were identified reporting on 9 different cardiopulmonary exercise test protocols. VO2max measured with cardiopulmonary exercise test and open spirometry was the construct of interest. The target population was adult persons after stroke. We included all studies that evaluated reliability, measurement error, criterion validity, content validity, hypothesis testing and/or responsiveness of cardiopulmonary exercise test protocols. Two researchers independently screened the literature, assessed methodological quality using the COnsensus-based Standards for the selection of health Measurement INstruments checklist and extracted data on measurement properties of cardiopulmonary exercise test protocols. Most studies reported on only one measurement property. Best-evidence synthesis was derived taking into account the methodological quality of the studies, the results and the consistency of the results. No judgement could be made on which protocol is "best" for measuring VO2max in persons after stroke due to lack of high-quality studies on the measurement properties of the cardiopulmonary exercise test.

Exercise performance during captopril and atenolol treatment in hypertensive patients.

OpenAIRE

Van Baak, M A; Koene, F M; Verstappen, F T; Tan, E S

1991-01-01

1. Maximal aerobic exercise capacity, submaximal endurance exercise performance, and exercise haemodynamics have been studied in sixteen patients with mild to moderate essential hypertension during treatment with captopril and atenolol. 2. Administration of atenolol (1 x 100 mg day-1) or captopril (1 x 100 mg day-1) for 6 weeks resulted in similar supine and erect systolic and diastolic blood pressures. Heart rate was significantly lower during atenolol treatment. 3. Exercise heart rate and s...

Ventilatory responses to exercise training in obese adolescents.

Science.gov (United States)

Mendelson, Monique; Michallet, Anne-Sophie; Estève, François; Perrin, Claudine; Levy, Patrick; Wuyam, Bernard; Flore, Patrice

2012-10-15

The aim of this study was to examine ventilatory responses to training in obese adolescents. We assessed body composition, pulmonary function and ventilatory responses (among which expiratory flow limitation and operational lung volumes) during progressive cycling exercise in 16 obese adolescents (OB) before and after 12 weeks of exercise training and in 16 normal-weight volunteers. As expected, obese adolescents' resting expiratory reserve volume was lower and inversely correlated with thoraco-abdominal fat mass (r = -0.74, p<0.0001). OB presented lower end expiratory (EELV) and end inspiratory lung volumes (EILV) at rest and during submaximal exercise, and modest expiratory flow limitation. After training, OB increased maximal aerobic performance (+19%) and maximal inspiratory pressure (93.7±31.4 vs. 81.9±28.2 cm H2O, +14%) despite lack of decrease in trunk fat and body weight. Furthermore, EELV and EILV were greater during submaximal exercise (+11% and +9% in EELV and EILV, respectively), expiratory flow limitation delayed but was not accompanied by increased V(T). However, submaximal exertional symptoms (dyspnea and leg discomfort) were significantly decreased (-71.3% and -70.7%, respectively). Our results suggest that exercise training can improve pulmonary function at rest (static inspiratory muscle strength) and exercise (greater operating lung volumes and delayed expiratory flow limitation) but these modifications did not entirely account for improved dyspnea and exercise performance in obese adolescents. Copyright © 2012 Elsevier B.V. All rights reserved.

The Athlete’s Brain: Cross-Sectional Evidence for Neural Efficiency during Cycling Exercise

Directory of Open Access Journals (Sweden)

Sebastian Ludyga

2016-01-01

Full Text Available The “neural efficiency” hypothesis suggests that experts are characterized by a more efficient cortical function in cognitive tests. Although this hypothesis has been extended to a variety of movement-related tasks within the last years, it is unclear whether or not neural efficiency is present in cyclists performing endurance exercise. Therefore, this study examined brain cortical activity at rest and during exercise between cyclists of higher (HIGH; n=14; 55.6 ± 2.8 mL/min/kg and lower (LOW; n=15; 46.4 ± 4.1 mL/min/kg maximal oxygen consumption (VO2MAX. Male and female participants performed a graded exercise test with spirometry to assess VO2MAX. After 3 to 5 days, EEG was recorded at rest with eyes closed and during cycling at the individual anaerobic threshold over a 30 min period. Possible differences in alpha/beta ratio as well as alpha and beta power were investigated at frontal, central, and parietal sites. The statistical analysis revealed significant differences between groups (F=12.04; p=0.002, as the alpha/beta ratio was increased in HIGH compared to LOW in both the resting state (p≤0.018 and the exercise condition (p≤0.025. The present results indicate enhanced neural efficiency in subjects with high VO2MAX, possibly due to the inhibition of task-irrelevant cognitive processes.

Effects of Supplementation with BCAA and L-glutamine on Blood Fatigue Factors and Cytokines in Juvenile Athletes Submitted to Maximal Intensity Rowing Performance.

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Koo, Ga Hee; Woo, Jinhee; Kang, Sungwhun; Shin, Ki Ok

2014-08-01

[Purpose] This study was conducted to understand the impacts of BCAA (branched-chain amino acid) and glutamine supplementation on the degree of blood fatigue factor stimulation and cytokines along with performance of exercise at the maximal intensity. [Subjects] Five male juvenile elite rowing athletes participated in this study as the subjects; they took 3 tests and received placebo supplementation (PS), BCAA supplementation (BS), and glutamine supplementation (GS). [Methods] The exercise applied in the tests was 2,000 m of rowing at the maximal intensity using an indoor rowing machine, and blood samples were collected 3 times, while resting, at the end of exercise, and after 30 min of recovery, to analyze the blood fatigue factors (lactate, phosphorous, ammonia, creatine kinase (CK)) and blood cytokines (IL (interleukin)-6, 8, 15). [Results] The results of the analysis showed that the levels of blood phosphorous in the BS and GS groups at the recovery stage were decreased significantly compared with at the end of exercise, and the level of CK appeared lower in the GS group alone at recovery stage than at the end of exercise. The level of blood IL-15 in the PS and BS groups appeared higher at the end of exercise compared with the resting stage. [Conclusion] It seemed that glutamine supplementation had a positive effect on the decrease in fatigue factor stimulation at the recovery stage after maximal intensity exercise compared with supplementation with the placebo or BCAA. Besides, pre-exercise glutamine supplementation seemed to help enhance immune function and the defensive inflammatory reaction.

Mechanism underlying the absence of ischemic changes on the exercise electrocardiogram in patients with abnormal exercise thallium-201 imaging and coronary artery disease

International Nuclear Information System (INIS)

Coplan, N.L.; Horowitz, S.F.; Hoffman, D.P.; Goldman, M.E.; Machac, J.

1985-01-01

Patients with coronary artery disease may have reversible abnormalities on a thallium myocardial perfusion study without simultaneous ischemic changes on the exercise electrocardiogram, but the mechanisms responsible for this disparity have not been fully elucidated. A group of 37 patients with angiographically demonstrated coronary artery disease and abnormal thallium perfusion imaging were divided into two groups on the basis of their exercise electrocardiographic ST segment response. Thirteen patients (Group A) had no significant electrocardiographic changes with exercise, while 24 patients (Group B) had ST changes consistent with ischemia during the test. There were no significant differences in clinical or angiographic characteristics between the two groups. Stress test results showed a similar mean duration of exercise in the two groups, but the patients in Group A achieved a significantly lower mean maximal heart rate and mean maximal double product. These results suggest that exercise thallium-electrocardiogram discordance is mediated by the level of myocardial workload achieved. An abnormal perfusion scan accompanying an exercise electrocardiogram which does not demonstrate any ischemic ST change may occur when there is sufficient increase in myocardial oxygen demand to result in differential augmentation of myocardial blood flow, but insufficient imbalance of supply and demand to result in signs of ischemia on the surface electrocardiogram

Exercise left ventricular performance in patients with chest pain, ischemic-appearing exercise electrocardiograms, and angiographically normal coronary arteries

International Nuclear Information System (INIS)

Berger, H.J.; Sands, M.J.; Davies, R.A.; Wackers, F.J.; Alexander, J.; Lachman, A.S.; Williams, B.W.; Zaret, B.L.

1981-01-01

Left ventricular performance was evaluated using first-pass radionuclide angiocardiography in 31 patients with chest pain, an ischemic-appearing exercise electrocardiogram, and angiographically normal coronary arteries at rest and during maximal upright bicycle exercise. 201 Tl imaging was done in all patients after treadmill exercise and in selected patients after ergonovine provocation. Resting left ventricular performance was normal in all patients. An abnormal ejection fraction response to exercise was detected in 12 of 31 patients. Regional dysfunction was present during exercise in four patients, all of whom also had abnormal global responses. Three of these 12 patients and two additional patients had exercise-induced 201 Tl perfusion defects. In all nine patients who underwent ergonovine testing, there was no suggestion of coronary arterial spasm. Thus, left ventricular dysfunction during exercise, in the presence of normal resting performance, was found in a substantial number of patients with chest pain, an ischemic-appearing exercise electrocardiogram, and normal coronary arteries

Influence of exercise modality on cardiac parasympathetic and sympathetic indices during post-exercise recovery.

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Michael, Scott; Jay, Ollie; Graham, Kenneth S; Davis, Glen M

2018-02-12

This study investigated indirect measures of post-exercise parasympathetic reactivation (using heart-rate-variability, HRV) and sympathetic withdrawal (using systolic-time-intervals, STI) following upper- and lower-body exercise. Randomized, counter-balanced, crossover. 13 males (age 26.4±4.7years) performed maximal arm-cranking (MAX-ARM) and leg-cycling (MAX-LEG). Subsequently, participants undertook separate 8-min bouts of submaximal HR-matched exercise of each mode (ARM and LEG). HRV (including natural-logarithm of root-mean-square-of-successive-differences, Ln-RMSSD) and STI (including pre-ejection-period, PEP) were assessed throughout 10-min seated recovery. Peak-HR was higher (p=0.001) during MAX-LEG (182±7beatsmin -1 ) compared with MAX-ARM (171±12beatsmin -1 ), while HR (preflecting sympathetic withdrawal). Exercise modality appears to influence post-exercise parasympathetic reactivation and sympathetic withdrawal in an intensity-dependent manner. These results highlight the need for test standardization and may be relevant to multi-discipline athletes and in clinical applications with varying modes of exercise testing. Copyright © 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Does body fat percentage predict post-exercise heart rate response in non-obese children and adolescents?

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Jezdimirovic, Tatjana; Stajer, Valdemar; Semeredi, Sasa; Calleja-Gonzalez, Julio; Ostojic, Sergej M

2017-05-24

A correlation between adiposity and post-exercise autonomic regulation has been established in overweight and obese children. However, little information exists about this link in non-obese youth. The main purpose of this cross-sectional study was to describe the relationship between body fat percentage (BFP) and heart rate recovery after exercise [post-exercise heart rate (PEHR)], a marker of autonomic regulation, in normal-weight children and adolescents. We evaluated the body composition of 183 children and adolescents (age 15.0±2.3 years; 132 boys and 51 girls) who performed a maximal graded exercise test on a treadmill, with the heart rate monitored during and immediately after exercise. A strong positive trend was observed in the association between BFP and PEHR (r=0.14; p=0.06). Hierarchical multiple regression revealed that our model explained 18.3% of the variance in PEHR (p=0.00), yet BFP accounted for only 0.9% of the variability in PEHR (p=0.16). The evaluation of the contribution of each independent variable revealed that only two variables made a unique statistically significant contribution to our model (pfatness seems to poorly predict PEHR in our sample of non-obese children and adolescents, while non-modifiable variables (age and gender) were demonstrated as strong predictors of heart rate recovery. The low amount of body fat reported in non-obese young participants was perhaps too small to cause disturbances in autonomic nervous system regulation.

Tri-maximal vs. bi-maximal neutrino mixing

International Nuclear Information System (INIS)

Scott, W.G

2000-01-01

It is argued that data from atmospheric and solar neutrino experiments point strongly to tri-maximal or bi-maximal lepton mixing. While ('optimised') bi-maximal mixing gives an excellent a posteriori fit to the data, tri-maximal mixing is an a priori hypothesis, which is not excluded, taking account of terrestrial matter effects

Neuromuscular fatigue during high-intensity intermittent exercise in individuals with intellectual disability.

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Borji, Rihab; Sahli, Sonia; Zarrouk, Nidhal; Zghal, Firas; Rebai, Haithem

2013-12-01

This study examined neuromuscular fatigue after high-intensity intermittent exercise in 10 men with mild intellectual disability (ID) in comparison with 10 controls. Both groups performed three maximal voluntary contractions (MVC) of knee extension with 5 min in-between. The highest level achieved was selected as reference MVC. The fatiguing exercise consists of five sets with a maximal number of flexion-extension cycles at 80% of the one maximal repetition (1RM) for the right leg at 90° with 90 s rest interval between sets. The MVC was tested again after the last set. Peak force and electromyography (EMG) signals were measured during the MVC tests. Root Mean Square (RMS) and Median Frequency (MF) were calculated. Neuromuscular efficiency (NME) was calculated as the ratio of peak force to the RMS. Before exercise, individuals with ID had a lower MVC (psport train ID individuals, they should consider this nervous system weakness. Copyright © 2013 Elsevier Ltd. All rights reserved.

Excessive exercise habits of runners as new signs of hypertension and arrhythmia.

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Kim, Young-Joo; Kim, Chul-Hyun; Park, Kyoung-Min

2016-08-15

Excessive exercise may induce arrhythmia, and this risk is higher in middle-aged people. The study aim was to compare the exercise characteristics of middle-aged runners participating in excessive endurance exercise. The subjects of this study were 552 runners (mean age; 49.0±7.4years) without structural heart disease who performed exercise at least twice per week, had consistently exercised for at least three years, and had finished at least five marathons. The arrhythmia runner group (ARG, n=14) and normal runner group (NRG, n=538) were compared with regard to hemodynamic response, cardiorespiratory fitness level, training history, number of finished races, finishing times, and exercise habits. The mean resting systolic (134.0±15.8mmHg) and diastolic (85.8±10.9mmHg) blood pressure values indicated pre-hypertension, while the mean maximal SBP (213.7±27.4mmHg) values indicated exercise-induced hypertension. The VO2max was significantly higher and the maximal DBP was significantly lower in the ARG than in the NRG (phypertension and exercise-induced hypertension, and the ARG had higher VO2max values, greater exercise intensities, and longer training histories than the NRG. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

High-intensity interval training using whole-body exercises: training recommendations and methodological overview.

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Machado, Alexandre F; Baker, Julien S; Figueira Junior, Aylton J; Bocalini, Danilo S

2017-05-04

HIIT whole body (HWB)-based exercise is a new calisthenics exercise programme approach that can be considered an effective and safe method to improve physical fitness and body composition. HWB is a method that can be applied to different populations and ages. The purpose of this study was to describe possible methodologies for performing physical training based on whole-body exercise in healthy subjects. The HWB sessions consist of a repeated stimulus based on high-intensity exercise that also include monitoring time to effort, time to recuperation and session time. The exercise intensity is related to the maximal number of movements possible in a given time; therefore, the exercise sessions can be characterized as maximal. The intensity can be recorded using ratings of perceived exertion. Weekly training frequency and exercise selection should be structured according to individual subject functional fitness. Using this simple method, there is potential for greater adherence to physical activity which can promote health benefits to all members of society. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Dynamic exercise in human pregnancy

NARCIS (Netherlands)

M.B. van Doorn (Marieke)

1991-01-01

textabstractThis thesis represents an effort to obtain a better understanding of the ability of pregnant women to perform aerobic exercise. It consists of four chapters. Chapter 2 describes a longitudinal study of maximal power and oxygen uptake in pregnant and postpartum women. Because only a

Responses to Exercise Differ For Chronic Fatigue Syndrome Patients with Fibromyalgia

Science.gov (United States)

Cook, Dane B.; Stegner, Aaron J.; Nagelkirk, Paul R.; Meyer, Jacob D.; Togo, Fumiharu; Natelson, Benjamin H.

2011-01-01

Chronic fatigue syndrome (CFS) and fibromyalgia (FM) are chronic multisymptom illnesses with substantial clinical and diagnostic overlap. We have previously shown that when controlling for aerobic fitness and accounting for comorbid FM, CFS patients do not exhibit abnormal cardiorespiratory responses during maximal aerobic exercise compared to healthy controls, despite differences in pain and exertion. Purpose The purpose of the present study was to examine cardiac and perceptual responses to steady-state, submaximal exercise in CFS patients and healthy controls. Methods Twenty-one CFS patients [13 CFS with comorbid FM (CFS+FM)] and 14 controls completed 20 minutes of submaximal cycling exercise. Impedance cardiography was used to determine cardiac responses during exercise. Systolic blood pressure (SBP), perceived exertion (RPE) and leg-muscle pain were also measured. Data were analyzed using a doubly-multivariate, repeated-measures MANOVA to model the exercise response. Results There was a significant multivariate Time by Group interaction (p exercise response characterized by higher stoke index, ventilatory equivalents for oxygen and carbon dioxide and RPE, lower SBP and similar HR responses. Conclusions The present results extend upon our previous work with maximal exercise and show that CFS and CFS+FM differ in their responses to steady-state exercise. These results highlight the importance of accounting for comorbid conditions when conducting CFS research, particularly when examining psychophysiological responses to exercise. PMID:22157881

The Ottawa panel clinical practice guidelines for the management of knee osteoarthritis. Part one: introduction, and mind-body exercise programs.

Science.gov (United States)

Brosseau, Lucie; Taki, Jade; Desjardins, Brigit; Thevenot, Odette; Fransen, Marlene; Wells, George A; Imoto, Aline Mizusaki; Toupin-April, Karine; Westby, Marie; Gallardo, Inmaculada C Álvarez; Gifford, Wendy; Laferrière, Lucie; Rahman, Prinon; Loew, Laurianne; Angelis, Gino De; Cavallo, Sabrina; Shallwani, Shirin Mehdi; Aburub, Ala'; Bennell, Kim L; Van der Esch, Martin; Simic, Milena; McConnell, Sara; Harmer, Alison; Kenny, Glen P; Paterson, Gail; Regnaux, Jean-Philippe; Lefevre-Colau, Marie-Martine; McLean, Linda

2017-05-01

To identify effective mind-body exercise programs and provide clinicians and patients with updated, high-quality recommendations concerning non-traditional land-based exercises for knee osteoarthritis. A systematic search and adapted selection criteria included comparative controlled trials with mind-body exercise programs for patients with knee osteoarthritis. A panel of experts reached consensus on the recommendations using a Delphi survey. A hierarchical alphabetical grading system (A, B, C+, C, D, D+, D-) was used, based on statistical significance ( P osteoarthritis. Hatha Yoga demonstrated significant improvement for pain relief (Grade B) and physical function (Grade C+). Tai Chi Qigong demonstrated significant improvement for quality of life (Grade B), pain relief (Grade C+) and physical function (Grade C+). Sun style Tai Chi gave significant improvement for pain relief (Grade B) and physical function (Grade B). Mind-body exercises are promising approaches to reduce pain, as well as to improve physical function and quality of life for individuals with knee osteoarthritis.

COMPARISON OF HAMSTRING MUSCLE ACTIVATION DURING HIGH-SPEED RUNNING AND VARIOUS HAMSTRING STRENGTHENING EXERCISES

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Solheim, Jens Asmund Brevik; Bencke, Jesper

2017-01-01

Purpose/Background Several studies have examined the effect of hamstring strength exercises upon hamstring strains in team sports that involve many sprints. However, there has been no cross comparison among muscle activation of these hamstring training exercises with actual sprinting. Therefore, the aim of this study was to examine different hamstring exercises and compare the muscle activity in the hamstring muscle group during various exercises with the muscular activity produced during maximal sprints. Methods Twelve male sports students (age 25 ± 6.2 years, 1.80 ± 7.1 m, body mass 81.1 ± 15.6 kg) participated in this study. Surface EMG electrodes were placed on semimembranosus, semitendinosus and biceps femoris to measure muscle activity during seven hamstrings exercises and sprinting together with 3D motion capture to establish at what hip and knee angles maximal muscle activation (EMG) occurs. Maximal EMG activity during sprints for each muscle was used in order to express each exercise as a percentage of max activation during sprinting. Results The main findings were that maximal EMG activity of the different hamstring exercises were on average between 40-65% (Semitendinosus), 18-40% (biceps femoris) and 40-75% (Semimembranosus) compared with the max EMG activity in sprints, which were considered as 100%. The laying kick together with the Nordic hamstring exercises and its variations had the highest muscle activations, while the cranes showed the lowest muscle activation (in all muscles) together with the standing kick for the semimembranosus. In addition, angles at which the peak EMG activity of the hamstring muscle occurs were similar for the Nordic hamstring exercises and different for the two crane exercises (hip angle), standing kick (hip angle) and the laying kick (knee angle) compared with the sprint. Conclusions Nordic hamstring exercises with its variation together with the laying kick activates the hamstrings at high levels and

Central hemodynamic responses during serial exercise tests in heart failure patients using implantable hemodynamic monitors.

Science.gov (United States)

Ohlsson, A; Steinhaus, D; Kjellström, B; Ryden, L; Bennett, T

2003-06-01

Exercise testing is commonly used in patients with congestive heart failure for diagnostic and prognostic purposes. Such testing may be even more valuable if invasive hemodynamics are acquired. However, this will make the test more complex and expensive and only provides information from isolated moments. We studied serial exercise tests in heart failure patients with implanted hemodynamic monitors allowing recording of central hemodynamics. Twenty-one NYHA Class II-III heart failure patients underwent maximal exercise tests and submaximal bike or 6-min hall walk tests to quantify their hemodynamic responses and to study the feasibility of conducting exercise tests in patients with such devices. Patients were followed for 2-3 years with serial exercise tests. During maximal tests (n=70), heart rate increased by 52+/-19 bpm while S(v)O(2) decreased by 35+/-10% saturation units. RV systolic and diastolic pressure increased 29+/-11 and 11+/-6 mmHg, respectively, while pulmonary artery diastolic pressure increased 21+/-8 mmHg. Submaximal bike (n=196) and hall walk tests (n=172) resulted in S(v)O(2) changes of 80 and 91% of the maximal tests, while RV pressures ranged from 72 to 79% of maximal responses. An added potential value of implantable hemodynamic monitors in heart failure patients may be to quantitatively determine the true hemodynamic profile during standard non-invasive clinical exercise tests and to compare that to hemodynamic effects of regular exercise during daily living. It would be of interest to study whether such information could improve the ability to predict changes in a patient's clinical condition and to improve tailoring patient management.

The health effects of exercising in air pollution.

Science.gov (United States)

Giles, Luisa V; Koehle, Michael S

2014-02-01

The health benefits of exercise are well known. Many of the most accessible forms of exercise, such as walking, cycling, and running often occur outdoors. This means that exercising outdoors may increase exposure to urban air pollution. Regular exercise plays a key role in improving some of the physiologic mechanisms and health outcomes that air pollution exposure may exacerbate. This problem presents an interesting challenge of balancing the beneficial effects of exercise along with the detrimental effects of air pollution upon health. This article summarizes the pulmonary, cardiovascular, cognitive, and systemic health effects of exposure to particulate matter, ozone, and carbon monoxide during exercise. It also summarizes how air pollution exposure affects maximal oxygen consumption and exercise performance. This article highlights ways in which exercisers could mitigate the adverse health effects of air pollution exposure during exercise and draws attention to the potential importance of land use planning in selecting exercise facilities.

Effect of music tempo on exercise performance and heart rate among young adults.

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Thakare, Avinash E; Mehrotra, Ranjeeta; Singh, Ayushi

2017-01-01

Music captures attention, triggers a range of emotions, alters or regulates mood, increases work output, heightens arousal, induces states of higher functioning, reduces inhibitions and encourages rhythmic movement. Music has ergo-genic effect as well, it increases exercise performance, delays fatigue and increases performance and endurance, power and strength. Our study tried to evaluate the effect of music on exercise performance in young untrained subjects. In this study, we tested the effect of music on sub maximal exercise performance time duration in young adults. 25 Male and 25 females were subjected to standard submaximal exercise with and without music. Resting HR and Max. HR during exercise and the exercise time duration was recorded. Total exercise duration in whole group with music (37.12 ± 16.26** min) was significantly greater than exercise duration without music (22.48 ± 10.26 min). Males (42.4 ± 15.6** min) outperformed significantly better than females (31.84 ± 15.48 min). Also, we observed statistically significant higher values of Maximal heart rate with music than without music. But there was no significant correlation between duration of exercise, music and change in Heart rate. We can conclude that Music increases duration of exercise in both sexes and hence endurance.

Pulmonary gas exchange at maximal exercise in Danish lowlanders during 8 wk of acclimatization to 4,100 m and in high-altitude Aymara natives

DEFF Research Database (Denmark)

Lundby, Carsten; Calbet, Jose A L; van Hall, Gerrit

2004-01-01

We aimed to test effects of altitude acclimatization on pulmonary gas exchange at maximal exercise. Six lowlanders were studied at sea level, in acute hypoxia (AH), and after 2 and 8 wk of acclimatization to 4,100 m (2W and 8W) and compared with Aymara high-altitude natives residing...... in AH but increased significantly with acclimatization (51 +/- 1.1, 58 +/- 1.7, and 62 +/- 1.6 mmHg in AH, 2W, and 8W, respectively). PaO2 in lowlanders reached levels that were not different from those in high-altitude natives (66 +/- 1.2 mmHg). Arterial O2 saturation (SaO2) decreased during maximum......, but even acclimatization for 8 wk is insufficient to achieve levels reached by high-altitude natives....

Peak heart rates at extreme altitudes

DEFF Research Database (Denmark)

Lundby, C; Van Hall, Gerrit

2001-01-01

We have measured maximal heart rate during a graded maximal bicycle exercise test to exhaustion in five healthy climbers before and during an expedition to Mt. Everest. Maximal heart rates at sea level were 186 (177-204) beats/min(-1) at sea level and 170 (169-182) beats/min(-1) with acute hypoxi...

Effects of acute exercise on the diameter of the spermatic vein, and duration of reflux in patients with varicocele.

Science.gov (United States)

Atar, Murat; Söylemez, Haluk; Oguz, Fatih; Beytur, Ali; Altunoluk, Bülent; Kahraman, Bayram; Islamoglu, Yahya; Soylu, Ahmet

2013-06-01

The aim of this study was to investigate the effects of acute exercise on the diameter of the spermatic vein, and on the duration of reflux in patients with varicocele. The study included 38 patients with complaints of infertility and scrotal pain between 2009 and 2010. The diagnoses were made by physical examination and colour Doppler ultrasound, with both performed before and after exercise tests. The mean age of the participants was 25.7 ± 4.9 years. During the first examination, the grades of the varicoceles detected were as follows: grade I, n = 7; II, n = 10; and III, n = 21. The diameters of veins in patients with grades I, II and III varicocele were 2.1 mm, 2.9 mm and 4.2 mm, respectively, before exercise, whereas they were 2.6 mm, 3.2 mm and 4.3 mm, respectively, after exercise. In patients with grade I varicoceles, compared with pre-exercise values, the diameter of the left spermatic vein and duration of reflux measured during Valsalva manoeuvres were increased significantly after exercise (p = 0.042 and p = 0.034, respectively); similar results were obtained for the patients with grade II varicoceles (p = 0.007 and p = 0.008, respectively). However, the minimal relative increase in cases with grade III varicoceles was not statistically significant (p > 0.05). This study demonstrates that acute exercise increases the spermatic vein diameter and reflux time in patients with varicoceles. These outcomes demonstrate that acute exercise may be an aggravating factor for varicocele, as seen in chronic exercise.

Acute Exercise Increases Plasma Total Antioxidant Status and Antioxidant Enzyme Activities in Untrained Men

Directory of Open Access Journals (Sweden)

C. Berzosa

2011-01-01

Full Text Available Antioxidant defences are essential for cellular redox regulation. Since free-radical production may be enhanced by physical activity, herein, we evaluated the effect of acute exercise on total antioxidant status (TAS and the plasma activities of catalase, glutathione reductase, glutathione peroxidase, and superoxide dismutase and its possible relation to oxidative stress resulting from exercise. Healthy untrained male subjects (=34 performed three cycloergometric tests, including maximal and submaximal episodes. Venous blood samples were collected before and immediately after each different exercise. TAS and enzyme activities were assessed by spectrophotometry. An increase of the antioxidant enzyme activities in plasma was detected after both maximal and submaximal exercise periods. Moreover, under our experimental conditions, exercise also led to an augmentation of TAS levels. These findings are consistent with the idea that acute exercise may play a beneficial role because of its ability to increase antioxidant defense mechanisms through a redox sensitive pathway.

Effects of Hemopure on maximal oxygen uptake and endurance performance in healthy humans.

Science.gov (United States)

Ashenden, M J; Schumacher, Y O; Sharpe, K; Varlet-Marie, E; Audran, M

2007-05-01

Haemoglobin-based oxygen carriers (HBOCs) such as Hemopure are touted as a tenable substitute for red blood cells and therefore potential doping agents, although the mechanisms of oxygen transport of HBOCs are incompletely understood. We investigated whether infusion of Hemopure increased maximal oxygen uptake (V.O 2max) and endurance performance in healthy subjects. Twelve male subjects performed two 4-minute submaximal exercise bouts equivalent to 60 % and 75 % of V.O (2max) on a cycle ergometer, followed by a ramped incremental protocol to elicit V.O (2max). A crossover design tested the effect of infusing either 30 g (6 subjects) or 45 g (6 subjects) of Hemopure versus a placebo. Under our study conditions, Hemopure did not increase V.O (2max) nor endurance performance. However, the infusion of Hemopure caused a decrease in heart rate of approximately 10 bpm (p=0.009) and an average increase in mean ( approximately 7 mmHg) and diastolic blood pressure ( approximately 8 mmHg) (p=0.046) at submaximal and maximal exercise intensities. Infusion of Hemopure did not bestow the same physiological advantages generally associated with infusion of red blood cells. It is conceivable that under exercise conditions, the hypertensive effects of Hemopure counter the performance-enhancing effect of improved blood oxygen carrying capacity.

Exercise addiction in CrossFit: Prevalence and psychometric properties of the Exercise Addiction Inventory.

Science.gov (United States)

Lichtenstein, Mia Beck; Jensen, Tanja Tang

2016-06-01

CrossFit is a mix of aerobic and anaerobic exercise regimes with the stated goal of improving fitness and physical performance. It is growing in popularity and has a strong community known to motivate and push the participants to maximal performance. The negative consequences of these extreme exercise patterns have rarely been described. The prevalence of injuries in CrossFit is high but exercise addiction and harmful exercise attitudes have not yet been assessed. The aim of this study was to measure the prevalence of exercise addiction in CrossFit and to evaluate the reliability and validity of the Exercise Addiction Inventory (EAI) in a CrossFit population. We invited crossfitters to participate in an online survey using Facebook groups. A total of 603 regular crossfitters completed the EAI and additional questions concerning exercise amounts and negative exercise attitudes and beliefs. We used principal component analyses and structural equation models to test the psychometric properties of the EAI and to describe the characteristics of the addicted crossfitters. We found that 5% of the crossfitters were addicted to exercise and that young males had a higher risk. The EAI had good internal reliability (0.73) and construct validity. Thus we found significant positive associations between exercise addiction and the tendency to exercise in spite of injury, feelings of guilt when unable to exercise, passion turning into obsession and taking medication to be able to exercise. Exercise addiction is prevalent in CrossFit and needs further exploration. The EAI is recommended for research in CrossFit communities and applied settings.

Cardiovascular responses to military antishock trouser inflation during standing arm exercise.

Science.gov (United States)

Ng, A V; Hanson, P; Aaron, E A; Demment, R B; Conviser, J M; Nagle, F J

1987-09-01

Military antishock trousers (MAST) inflated to 50 mmHg were used with 12 healthy males (mean age 28 +/- 1 yr) to determine the effects of lower-body positive pressure on cardiac output (Q), stroke volume (SV), heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MABP), total peripheral resistance (TPR), and O2 uptake (VO2) during graded arm-cranking exercise. Subjects were studied while standing at rest and at 25, 50, and 75% of maximal arm-cranking VO2. At each level, rest or work was continued for 6 min with MAST inflated and for 6 min with MAST deflated. Order of inflation and deflation was alternated at each experimental rest or exercise level. Measurements were obtained during the last 2 min at each level. Repeated-measures analysis of variance revealed significant increases (P less than 0.001) in Q, SV, and MABP and a consistent decrease in HR with MAST inflation. There was no apparent change in Q/VO2 between inflated and control conditions. There was no effect of MAST inflation on VO2 or TPR. MAST inflation counteracts the gravitational effect of venous return in upright exercise, restoring central blood volume and thereby increasing Q and MABP from control. HR is decreased consequent to increased MABP through arterial baroreflexes. The associated decrease in TPR is not observed, being offset by the mechanical compression of leg vasculature with MAST inflation.

Mechanisms of impaired exercise capacity in short duration experimental hyperthyroidism.

Science.gov (United States)

Martin, W H; Spina, R J; Korte, E; Yarasheski, K E; Angelopoulos, T J; Nemeth, P M; Saffitz, J E

1991-01-01

To investigate the mechanism of reduced exercise tolerance in hyperthyroidism, we characterized cardiovascular function and determinants of skeletal muscle metabolism in 18 healthy subjects aged 26 +/- 1 yr (mean +/- SE) before and after 2 wk of daily ingestion of 100 micrograms of triiodothyronine (T3). Resting oxygen uptake, heart rate, and cardiac output increased and heart rate and cardiac output at the same submaximal exercise intensity were higher in the hyperthyroid state (P less than 0.05). However, maximal oxygen uptake decreased after T3 administration (3.08 +/- 0.17 vs. 2.94 +/- 0.19 l/min; P less than 0.001) despite increased heart rate and cardiac output at maximal exercise (P less than 0.05). Plasma lactic acid concentration at an equivalent submaximal exercise intensity was elevated 25% (P less than 0.01) and the arteriovenous oxygen difference at maximal effort was reduced (P less than 0.05) in the hyperthyroid state. These effects were associated with a 21-37% decline in activities of oxidative (P less than 0.001) and glycolytic (P less than 0.05) enzymes in skeletal muscle and a 15% decrease in type IIA muscle fiber cross-sectional area (P less than 0.05). Lean body mass was reduced (P less than 0.001) and the rates of whole body leucine oxidation and protein breakdown were enhanced (P less than 0.05). Thus, exercise tolerance is impaired in short duration hyperthyroidism because of decreased skeletal muscle mass and oxidative capacity related to accelerated protein catabolism but cardiac pump function is not reduced. PMID:1752962

Handgrip and general muscular strength and endurance during prolonged bedrest with isometric and isotonic leg exercise training

Science.gov (United States)

Greenleaf, J. E.; Starr, J. C.; Van Beaumont, W.; Convertino, V. A.

1983-01-01

Measurements of maximal grip strength and endurance at 40 percent max strength were obtained for 7 men 19-21 years of age, 1-2 days before and on the first recovery day during three 2-week bedrest (BR) periods, each separated by a 3-week ambulatory recovery period. The subjects performed isometric exercise (IME) for 1 hr/day, isotonic exercise (ITE) for 1 hr/day, and no exercise (NOE) in the three BR periods. It was found that the mean maximal grip strength was unchanged after all three BR periods. Mean grip endurance was found to be unchanged after IME and ITE training, but was significantly reduced after NOE. These results indicate that IME and ITE training during BR do not increase or decrease maximal grip strength, alghough they prevent loss of grip endurance, while the maximal strength of all other major muscle groups decreases in proportion to the length of BR to 70 days. The maximal strength reduction of the large muscle groups was found to be about twice that of the small muscle groups during BR. In addition, it is shown that changes in maximal strength after spaceflight, BR, or water immersion deconditioning cannot be predicted from changes in submaximal or maximal oxygen uptake values.

Splanchnic blood flow and hepatic glucose production in exercising humans

DEFF Research Database (Denmark)

Bergeron, R; Kjaer, M; Simonsen, L

2001-01-01

The study examined the implication of the renin-angiotensin system (RAS) in regulation of splanchnic blood flow and glucose production in exercising humans. Subjects cycled for 40 min at 50% maximal O(2) consumption (VO(2 max)) followed by 30 min at 70% VO(2 max) either with [angiotensin-converti......The study examined the implication of the renin-angiotensin system (RAS) in regulation of splanchnic blood flow and glucose production in exercising humans. Subjects cycled for 40 min at 50% maximal O(2) consumption (VO(2 max)) followed by 30 min at 70% VO(2 max) either with [angiotensin......-converting enzyme (ACE) blockade] or without (control) administration of the ACE inhibitor enalapril (10 mg iv). Splanchnic blood flow was estimated by indocyanine green, and splanchnic substrate exchange was determined by the arteriohepatic venous difference. Exercise led to an approximately 20-fold increase (P ...-blockade group vs. the control group, hormones, metabolites, VO(2), and RER followed the same pattern of changes in ACE-blockade and control groups during exercise. Splanchnic blood flow (at rest: 1.67 +/- 0.12, ACE blockade; 1.59 +/- 0.18 l/min, control) decreased during moderate exercise (0.78 +/- 0.07, ACE...

Brain activity and fatigue during prolonged exercise in the heat

DEFF Research Database (Denmark)

Nielsen, Bodil; Hyldig, Tino; Bidstrup, F.

2001-01-01

We hypothesized that fatigue due to hyperthermia during prolonged exercise in the heat is in part related to alterations in frontal cortical brain activity. The electroencephalographic activity (EEG) of the frontal cortex of the brain was measured in seven cyclists [maximal O2 uptake (VO2max) 4...... min of exercise; P

Exercise capacity and selected physiological factors by ancestry and residential altitude

DEFF Research Database (Denmark)

Bianba; Berntsen, Sveinung; Andersen, Lars Bo

2014-01-01

AIM: Several physiological compensatory mechanisms have enabled Tibetans to live and work at high altitude, including increased ventilation and pulmonary diffusion capacity, both of which serve to increase oxygen transport in the blood. The aim of the present study was to compare exercise capacity...... Tibetans vs. Han Chinese may reflect a better adaptation to life at high altitude. Tibetans at the lower residential altitude of 3700 m demonstrated a better exercise capacity than residents at a higher altitude of 4300 m when measured at their respective residential altitudes. Such altitude- or ancestry...... (maximal power output) and selected physiological factors (arterial oxygen saturation and heart rate at rest and during maximal exercise, resting hemoglobin concentration, and forced vital capacity) in groups of native Tibetan children living at different residential altitudes (3700 vs. 4300 m above sea...

The relationship between blood potassium, blood lactate, and electromyography signals related to fatigue in a progressive cycling exercise test.

Science.gov (United States)

Tenan, Matthew S; McMurray, Robert G; Blackburn, B Troy; McGrath, Melanie; Leppert, Kyle

2011-02-01

Local muscle fatigue may be related to potassium efflux from the muscle cell and/or lactate accumulation within the muscle. Local fatigue causes a decrease in median frequency (MPF) of the electromyogram's power spectrum during isometric contractions but its relationship to changes in potassium and lactate during dynamic exercise is equivocal. Thus, this investigation evaluated relationships between changes in the MPF from the vastus lateralis and blood levels of lactate and potassium during an incremental cycling test and recovery. Trained cyclists (n=8) completed a discontinuous, graded cycle test to exhaustion under normal and glycogen-reduced conditions. The glycogen reduced condition promoted an environment of lower lactate production while permitting a consistent potassium response. Blood samples and maximal isometric EMG data were collected at the end of each stage and during recovery. Maximal lactate levels were ∼ 60% lower in the glycogen reduced condition; potassium was similar between trials. MPF did not change significantly at volitional fatigue. Further, MPF was not significantly related to lactate (p>0.27) or potassium (p>0.16) in either condition. Though both lactate and potassium have been implicated as factors relating to local muscle fatigue, neither is significantly related to changes in MPF during or after progressive exercise on a cycle ergometer. Copyright © 2010 Elsevier Ltd. All rights reserved.

Parallel changes in the onset of blood lactate accumulation (OBLA) and threshold of psychomotor performance deterioration during incremental exercise after training in athletes.

Science.gov (United States)

Chmura, Jan; Nazar, Krystyna

2010-03-01

During aerobic exercise with increasing intensities choice reaction time (CRT) progressively shortens up to 60-80% of maximal workload, and then it rapidly increases. The aim of this study was to determine whether workload associated with the shortest CRT operationally called "the psychomotor fatigue threshold" is related to the metabolic response to exercise. Thirteen male soccer players (aged 23.3 + or - 1.0 yrs) participated in this study. Before and after 6 weeks of training in the pre-competition period they underwent treadmill test at 0 grade with running speed increasing every 3 min by 2 km/h starting from 6 km/h until exhaustion. At each stage of exercise CRT, heart rate, respiratory gas exchange and blood lactate [LA] were measured and the workload corresponding to [LA] of 4 mmol/l (OBLA) was recorded. After training, CRT was significantly shortened at rest (from m + or - SEM = 345 + or - 12 to 317 + or - 12 ms) and during exercise (from 304 + or - 10 to 285 + or - 11 ms at the psychomotor fatigue threshold and from 359 + or - 13 to 331 + or - 13 ms, pchanges in OBLA occurring during training and those in psychomotor fatigue threshold (r = 0.88). It is concluded that endurance training not only increases exercise tolerance due to its influence on metabolism but also facilitates psychomotor performance during heavy exercise. Copyright 2010 Elsevier B.V. All rights reserved.

Acute effects of dynamic exercises on the relationship between the motor unit firing rate and the recruitment threshold.

Science.gov (United States)

Ye, Xin; Beck, Travis W; DeFreitas, Jason M; Wages, Nathan P

2015-04-01

The aim of this study was to compare the acute effects of concentric versus eccentric exercise on motor control strategies. Fifteen men performed six sets of 10 repetitions of maximal concentric exercises or eccentric isokinetic exercises with their dominant elbow flexors on separate experimental visits. Before and after the exercise, maximal strength testing and submaximal trapezoid isometric contractions (40% of the maximal force) were performed. Both exercise conditions caused significant strength loss in the elbow flexors, but the loss was greater following the eccentric exercise (t=2.401, P=.031). The surface electromyographic signals obtained from the submaximal trapezoid isometric contractions were decomposed into individual motor unit action potential trains. For each submaximal trapezoid isometric contraction, the relationship between the average motor unit firing rate and the recruitment threshold was examined using linear regression analysis. In contrast to the concentric exercise, which did not cause significant changes in the mean linear slope coefficient and y-intercept of the linear regression line, the eccentric exercise resulted in a lower mean linear slope and an increased mean y-intercept, thereby indicating that increasing the firing rates of low-threshold motor units may be more important than recruiting high-threshold motor units to compensate for eccentric exercise-induced strength loss. Copyright © 2014 Elsevier B.V. All rights reserved.

Exercise Training During +Gz Acceleration

Science.gov (United States)

Greenleaf, J. E.; Chou, J. L.; Simonson, S. R.; Jackson, C. G. R.; Barnes, P. R.

1999-01-01

The overall purpose is to study the effect of passive (without exercise) and active (with exercise) +Gz (head-to-foot) acceleration training, using a short-arm (1.9m radius) centrifuge, on post- training maximal oxygen uptake (VO2 max, work capacity) and 70 deg head-up tilt (orthostatic) tolerance in ambulatory subjects to test the hypothesis that (a) both passive and active acceleration training will improve post-training tilt-tolerance, and (b) there will be no difference in tilt-tolerance between passive and active exercise acceleration training because increased hydrostatic and blood pressures, rather than increased muscular metabolism, will provide the major adaptive stimulus. The purpose of the pilot study was to test the hypothesis that there would be no significant difference in the metabolic responses (oxygen uptake, heart rate, pulmonary ventilation, or respiratory exchange ratio) during supine exercise with moderate +Gz acceleration.

Correlation of resting and exercising endoscopic findings for horses with dynamic laryngeal collapse and palatal dysfunction.

Science.gov (United States)

Barakzai, S Z; Dixon, P M

2011-01-01

To correlate resting and exercising endoscopic grades of laryngeal function in horses undergoing high-speed treadmill endoscopy (HSTE) using the Havemeyer grading system. To correlate dorsal displacement of the soft palate (DDSP) seen at rest with palatal function during exercise. Records of horses that underwent HSTE examination (1999-2009) were reviewed. Resting laryngeal function score and other abnormalities noted on resting endoscopy were recorded as were results of HSTE. Results of resting and exercising endoscopic findings were correlated. 281 horses underwent HSTE. There was significant correlation between grade of laryngeal function at rest (grades 1-4) and exercise (ρ=0.53, Pexercising grades of laryngeal function (ρ=0.43, P=0.0017). DDSP was observed at rest significantly more often in horses that developed DDSP during HSTE than those without DDSP during HSTE (RR=4.1, Pexercise were 25.5 and 95.1% respectively (positive predictive value 0.57, negative predictive value 0.83). The results of the current study support the use of the Havemeyer system for grading laryngeal function in the resting horse, and corroborate findings of previous studies correlating resting and exercising palatal abnormalities. Studies that use the presence of spontaneous DDSP during resting endoscopic examination as an inclusion criterion for investigating efficacy of treatments for DDSP are likely to have a low proportion of horses with false positive diagnoses. © 2010 EVJ Ltd.

The influence of training status on the drop in muscle strength after acute exercise

DEFF Research Database (Denmark)

Pingel, Jessica; Moerch, L; Kjaer, M

2009-01-01

to running exercise immediately after immobilization, the muscle strength of the triceps-surae muscles dropped even further, but just in the immobilized leg (41%; P importance of determining the muscle endurance when evaluating the effect of immobilization on muscle......Skeletal muscles fatigue after exercise, and reductions in maximal force appear. A difference in training status between the legs was introduced by unilateral immobilization of the calf muscles for 2 weeks in young men, who were randomly assigned to two groups, either a RUN group (n = 8......) that was exposed to prolonged exercise (1-h running: individual pace) or a REST group (n = 12) that did no exercise after immobilization. Cross-sectional area (CSA) of the triceps-surae muscles was calculated by magnetic resonance imaging (MRI), and maximal voluntary contraction (MVC) force of the plantar flexors...

Acute Exercise and Motor Memory Consolidation: The Role of Exercise Timing

Directory of Open Access Journals (Sweden)

Richard Thomas

2016-01-01

Full Text Available High intensity aerobic exercise amplifies offline gains in procedural memory acquired during motor practice. This effect seems to be evident when exercise is placed immediately after acquisition, during the first stages of memory consolidation, but the importance of temporal proximity of the exercise bout used to stimulate improvements in procedural memory is unknown. The effects of three different temporal placements of high intensity exercise were investigated following visuomotor skill acquisition on the retention of motor memory in 48 young (24.0 ± 2.5 yrs, healthy male subjects randomly assigned to one of four groups either performing a high intensity (90% Maximal Power Output exercise bout at 20 min (EX90, 1 h (EX90+1, 2 h (EX90+2 after acquisition or rested (CON. Retention tests were performed at 1 d (R1 and 7 d (R7. At R1 changes in performance scores after acquisition were greater for EX90 than CON (p<0.001 and EX90+2 (p=0.001. At R7 changes in performance scores for EX90, EX90+1, and EX90+2 were higher than CON (p<0.001, p=0.008, and p=0.008, resp.. Changes for EX90 at R7 were greater than EX90+2 (p=0.049. Exercise-induced improvements in procedural memory diminish as the temporal proximity of exercise from acquisition is increased. Timing of exercise following motor practice is important for motor memory consolidation.

Exercise Self-Efficacy Moderates the Relation between Anxiety Sensitivity and Body Mass Index and Exercise Tolerance in Treatment-Seeking Smokers

Science.gov (United States)

Farris, Samantha G.; Davis, Michelle L.; Rosenfield, David; Kauffman, Brooke Y.; Baird, Scarlett O.; Powers, Mark B.; Otto, Michael W.; Marcus, Bess H.; Church, Timothy S.; Smits, Jasper A. J.; Zvolensky, Michael J.

2016-01-01

There is little known about factors that contribute to the comorbidity of cigarette smoking and obesity. The current study sought to test whether exercise self-efficacy moderated the relation between anxiety sensitivity (fear of internal sensations) and BMI and exercise tolerance among cigarette smokers. Smokers (n = 72; 50% female; Mcpd = 19.3, SD = 10.65) were recruited to participate in a smoking cessation treatment trial. During medical screen, we measured weight, height, and exercise tolerance (functional capacity) employing a standardized maximal exercise testing protocol. After adjusting for participant sex and cigarettes per day, exercise self-efficacy moderated the association between anxiety sensitivity and BMI, such that the positive association between anxiety sensitivity and BMI was significantly stronger when exercise self-efficacy was low. The same pattern of results emerged for exercise tolerance. Exercise self-efficacy moderated the association between anxiety sensitivity and exercise tolerance, such that the negative association between anxiety sensitivity and exercise tolerance was significantly stronger when exercise self-efficacy was low. Among smokers, anxiety sensitivity may be a risk variable that, directly and indirectly in the context of low self-efficacy for exercise, causes or maintains higher body weight and lower exercise tolerance. PMID:27725844

The Influence of Goal Setting on Exercise Adherence.

Science.gov (United States)

Cobb, Lawrence E.; Stone, William J.; Anonsen, Lori J.; Klein, Diane A.

2000-01-01

Assessed the influence of fitness- and health-related goal setting on exercise adherence. Students in a college fitness program participated in goal setting, reading, or control groups. No significant differences in exercise adherence were found. Students enrolled for letter grades had more fitness center visits and hours of activity than students…

Cerebral blood flow during submaximal and maximal dynamic exercise in humans

DEFF Research Database (Denmark)

Thomas, S N; Schroeder, T; Secher, N H

1989-01-01

not differ significantly between work loads from 32 (24-33) to 86% (74-96) of VO2max (n = 10). During exercise, mean arterial pressure increased from 84 (60-100) to 101 (78-124) Torr (P less than 0.01) and PCO2 remained unchanged [5.1 (4.6-5.6) vs. 5.4 (4.4-6.3) kPa, n = 6]. These results demonstrate...

Video game-based exercise, Latino children's physical health, and academic achievement.

Science.gov (United States)

Gao, Zan; Hannan, Peter; Xiang, Ping; Stodden, David F; Valdez, Verónica E

2013-03-01

There is a paucity of research investigating the effects of innovative physical activity programs on physical health and academic performance in the Latino population. To examine the impact of Dance Dance Revolution [DDR]-based exercise on Latino children's physical fitness and academic achievement. A repeated-measures crossover design was used. In Year 1, Grade-4 students were assigned to the intervention group and offered 30 minutes of exercise (DDR, aerobic dance) three times per week. Grade-3 and Grade-5 students made up the comparison group and were offered no structured exercise at school. In Year 2, the Grade-4 students were again assigned to the intervention, whereas Grade-5 and Grade-6 students were in the comparison group. Assessments were conducted with 208 Latino school children. The baseline measures included time to complete a 1-mile run, BMI, and reading and math scores. Data were collected again 9 months later. Overall, data were collected in 2009-2011 and analyzed in 2012. Data yielded significant differences between the intervention and comparison groups in differences in 1-mile run and math scores in Year 1 and Year 2. The results also revealed net differences in the intervention versus comparison group scores on the 1-mile run for Grade 3 (p<0.01). Additionally, children's yearly pre-test and post-test BMI group changes differed (χ(2)((2)) = 6.6, p<0.05) only for the first year of intervention. The DDR-based exercise intervention improved children's cardiorespiratory endurance and math scores over time. Professionals should consider integrating exergaming at schools to achieve the goals of promoting a physically active lifestyle and enhancing academic success among Latino children. Copyright © 2013 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

[Chronic fatigue syndrome--exercise and physical activity].

Science.gov (United States)

Greenberg, Shai; Frid, Mordechai

2006-04-01

One of the major symptoms of chronic fatigue syndrome (CFS) is reduced exercise and functional capacity and increased fatigue symptoms following physical effort. A review of the literature indicates that patients that suffer from CFS are characterized by: low aerobic capacity, higher heart rate during sub-maximal exercise, higher subjective effort prescription, reduced muscle strength, and prolonged recovery period. Although several symptoms are a result of lack of physical activity, several mechanisms were suggested to explain those symptoms: pathological heart rate control, reduced aerobic metabolic capacity, reduced blood supply to the working muscles and nerve system dysfunction. Participating in guided exercise programs was found to be the most effective treatment in improving exercise and functional capacity, reducing fatigue syndromes and improving patients' daily function.

CATECHOLAMINES AND β2-ADRENOCEPTOR GENE EXPRESSION BEFORE AND AFTER MAXIMAL INCREMENTAL CYCLE TEST IN YOUNG ICE HOCKEY PLAYERS: RELATION TO WORK PERFORMED

Directory of Open Access Journals (Sweden)

Urszula Mazurek

2013-04-01

Full Text Available The aim of this study was to assess the plasma adrenaline and noradrenaline concentrations as well as whole blood β2-adrenoceptor gene (ADRB2 expression in young ice hockey players before and immediately after exercise in relation to performed work. Nineteen Youth National Team ice hockey players were subjected to the maximal incremental cycloergometer exercise. The test was done in the pre-competitive phase of training. Among many parameters the plasma adrenaline and noradrenaline concentrations and ADRB2 gene expression in peripheral blood mononuclear cells (PBMC were determined before and after exercise. The average performed work was 3261.3 ± 558.3 J · kg-1 and maximal oxygen consumption (VO2max for all players was 53.85 ± 3.91 mL · kg-1 min-1. The geometric mean of the ADRB2 gene expression was statistically significantly different before and after exercise (P ≤ 0.05, while adrenaline and noradrenaline levels in plasma significantly increased after exercise. In the analysed group of athletes we found that initial level of plasma noradrenaline correlated with the performed work (r = - 0.55, P < 0.014 and normalized ADRB2 expression before the exercise correlated with the work done by them (r = 0.48, P<0.039. However, no statistically significant correlations were found between the plasma adrenaline or noradrenaline concentrations and ADRB2 gene expression in peripheral blood of the players. The performed work in the maximal incremental exercise test of regularly training young ice hockey players depends on the initial levels of noradrenaline in plasma and ADRB2 mRNA in PBMC.

Aerobic exercise increases resistance to oxidative stress in sedentary older middle-aged adults. A pilot study.

Science.gov (United States)

Done, Aaron J; Traustadóttir, Tinna

2016-12-01

Older individuals who exercise regularly exhibit greater resistance to oxidative stress than their sedentary peers, suggesting that exercise can modify age-associated loss of resistance to oxidative stress. However, we recently demonstrated that a single bout of exercise confers protection against a subsequent oxidative challenge in young, but not older adults. We therefore hypothesized that repeated bouts of exercise would be needed to increase resistance to an oxidative challenge in sedentary older middle-aged adults. Sedentary older middle-aged men and women (50-63 years, n = 11) participated in an 8-week exercise intervention. Maximal oxygen consumption was measured before and after the intervention. The exercise intervention consisted of three sessions per week, for 45 min at an intensity corresponding to 70-85 % maximal heart rate (HR max ). Resistance to oxidative stress was measured by F 2 -isoprostane response to a forearm ischemia/reperfusion (I/R) trial. Each participant underwent the I/R trial before and after the exercise intervention. The intervention elicited a significant increase in maximal oxygen consumption (VO 2max ) (P exercise intervention (time-by-trial interaction, P = 0.043). Individual improvements in aerobic fitness were associated with greater improvements in the F 2 -isoprostane response (r = -0.761, P = 0.011), further supporting the role of aerobic fitness in resistance to oxidative stress. These data demonstrate that regular exercise with improved fitness leads to increased resistance to oxidative stress in older middle-aged adults and that this measure is modifiable in previously sedentary individuals.

Maximal respiratory pressures and pulmonary function in male runners.

OpenAIRE

Cordain, L; Glisan, B J; Latin, R W; Tucker, A; Stager, J M

1987-01-01

To determine the effects of long term exercise on respiratory muscle strength, maximal inspiratory (Pl max) and expiratory (PE max) pressures, pulmonary volumes and capacities and anthropometric parameters were measured in a group of 101 male runners aged 16 to 58 years. The runners exhibited significantly (p less than 0.05) lower PE max (202 +/- 41 cm H2O and significantly greater residual lung volumes (RV) (2.08 +/- 0.49 L) than predicted values for normal subjects of similar height and age...

Simultaneous maximal exercise radionuclide angiography and thallium stress perfusion imaging

International Nuclear Information System (INIS)

Narahara, K.A.; Mena, I.; Maublant, J.C.; Brizendine, M.; Criley, J.M.

1984-01-01

Gold-195m is a new ultra-short-lived radionuclide that can be used for cardiac studies. Accurate, reproducible ejection fraction and ventricular wall motion studies can be obtained from first-transit angiography using commercially available imaging and image-processing equipment. The short half-life of gold-195m (30.5 seconds) makes simultaneous dual isotope imaging possible and substantially reduces the radiation exposure from the isotope angiography. The feasibility and possible benefits of performing dual radionuclide studies were evaluated during a single exercise stress test in 24 subjects with known coronary artery disease (CAD) and in 20 normal volunteers. High-quality first-transit angiograms were obtained in all subjects. An 83% sensitivity and 95% specificity for detecting CAD with thallium-201 imaging was noted in this investigation, suggesting that its diagnostic accuracy was not altered by simultaneous dual isotone imaging. When segmental left ventricular (LV) wall motion was compared with thallium-201 perfusion imaging, divergent results were noted in 15 of 44 subjects. An analysis of the ejection fraction (EF) results at rest and stress provided additional information that could be useful in assessing the clinical significance of such differences in segmental wall motion and perfusion. Simultaneous dual isotope imaging appears to be appropriate for situations in which both LV perfusion and function require evaluation. The use of gold-195m allows such information to be obtained from a single exercise test and can thereby reduce the cost and time required for noninvasive evaluations of patients for CAD

Prognostic implications of normal exercise thallium 201 images

International Nuclear Information System (INIS)

Wahl, J.M.; Hakki, A.H.; Iskandrian, A.S.

1985-01-01

A study was made of 455 patients (mean age, 51 years) in whom exercise thallium 201 scintigrams performed for suspected coronary artery disease were normal. Of those, 322 (71%) had typical or atypical angina pectoris and 68% achieved 85% or more maximal predicted heart rate. The exercise ECGs were abnormal in 68 patients (15%), normal in 229 (50%), and inconclusive in 158 (35%). Ventricular arrhythmias occurred during exercise in 194 patients (43%). After a mean follow-up period of 14 months, four patients had had cardiac events, sudden cardiac death in one and nonfatal myocardial infarctions in three. None of the four patients had abnormal exercise ECGs. Two had typical and two had atypical angina pectoris. Normal exercise thallium 201 images identify patients at a low risk for future cardiac events (0.8% per year), patients with abnormal exercise ECGs but normal thallium images have good prognoses, and exercise thallium 201 imaging is a better prognostic predictor than treadmill exercise testing alone, because of the high incidence of inconclusive exercise ECGs and the good prognosis in patients with abnormal exercise ECGs

Acute exercise and motor memory consolidation

DEFF Research Database (Denmark)

Thomas, Richard; Beck, Mikkel Malling; Lind, Rune Rasmussen

2016-01-01

High intensity aerobic exercise amplifies offline gains in procedural memory acquired during motor practice. This effect seems to be evident when exercise is placed immediately after acquisition, during the first stages of memory consolidation, but the importance of temporal proximity...... of the exercise bout used to stimulate improvements in procedural memory is unknown. The effects of three different temporal placements of high intensity exercise were investigated following visuomotor skill acquisition on the retention of motor memory in 48 young (24.0 ± 2.5 yrs), healthy male subjects randomly...... assigned to one of four groups either performing a high intensity (90% Maximal Power Output) exercise bout at 20 min (EX90), 1 h (EX90+1), 2 h (EX90+2) after acquisition or rested (CON). Retention tests were performed at 1 d (R1) and 7 d (R7). At R1 changes in performance scores after acquisition were...

Is Walking Capacity in Subjects with Multiple Sclerosis Primarily Related to Muscle Oxidative Capacity or Maximal Muscle Strength? A Pilot Study

Directory of Open Access Journals (Sweden)

Dominique Hansen

2014-01-01

Full Text Available Background and Purpose. Walking capacity is reduced in subjects with multiple sclerosis (MS. To develop effective exercise interventions to enhance walking capacity, it is important to determine the impact of factors, modifiable by exercise intervention (maximal muscle strength versus muscle oxidative capacity, on walking capacity. The purpose of this pilot study is to discriminate between the impact of maximal muscle strength versus muscle oxidative capacity on walking capacity in subjects with MS. Methods. From 24 patients with MS, muscle oxidative capacity was determined by calculation of exercise-onset oxygen uptake kinetics (mean response time during submaximal exercise bouts. Maximal muscle strength (isometric knee extension and flexion peak torque was assessed on dynamometer. All subjects completed a 6-minute walking test. Relationships between walking capacity (as a percentage of normal value and muscle strength (of knee flexors and extensors versus muscle oxidative capacity were assessed in multivariate regression analyses. Results. The expanded disability status score (EDSS showed a significant univariate correlation (r=-0.70, P<0.004 with walking capacity. In multivariate regression analyses, EDSS and mean response time, but not muscle strength, were independently related to walking capacity (P<0.05. Conclusions. Walking distance is, next to disability level and not taking neurologic symptoms/deficits into account, primarily related to muscle oxidative capacity in subjects with MS. Additional study is needed to further examine/verify these findings.

Diet and exercise reduce low-grade inflammation and macrophage infiltration in adipose tissue but not in skeletal muscle in severely obese subjects

DEFF Research Database (Denmark)

Bruun, Jens M; Helge, Jørn W; Richelsen, Bjørn

2006-01-01

Obesity is associated with low-grade inflammation, insulin resistance, type 2 diabetes, and cardiovascular disease. This study investigated the effect of a 15-wk lifestyle intervention (hypocaloric diet and daily exercise) on inflammatory markers in plasma, adipose tissue (AT), and skeletal muscle...... (SM) in 27 severely obese subjects (mean body mass index: 45.8 kg/m2). Plasma samples, subcutaneous abdominal AT biopsies, and vastus lateralis SM biopsies were obtained before and after the intervention and analyzed by ELISA and RT-PCR. The intervention reduced body weight (P

Endurance training-induced changes in the GH-IGF-I axis influence maximal muscle strength in previously untrained men.

Science.gov (United States)

Grandys, Marcin; Majerczak, Joanna; Kuczek, Piotr; Sztefko, Krystyna; Duda, Krzysztof; Zoladz, Jerzy A

2017-02-01

In this study we have determined the effects of 20weeks of endurance running training on the GH-IGF-I axis changes in the context of the skeletal muscle performance and physical capacity level. Before and after the endurance training program a maximal incremental exercise tests, a 1500m race and a muscle strength measurements were performed and the blood samples were taken to determine both resting as well as end-exercise serum growth hormone (GH), insulin-like growth hormone-I (IGF-I), insulin-like growth hormone binding protein-3 (IGFBP-3) and plasma interleukin-6 (IL-6) concentrations. 20weeks of endurance running training improved power output generated at the end of the maximal incremental test by 24% (P<0.012), 1500m running time by 13% (P<0.012) and maximal muscle strength by 9% (P<0.02). End-exercise IGF-I/IGFBP-3 ratio was decreased by 22% after the training (P<0.04) and the magnitude of IGF-I/IGFBP-3 ratio decrease (ΔIGF-I/IGFBP-3 ex ) was 2.3 times higher after the training (P<0.04). The magnitude of the exercise-induced changes in IGFBP-3 concentration was also significantly higher (P<0.04) and there was a trend toward lower end-exercise IGF-I concentration (P=0.08) after the training. These changes were accompanied by a significantly higher (30%) end-exercise IL-6 concentration (P<0.01) as well as by a 3.4 times higher magnitude of IL-6 increase (P<0.02) after the training. Moreover, there were strong positive correlations between changes in resting serum IGF-I concentration (ΔIGF-I res ) and IGF-I/IGFBP-3 ratio (ΔIGF-I/IGFBP-3 res ) and changes in muscle strength (ΔMVC) (r=0.95, P=0.0003 and r=0.90, P=0.002, respectively). The training-induced changes in the components of the GH-IGF-I axis may have additive effects on skeletal muscle performance and physical capacity improvement. Copyright © 2016 Elsevier Ltd. All rights reserved.

High Intensity Exercise in Multiple Sclerosis

DEFF Research Database (Denmark)

Wens, Inez; Dalgas, Ulrik; Vandenabeele, Frank

2015-01-01

Introduction Low-to-moderate intensity exercise improves muscle contractile properties and endurance capacity in multiple sclerosis (MS). The impact of high intensity exercise remains unknown. Methods Thirty-four MS patients were randomized into a sedentary control group (SED, n = 11) and 2...... exercise groups that performed 12 weeks of a high intensity interval (HITR, n = 12) or high intensity continuous cardiovascular training (HCTR, n = 11), both in combination with resistance training. M.vastus lateralis fiber cross sectional area (CSA) and proportion, knee-flexor/extensor strength, body...... composition, maximal endurance capacity and self-reported physical activity levels were assessed before and after 12 weeks. Results Compared to SED, 12 weeks of high intensity exercise increased mean fiber CSA (HITR: +21±7%, HCTR: +23±5%). Furthermore, fiber type I CSA increased in HCTR (+29±6%), whereas type...

Mechanical demands of kettlebell swing exercise.

Science.gov (United States)

Lake, Jason P; Lauder, Mike A

2012-12-01

The aims of this study were to establish mechanical demands of kettlebell swing exercise and provide context by comparing them to mechanical demands of back squat and jump squat exercise. Sixteen men performed 2 sets of 10 swings with 16, 24, and 32 kg, 2 back squats with 20, 40, 60, and 80% 1-repetition maximum (1RM), and 2 jump squats with 0, 20, 40, and 60% 1RM. Sagittal plane motion and ground reaction forces (GRFs) were recorded during swing performance, and GRFs were recorded during back and jump squat performances. Net impulse, and peak and mean propulsion phase force and power applied to the center of mass (CM) were obtained from GRF data and kettlebell displacement and velocity from motion data. The results of repeated measures analysis of variance showed that all swing CM measures were maximized during the 32-kg condition but that velocity of the kettlebell was maximized during the 16-kg condition; displacement was consistent across different loads. Peak and mean force tended to be greater during back and jump squat performances, but swing peak and mean power were greater than back squat power and largely comparable with jump squat power. However, the highest net impulse was recorded during swing exercise with 32 kg (276.1 ± 45.3 N·s vs. 60% 1RM back squat: 182.8 ± 43.1 N·s, and 40% jump squat: 231.3 ± 47.1 N·s). These findings indicate a large mechanical demand during swing exercise that could make swing exercise a useful addition to strength and conditioning programs that aim to develop the ability to rapidly apply force.

Setting standards to determine core clerkship grades in pediatrics.

Science.gov (United States)

Dudas, Robert A; Barone, Michael A

2014-01-01

One of the greatest challenges for clerkship directors is assigning a final grade and determining the precise point at which a student either passes or fails a clinical clerkship. The process of incorporating both subjective and objective assessment data to provide a final summative grade can be challenging. We describe our experience conducting a standard-setting exercise to set defensible cut points in a 4-tiered grading system in our pediatric clerkship. Using the Hofstee standard-setting approach, 8 faculty members participated in an exercise to establish grade cut points. These faculty members were subsequently surveyed to assess their attitudes toward the standard-setting process as well as their reactions to these newly proposed standards. We applied the new cut points to a historic cohort of 116 Johns Hopkins University School of Medicine students from the academic year 2012-2013 to assess the potential impact on grade distributions. The resultant grading schema would lead to a significant increase in the number of students receiving a failing grade and a decrease in the number of students receiving a grade of honors in a historical cohort. Faculty reported that the Hofstee method was easy to understand and fair. All faculty members thought that grade inflation presently exists within the pediatric clerkship. This study demonstrates that practical standards using the Hofstee method can be set for medical students in a pediatric clerkship in which multiple performance measures are used. Copyright © 2014 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Effects of p-Synephrine and Caffeine Ingestion on Substrate Oxidation during Exercise.

Science.gov (United States)

Gutiérrez-Hellín, Jorge; Del Coso, Juan

2018-04-27

Caffeine and p-synephrine are substances usually included in commercially-available products for weight loss because of their purported thermogenic effects. However, scientific information is lacking about the effects of combining these substances on substrate oxidation during exercise. The purpose of this investigation was to determine the isolated and combined effects of p-synephrine and caffeine on fat oxidation rate during exercise. In a double-blind randomized experiment, 13 healthy subjects participated in 4 experimental trials after the ingestion of a capsule containing either a placebo, 3 mg·kg of caffeine, 3 mg·kg of p-synephrine, or the combination of these doses of caffeine and p-synephrine. Energy expenditure and substrate oxidation rates were measured by indirect calorimetry during a cycle ergometer ramp test from 30 to 90% of VO2max. In comparison to the placebo, the ingestion of caffeine, p-synephrine, or p-synephrine+caffeine did not alter total energy expenditure or heart rate during the whole exercise test. However, the ingestion of caffeine (0.44 ± 0.15 g·min, P = 0.03), p-synephrine (0.43 ± 0.19 g·min, P < 0.01), and p-synephrine+caffeine (0.45 ± 0.15 g·min, P = 0.02) increased the maximal rate of fat oxidation during exercise when compared to the placebo (0.30 ± 0.12 g·min). The exercise intensity that elicited maximal fat oxidation was similar in all trials (~46.2 ± 10.2% of VO2max). Caffeine, p-synephrine and p-synephrine+caffeine increased the maximal rate of fat oxidation during exercise compared to a placebo, without modifying energy expenditure or heart rate. However, the co-ingestion of p-synephrine and caffeine did not present an additive effect to further increase fat oxidation during exercise.

Effects of exercise training in patients with idiopathic pulmonary arterial hypertension

OpenAIRE

de Man, F.S.; Handoko, M.L.; Groepenhoff, H.; van 't Hul, A.J.; Abbink, J.; Koppers, R.J.H.; Grotjohan, H.P.; Twisk, J.W.R.; Bogaard, H.J.; Boonstra, A.; Postmus, P.E.; Westerhof, N.; van der Laarse, W.J.; Vonk Noordegraaf, A.

2009-01-01

We determined the physiological effects of exercise training on exercise capacity and quadriceps muscle function in patients with idiopathic pulmonary arterial hypertension (iPAH). In total, 19 clinically stable iPAH patients (New York Heart Association II-III) underwent a supervised exercise training programme for the duration of 12 weeks. Maximal capacity, endurance capacity and quadriceps function were assessed at baseline and after 12 weeks. In 12 patients, serial quadriceps muscle biopsi...

Augmentation of Deglutitive Thyrohyoid Muscle Shortening by the Shaker Exercise

Science.gov (United States)

Mepani, Rachel; Antonik, Stephen; Massey, Benson; Kern, Mark; Logemann, Jerilyn; Pauloski, Barbara; Rademaker, Alfred; Easterling, Caryn

2010-01-01

Earlier studies of the effect of 6 weeks of the Shaker Exercise have shown significant increase in UES opening and anterior excursion of larynx and hyoid during swallowing in patients with upper esophageal sphincter (UES) dysfunction, resulting in elimination of aspiration and resumption of oral intake. This effect is attributed to strengthening of the suprahyoid muscles, as evidenced by comparison of electromyographic changes in muscle fatigue before and after completion of the exercise regime. The effect of this exercise on thyrohyoid muscle shortening is unknown. Therefore the aim of this study was to determine the effect of the exercise on thyrohyoid muscle shortening. We studied 11 dysphagic patients with UES dysfunction. Six were randomized to traditional swallowing therapy and five to the Shaker Exercise. Videofluoroscopy was used to measure deglutitive thyrohyoid shortening before and after completion of assigned therapy regimen. Maximum thyrohyoid muscle shortening occurred at close temporal proximity to the time of maximal thyroid cartilage excursion. The percent change in thyrohyoid distance from initiation of deglutition to maximal anterior/superior hyoid excursion showed no statistically significant difference between the two groups prior to either therapy (p = 0.54). In contrast, after completion of therapy, the percent change in thyrohyoid distance in the Shaker Exercise group was significantly greater compared to the traditional therapy (p = 0.034). The Shaker Exercise augments the thyrohyoid muscle shortening in addition to strengthening the suprahyoid muscles. The combination of increased thyrohyoid shortening and suprahyoid strengthening contributes to the Shaker Exercise outcome of deglutitive UES opening augmentation. PMID:18685891

A randomised clinical trial of a comprehensive exercise program for chronic whiplash: trial protocol

Directory of Open Access Journals (Sweden)

Latimer Jane

2009-12-01

Full Text Available Abstract Background Whiplash is the most common injury following a motor vehicle accident. Approximately 60% of people suffer persistent pain and disability six months post injury. Two forms of exercise; specific motor relearning exercises and graded activity, have been found to be effective treatments for this condition. Although the effect sizes for these exercise programs, individually, are modest, pilot data suggest much larger effects on pain and disability are achieved when these two treatments are combined. The aim of this study is to investigate the effectiveness and cost-effectiveness of this comprehensive exercise approach for chronic whiplash. Methods/Design A multicentre randomised controlled trial will be conducted. One hundred and seventy-six participants with chronic grade I to II whiplash will be recruited in Sydney and Brisbane, Australia. All participants will receive an educational booklet on whiplash and in addition, those randomised to the comprehensive exercise group (specific motor relearning and graded activity exercises will receive 20 progressive and individually-tailored, 1 hour exercise sessions over a 12 week period (specific motor relearning exercises: 8 sessions over 4 weeks; graded activity: 12 sessions over 8 weeks. The primary outcome to be assessed is pain intensity. Other outcomes of interest include disability, health-related quality of life and health service utilisation. Outcomes will be measured at baseline, 14 weeks, 6 months and 12 months by an assessor who is blinded to the group allocation of the subjects. Recruitment is due to commence in late 2009. Discussion The successful completion of this trial will provide evidence on the effectiveness and cost-effectiveness of a simple treatment for the management of chronic whiplash. Trial registration ACTRN12609000825257

Aerobic exercise and respiratory muscle strength in patients with cystic fibrosis.

Science.gov (United States)

Dassios, Theodore; Katelari, Anna; Doudounakis, Stavros; Dimitriou, Gabriel

2013-05-01

The beneficial role of exercise in maintaining health in patients with cystic fibrosis (CF) is well described. Few data exist on the effect of exercise on respiratory muscle function in patients with CF. Our objective was to compare respiratory muscle function indices in CF patients that regularly exercise with those CF patients that do not. This cross-sectional study assessed nutrition, pulmonary function and respiratory muscle function in 37 CF patients that undertook regular aerobic exercise and in a control group matched for age and gender which consisted of 44 CF patients that did not undertake regular exercise. Respiratory muscle function in CF was assessed by maximal inspiratory pressure (Pimax), maximal expiratory pressure (Pemax) and pressure-time index of the respiratory muscles (PTImus). Median Pimax and Pemax were significantly higher in the exercise group compared to the control group (92 vs. 63 cm H2O and 94 vs. 64 cm H2O respectively). PTImus was significantly lower in the exercise group compared to the control group (0.089 vs. 0.121). Upper arm muscle area (UAMA) and mid-arm muscle circumference were significantly increased in the exercise group compared to the control group (2608 vs. 2178 mm2 and 23 vs. 21 cm respectively). UAMA was significantly related to Pimax in the exercising group. These results suggest that CF patients that undertake regular aerobic exercise maintain higher indices of respiratory muscle strength and lower PTImus values, while increased UAMA values in exercising patients highlight the importance of muscular competence in respiratory muscle function in this population. Copyright © 2013 Elsevier Ltd. All rights reserved.

Preconditioning by light-load eccentric exercise is equally effective as low-level laser therapy in attenuating exercise-induced muscle damage in collegiate men

Directory of Open Access Journals (Sweden)

Nausheen S

2017-09-01

Full Text Available Samar Nausheen,1 Jamal Ali Moiz,1 Shahid Raza,1 Mohammad Yakub Shareef,2 Shahnawaz Anwer,3,4 Ahmad H Alghadir3 1Centre for Physiotherapy and Rehabilitation Sciences, Jamia Millia Islamia, New Delhi, India; 2Faculty of Dentistry, Jamia Millia Islamia, New Delhi, India; 3Rehabilitation Research Chair, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia; 4Dr. D. Y. Patil College of Physiotherapy, Dr. D. Y. Patil Vidyapeeth, Pune, India Background/objective: Previous studies have already reported an independent effect of light-load eccentric exercise (10% eccentric exercise contraction [EEC] and low-level laser therapy (LLLT as a protective measure against more strenuous eccentric exercise. However, the difference between these two interventions is largely unknown. Therefore, the present study aimed to compare the preconditioning effect of 10% EEC vs. LLLT on subjective, physiological, and biochemical markers of muscle damage in elbow flexors in collegiate men.Methods: All 36 enrolled subjects were randomly assigned to either 10% EEC or LLLT group. Subjects in 10% EEC group performed 30 repetitions of an eccentric exercise with 10% maximal voluntary contraction strength 2 days prior to maximal eccentric exercise bout, whereas subjects in LLLT group were given LLLT. All the indirect markers of muscle damage were measured pre-exercise and at 24, 48, and 72 hours after the exercise-induced muscle damage protocol.Results: The muscle soreness was reduced in both groups (p = 0.024; however, soreness was attenuated more in LLLT group at 48 hours (33.5 vs. 42.7, p = 0.004. There was no significant difference between the effect of 10% EEC and LLLT groups on other markers of muscle damage like a maximum voluntary isometric contraction (p = 0.47, range of motion (p = 0.16, upper arm circumference (p = 0.70, creatine kinase (p = 0.42, and lactate dehydrogenase (p = 0.08. Within-group analysis showed both interventions provided

Comparison of Critical Power and W' Derived From 2 or 3 Maximal Tests.

Science.gov (United States)

Simpson, Len Parker; Kordi, Mehdi

2017-07-01

Typically, accessing the asymptote (critical power; CP) and curvature constant (W') parameters of the hyperbolic power-duration relationship requires multiple constant-power exhaustive-exercise trials spread over several visits. However, more recently single-visit protocols and personal power meters have been used. This study investigated the practicality of using a 2-trial, single-visit protocol in providing reliable CP and W' estimates. Eight trained cyclists underwent 3- and 12-min maximal-exercise trials in a single session to derive (2-trial) CP and W' estimates. On a separate occasion a 5-min trial was performed, providing a 3rd trial to calculate (3-trial) CP and W'. There were no differences in CP (283 ± 66 vs 282 ± 65 W) or W' (18.72 ± 6.21 vs 18.27 ± 6.29 kJ) obtained from either the 2-trial or 3-trial method, respectively. After 2 familiarization sessions (completing a 3- and a 12-min trial on both occasions), both CP and W' remained reliable over additional separate measurements. The current study demonstrates that after 2 familiarization sessions, reliable CP and W' parameters can be obtained from trained cyclists using only 2 maximal-exercise trials. These results offer practitioners a practical, time-efficient solution for incorporating power-duration testing into applied athlete support.

The effects of creatine pyruvate and creatine citrate on performance during high intensity exercise

Directory of Open Access Journals (Sweden)

Purpura Martin

2008-02-01

Full Text Available Abstract Background A double-blind, placebo-controlled, randomized study was performed to evaluate the effect of oral creatine pyruvate (Cr-Pyr and creatine citrate (Cr-Cit supplementation on exercise performance in healthy young athletes. Methods Performance during intermittent handgrip exercise of maximal intensity was evaluated before (pretest and after (posttest 28 days of Cr-Pyr (5 g/d, n = 16, Cr-Cit (5 g/d, n = 16 or placebo (pla, 5 g/d, n = 17 intake. Subjects performed ten 15-sec exercise intervals, each followed by 45 sec rest periods. Results Cr-Pyr (p Conclusion It is concluded that four weeks of Cr-Pyr and Cr-Cit intake significantly improves performance during intermittent handgrip exercise of maximal intensity and that Cr-Pyr might benefit endurance, due to enhanced activity of the aerobic metabolism.

Relación entre la fuerza máxima en squat y acciones de salto, sprint y golpeo de balón. (Relationship among maximal strength in squat exercise, jump, sprint and kicking ball performance.

Directory of Open Access Journals (Sweden)

Alfredo Arija Blázquez

2008-01-01

Full Text Available ResumenEl objetivo del presente estudio fue analizar las posibles relaciones entre la fuerza máxima en squat y accionesexplosivas de salto, sprint y golpeo de balón. Para ello, se contó con una muestra formada por estudiantes de Ciencias del Deporte (N= 16; 19,6 ± 1,7 años de sexo masculino (con escasa experiencia en el entrenamiento de fuerza, que llevaron a cabo un test de 1RM en squat (calculándose el peso levantado, la fuerza media total y la fuerza dinámica máxima, tests de salto vertical (SJ, CMJ y CMJa, un test de sprint de 20 m (con mediciones de tiempo cada 5 m, y un test de golpeo con el pie donde se calculaba la velocidad del balón. Se encontraron coeficientes de correlación moderados (entre 0,52 y 0,67 y significativos de las medidas de fuerza máxima y las alturas de salto, mientras que los coeficientes obtenidos entre los tiempos de sprint y dichas medidas de fuerza máxima se situaron entre -0,06 y -0,32, no siendo ninguno de ellos significativo; al igual que tampoco fueron significativos los coeficientes de correlación de las medidas de fuerza máxima y la velocidad de tiro, se situaron entre 0,25 y 0,34. Por tanto, la relación entre la fuerza máxima en squat y la altura de salto en sujetos con escasa experiencia en el entrenamiento de fuerza resultó moderada, mientras que no parece existir relación con el tiempo de sprint y la velocidad de tiro.AbstractThe purpose of the present study was to analyze the possible relationships between maximal strength insquat exercise and jump, sprint and kicking ball actions. Sixteen males sport science students (19,6 ± 1,7years, with little experience in strength training, performed a 1RM in squat exercise (from which liftedweight, the total average- and maximal-dynamic strength was assessed, vertical jump (SJ, CMJ and CMJa, a 20 m sprint test (with time measurement every 5 m, and a kicking ball test where the velocity of the ball was calculated. Moderate (0,52 - 0,67 and

Perceived loading and muscle activity during hip strengthening exercises

DEFF Research Database (Denmark)

Brandt, Mikkel; Jakobsen, Markus Due; Thorborg, Kristian

2013-01-01

hip muscle activity during hip abduction and hip adduction exercises using elastic resistance and isotonic machines, using electromyography (EMG). METHODS: EMG activity was recorded from 11 muscles at the hip, thigh and trunk during hip adduction and hip abduction exercises in 16 untrained women......, using elastic resistance and isotonic exercise machines. These recordings were normalized to maximal voluntary contraction (MVC) EMG (nEMG). The exercises were performed at four levels of perceived loading reported using the Borg CR10: light (Borg ≤2), moderate (Borg >2-... (r =0.62±0.54). The abduction exercise performed with elastic resistance displayed significantly higher gluteus medius nEMG recruitment than the in machine exercise. CONCLUSIONS: The results of this study show that the Borg CR10 scale can be a useful tool for estimating intensity levels during...

Benefits of Moderate-Intensity Exercise during a Calorie-Restricted Low-Fat Diet

Science.gov (United States)

Apekey, Tanefa A.; Morris, A. E. J.; Fagbemi, S.; Griffiths, G. J.

2012-01-01

Objective: Despite the health benefits, many people do not undertake regular exercise. This study investigated the effects of moderate-intensity exercise on cardiorespiratory fitness (lung age, blood pressure and maximal aerobic power, VO[subscript 2]max), serum lipids concentration and body mass index (BMI) in sedentary overweight/obese adults…

Influence of music on maximal self-paced running performance and passive post-exercise recovery rate.

Science.gov (United States)

Lee, Sam; Kimmerly, Derek S

2016-01-01

The purpose of this study was to examine the influence of fast tempo music (FM) on self-paced running performance (heart rate, running speed, ratings of perceived exertion), and slow tempo music (SM) on post-exercise heart rate and blood lactate recovery rates. Twelve participants (5 women) completed three randomly assigned conditions: static noise (control), FM and SM. Each condition consisted of self-paced treadmill running, and supine postexercise recovery periods (20 min each). Average running speed, heart rate (HR) and ratings of perceived exertion (RPE) were measured during the treadmill running period, while HR and blood lactate were measured during the recovery period. Listening to FM during exercise resulted in a faster self-selected running speed (10.8±1.7 vs. 9.9±1.4 km•hour-1, Peffect P<0.001) and blood lactate at the end of recovery (2.8±0.4 vs. 4.7±0.8 mmol•L-1, P<0.05). Listening to FM during exercise can increase self-paced intensity without altering perceived exertion levels while listening to SM after exercise can accelerate the recovery rate back to resting levels.

Influence of prior intense exercise and cold water immersion in recovery for performance and physiological response during subsequent exercise

DEFF Research Database (Denmark)

Christensen, Peter Møller; Bangsbo, Jens

2016-01-01

) and the influence from prior intense exercise on subsequent performance and physiological response to moderate and maximal exercise with and without the use of cold water immersion (CWI) in recovery (part B). In part A, performance times during eight World championships for male track cyclists were extracted from...... min preceded by an identical warm-up period in both a control setting (CON) and using cold water immersion in recovery (CWI; 15 min at 15°C). Performance was lowered (P

[Hypertension and exercise. Sports methods for the hypertensive patient].

Science.gov (United States)

Thiele, Holger; Pohlink, Carla; Schuler, Gerhard

2004-06-01

Physical exercise is of paramount therapeutic importance in nonpharmacological interventions of arterial hypertension. The extent and the effects of exercise on blood pressure lowering are analyzed according to the actual literature. Suitable and nonsuitable activities are considered. Dynamic isotonic endurance training is more effective than static isometric exercise. A rather low or moderate extent of endurance training lowers the systolic and diastolic blood pressure by approximately 5-11 mmHg and 3-8 mmHg, respectively. This effect of exercise can be achieved besides the favorable effects on other cardiovascular risk factors. Intensity of exercise should be monitored by the heart rate. The mean intensity should not exceed 70% of the maximal heart rate. An initial ergometry might be suitable for the planning of training recommendations.

The impact of brief high-intensity exercise on blood glucose levels

Directory of Open Access Journals (Sweden)

Adams OP

2013-02-01

Full Text Available O Peter AdamsFaculty of Medical Sciences, the University of the West Indies, Cave Hill Campus, St Michael, BarbadosBackground: Moderate-intensity exercise improves blood glucose (BG, but most people fail to achieve the required exercise volume. High-intensity exercise (HIE protocols vary. Maximal cycle ergometer sprint interval training typically requires only 2.5 minutes of HIE and a total training time commitment (including rest and warm up of 25 minutes per session. The effect of brief high-intensity exercise on blood glucose levels of people with and without diabetes is reviewed.Methods: HIE (≥80% maximal oxygen uptake, VO2max studies with ≤15 minutes HIE per session were reviewed.Results: Six studies of nondiabetics (51 males, 14 females requiring 7.5 to 20 minutes/week of HIE are reviewed. Two weeks of sprint interval training increased insulin sensitivity up to 3 days postintervention. Twelve weeks near maximal interval running (total exercise time 40 minutes/week improved BG to a similar extent as running at 65% VO2max for 150 minutes/week. Eight studies of diabetics (41 type 1 and 22 type 2 subjects were reviewed. Six were of a single exercise session with 44 seconds to 13 minutes of HIE, and the others were 2 and 7 weeks duration with 20 and 2 minutes/week HIE, respectively. With type 1 and 2 diabetes, BG was generally higher during and up to 2 hours after HIE compared to controls. With type 1 diabetics, BG decreased from midnight to 6 AM following HIE the previous morning. With type 2 diabetes, a single session improved postprandial BG for 24 hours, while a 2-week program reduced the average BG by 13% at 48 to 72 hours after exercise and also increased GLUT4 by 369%.Conclusion: Very brief HIE improves BG 1 to 3 days postexercise in both diabetics and nondiabetics. HIE is unlikely to cause hypoglycemia during and immediately after exercise. Larger and longer randomized studies are needed to determine the safety, acceptability, long

Myocardial 201Tl washout after combined dipyridamole submaximal exercise stress: Reference values from different patient groups

International Nuclear Information System (INIS)

Fridrich, L.

1989-01-01

Dipyridamole stress is favorable in patients unable to exercise maximally for 201 Tl myocardial scintigraphy. Aside from an analysis of uptake defects, proper washout analysis can be limited by heart rate variations when isolated dipyridamole stress is used. Heart rate standardized 201 Tl washout kinetics after a combined dipyridamole and submaximal exercise stress protocol (CDSE), feasible in elderly patients as well as in patients with peripheral artery disease, were therefore studied to investigate the 201 Tl washout after CDSE in differently defined patient groups: Group I comprised 19 patients with documented heart disease and angiographically excluded coronary artery disease (CAD); group II contained 17 patients with a very low likelihood of CAD determined by both normal exercise radionuclide ventriculography and normal 201 Tl uptake. Group III comprised 56 patients with a 50% pretest likelihood of CAD but normal 201 Tl uptake. Mean washout values were nearly identical in all groups. Despite similar uptake patterns, however, washout standardized by CDSE was significantly lower than the normal washout values after maximal treadmill exercise. Thus an obviously lower 201 Tl washout after CDSE than after maximal treadmill exercise must be considered if washout analysis criteria after dipyridamole are applied to evaluate ischemic heart disease. Nevertheless, heart rate elevation achieved by additional submaximal exercise stress seems necessary, adequate and clinically safe for standardisation of washout analysis in dipyridamole 201 Tl scintigraphy. (orig.)

Relationship between fatty acid delivery and fatty acid oxidation during strenuous exercise

NARCIS (Netherlands)

Romijn, J. A.; Coyle, E. F.; Sidossis, L. S.; Zhang, X. J.; Wolfe, R. R.

1995-01-01

To evaluate the extent to which decreased plasma free fatty acid (FFA) concentration contributes to the relatively low rates of fat oxidation during high-intensity exercise, we studied FFA metabolism in six endurance-trained cyclists during 20-30 min of exercise [85% of maximal O2 uptake (VO2max)].

Effect of exercise intensity on albuminuria in adolescents with Type 1 diabetes mellitus.

Science.gov (United States)

Kornhauser, C; Malacara, J-M; Macías-Cervantes, M-H; Rivera-Cisneros, A-E

2012-01-01

Exercise may be useful to detect patients with diabetes prone to develop persistent microalbuminuria. We studied the relationship between exercise intensity, measured as maximal oxygen consumption (VO(2)max), and microalbuminuria in patients with Type 1 diabetes mellitus patients. We studied 10 patients, age range 10-18 years, with Type 1 diabetes who were normotensive and normoalbuminuric, with less than 10 years since diagnosis. Patients had normal renal function, without infections or clinical evidence of complications. Metabolic control was intensively adjusted in all patients. They underwent three consecutive physical exercise tests, reaching 100, 80 and 60% of the maximal cardiac frequency response. Eight patients had adequate to regular metabolic control. All patients had lower than predicted VO(2)max values. At 60%, only three patients showed microalbuminuria in excess of 20 μg/min, two of them had inadequate metabolic control. Post-exercise microalbuminuria exceeded normal values in nine, seven and three patients when submitted to 100, 80 and 60% of exercise intensity, respectively. Microalbuminuria increased with exercise intensity. Sex, body composition and VO(2)max were the main factors associated with microalbuminuria. The prognostic significance of albuminuria induced by intense exercise in these subjects with Type 1 diabetes is not yet known. © 2011 The Authors. Diabetic Medicine © 2011 Diabetes UK.

Cardiovascular responses to treadmill exercise in Nigerian ...

African Journals Online (AJOL)

The systolic blood pressure (SBP) and pressure rate product (PRP) during maximal exercise were also increased in hypertensives with LVH and hypertensive without LVH when compared to normotensive controls. The hypertensives with LVH and hypertensives without LVH also showed significant limitation to heart rate ...

Fasting and prolonged exercise increase vasoactive intestinal polypeptide (VIP) in plasma

DEFF Research Database (Denmark)

Galbo, H; Hilsted, J; Fahrenkrug, J

1979-01-01

and maximal exercise. During 59 h of fasting, VIP increased from 3.6 (0.6--6.6) to 10.2 (6.6--13.8) pmol.1(-1) (p less than 0.05). The concentration of glucose in plasma decreased significantly during the prolonged exercise as well as during fasting. The known metabolic actions of VIP and the demonstrated...

Symptom-limited exercise testing causes sustained diastolic dysfunction in patients with coronary disease and low effort tolerance.

Science.gov (United States)

Fragasso, G; Benti, R; Sciammarella, M; Rossetti, E; Savi, A; Gerundini, P; Chierchia, S L

1991-05-01

Exercise stress testing is routinely used for the noninvasive assessment of coronary artery disease and is considered a safe procedure. However, the provocation of severe ischemia might potentially cause delayed recovery of myocardial function. To investigate the possibility that maximal exercise testing could induce prolonged impairment of left ventricular function, 15 patients with angiographically proved coronary disease and 9 age-matched control subjects with atypical chest pain and normal coronary arteries were studied. Radionuclide ventriculography was performed at rest, at peak exercise, during recovery and 2 and 7 days after exercise. Ejection fraction, peak filling and peak emptying rates and left ventricular wall motion were analyzed. All control subjects had a normal exercise test at maximal work loads and improved left ventricular function on exercise. Patients developed 1 mm ST depression at 217 +/- 161 s at a work load of 70 +/- 30 W and a rate-pressure product of 18,530 +/- 4,465 mm Hg x beats/min. Although exercise was discontinued when angina or equivalent symptoms occurred, in all patients diagnostic ST depression (greater than or equal to 1 mm) developed much earlier than symptoms. Predictably, at peak exercise patients showed a decrease in ejection fraction and peak emptying and filling rates. Ejection fraction and peak emptying rate normalized within the recovery period, whereas peak filling rate remained depressed throughout recovery (p less than 0.002) and was still reduced 2 days after exercise (p less than 0.02). In conclusion, in patients with severe impairement of coronary flow reserve, maximal exercise may cause sustained impairement of diastolic function.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of exercise on fitness and health of adults with spinal cord injury: A systematic review.

Science.gov (United States)

van der Scheer, Jan W; Martin Ginis, Kathleen A; Ditor, David S; Goosey-Tolfrey, Victoria L; Hicks, Audrey L; West, Christopher R; Wolfe, Dalton L

2017-08-15

To synthesize and appraise research testing the effects of exercise interventions on fitness, cardiometabolic health, and bone health among adults with spinal cord injury (SCI). Electronic databases were searched (1980-2016). Included studies employed exercise interventions for a period ≥2 weeks, involved adults with acute or chronic SCI, and measured fitness (cardiorespiratory fitness, power output, or muscle strength), cardiometabolic health (body composition or cardiovascular risk factors), or bone health outcomes. Evidence was synthesized and appraised using Grading of Recommendations Assessment, Development, and Evaluation (GRADE). A total of 211 studies met the inclusion criteria (22 acute, 189 chronic). For chronic SCI, GRADE confidence ratings were moderate to high for evidence showing exercise can improve all of the reviewed outcomes except bone health. For acute SCI, GRADE ratings were very low for all outcomes. For chronic SCI, there was low to moderate confidence in the evidence showing that 2-3 sessions/week of upper body aerobic exercise at a moderate to vigorous intensity for 20-40 minutes, plus upper body strength exercise (3 sets of 10 repetitions at 50%-80% 1-repetition maximum for all large muscle groups), can improve cardiorespiratory fitness, power output, and muscle strength. For chronic SCI, there was low to moderate confidence in the evidence showing that 3-5 sessions per week of upper body aerobic exercise at a moderate to vigorous intensity for 20-44 minutes can improve cardiorespiratory fitness, muscle strength, body composition, and cardiovascular risk. Exercise improves fitness and cardiometabolic health of adults with chronic SCI. The evidence on effective exercise types, frequencies, intensities, and durations should be used to formulate exercise guidelines for adults with SCI. © 2017 American Academy of Neurology.

Comparison of exercise capacity with resting left ventricular function evaluated by various non-invasive methods in patients with old myocardial infarction

International Nuclear Information System (INIS)

Yamabe, Hiroshi; Kobayashi, Katsuya; Tajiri, Eiichi; Hayakawa, Masanori; Minamiji, Katsumi

1982-01-01

The relationship between exercise capacity and resting left ventricular function assessed by several non-invasive methods in patients with old myocardial infarction was investigated. Subjects were 25 male patients whose endpoint was either dyspnea or general fatigue at the symptom-limited maximal graded treadmill exercise test according to Bruce protocol. The indices obtained by non-invasive cardiac examinations included left ventricular fractional shortening (% FS), scintigraphic infact size (% SIS) by 201 Tl myocardial scintigraphy and PEP/ET. A significant correlation of exercise duration with % FS (r = 0.67, p < 0.001) or with % SIS (r = -0.55, p < 0.02) indicated that the more impaired resting left ventricular function, the more was decreased exercise capacity. Also, a significant correlation of systolic blood pressure at the endpoint in exercise test with % FS (r = 0.58, p < 0.005) or with % SIS (r = 0.69, p < 0.001) indicated that inadequate blood pressure response might be partially attributed to impaired left ventricular function during exercise. The response of heart rate at the Bruce protocol stage I correlated with % FS (r = -0.67, p < 0.001) and with % SIS (r = 0.53, p < 0.02), respectively. These findings may be interpreted as chronotropic compensatory mechanism for limited stroke volume during exercise in patients with impaired left ventricular function. Thus, it was concluded that resting left ventricular function assessed by non-invasive cardiac examinations may predict exercise capacity prior to the test to some extent. These informations can be utilized for the decision of the planning at cardiac rehabilitation and also for the guidance in daily activities. (J.P.N.)

Phenomenology of maximal and near-maximal lepton mixing

International Nuclear Information System (INIS)

Gonzalez-Garcia, M. C.; Pena-Garay, Carlos; Nir, Yosef; Smirnov, Alexei Yu.

2001-01-01

The possible existence of maximal or near-maximal lepton mixing constitutes an intriguing challenge for fundamental theories of flavor. We study the phenomenological consequences of maximal and near-maximal mixing of the electron neutrino with other (x=tau and/or muon) neutrinos. We describe the deviations from maximal mixing in terms of a parameter ε(equivalent to)1-2sin 2 θ ex and quantify the present experimental status for |ε| e mixing comes from solar neutrino experiments. We find that the global analysis of solar neutrino data allows maximal mixing with confidence level better than 99% for 10 -8 eV 2 ∼ 2 ∼ -7 eV 2 . In the mass ranges Δm 2 ∼>1.5x10 -5 eV 2 and 4x10 -10 eV 2 ∼ 2 ∼ -7 eV 2 the full interval |ε| e mixing in atmospheric neutrinos, supernova neutrinos, and neutrinoless double beta decay

An Evidence-Based Approach To Exercise Prescriptions on ISS

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Ploutz-Snyder, Lori

2009-01-01

This presentation describes current exercise countermeasures and exercise equipment for astronauts onboard the ISS. Additionally, a strategy for evaluating evidence supporting spaceflight exercise is described and a new exercise prescription is proposed. The current exercise regimen is not fully effective as the ISS exercise hardware does not allow for sufficient exercise intensity, the exercise prescription is adequate and crew members are noncompliant with the prescription. New ISS hardware is proposed, Advanced Resistance Exercise Device (ARED), which allows additional exercises, is instrumented for data acquisition and offers improved loading. The new T2 hardware offers a better harness and subject loading system, is instrumented to allow ground reaction force data, and offers improved speed. A strategy for developing a spaceflight exercise prescription is described and involves identifying exercise training programs that have been shown to maximize adaptive benefits of people exercising in both 0 and 1 g environments. Exercise intensity emerged as an important factor in maintaining physiologic adaptations in the spaceflight environment and interval training is suggested. New ISS exercise hardware should allow for exercise at intensities high enough to elicit adaptive responses. Additionally, new exercise prescriptions should incorporate higher intensity exercises and seek to optimize intensity, duration and frequency for greater efficiency.

Maximal and anaerobic threshold cardiorespiratory responses during deepwater running

Directory of Open Access Journals (Sweden)

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

Physical exercise training for cystic fibrosis.

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Radtke, Thomas; Nevitt, Sarah J; Hebestreit, Helge; Kriemler, Susi

2017-11-01

Physical exercise training may form an important part of regular care for people with cystic fibrosis. This is an update of a previously published review. To assess the effects of physical exercise training on exercise capacity by peak oxygen consumption, pulmonary function by forced expiratory volume in one second, health-related quality of life and further important patient-relevant outcomes in people with cystic fibrosis. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings.Date of the most recent search: 04 May 2017.We searched ongoing trials registers (clinicaltrials.gov and the WHO ICTRP). Date of most recent search: 10 August 2017. All randomised and quasi-randomised controlled clinical trials comparing exercise training of any type and a minimum duration of two weeks with conventional care (no training) in people with cystic fibrosis. Two authors independently selected studies for inclusion, assessed methodological quality and extracted data. The quality of the evidence was assessed using the GRADE system. Of the 83 studies identified, 15 studies which included 487 participants, met the inclusion criteria. The numbers in each study ranged from nine up to 72 participants; two studies were in adults, seven were in children and adolescents and six studies included all age ranges. Four studies of hospitalised participants lasted less than one month and 11 studies were outpatient-based, lasting between two months and three years. The studies included participants with a wide range of disease severity and employed differing levels of supervision with a mixture of types of training. There was also wide variation in the quality of the included studies.This systematic review shows very low- to low-quality evidence from both short- and long-term studies that in people

Maximal heart rate in soccer players: Measured versus age-predicted

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Pantelis T Nikolaidis

2015-02-01

Full Text Available Background: Although maximal heart rate (HR max is widely used to assess exercise intensity in sport training, and particularly in soccer, there are limited data with regards to the use of age-based prediction equations of HR max in soccer players. The aim of this study was to compare the measured-HR max with two prediction equations (Fox-HR max = 220 – age and Tanaka-HR max = 208 – 0.7 × age in soccer players. Methods: Adolescent (n = 162, 15.8 ± 1.5 years and adult players (n = 158, 23.4 ± 4.6 years, all members of competitive clubs, voluntarily performed a graded exercise field test (Conconi protocol to assess HR max . Results: The measured-HR max (197.6 ± 9.4 bpm in total, 200.2 ± 7.9 bpm in adolescent players, and 195.0 ± 10.0 bpm in adult players was explained by the formula HR max = 212.3 – 0.75 × age (r = −0.41, standard error of the estimate = 8.6. In the total sample, Fox-HR max overestimated measured-HR max [mean difference (95% confidence intervals = 2.8 bpm (1.6; 3.9], while Tanaka-HR max underestimated HR max [–3.3 bpm (–4.5; –2.2]. In adolescents, Fox-HR max overestimated measured-HR max [4.0 bpm (2.5; 5.5] and Tanaka-HR max underestimated HR max [– 3.2 bpm (–4.7; –1.8]. In adults, Tanaka-HR max underestimated HR max [–5.0 bpm (–5.3; –4.7], while there was not any difference between Fox-HR max and measured-HR max [1.6 bpm (–3.4; 0.2]. Conclusions: The results of this study failed to validate two widely used prediction equations in a large sample of soccer players, indicating the need for a sport-specific equation. On the other hand, the new equation that we presented should be investigated further by future studies before being adopted by coaches and fitness trainers.

Does exercise improve symptoms in fibromyalgia?

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Rain, Carmen; Seguel, Willy; Vergara, Luis

2015-12-14

It has been proposed that fibromyalgia could be managed by pharmacological and non-pharmacological interventions. Regular physical exercise is commonly used as a non-pharmacological intervention. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified 14 systematic reviews including 25 randomized trials. We combined the evidence using meta-analysis and generated a summary of findings table following the GRADE approach. We conclude that regular physical exercise probably reduces pain in patients with fibromyalgia.

Physical exercise restores microvascular function in obese rats with metabolic syndrome.

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Machado, Marcus Vinicius; Vieira, Aline Bomfim; Nascimento, Alessandro Rodrigues; Martins, Rômulo Lanza; Daleprane, Julio Beltrame; Lessa, Marcos Adriano; Tibiriçá, Eduardo

2014-11-01

Obesity and metabolic syndrome are related to systemic functional microvascular alterations, including a significant reduction in microvessel density. The aim of this study was to investigate the effects of exercise training on functional capillary density in the skeletal muscle and skin of obese rats with metabolic syndrome. We used male Wistar-Kyoto rats that had been fed a standard commercial diet (CON) or high-fat diet (HFD) for 32 weeks. Animals receiving the HFD were randomly divided into sedentary (HFD+SED) and training groups (HFD+TR) at the 20(th) week. After 12 weeks of aerobic treadmill training, the maximal oxygen uptake (VO2max); hemodynamic, biochemical, and anthropometric parameters; and functional capillary density were assessed. In addition, a maximal exercise test was performed. Exercise training increased the VO2max (69 ± 3 mL/kg per min) and exercise tolerance (30 ± 1 min) compared with the HFD+SED (41 ± 6 mL/kg per min, P Exercise training also increased the number of spontaneously perfused capillaries in the skeletal muscle (252 ± 9 vs. 207 ± 9 capillaries/mm(2)) of the training group compared with that in the sedentary animals (260 ± 15 capillaries/mm(2)). These results demonstrate that exercise training reverses capillary rarefaction in our experimental model of metabolic syndrome and obesity.

Exercise excess pressure and exercise-induced albuminuria in patients with type 2 diabetes mellitus.

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Climie, Rachel E D; Srikanth, Velandai; Keith, Laura J; Davies, Justin E; Sharman, James E

2015-05-01

Exercise-induced albuminuria is common in patients with type 2 diabetes mellitus (T2DM) in response to maximal exercise, but the response to light-moderate exercise is unclear. Patients with T2DM have abnormal central hemodynamics and greater propensity for exercise hypertension. This study sought to determine the relationship between light-moderate exercise central hemodynamics (including aortic reservoir and excess pressure) and exercise-induced albuminuria. Thirty-nine T2DM (62 ± 9 yr; 49% male) and 39 nondiabetic controls (53 ± 9 yr; 51% male) were examined at rest and during 20 min of light-moderate cycle exercise (30 W; 50 revolutions/min). Albuminuria was assessed by the albumin-creatinine ratio (ACR) at rest and 30 min postexercise. Hemodynamics recorded included brachial and central blood pressure (BP), aortic stiffness, augmented pressure (AP), aortic reservoir pressure, and excess pressure integral (Pexcess). There was no difference in ACR between groups before exercise (P > 0.05). Exercise induced a significant rise in ACR in T2DM but not controls (1.73 ± 1.43 vs. 0.53 ± 1.0 mg/mol, P = 0.002). All central hemodynamic variables were significantly higher during exercise in T2DM (i.e., Pexcess, systolic BP and AP; P exercise Pexcess was associated with postexercise ACR (r = 0.51, P = 0.002), and this relationship was independent of age, sex, body mass index, heart rate, aortic stiffness, antihypertensive medication, and ambulatory daytime systolic BP (β = 0.003, P = 0.003). Light-moderate exercise induced a significant rise in ACR in T2DM, and this was independently associated with Pexcess, a potential marker of vascular dysfunction. These novel findings suggest that Pexcess could be important for appropriate renal function in T2DM. Copyright © 2015 the American Physiological Society.

Absence of resting cardiovascular dysfunction in middle-aged endurance-trained athletes with exaggerated exercise blood pressure responses.

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Currie, Katharine D; Sless, Ryan T; Notarius, Catherine F; Thomas, Scott G; Goodman, Jack M

2017-08-01

Untrained individuals with exaggerated blood pressure (EBP) responses to graded exercise testing are characterized as having resting dysfunction of the sympathetic and cardiovascular systems. The purpose of this study was to determine the resting cardiovascular state of endurance-trained individuals with EBP through a comparison of normotensive athletes with and without EBP. EBP was defined as a maximal systolic blood pressure (SBP) at least 190 mmHg and at least 210 mmHg for women and men respectively, in response to a graded exercise test. Twenty-two life-long endurance-trained athletes (56 ± 5 years, 16 men) with EBP (EBP+) and 11 age and sex-matched athletes (55 ± 5 years, eight men) without EBP (EBP-) participated in the study. Sympathetic reactivity was assessed using BP responses to a cold pressor test, isometric handgrip exercise, and postexercise muscle ischemia. Resting left ventricular structure and function was assessed using two-dimensional echocardiography, whereas central arterial stiffness was assessed using carotid-to-femoral pulse wave velocity. Calf vascular conductance was measured at rest and peak postexercise using strain-gauge plethysmography. All sympathetic reactivity, left ventricular, and arterial stiffness indices were similar between groups. There was no between-group difference in resting vascular conductance, whereas peak vascular conductance was higher in EBP+ relative to EBP- (1.81 ± 0.65 vs. 1.45 ± 0.32 ml/100 ml/min/mmHg, P < 0.05). Findings from this study suggest that athletes with EBP do not display the resting cardiovascular state typically observed in untrained individuals with EBP. This response in athletes, therefore, is likely a compensatory mechanism to satisfy peripheral blood-flow demands rather than indicative of latent dysfunction.

CNS fatigue provoked by prolonged exercise in the heat

DEFF Research Database (Denmark)

Nybo, Lars

2010-01-01

to the brain. However, exercise with superimposed hyperthermia is not only a challenge to the brain it also provides an excellent model for studying factors of importance for central fatigue. Excessive heat storage within the brain appears to be the primary cause for the central fatigue during exercise......Exercise-induced hyperthermia is associated with central fatigue as indicated by an impaired ability to sustain maximal motor activation during prolonged voluntary efforts. Therefore, exercise in hot environments challenges not only to the cardiorespiratory and locomotive systems but also...... to aggravate central fatigue and degrade exercise performance. Hyperthermia mediated central fatigue may include other cerebral perturbations such as reduced perfusion of the brain, accumulation of ammonia or depletion of neuronal energy stores, but further research is needed to elucidate their possible...

The Effects of Hypobaric Hypoxia on Erythropoiesis, Maximal Oxygen Uptake and Energy Cost of Exercise Under Normoxia in Elite Biathletes

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Milosz Czuba

2014-12-01

Full Text Available The aim of the present study was to evaluate the effects of 3 weeks altitude training according to the HiHiLo (live high-base train high-interval train low procedure as described by Chapman et al. (1998, on erythropoiesis, maximal oxygen uptake and energy cost of exercise under normoxia in elite biathletes. Fifteen male elite biathletes randomly divided into an experimental (H group (n = 7; age 27.1 ± 4.6 years; maximal oxygen uptake (VO2max 66.9 ± 3.3 ml·kg–1·min–1; body height (BH 1.81 ± 0.06 m; body mass (BM 73.1 ± 5.4kg, and a control (C group (n = 8; age 23.2 ± 0.9 years; VO2max 68.2 ± 4.1 ml·kg–1·min–1; BH 1.75 ± 0.03 m; BM 63.1 ± 1.5 kg took part in the study. The H group stayed for 3 weeks at an altitude of 2015 m and performed endurance training on skis four times per week at 3000 m. Additionally, the training protocol included three high-intensity interval sessions at an altitude of 1000 m. The C group followed the same training protocol with skirollers in normoxia at an altitude of 600 m. The HiHiLo protocol applied in our study did not change VO2max or maximal workload (WRmax significantly during the incremental treadmill test in group H. However, the energy cost for selected submaximal workloads in group H was significantly (p < 0.01 reduced compared to group C (-5.7%, -4.4%, -6% vs. -3.5%, -2.1%, -2.4%. Also a significant (p < 0.001 increase in serum EPO levels during the first two weeks of HiHiLo training at 2015 m was observed, associated with a significant (p < 0.05 increase in hemoglobin mass, number of erythrocytes, hematocrit value and percent of reticulocytes compared with initial values (by 6.4%, 5%, 4.6% and 16,6%, respectively. In group C, changes in these variables were not observed. These positive changes observed in our study led to a conclusion that the HiHiLo training method could improve endurance in normoxia, since most of the biathlon competitions are performed at submaximal intensities.

Crossfit-based high-intensity power training improves maximal aerobic fitness and body composition.

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Smith, Michael M; Sommer, Allan J; Starkoff, Brooke E; Devor, Steven T

2013-11-01

The purpose of this study was to examine the effects of a crossfit-based high-intensity power training (HIPT) program on aerobic fitness and body composition. Healthy subjects of both genders (23 men, 20 women) spanning all levels of aerobic fitness and body composition completed 10 weeks of HIPT consisting of lifts such as the squat, deadlift, clean, snatch, and overhead press performed as quickly as possible. Additionally, this crossfit-based HIPT program included skill work for the improvement of traditional Olympic lifts and selected gymnastic exercises. Body fat percentage was estimated using whole-body plethysmography, and maximal aerobic capacity (VO2max) was measured by analyzing expired gasses during a Bruce protocol maximal graded treadmill test. These variables were measured again after 10 weeks of training and compared for significant changes using a paired t-test. Results showed significant (p < 0.05) improvements of VO2max in men (43.10 ± 1.40 to 48.96 ± 1.42 ml · kg · min) and women (35.98 ± 1.60 to 40.22 ± 1.62 ml · kg · min) and decreased body fat percentage in men (22.2 ± 1.3 to 18.0 ± 1.3) and women (26.6 ± 2.0 to 23.2 ± 2.0). These improvements were significant across all levels of initial fitness. Significant correlations between absolute oxygen consumption and oxygen consumption relative to body weight was found in both men (r = 0.83, p < 0.001) and women (r = 0.94, p < 0.001), indicating that HIPT improved VO2max scaled to body weight independent of changes to body composition. Our data show that HIPT significantly improves VO2max and body composition in subjects of both genders across all levels of fitness.

The cardiovascular system after exercise

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Romero, Steven A.; Minson, Christopher T.

2017-01-01

Recovery from exercise refers to the time period between the end of a bout of exercise and the subsequent return to a resting or recovered state. It also refers to specific physiological processes or states occurring after exercise that are distinct from the physiology of either the exercising or the resting states. In this context, recovery of the cardiovascular system after exercise occurs across a period of minutes to hours, during which many characteristics of the system, even how it is controlled, change over time. Some of these changes may be necessary for long-term adaptation to exercise training, yet some can lead to cardiovascular instability during recovery. Furthermore, some of these changes may provide insight into when the cardiovascular system has recovered from prior training and is physiologically ready for additional training stress. This review focuses on the most consistently observed hemodynamic adjustments and the underlying causes that drive cardiovascular recovery and will highlight how they differ following resistance and aerobic exercise. Primary emphasis will be placed on the hypotensive effect of aerobic and resistance exercise and associated mechanisms that have clinical relevance, but if left unchecked, can progress to symptomatic hypotension and syncope. Finally, we focus on the practical application of this information to strategies to maximize the benefits of cardiovascular recovery, or minimize the vulnerabilities of this state. We will explore appropriate field measures, and discuss to what extent these can guide an athlete’s training. PMID:28153943

Maximal exercise electrocardiographic responses and coronary heart disease mortality among men with metabolic syndrome.

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

2010-03-01

To examine the association between abnormal exercise electrocardiographic (E-ECG) test results and mortality (all-cause and that resulting from coronary heart disease [CHD] or cardiovascular disease [CVD]) in a large population of asymptomatic men with metabolic syndrome (MetS). A total of 9191 men (mean age, 46.9 years) met the criteria of having MetS. All completed a maximal E-ECG treadmill test (May 14, 1979, through April 9, 2001) and were without a previous CVD event or diabetes at baseline. Main outcomes were all-cause mortality, mortality due to CHD, and mortality due to CVD. Cox regression analysis was used to quantify the mortality risk according to E-ECG responses. During a follow-up of 14 years, 633 deaths (242 CVD and 150 CHD) were identified. Mortality rates and hazard ratios (HRs) across E-ECG responses were the following: for all-cause mortality: HR, 1.36; 95% confidence interval (CI), 1.09-1.70 for equivocal responses and HR, 1.41; 95% CI, 1.12-1.77 for abnormal responses (P(trend)<.001); for mortality due to CVD: HR, 1.29; 95% CI, 0.88-1.88 for equivocal responses and HR, 2.04; 95% CI, 1.46-2.84 for abnormal responses (P(trend)<.001); and for mortality due to CHD: HR, 1.62; 95% CI, 1.02-2.56 for equivocal responses and HR, 2.45; 95% CI, 1.62-3.69 for abnormal responses (P(trend)<.001). A positive gradient for CHD, CVD, and all-cause mortality rates across E-ECG categories within 3, 4, or 5 MetS components was observed (P<.001 for all). Among men with MetS, an abnormal E-ECG response was associated with higher risk of all-cause, CVD, and CHD mortality. These findings underscore the importance of E-ECG tests to identify men with MetS who are at risk of dying.

The role of cardiopulmonary exercise test for individualized exercise training recommendation in young obese subjects

Directory of Open Access Journals (Sweden)

Lucian Hoble

2010-06-01

Full Text Available Obesity is affecting a growing segment of the population and should be considered a serious health problem which will lead to medical complications and decreased life span. Lifestyle changes by adopting healthy food and increase energy consumption through physical activity is the most important treatment for obesity. Cardiopulmonary exercise test (CPET is considered the gold standard for exercise capacity assessment. Purpose: This study is aiming to demonstrate that individualized exercise training programs, designed using CPET results, leads to increase of physical fitness, aerobic capacity, ventilatory and cardiac exercise performance in young obese subjects.Material and method:We performed a prospective research study of 6 months. 43 sedentary subjects without contraindications to exercise, 21.3±3.1 years old, 93% female were included in the study. Assessments were made at baseline and after six months of intervention and consists of cardiopulmonary exercise test on bicycle ergometer. After we recorded oxygen uptake at aerobic threshold (AT, anaerobic threshold (in the range of respiratory compensation point – RCP and maximal oxygen uptake (VO2max we designed the training program according to these parameters and individualized heart rate training zones of each subject. Exercise training (60 minutes/session, 3 sessions/week was performed taking in consideration the training zones and using a circuit on cardio devices. Each subject was supervised by a physiotherapist and using heart rate monitors. The number of subjects evaluated at the end of the study was 27 (dropout rate 37%.Results:After six months of intervention we noticed an improvement of maximum oxygen uptake (VO2max (from 22.7±3.69 to 27.44±5.55, aerobic threshold (VO2_AT (from 15.48±2.66 to 20.07±4.64 ml/min/kg, p<0.0001 and anaerobic threshold (VO2_RCP (from 20.3±3.66 to 25.11±5.84 ml/min/kg, p<0.0001, cardiac performance during exercise evaluated trough maximal oxygen

Effects of an Aerobic Exercise Program on Community-Based Adults with Mental Retardation.

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Pommering, Thomas L.; And Others

1994-01-01

Evaluation of a 10-week aerobic exercise program on 14 community-based adults with mental retardation found a 91.3% attendance rate and significant increases in maximal oxygen consumption, oxygen pulse, maximum ventilation, exercise stress test duration, and flexibility. However, no significant changes were observed in weight or body composition.…

Effect of exercise on arterial stiffness

DEFF Research Database (Denmark)

Montero, David; Andersen, Andreas Breenfeldt; Oberholzer, Laura

2017-01-01

points (P = 0.196) although a linear decreasing trend was detected (P = 0.016). CONCLUSIONS: Central AS augments during a conventional ET intervention that effectively enhances aerobic exercise capacity in young individuals. This suggests that normal, healthy elastic arteries are not amendable......BACKGROUND: Whether arterial stiffness (AS) can be improved by regular exercise in healthy individuals remains equivocal according to cross-sectional and longitudinal studies assessing arterial properties at discrete time points. The purpose of the present study was to pinpoint the time course......), in 9 previously untrained healthy normotensive adults (27 ± 4 years) with no history of cardiovascular disease. Exercise capacity was assessed by maximal oxygen consumption (VO2max) elicited by incremental ergometry. RESULTS: VO2max increased throughout the ET intervention (+12% from week 0 to week 8...

[Silent myocardial ischemia and exercise-induced arrhythmia detected by the exercise test in the total health promotion plan (THP)].

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Iwane, M; Shibe, Y; Itoh, K; Kinoshita, F; Kanagawa, Y; Kobayashi, M; Mugitani, K; Ohta, M; Ohata, H; Yoshikawa, A; Ikuta, Z; Nakamura, Y; Mohara, O

2001-03-01

We investigated the prevalence and characteristics of ischemic heart disease especially silent myocardial ischemia (SMI) and arrhythmia in need of careful observation in the exercise stress tests in the Total Health Promotion Plan (THP), which was conducted between 1994-96 for the purpose of measuring cardiopulmonary function. All workers (n = 4,918, 4,426 males) aged 18-60 yr old in an occupational field were studied. Exercise tests with an ergometer were performed by the LOPS protocol, in which the maximal workload was set up as a presumed 70-80% maximal oxygen intake, or STEP (original multistage protocol). ECG changes were evaluated with a CC5 lead. Two hundred and fifteen people refused the study because of a common cold, lumbago and so on. Of 4,703 subjects, 17 with abnormal rest ECG and 19 with probable anginal pain were excluded from the exercise tests. Of 4,667 who underwent the exercise test, 37 (0.79%) had ischemic ECG change, and 155 (3.32%) had striking arrhythmia. These 228 subjects then did a treadmill exercise test with Bruce protocol. Twenty-two (0.47% of 4,703) showed positive ECG change, 9 (0.19%) of 22 had abnormal findings on a 201Tl scan. 8 (0.17%) were diagnosed as SMI (Cohn I), in which the prevalence of hypertension, hyperlipidemia, diabetes mellitus, smoker and positive familial history of ischemic heart disease was greater than that of all subjects. In a 15-30 month follow up, none has developed cardiac accidents. Exercise-induced arrhythmia was detected in 11 (0.23%) subjects. Four were non-sustained ventricular tachycardia without any organic disease, 4 were ventricular arrhythmia based on cardiomyopathy detected by echocardiography, 2 were atrial fibrillation and another was WPW syndrome. It is therefore likely that the ergometer exercise test in THP was effective in preventing sudden death caused by ischemic heart disease or striking arrhythmia.

Respiratory exercise in amyotrophic lateral sclerosis.

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Pinto, Susana; Swash, Michael; de Carvalho, Mamede

2012-01-01

We have evaluated the potential role of respiratory exercise by implementing specific inspiratory muscle training in a selected population of early-affected amyotrophic lateral sclerosis (ALS) patients. We studied 26 patients with ALS with normal respiratory function using two groups of patients in a parallel, control-group, randomized, delayed-start design. Patients in the first group (G1) started the active inspiratory exercise programme at entry and were followed for eight months, while the second group (G2) of patients followed a placebo exercise programme for the first four months and then active exercise for the second four-month period. The primary outcome measure was the ALSFRS. Respiratory tests, neurophysiological measurements, fatigue and quality of life scales were secondary outcomes. Analysis of covariance was used to compare changes between and within groups. Results showed that there was no significant difference between the two patient groups. Within-group analysis suggested that inspiratory exercise promotes a transient improvement in the respiratory subscore and in the maximal voluntary ventilation, peak expiratory flow, and sniff inspiratory pressure. In conclusion, there was no clear positive or negative outcome of the respiratory exercise protocol we have proposed, but we cannot rule out a minor positive effect. Exercise regimes merit more detailed clinical evaluation in ALS.

What do we know about the cardiac benefits of exercise?

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Wei, Xin; Liu, Xiaojun; Rosenzweig, Anthony

2015-08-01

Exercise has long been considered an essential element for sustaining cardiovascular health. A vast literature of clinical studies suggests that exercise serves as an effective intervention for the primary and secondary prevention of cardiovascular disease, although the optimal nature, intensity, and duration of exercise for maximizing these cardiovascular benefits remain unclear. On a molecular level, exercise induces physiologic growth of the heart primarily by driving cardiomyocyte hypertrophy, notably through the interconnected IGF-1-PI3K-AKT1 and C/EBPβ-CITED4 pathways. Here, we explore the range of clinical evidence supporting the cardiovascular benefits of exercise and outline the molecular pathways that play major roles in regulating these protective effects. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of aerobic training intensity on resting, exercise and post-exercise blood pressure, heart rate and heart-rate variability.

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Cornelissen, V A; Verheyden, B; Aubert, A E; Fagard, R H

2010-03-01

We aimed to investigate the effects of endurance training intensity (1) on systolic blood pressure (SBP) and heart rate (HR) at rest before exercise, and during and after a maximal exercise test; and (2) on measures of HR variability at rest before exercise and during recovery from the exercise test, in at least 55-year-old healthy sedentary men and women. A randomized crossover study comprising three 10-week periods was performed. In the first and third period, participants exercised at lower or higher intensity (33% or 66% of HR reserve) in random order, with a sedentary period in between. Training programmes were identical except for intensity, and were performed under supervision thrice for 1 h per week. The results show that in the three conditions, that is, at rest before exercise, during exercise and during recovery, we found endurance training at lower and higher intensity to reduce SBP significantly (Pendurance training did not affect the response of SBP after an acute bout of exercise. The effect of training on HR at rest, during exercise and recovery was more pronounced (Pendurance training had no significant effect on sympathovagal balance. In conclusion, in participants at higher age, both training programmes exert similar effects on SBP at rest, during exercise and during post-exercise recovery, whereas the effects on HR are more pronounced after higher intensity training.

Importance of Non-invasive Right and Left Ventricular Variables on Exercise Capacity in Patients with Tetralogy of Fallot Hemodynamics.

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Meierhofer, Christian; Tavakkoli, Timon; Kühn, Andreas; Ulm, Kurt; Hager, Alfred; Müller, Jan; Martinoff, Stefan; Ewert, Peter; Stern, Heiko

2017-12-01

Good quality of life correlates with a good exercise capacity in daily life in patients with tetralogy of Fallot (ToF). Patients after correction of ToF usually develop residual defects such as pulmonary regurgitation or stenosis of variable severity. However, the importance of different hemodynamic parameters and their impact on exercise capacity is unclear. We investigated several hemodynamic parameters measured by cardiovascular magnetic resonance (CMR) and echocardiography and evaluated which parameter has the most pronounced effect on maximal exercise capacity determined by cardiopulmonary exercise testing (CPET). 132 patients with ToF-like hemodynamics were tested during routine follow-up with CMR, echocardiography and CPET. Right and left ventricular volume data, ventricular ejection fraction and pulmonary regurgitation were evaluated by CMR. Echocardiographic pressure gradients in the right ventricular outflow tract and through the tricuspid valve were measured. All data were classified and correlated with the results of CPET evaluations of these patients. The analysis was performed using the Random Forest model. In this way, we calculated the importance of the different hemodynamic variables related to the maximal oxygen uptake in CPET (VO 2 %predicted). Right ventricular pressure showed the most important influence on maximal oxygen uptake, whereas pulmonary regurgitation and right ventricular enddiastolic volume were not important hemodynamic variables to predict maximal oxygen uptake in CPET. Maximal exercise capacity was only very weakly influenced by right ventricular enddiastolic volume and not at all by pulmonary regurgitation in patients with ToF. The variable with the most pronounced influence was the right ventricular pressure.

Prescribing Optimal Nutrition and Physical Activity as “First-Line” Interventions for Best Practice Management of Chronic Low-Grade Inflammation Associated with Osteoarthritis: Evidence Synthesis

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Elizabeth Dean

2012-01-01

Full Text Available Low-grade inflammation and oxidative stress underlie chronic osteoarthritis. Although best-practice guidelines for osteoarthritis emphasize self-management including weight control and exercise, the role of lifestyle behavior change to address chronic low-grade inflammation has not been a focus of first-line management. This paper synthesizes the literature that supports the idea in which the Western diet and inactivity are proinflammatory, whereas a plant-based diet and activity are anti-inflammatory, and that low-grade inflammation and oxidative stress underlying osteoarthritis often coexist with lifestyle-related risk factors and conditions. We provide evidence-informed recommendations on how lifestyle behavior change can be integrated into “first-line” osteoarthritis management through teamwork and targeted evidence-based interventions. Healthy living can be exploited to reduce inflammation, oxidative stress, and related pain and disability and improve patients’ overall health. This approach aligns with evidence-based best practice and holds the promise of eliminating or reducing chronic low-grade inflammation, attenuating disease progression, reducing weight, maximizing health by minimizing a patient’s risk or manifestations of other lifestyle-related conditions hallmarked by chronic low-grade inflammation, and reducing the need for medications and surgery. This approach provides an informed cost effective basis for prevention, potential reversal, and management of signs and symptoms of chronic osteoarthritis and has implications for research paradigms in osteoarthritis.

mTOR and the health benefits of exercise.

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Watson, Kurt; Baar, Keith

2014-12-01

Exercise is the greatest physiological stress that our bodies experience. For example, during maximal endurance exercise in elite athlete's cardiac output can increase up to 8-fold and the working muscles receive 21-times more blood each minute than at rest. Given the physiological stress associated with exercise and the adaptations that occur to handle this stress, it is not surprising that exercise training is known to prevent or effectively treat a multitude of degenerative conditions including cardiovascular disease, cancer, diabetes, depression, Alzheimer's disease, Parkinson's disease, and many others. Many of the health benefits of exercise are mediated by the mammalian/mechanistic target of rapamycin (mTOR), either in complex 1 or 2, not only within the working muscle, but also in distant tissues such as fat, liver, and brain. This review will discuss how exercise activates mTOR in diverse tissues and the ways that mTOR is important in the adaptive response that makes us bigger, stronger, and healthier as a result of exercise. Copyright © 2014 Elsevier Ltd. All rights reserved.

Core Muscle Activation in Suspension Training Exercises.

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Cugliari, Giovanni; Boccia, Gennaro

2017-02-01

A quantitative observational laboratory study was conducted to characterize and classify core training exercises executed in a suspension modality on the base of muscle activation. In a prospective single-group repeated measures design, seventeen active male participants performed four suspension exercises typically associated with core training (roll-out, bodysaw, pike and knee-tuck). Surface electromyographic signals were recorded from lower and upper parts of rectus abdominis, external oblique, internal oblique, lower and upper parts of erector spinae muscles using concentric bipolar electrodes. The average rectified values of electromyographic signals were normalized with respect to individual maximum voluntary isometric contraction of each muscle. Roll-out exercise showed the highest activation of rectus abdominis and oblique muscles compared to the other exercises. The rectus abdominis and external oblique reached an activation higher than 60% of the maximal voluntary contraction (or very close to that threshold, 55%) in roll-out and bodysaw exercises. Findings from this study allow the selection of suspension core training exercises on the basis of quantitative information about the activation of muscles of interest. Roll-out and bodysaw exercises can be considered as suitable for strength training of rectus abdominis and external oblique muscles.

Exercise supplementation of dipyridamole for myocardial perfusion imaging

International Nuclear Information System (INIS)

DePuey, E.G.

1991-01-01

The substitution of intravenous dipyridamole for symptom-limited treadmill exercise has provided a non-invasive means to diagnose coronary artery disease with 201Tl scintigraphy in patients unable to adequately exercise. Limitations of dipyridamole/thallium imaging are primarily due to suboptimal image quality secondary to hepatic tracer concentration and decreased test sensitivity in patients who are dipyridamole non-responders. Low-level treadmill exercise supplementation improves image quality, whereas handgrip has little, if any, benefit. The effect of low-level exercise in augmenting coronary blood flow is unknown and reports regarding the effect of handgrip are conflicting. The diagnostic benefit of these maneuvers in improving test sensitivity and decreasing the number of non-responders has not been documented. The combination of maximal, symptom-limited treadmill exercise and intravenous dipyridamole is a theoretically attractive option to improve overall test sensitivity, but the physiologic consequences and potential side effects should be more thoroughly investigated

Associations of maximal strength and muscular endurance test scores with cardiorespiratory fitness and body composition.

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Vaara, Jani P; Kyröläinen, Heikki; Niemi, Jaakko; Ohrankämmen, Olli; Häkkinen, Arja; Kocay, Sheila; Häkkinen, Keijo

2012-08-01

The purpose of the present study was to assess the relationships between maximal strength and muscular endurance test scores additionally to previously widely studied measures of body composition and maximal aerobic capacity. 846 young men (25.5 ± 5.0 yrs) participated in the study. Maximal strength was measured using isometric bench press, leg extension and grip strength. Muscular endurance tests consisted of push-ups, sit-ups and repeated squats. An indirect graded cycle ergometer test was used to estimate maximal aerobic capacity (V(O2)max). Body composition was determined with bioelectrical impedance. Moreover, waist circumference (WC) and height were measured and body mass index (BMI) calculated. Maximal bench press was positively correlated with push-ups (r = 0.61, p strength (r = 0.34, p strength correlated positively (r = 0.36-0.44, p test scores were related to maximal aerobic capacity and body fat content, while fat free mass was associated with maximal strength test scores and thus is a major determinant for maximal strength. A contributive role of maximal strength to muscular endurance tests could be identified for the upper, but not the lower extremities. These findings suggest that push-up test is not only indicative of body fat content and maximal aerobic capacity but also maximal strength of upper body, whereas repeated squat test is mainly indicative of body fat content and maximal aerobic capacity, but not maximal strength of lower extremities.

Skeletal muscle mass and exercise performance in stable ambulatory patients with heart failure.

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Lang, C C; Chomsky, D B; Rayos, G; Yeoh, T K; Wilson, J R

1997-01-01

The purpose of this study was to determine whether skeletal muscle atrophy limits the maximal exercise capacity of stable ambulatory patients with heart failure. Body composition and maximal exercise capacity were measured in 100 stable ambulatory patients with heart failure. Body composition was assessed by using dual-energy X-ray absorption. Peak exercise oxygen consumption (VO2peak) and the anaerobic threshold were measured by using a Naughton treadmill protocol and a Medical Graphics CardioO2 System. VO2peak averaged 13.4 +/- 3.3 ml.min-1.kg-1 or 43 +/- 12% of normal. Lean body mass averaged 52.9 +/- 10.5 kg and leg lean mass 16.5 +/- 3.6 kg. Leg lean mass correlated linearly with VO2peak (r = 0.68, P < 0.01), suggesting that exercise performance is influences by skeletal muscle mass. However, lean body mass was comparable to levels noted in 1,584 normal control subjects, suggesting no decrease in muscle mass. Leg muscle mass was comparable to levels noted in 34 normal control subjects, further supporting this conclusion. These findings suggest that exercise intolerance in stable ambulatory patients with heart failure is not due to skeletal muscle atrophy.

Fatigue and muscle-tendon stiffness after stretch-shortening cycle and isometric exercise.

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Toumi, Hechmi; Poumarat, Georges; Best, Thomas M; Martin, Alain; Fairclough, John; Benjamin, Mike

2006-10-01

The purpose of the present study was to compare vertical jump performance after 2 different fatigue protocols. In the first protocol, subjects performed consecutive sets of 10 repetitions of stretch-shortening cycle (SSC) contractions. In the second protocol, successive sets of 10 repetitions of isometric contractions were performed for 10 s with the knee at 90 degrees of flexion. The exercises were stopped when the subjects failed to reach 50% of their maximum voluntary isometric contractions. Maximal isometric force and maximal concentric power were assessed by performing supine leg presses, squat jumps, and drop jumps. Surface EMG was used to determine changes in muscle activation before and after fatigue. In both groups, the fatigue exercises reduced voluntary isometric force, maximal concentric power, and drop jump performance. Kinematic data showed a decrease in knee muscle-tendon stiffness accompanied by a lengthened ground contact time. EMG analysis showed that the squat and drop jumps were performed similarly before and after the fatigue exercise for both groups. Although it was expected that the stiffness would decrease more after SSC than after isometric fatigue (as a result of a greater alteration of the reflex sensitivity SSC), our results showed that both protocols had a similar effect on knee muscle stiffness during jumping exercises. Both fatigue protocols induced muscle fatigue, and the decrease in jump performance was linked to a decrease in the strength and stiffness of the knee extensor muscles.

Effects of air-pulsed cryotherapy on neuromuscular recovery subsequent to exercise-induced muscle damage.

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Guilhem, Gaël; Hug, François; Couturier, Antoine; Regnault, Stéphanie; Bournat, Laure; Filliard, Jean-Robert; Dorel, Sylvain

2013-08-01

Localized cooling has been proposed as an effective strategy to limit the deleterious effects of exercise-induced muscle damage on neuromuscular function. However, the literature reports conflicting results. This randomized controlled trial aimed to determine the effects of a new treatment, localized air-pulsed cryotherapy (-30°C), on the recovery time-course of neuromuscular function following a strenuous eccentric exercise. Controlled laboratory study. A total of 24 participants were included in either a control group (CONT) or a cryotherapy group (CRYO). Immediately after 3 sets of 20 maximal isokinetic eccentric contractions of elbow flexors, and then 1, 2, and 3 days after exercise, the CRYO group received a cryotherapy treatment (3 × 4 minutes at -30°C separated by 1 minute). The day before and 1, 2, 3, 7, and 14 days after exercise, several parameters were quantified: maximal isometric torque and its associated maximal electromyographic activity recorded by a 64-channel electrode, delayed-onset muscle soreness (DOMS), biceps brachii transverse relaxation time (T2) measured using magnetic resonance imaging, creatine kinase activity, interleukin-6, and C-reactive protein. Maximal isometric torque decreased similarly for the CONT (-33% ± 4%) and CRYO groups (-31% ± 6%). No intergroup differences were found for DOMS, electromyographic activity, creatine kinase activity, and T2 level averaged across the whole biceps brachii. C-reactive protein significantly increased for CONT (+93% at 72 hours, P cryotherapy delayed the significant increase of T2 and the decrease of electromyographic activity level for CRYO compared with CONT (between day 1 and day 3) in the medio-distal part of the biceps brachii. Although some indicators of muscle damage after severe eccentric exercise were delayed (ie, local formation of edema and decrease of muscle activity) by repeated air-pulsed cryotherapy, we provide evidence that this cooling procedure failed to improve long

Benefits of aerobic exercise after stroke.

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Potempa, K; Braun, L T; Tinknell, T; Popovich, J

1996-05-01

The debilitating loss of function after a stroke has both primary and secondary effects on sensorimotor function. Primary effects include paresis, paralysis, spasticity, and sensory-perceptual dysfunction due to upper motor neuron damage. Secondary effects, contractures and disuse muscle atrophy, are also debilitating. This paper presents theoretical and empirical benefits of aerobic exercise after stroke, issues relevant to measuring peak capacity, exercise training protocols, and the clinical use of aerobic exercise in this patient population. A stroke, and resulting hemiparesis, produces physiological changes in muscle fibres and muscle metabolism during exercise. These changes, along with comorbid cardiovascular disease, must be considered when exercising stroke patients. While few studies have measured peak exercise capacity in hemiparetic populations, it has been consistently observed in these studies that stroke patients have a lower functional capacity than healthy populations. Hemiparetic patients have low peak exercise responses probably due to a reduced number of motor units available for recruitment during dynamic exercise, the reduced oxidative capacity of paretic muscle, and decreased overall endurance. Consequently, traditional methods to predict aerobic capacity are not appropriate for use with stroke patients. Endurance exercise training is increasingly recognised as an important component in rehabilitation. An average improvement in maximal oxygen consumption (VO2max) of 13.3% in stroke patients who participated in a 10-week aerobic exercise training programme has been reported compared with controls. This study underscored the potential benefits of aerobic exercise training in stroke patients. In this paper, advantages and disadvantages of exercise modalities are discussed in relation to stroke patients. Recommendations are presented to maximise physical performance and minimise potential cardiac risks during exercise.

Cardiovascular adaptations to exercise training

DEFF Research Database (Denmark)

Hellsten, Ylva; Nyberg, Michael

2016-01-01

Aerobic exercise training leads to cardiovascular changes that markedly increase aerobic power and lead to improved endurance performance. The functionally most important adaptation is the improvement in maximal cardiac output which is the result of an enlargement in cardiac dimension, improved...... and peripheral cardiovascular adaptations with a focus on humans, but also covers animal data. © 2016 American Physiological Society. Compr Physiol 6:1-32, 2016....

Effects of chronic nitric oxide synthase inhibition on V'O2max and exercise capacity in mice.

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Wojewoda, M; Przyborowski, K; Sitek, B; Zakrzewska, A; Mateuszuk, L; Zoladz, J A; Chlopicki, S

2017-03-01

Acute inhibition of NOS by L-NAME (N ω -nitro-L-arginine methyl ester) is known to decrease maximal oxygen consumption (V'O 2max ) and impair maximal exercise capacity, whereas the effects of chronic L-NAME treatment on V'O 2max and exercise performance have not been studied so far. In this study, we analysed the effect of L-NAME treatment, (LN2 and LN12, respectively) on V'O 2max and exercise capacity (in maximal incremental running and prolonged sub-maximal incremental running tests), systemic NO bioavailability (plasma nitrite (NO 2 - ) and nitrate (NO 3 - )) and prostacyclin (PGI 2 ) production in C57BL6/J mice. Mice treated with L-NAME for 2 weeks (LN2) displayed higher V'O 2max and better running capacity than age-matched control mice. In LN2 mice, NO bioavailability was preserved, as evidenced by maintained NO 2 - plasma concentration. PGI 2 production was activated (increased 6-keto-PGF 1α plasma concentration) and the number of circulating erythrocytes (RBC) and haemoglobin concentration were increased. In mice treated with L-NAME for 12 weeks (LN12), NO bioavailability was decreased (lower NO 2 - plasma concentration), and 6-keto-PGF 1α plasma concentration and RBC number were not elevated compared to age-matched control mice. However, LN12 mice still performed better during the maximal incremental running test despite having lower V'O 2max . Interestingly, the LN12 mice showed poorer running capacity during the prolonged sub-maximal incremental running test. To conclude, short-term (2 weeks) but not long-term (12 weeks) treatment with L-NAME activated robust compensatory mechanisms involving preservation of NO2- plasma concentration, overproduction of PGI 2 and increased number of RBCs, which might explain the fully preserved exercise capacity despite the inhibition of NOS.

Strength Training Prior to Endurance Exercise: Impact on the Neuromuscular System, Endurance Performance and Cardiorespiratory Responses

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Conceição Matheus

2014-12-01

Full Text Available This study aimed to investigate the acute effects of two strength-training protocols on the neuromuscular and cardiorespiratory responses during endurance exercise. Thirteen young males (23.2 ± 1.6 years old participated in this study. The hypertrophic strength-training protocol was composed of 6 sets of 8 squats at 75% of maximal dynamic strength. The plyometric strength-training protocol was composed of 6 sets of 8 jumps performed with the body weight as the workload. Endurance exercise was performed on a cycle ergometer at a power corresponding to the second ventilatory threshold until exhaustion. Before and after each protocol, a maximal voluntary contraction was performed, and the rate of force development and electromyographic parameters were assessed. After the hypertrophic strengthtraining and plyometric strength-training protocol, significant decreases were observed in the maximal voluntary contraction and rate of force development, whereas no changes were observed in the electromyographic parameters. Oxygen uptake and a heart rate during endurance exercise were not significantly different among the protocols. However, the time-to-exhaustion was significantly higher during endurance exercise alone than when performed after hypertrophic strength-training or plyometric strength-training (p <0.05. These results suggest that endurance performance may be impaired when preceded by strength-training, with no oxygen uptake or heart rate changes during the exercise.

Fasting- and Exercise-Induced PDH Regulation in Skeletal Muscle

DEFF Research Database (Denmark)

Gudiksen, Anders

in selected mitochondrial proteins. Lastly, increased oxidative capacity leads to exercise-induced skeletal muscle PDH activation that is closely matched to the relative exercise intensity at submaximal exercise, while reaching a higher level at maximal exercise in trained individuals. These responses......Pyruvate dehydrogenase PDH constitutes the only mammalian pathway for irreversible conversion of pyruvate to acetyl-CoA thus providing the vital link between glycolytic energy production, the TCA cycle, and oxidative phosphorylation. Because the PDC controls the conversion of pyruvate it occupies...... a central position in relation to the control of mitochondrial energy production and cellular substrate metabolism. Suppression and activation of PDH becomes essential in situations where glucose availability and/or use changes with swift and appropriate regulation of the complex to maintain energy...

THE EFFECT OF CORE EXERCISES ON TRANSDIAPHRAGMATIC PRESSURE

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Lisa M. Strongoli

2010-06-01

Full Text Available Abdominal exercises, such as sit ups and leg lifts, are used to enhance strength of the core muscles. An overlooked aspect of abdominal exercises is the compression the abdomen, leading to increased diaphragmatic work. We hypothesized that core exercises would produce a variety of transdiaphragmatic pressures. We also sought to determine if some of the easy exercises would produce pressures sufficient for a training stimulus to the diaphragm. We evaluated the effect of 13 different abdominal exercises, ranging in difficulty, on transdiaphragmatic pressure (Pdi, an index of diaphragmatic activity. Six healthy subjects, aged 22 to 53, participated. Each subject was instrumented with two balloon-tipped catheters to obtain gastric and esophageal pressures, from which Pdi was calculated. Prior to initiating the exercises, each subject performed a maximal inspiratory pressure (MIP maneuver. Resting Pdi was also measured. The exercises were performed from least to most difficult, with five repetitions each. There was a significant difference between the exercises and the MIP Pdi, as well as between the exercises and resting Pdi (p 50% of the Pdi during the MIP maneuver, which may provide a training stimulus to the diaphragm if used as a regular exercise. The Pdi measurements also provide insight into diaphragm recruitment during different core exercises, and may aid in the design of exercises to improve diaphragm strength and endurance

Effectivenes of Aerobic and Yoga Exercise to Increase Cardiorespiration Stamina in Carier Women

OpenAIRE

Yunitasari, Esti; Qur'aniati, Nuzul; Arunia, Ida

2009-01-01

Introduction : Cardiorespiratory endurance is one of the components of fitness. Cardiorespiratory endurance is considered to have relation with health because the low grade of fitness connected to high risk of immature death especially cardiovascular disease. Sport such as aerobic exercise and yoga exercise is one of efforts to increase cardiorespiratory endurance. This study was aimed to analyze the effectiveness aerobic exercise and yoga exercise to increase of cardiorespiratory endurance i...

Dehydration affects cerebral blood flow but not its metabolic rate for oxygen during maximal exercise in trained humans

DEFF Research Database (Denmark)

Trangmar, Steven J; Chiesa, Scott T; Stock, Christopher G

2014-01-01

Intense exercise is associated with a reduction in cerebral blood flow (CBF), but regulation of CBF during strenuous exercise in the heat with dehydration is unclear. We assessed internal (ICA) and common carotid artery (CCA) haemodynamics (indicative of CBF and extra-cranial blood flow), middle...... cerebral artery velocity (MCA Vmean), arterial-venous differences and blood temperature in 10 trained males during incremental cycling to exhaustion in the heat (35°C) in control, dehydrated and rehydrated states. Dehydration reduced body mass (75.8 ± 3 vs. 78.2 ± 3 kg), increased internal temperature (38.......3 ± 0.1 vs. 36.8 ± 0.1°C), impaired exercise capacity (269 ± 11 vs. 336 ± 14 W), and lowered ICA and MCA Vmean by 12-23% without compromising CCA blood flow. During euhydrated incremental exercise on a separate day, however, exercise capacity and ICA, MCA Vmean and CCA dynamics were preserved. The fast...

Caffeine delays autonomic recovery following acute exercise.

Science.gov (United States)

Bunsawat, Kanokwan; White, Daniel W; Kappus, Rebecca M; Baynard, Tracy

2015-11-01

Impaired autonomic recovery of heart rate (HR) following exercise is associated with an increased risk of sudden death. Caffeine, a potent stimulator of catecholamine release, has been shown to augment blood pressure (BP) and sympathetic nerve activity; however, whether caffeine alters autonomic function after a bout of exercise bout remains unclear. In a randomized, crossover study, 18 healthy individuals (26 ± 1 years; 23.9 ± 0.8 kg·m(-2)) ingested caffeine (400 mg) or placebo pills, followed by a maximal treadmill test to exhaustion. Autonomic function and ventricular depolarization/repolarization were determined using heart rate variability (HRV) and corrected QT interval (QTc), respectively, at baseline, 5, 15, and 30 minutes post-exercise. Maximal HR (HRmax) was greater with caffeine (192 ± 2 vs. 190 ± 2 beat·min(-1), p < 0.05). During recovery, HR, mean arterial pressure (MAP), and diastolic blood pressure (DBP) remained elevated with caffeine (p < 0.05). Natural log transformation of low-to-high frequency ratio (LnLF/LnHF) of HRV was increased compared with baseline at all time points in both trials (p < 0.05), with less of an increase during 5 and 15 minutes post-exercise in the caffeine trial (p < 0.05). QTc increased from baseline at all time points in both trials, with greater increases in the caffeine trial (p < 0.05). Caffeine ingestion disrupts post-exercise autonomic recovery because of increased sympathetic nerve activity. The prolonged sympathetic recovery time could subsequently hinder baroreflex function during recovery and disrupt the stability of autonomic function, potentiating a pro-arrhythmogenic state in young adults. © The European Society of Cardiology 2014.

Maximal Bell's inequality violation for non-maximal entanglement

International Nuclear Information System (INIS)

Kobayashi, M.; Khanna, F.; Mann, A.; Revzen, M.; Santana, A.

2004-01-01

Bell's inequality violation (BIQV) for correlations of polarization is studied for a product state of two two-mode squeezed vacuum (TMSV) states. The violation allowed is shown to attain its maximal limit for all values of the squeezing parameter, ζ. We show via an explicit example that a state whose entanglement is not maximal allow maximal BIQV. The Wigner function of the state is non-negative and the average value of either polarization is nil

Changes in transcutaneous oxygen tension during exercise in pulmonary emphysema.

OpenAIRE

Hughes, J A; Gray, B J; Hutchison, D C

1984-01-01

Continuous measurements of transcutaneous oxygen tension (tcPO2) were made in 23 patients with radiological evidence of emphysema, at rest and during a maximal progressive exercise test. tcPO2 during the final phase of exercise was compared with tcPO2 at rest; the mean change (exercising minus resting value) in tcPO2 (delta tcPO2) was -0.8 mm Hg (SD 10.5, range -18 to +25) (-0.1 kPa (SD 1.4, range -2.4 to +3.3]. delta tcPO2 was correlated with: resting arterial oxygen tension (PaO2) (r = 0.60...

Evaluation of Maximal O[subscript 2] Uptake with Undergraduate Students at the University of La Reunion

Science.gov (United States)

Tarnus, Evelyne; Catan, Aurelie; Verkindt, Chantal; Bourdon, Emmanuel

2011-01-01

The maximal rate of O[subscript 2] consumption (VO[subscript 2max]) constitutes one of the oldest fitness indexes established for the measure of cardiorespiratory fitness and aerobic performance. Procedures have been developed in which VO[subscript 2max]is estimated from physiological responses during submaximal exercise. Generally, VO[subscript…

Estimating Hemodynamic Responses to the Wingate Test Using Thoracic Impedance

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Todd A. Astorino, Curtis Bovee, Ashley DeBoe

2015-12-01

Full Text Available Techniques including direct Fick and Doppler echocardiography are frequently used to assess hemodynamic responses to exercise. Thoracic impedance has been shown to be a noninvasive alternative to these methods for assessing these responses during graded exercise to exhaustion, yet its feasibility during supramaximal bouts of exercise is relatively unknown. We used thoracic impedance to estimate stroke volume (SV and cardiac output (CO during the Wingate test (WAnT and compared these values to those from graded exercise testing (GXT. Active men (n = 9 and women (n = 7 (mean age = 24.8 ± 5.9 yr completed two Wingate tests and two graded exercise tests on a cycle ergometer. During exercise, heart rate (HR, SV, and CO were continuously estimated using thoracic impedance. Repeated measures analysis of variance was used to identify potential differences in hemodynamic responses across protocols. Results: Maximal SV (138.6 ± 37.4 mL vs. 135.6 ± 26.9 mL and CO (24.5 ± 6.1 L·min-1 vs. 23.7 ± 5.1 L·min-1 were similar (p > 0.05 between repeated Wingate tests. Mean maximal HR was higher (p < 0.01 for GXT (185 ± 7 b·min-1 versus WAnT (177 ± 11 b·min-1, and mean SV was higher in response to WAnT (137.1 ± 32.1 mL versus GXT (123.0 ± 32.0 mL, leading to similar maximal cardiac output between WAnT and GXT (23.9 ± 5.6 L·min-1 vs. 22.5 ± 6.0 L·min-1. Our data show no difference in hemodynamic responses in response to repeated administrations of the Wingate test. In addition, the Wingate test elicits similar cardiac output compared to progressive cycling to VO2max.

Effect of exercise on erythrocyte count and blood activity concentration after technetium-99m in vivo red blood cell labeling

International Nuclear Information System (INIS)

Konstom, M.A.; Tu'meh, S.; Wynne, J.; Beck, J.R.; Kozlowski, J.; Holman, B.L.

1982-01-01

The effects of exercise on blood radiotracer concentration after technetium-99m in vivo red blood cell labeling was studied. After red blood cell labeling, 13 subjects underwent maximal supine bicycle exercise. Radioactivity, analyzed with a well counter, was measured in heparinized venous blood samples drawn at rest and during peak exercise. Changes in activity were compared with changes in erythrocyte count. Activity and erythrocyte counts increased in erythrocyte count (r=0.78), but did not correlate with either duration of exercise or maximal heart rate. Twenty minutes after termination of exercise, activity and erythrocyte count had decreased from peak exercise values but remained higher than preexercise values. In nine nonexercised control subjects, samples drawn 20 minutes apart showed no change in activity or in erythrocyte count. It was concluded that exercise increases blood activity, primarily because of an increase in erythrocyte count. During radionuclide ventriculography, blood activity must be measured before and after any intervention, particularly exercise, before a change in left ventricular activity can be attributed to a change in left ventricular volume

Is dipyridamole test equivalent to exercise testing for the performing of myocardial tomo-scintigraphy? preliminary results of a systematic comparative analysis in patients having documented episodes of myocardial ischemia

International Nuclear Information System (INIS)

David, N.; Quiri, N.; Hassan, N.; Arsena, T.; Py, M.; Olivier, P.; Karcher, G.; Bertrand, A.; Houriez, P.; Grentzinger, A.; Angioi, M.; Danchin, N.; Juilliere, Y.

1997-01-01

Dipyridamole test is generally used rather than exercise testing when myocardial tomo-scintigraphy (MTS) is performed with patients unable to perform a maximal exercise test. However, this choice has never been validated by a systematic comparative analysis of the results provided by these two stress techniques with patients having a documented myocardial ischemia. We have included 20 patients who had a known coronary artery disease, for whom exercise test was positive at the time of an exercise MTS-TI201 performed in our department and who underwent an additional MTS-TI201 after intravenous administration of 0,56 mg/kg of dipyridamole and low-level exercise testing (40 W). The extent of perfusion abnormalities, observed after dipyvirdamole, was not significantly different from that evidenced at exercise, even in the analysis restricted to the eight patients who had a sub-maximal test (<80 % of predicted maximal heart rate) at the time of exercise-MTS (% of left ventricle: 17 ± 13 vs 15 ± 8). By contrast, there were important individual variations: a difference in defect-extent (≥ 10 % of left ventricle) was observed between the two tests for 11 patients (55 %), the largest defect being that observed at exercise in six cases, and after dipyridamole in five cases. With patients having exercise myocardial ischemia, the MTS obtained after dipyridamole are frequently very different from those performed after exercise, and the criterion of a low maximal heart rate doses not imply an underestimation of the perfusion abnormalities observed at exercise. (authors)

Is exercise important in chronic obstructive pulmonary disease?

Science.gov (United States)

Make, Barry; Casaburi, Richard

2007-09-01

Chronic obstructive pulmonary disease impairs the ability of patients to perform maximal physical exercise, particularly in patients with severe lung disease. However, differing perceptions of the meaning and importance of exercise to patients and caregivers is likely to impair patient-physician communication about current medical status and outcomes of therapeutic interventions. Other outcomes of importance to patients including actual performance of functional activity during daily life and health-related quality of life may also be affected by impaired exercise capacity. However, the relationships between exercise, activity, and quality of life are inconsistent. Thus, measurement of physiologic and patient-centered outcomes may provide the best approach to assessing responses to therapeutic interventions. These concepts were explored in a conference sponsored by Boehringer Ingelheim Pharmaceuticals, Inc. and Pfizer Inc and reviewed in the articles generated from the symposium in this issue of COPD.

Role of PGC-1α in exercise training- and resveratrol-induced prevention of age-associated inflammation

DEFF Research Database (Denmark)

Olesen, Jesper; Jørgensen, Stine Ringholm; Nielsen, Maja Munk

2013-01-01

Age-related metabolic diseases are often associated with low-grade inflammation. The aim of the present study was to investigate the role of the transcriptional co-activator PGC-1α in the potential beneficial effects of exercise training and/or resveratrol in the prevention of age-associated low......-grade inflammation. To address this, a long-term voluntary exercise training and resveratrol supplementation study was conducted....

Endothelin-1 and Exercise Intensity in Sedentary Adolescents with Obesity

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Brooke E. Starkoff

2015-01-01

Full Text Available Inactivity combined with obesity during adolescence increases the risk of future cardiovascular disease. The study purpose was to compare the influence of differing intensities of exercise on endothelial function in sedentary adolescents with obesity. Participants were randomized to one of two groups in a 6-week exercise intervention: moderate intensity (MOD or high intensity interval exercise (HIIE. Endothelial function was assessed pre- and post-intervention via fasted serum levels of endothelin-1 (ET-1. Pre-measures of ET-1 concentrations were elevated at baseline. No significant differences in ET-1 were found between or within exercise groups. However, in the HIIE group, ET-1 was inversely associated with percentages of age predicted maximal heart rate achieved during the intervention (p=0.035, r=-0.567. The exercise interventions did not positively change ET-1 levels, yet participants who exercised at higher intensities in the HIIE group experienced greater decreases in ET-1. Keywords: childhood obesity, endothelial function, high intensity interval exercise

Exercise at an onsite facility with or without direct exercise supervision improves health-related physical fitness and exercise participation: An 8-week randomised controlled trial with 15-month follow-up.

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Hunter, Jayden R; Gordon, Brett A; Lythgo, Noel; Bird, Stephen R; Benson, Amanda C

2018-04-01

Physical activity and exercise participation is limited by a perceived lack of time, poor access to facilities and low motivation. The aim was to assess whether providing an exercise program to be completed at the workplace with or without direct supervision was effective for promoting health-related physical fitness and exercise participation. Fifty university employees aged (Mean ± SD) 42.5 ± 11.1 years were prescribed a moderate- to vigorous-intensity aerobic and resistance exercise program to be completed at an onsite facility for 8 weeks. Participants were randomly allocated to receive direct exercise supervision or not. Cardiorespiratory fitness (V̇O 2max ) and maximal muscular strength were assessed at baseline and 8 weeks. Self-report physical activity was assessed at baseline, 8 weeks and 15 months post-intervention. Attendance or exercise session volume were not different between groups. Cardiorespiratory fitness (Mean ± 95% CI); +1.9 ± 0.7 mL·kg·min -1 ; P exercise facility to complete an individually-prescribed 8-week exercise program is sufficient to improve health-related physical fitness in the short-term independent to the level of supervision provided, but does not influence long-term participation. SO WHAT?: Lower cost onsite exercise facility supervision is as effective at improving physical health and fitness as directly supervised exercise, however ongoing support may be required for sustained physical activity behaviour change. © 2017 Australian Health Promotion Association.

Coronary and muscle blood flow during physical exercise in humans; heterogenic alliance.

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Zoladz, Jerzy A; Majerczak, Joanna; Duda, Krzysztof; Chlopicki, Stefan

2015-08-01

In this review, we present the relation between power generation capabilities and pulmonary oxygen uptake during incremental cycling exercise in humans and the effect of exercise intensity on the oxygen cost of work. We also discuss the importance of oxygen delivery to the working muscles as a factor determining maximal oxygen uptake in humans. Subsequently, we outline the importance of coronary blood flow, myocardial oxygen uptake and myocardial metabolic stability for exercise tolerance. Finally, we describe mechanisms of endothelium-dependent regulation of coronary and skeletal muscle blood flow, dysregulation of which may impair exercise capacity and increase the cardiovascular risk of exercise. Copyright © 2015 Institute of Pharmacology, Polish Academy of Sciences. All rights reserved.

Functional role of AMP-activated protein kinase in the heart during exercise.

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Musi, Nicolas; Hirshman, Michael F; Arad, Michael; Xing, Yanqiu; Fujii, Nobuharu; Pomerleau, Jason; Ahmad, Ferhaan; Berul, Charles I; Seidman, Jon G; Tian, Rong; Goodyear, Laurie J

2005-04-11

AMP-activated protein kinase (AMPK) plays a critical role in maintaining energy homeostasis and cardiac function during ischemia in the heart. However, the functional role of AMPK in the heart during exercise is unknown. We examined whether acute exercise increases AMPK activity in mouse hearts and determined the significance of these increases by studying transgenic (TG) mice expressing a cardiac-specific dominant-negative (inactivating) AMPKalpha2 subunit. Exercise increased cardiac AMPKalpha2 activity in the wild type mice but not in TG. We found that inactivation of AMPK did not result in abnormal ATP and glycogen consumption during exercise, cardiac function assessed by heart rhythm telemetry and stress echocardiography, or in maximal exercise capacity.

Effects of exercise training on coronary transport capacity

International Nuclear Information System (INIS)

Laughlin, M.H.

1985-01-01

Coronary transport capacity was estimated in eight sedentary control and eight exercise-trained anesthetized dogs by determining the differences between base line and the highest coronary blood flow and permeability-surface area product (PS) obtained during maximal adenosine vasodilation with coronary perfusion pressure constant. The anterior descending branch of the left coronary artery was cannulated and pump- perfused under constant-pressure conditions (approximately equal to 100 Torr) while aortic, central venous, and coronary perfusion pressures, heart rate, electrocardiogram, and coronary flow were monitored. Myocardial extraction and PS of 51 Cr-labeled ethylenediaminetetraacetic acid were determined with the single-injection indicator-diffusion method. The efficacy of the 16 +/- 1 wk exercise training program was shown by significant increases in the succinate dehydrogenase activities of the gastrocnemius, gluteus medialis, and long head of triceps brachii muscles. There were no differences between control and trained dogs for either resting coronary blood flow or PS. During maximal vasodilation with adenosine, the trained dogs had significantly lower perfusion pressures with constant flow and, with constant-pressure vasodilation, greater coronary blood flow and PS. It is concluded that exercise training in dogs induces an increased coronary transport capacity that includes increases in coronary blood flow capacity (26% of control) and capillary diffusion capacity (82% of control)

Maximising the clinical use of exercise gaseous exchange testing in children with repaired cyanotic congenital heart defects: the development of an appropriate test strategy.

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McManus, A; Leung, M

2000-04-01

Implicit in deciding upon an exercise test strategy to elucidate cardiopulmonary function in children with congenital heart disease are appropriate application of gas exchange techniques and the significance of the data collected to the specific congenital heart disorder. Post-operative cardiopulmonary responses to exercise in cyanotic disorders are complex and, despite a large body of extant literature in paediatric patients, there has been much difficulty in achieving quality and consistency of data. Maximal oxygen uptake is widely recognised as the best single indicator of cardiopulmonary function and has therefore been the focus of most clinical exercise tests in children. Many children with various heart anomalies are able to exercise to maximum without adverse symptoms, and it is essential that test termination is based on the same criteria for these children. Choosing appropriate, valid indicators of maximum in children with congenital heart disease is beset by difficulties. Such maximal intensity exercise testing procedures have been challenged on the grounds that they do not give a good indication of cardiopulmonary function that is relevant to real life situations. Furthermore, they are prone to much interindividual variability and error in the definition of maximal exertion. Alternative strategies have been proposed which focus upon dynamic submaximal and kinetic cardiopulmonary responses, which are thought to be less dependent on maximal voluntary effort and more suited to the daily activity patterns of children. These methods are also not without problems. Variability in anaerobic threshold measurements and controversy regarding its physiological meaning have been debated. It is recommended that an appropriate cardiopulmonary exercise gas exchange test strategy, which provides clinically useful information for children with cyanotic congenital heart disease, should include both maximal and submaximal data. The inclusion of oxygen uptake kinetics and

The comparison of cold-water immersion and cold air therapy on maximal cycling performance and recovery markers following strength exercises

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Kane J. Hayter

2016-03-01

Full Text Available This study examined the effects of cold-water immersion (CWI and cold air therapy (CAT on maximal cycling performance (i.e. anaerobic power and markers of muscle damage following a strength training session. Twenty endurance-trained but strength-untrained male (n = 10 and female (n = 10 participants were randomised into either: CWI (15 min in 14 °C water to iliac crest or CAT (15 min in 14 °C air immediately following strength training (i.e. 3 sets of leg press, leg extensions and leg curls at 6 repetition maximum, respectively. Creatine kinase, muscle soreness and fatigue, isometric knee extensor and flexor torque and cycling anaerobic power were measured prior to, immediately after and at 24 (T24, 48 (T48 and 72 (T72 h post-strength exercises. No significant differences were found between treatments for any of the measured variables (p > 0.05. However, trends suggested recovery was greater in CWI than CAT for cycling anaerobic power at T24 (10% ± 2%, ES = 0.90, T48 (8% ± 2%, ES = 0.64 and T72 (8% ± 7%, ES = 0.76. The findings suggest the combination of hydrostatic pressure and cold temperature may be favourable for recovery from strength training rather than cold temperature alone.

Changes of glucose utilization by erythrocytes, lactic acid concentration in the serum and blood cells, and haematocrit value during one hour rest after maximal effort in individuals differing in physical efficiency.

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Tomasik, M

1982-01-01

Glucose utilization by the erythrocytes, lactic acid concentration in the blood and erythrocytes, and haematocrit value were determined before exercise and during one hour rest following maximal exercise in 97 individuals of either sex differing in physical efficiency. In the investigations reported by the author individuals with strikingly high physical fitness performed maximal work one-third greater than that performed by individuals with medium fitness. The serum concentration of lactic acid was in all individuals above the resting value still after 60 minutes of rest. On the other hand, this concentration returned to the normal level in the erythrocytes but only in individuals with strikingly high efficiency. Glucose utilization by the erythrocytes during the restitution period was highest immediately after the exercise in all studied individuals and showed a tendency for more rapid return to resting values again in individuals with highest efficiency. The investigation of very efficient individuals repeated twice demonstrated greater utilization of glucose by the erythrocytes at the time of greater maximal exercise. This was associated with greater lactic acid concentration in the serum and erythrocytes throughout the whole one-hour rest period. The observed facts suggest an active participation of erythrocytes in the process of adaptation of the organism to exercise.

Exercise Blood Pressure and the Risk for Future Hypertension Among Normotensive Middle‐Aged Adults

OpenAIRE

Berger, Assaf; Grossman, Ehud; Katz, Moshe; Kivity, Shaye; Klempfner, Robert; Segev, Shlomo; Goldenberg, Ilan; Sidi, Yehezkel; Maor, Elad

2015-01-01

Background The aim of the present study was to examine whether exercise blood pressure can be used to predict the development of hypertension in normotensive middle‐aged adults. Methods and Results We investigated 7082 normotensive subjects who were annually screened in a tertiary medical center and completed maximal treadmill exercise tests at each visit. After the initial 3 years, subjects were divided into approximate quartiles according to their average exercise systolic and diastolic blo...

Exercise tolerance in children and adolescents with musculoskeletal pain in joint hypermobility and joint hypomobility syndrome

NARCIS (Netherlands)

Engelbert, Raoul H. H.; van Bergen, Monique; Henneken, Thamar; Helders, Paul J. M.; Takken, Tim

2006-01-01

Musculoskeletal pain is a common complaint in a pediatric health care practice, but exercise tolerance has never been described in detail in these children. Our objectives for this study were to evaluate the maximal exercise capacity, including peak heart rate and oxygen consumption, of children

The acute effects of graded physiological strain on soccer kicking performance: a randomized, controlled cross-over study.

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Radman, Ivan; Wessner, Barbara; Bachl, Norbert; Ruzic, Lana; Hackl, Markus; Prpic, Tomislav; Markovic, Goran

2016-02-01

The aim of the present study was to examine the acute effects of graded physiological strain on soccer kicking performance. Twenty-eight semi-professional soccer players completed both experimental and control procedure. The experimental protocol incorporated repeated shooting trials combined with a progressive discontinuous maximal shuttle-run intervention. The initial running velocity was 8 km/h and increasing for 1 km/h every 3 min until exhaustion. The control protocol comprised only eight subsequent shooting trials. The soccer-specific kicking accuracy (KA; average distance from the ball-entry point to the goal center), kicking velocity (KV), and kicking quality (KQ; kicking accuracy divided by the time elapsed from hitting the ball to the point of entry) were evaluated via reproducible and valid test over five individually determined exercise intensity zones. Compared with baseline or exercise at intensities below the second lactate threshold (LT2), physiological exertion above the LT2 (blood lactate > 4 mmol/L) resulted in meaningful decrease in KA (11-13%; p soccer kicking performance. The results suggest that high-intensity physiological exertion above the player's LT2 impairs soccer kicking performance. In contrast, light to moderate physiological stress appears to be neither harmful nor beneficial for kicking performance.

The effect of α1 -adrenergic blockade on post-exercise brachial artery flow-mediated dilatation at sea level and high altitude.

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Tymko, Michael M; Tremblay, Joshua C; Hansen, Alex B; Howe, Connor A; Willie, Chris K; Stembridge, Mike; Green, Daniel J; Hoiland, Ryan L; Subedi, Prajan; Anholm, James D; Ainslie, Philip N

2017-03-01

Our objective was to quantify endothelial function (via brachial artery flow-mediated dilatation) at sea level (344 m) and high altitude (3800 m) at rest and following both maximal exercise and 30 min of moderate-intensity cycling exercise with and without administration of an α 1 -adrenergic blockade. Brachial endothelial function did not differ between sea level and high altitude at rest, nor following maximal exercise. At sea level, endothelial function decreased following 30 min of moderate-intensity exercise, and this decrease was abolished with α 1 -adrenergic blockade. At high altitude, endothelial function did not decrease immediately after 30 min of moderate-intensity exercise, and administration of α 1 -adrenergic blockade resulted in an increase in flow-mediated dilatation. Our data indicate that post-exercise endothelial function is modified at high altitude (i.e. prolonged hypoxaemia). The current study helps to elucidate the physiological mechanisms associated with high-altitude acclimatization, and provides insight into the relationship between sympathetic nervous activity and vascular endothelial function. We examined the hypotheses that (1) at rest, endothelial function would be impaired at high altitude compared to sea level, (2) endothelial function would be reduced to a greater extent at sea level compared to high altitude after maximal exercise, and (3) reductions in endothelial function following moderate-intensity exercise at both sea level and high altitude are mediated via an α 1 -adrenergic pathway. In a double-blinded, counterbalanced, randomized and placebo-controlled design, nine healthy participants performed a maximal-exercise test, and two 30 min sessions of semi-recumbent cycling exercise at 50% peak output following either placebo or α 1 -adrenergic blockade (prazosin; 0.05 mg kg  -1 ). These experiments were completed at both sea-level (344 m) and high altitude (3800 m). Blood pressure (finger photoplethysmography

Effects of an acute bout of exercise on memory in 6th grade children.

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Etnier, Jennifer; Labban, Jeffrey D; Piepmeier, Aaron; Davis, Matthew E; Henning, David A

2014-08-01

Research supports the positive effects of exercise on cognitive performance by children. However, a limited number of studies have explored the effects specifically on memory. The purpose of this study was to compare the effects of an acute bout of exercise on learning, short-term memory, and long-term memory in a sample of children. Children were randomly assigned to an exercise condition or to a no-treatment control condition and then performed repeated trials on an auditory verbal learning task. In the exercise condition, participants performed the PACER task, an aerobic fitness assessment, in their physical education class before performing the memory task. In the control condition, participants performed the memory task at the beginning of their physical education class. Results showed that participants in the exercise condition demonstrated significantly better learning of the word lists and significantly better recall of the words after a brief delay. There were not significant differences in recognition of the words after an approximately 24-hr delay. These results provide evidence in a school setting that an acute bout of exercise provides benefits for verbal learning and long-term memory. Future research should be designed to identify the extent to which these findings translate to academic measures.

Maximizing and customer loyalty: Are maximizers less loyal?

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Linda Lai

2011-06-01

Full Text Available Despite their efforts to choose the best of all available solutions, maximizers seem to be more inclined than satisficers to regret their choices and to experience post-decisional dissonance. Maximizers may therefore be expected to change their decisions more frequently and hence exhibit lower customer loyalty to providers of products and services compared to satisficers. Findings from the study reported here (N = 1978 support this prediction. Maximizers reported significantly higher intentions to switch to another service provider (television provider than satisficers. Maximizers' intentions to switch appear to be intensified and mediated by higher proneness to regret, increased desire to discuss relevant choices with others, higher levels of perceived knowledge of alternatives, and higher ego involvement in the end product, compared to satisficers. Opportunities for future research are suggested.

Effects of graded exercise-induced dehydration and rehydration on circulatory markers of oxidative stress across the resting and exercising human leg.

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Laitano, Orlando; Kalsi, Kameljit Kaur; Pearson, James; Lotlikar, Makra; Reischak-Oliveira, Alvaro; González-Alonso, José

2012-05-01

Exercise in the heat enhances oxidative stress markers in the human circulation, but the contribution of active skeletal muscle and the influence of hydration status remain unknown. To address this question, we measured leg exchange of glutathione (GSH), glutathione disulfide (GSSG), superoxide dismutase activity (SOD) and isoprostanes in seven males at rest and during submaximal one-legged knee extensor exercise in the following four conditions: (1) control euhydration (0% reduction in body mass), (2) mild-dehydration (2%), (3) moderate-dehydration (3.5%), (4) rehydration (0%). In all resting and control exercise conditions, a net GSH uptake was observed across the leg. In contrast, a significant leg release of GSH into the circulation (-354 ± 221 μmol/min, P exercise with moderate-dehydration, which was still present following full rehydration (-206 ± 122 μmol/min, P exercise, mild and moderate-dehydration decreased both femoral venous erythrocyte SOD activity (195 ± 6 vs. 180 ± 5 U/L, P release GSH into the circulation under moderate dehydration and subsequent rehydration, possibly to enhance the antioxidant defense.

Brain temperature and exercise performance

DEFF Research Database (Denmark)

Nybo, Lars

2012-01-01

Events arising within the central nervous system seem to play a major factor in the aetiology of hyperthermia-induced fatigue. Thus, various studies with superimposed electrical nerve stimulation or transcranial magnetic stimulation have shown that both passive and exercise-induced hyperthermia...... temperature in exercising goats indicate that excessive brain hyperthermia will directly affect motor performance. However, several homeostatic changes arise in parallel with hyperthermia including factors that may influence both peripheral and central fatigue and it is likely that these changes interact...... will impair voluntary motor activation during sustained maximal contractions. In humans the brain temperature increases in parallel with that of the body core making it very difficult to evaluate the independent effect of the cerebral temperature. Experiments with separate manipulation of the brain...

Discordance of exercise thallium testing with coronary arteriography in patients with atypical presentations

International Nuclear Information System (INIS)

Bungo, M.W.; Leland, O.S. Jr.

1983-01-01

Eighty-one patients with diagnostically difficult clinical presentations suggesting coronary disease underwent symptom-limited maximal-exercise treadmill testing (ETT) and exercise radionuclide scanning with 201 Tl. Results of these tests were in agreement in only 47 percent of the cases. Either exercise thallium or ETT was positive in 94 percent of patients with disease. Among a population with a disease prevalence of 67 percent, agreement between exercise thallium an ETT predicted disease in 92 percent of instances or excluded disease in 82 percent of instances. Frequent discordance between these two tests in 53 percent of the cases unfortunately limits this usefulness

Breathing exercises with vagal biofeedback may benefit patients with functional dyspepsia.

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Hjelland, Ina E; Svebak, Sven; Berstad, Arnold; Flatabø, Geir; Hausken, Trygve

2007-09-01

Many patients with functional dyspepsia (FD) have postprandial symptoms, impaired gastric accommodation and low vagal tone. The aim of this study was to improve vagal tone, and thereby also drinking capacity, intragastric volume and quality of life, using breathing exercises with vagal biofeedback. Forty FD patients were randomized to either a biofeedback group or a control group. The patients received similar information and care. Patients in the biofeedback group were trained in breathing exercises, 6 breaths/min, 5 min each day for 4 weeks, using specially designed software for vagal biofeedback. Effect variables included maximal drinking capacity using a drink test (Toro clear meat soup 100 ml/min), intragastric volume at maximal drinking capacity, respiratory sinus arrhythmia (RSA), skin conductance (SC) and dyspepsia-related quality of life scores. Drinking capacity and quality of life improved significantly more in the biofeedback group than in the control group (p=0.02 and p=0.01) without any significant change in baseline autonomic activity (RSA and SC) or intragastric volume. After the treatment period, RSA during breathing exercises was significantly correlated to drinking capacity (r=0.6, p=0.008). Breathing exercises with vagal biofeedback increased drinking capacity and improved quality of life in FD patients, but did not improve baseline vagal tone.

Effects of Exercise Training on Haematology and Maximal Cardiac Output

DEFF Research Database (Denmark)

Bonne, Thomas Christian

= 0.051) and time to complete 3000 m tended (P = 0.09) to increase in LHTH but not after sea level training. In study III haematological parameters were determined weekly three times before and four times after classical altitude and sea level training and ABP thresholds for [Hb], %ret, OFF......-score and the abnormal blood profile score (ABPS) were generated using the official ABP software. After altitude training, six swimmers exceeded the 99% ABP thresholds: Two swimmers exceeded the OFF-score thresholds at day 7; One swimmer exceeded the OFF-score threshold at day 28; One swimmer exceeded the threshold...... for %ret at day 14; One swimmer surpassed the ABPS threshold at day 7 and one swimmer exceeded the ABPS threshold 28 days after altitude training. No values exceeded the individual thresholds in the control group. In conclusion, this thesis demonstrated that BV is a main determinant of the exercise induced...

Exercise thallium-201 scintigraphy and prognosis in typical angina pectoris and negative exercise electrocardiography

International Nuclear Information System (INIS)

Bairey, C.N.; Rozanski, A.; Maddahi, J.; Resser, K.J.; Berman, D.S.

1989-01-01

Patients with a history of typical angina but negative exercise electrocardiography represent a subgroup with an intermediate likelihood of having coronary artery disease and future cardiac events. A retrospective study of the prognostic utility of stress-redistribution thallium-201 scintigraphy was performed in 190 such patients. A second group of 203 patients with typical angina and a positive exercise electrocardiogram were analyzed for comparative scintigraphic purposes. The cardiac event rate for the 144 negative exercise electrocardiogram patients with normal thallium results was 5 vs 15% in the 46 patients with abnormal thallium results (p = 0.01). These patients were further stratified into high (14 to 18%), intermediate (9%) and low (less than 2%) risk groups for future cardiac events based on combining the thallium results with the percentage of maximal predicted heart rate achieved. A multivariate analysis revealed that an abnormal thallium result was the only significant correlate of future cardiac events. Mechanisms responsible for the discordant finding of a negative exercise electrocardiogram in patients with typical angina include (1) false-positive angina symptomatology in low prevalence coronary artery disease groups in whom the thallium test is negative, and (2) electrocardiographically silent ischemia in patients in whom the thallium test is positive. These findings reveal that thallium stress-redistribution scintigraphy can be used to stratify 1-year prognosis in this subgroup of patients with typical angina and negative exercise electrocardiograms

[Exercise in haemodyalisis patients: a literature systematic review].

Science.gov (United States)

Segura-Ortí, Eva

2010-01-01

Exercise as a therapeutic tool used in End-stage renal disease patients (ESRD) in hemodialysis (HD) is not routinately applied, as it occurs with cardiac or respiratory patients. Lack of awareness of research in this field may contribute to the current situation. Thus, the aims of this review are: 1) to systematically review the literature of exercise training on adult HD patients or patients at a pre-HD stage; 2) to show the evidence on the benefits of exercise for counteracting physiological, functional and psychological impairments found even in older ESRD patients; 3) to recommend requirements of future research in order to include exercise prescription in the HD patients treatment. The Data bases reviewed from 2005 to 2009 were: MEDLINE (Ovid), CINAHL (EBSCOHost), SportDicus (EBSCOHost), Academic Search Complete (EBSCOHost), Fuente Académica (EBSCOHost), MedicLatina (EBSCOHost), PEDro y PubMed. Additionally, references from identified articles, several reviews on ESRD and abstracts to Nephrology Congresses were also reviewed. Randomized Controlled Trials on aerobic, strength and combined programs for HD patients were selected. Data from the studies was compiled and Van Tulder criteria were used for methodological quality assessment. Metanalysis included 6 studies on aerobic exercise, 2 on strength exercise and 5 on combined exercise programs. 640 patients were included in 16 included studies. Effects on physical function, health related quality of life and other secondary measurements were summarized by the Standardized Mean Difference (SMD) Moderate evidence exists on positive effects of aerobic training on peak oxygen consumption at the graded exercise test (SMD 6.55; CI 95%: 4.31-8.78). There is high evidence on positive effects of strength training on health related quality of life (SMD 11.03; CI 95%: 5.63-16.43). Finally, moderate evidence exists on positive effects of combined exercise on peak oxygen consumption at the graded exercise test (SMD 5.57; CI

Comparison between maximal lengthening and shortening contractions for biceps brachii muscle oxygenation and hemodynamics.

Science.gov (United States)

Muthalib, Makii; Lee, Hoseong; Millet, Guillaume Y; Ferrari, Marco; Nosaka, Kazunori

2010-09-01

Eccentric contractions (ECC) require lower systemic oxygen (O2) and induce greater symptoms of muscle damage than concentric contractions (CON); however, it is not known if local muscle oxygenation is lower in ECC than CON during and following exercise. This study compared between ECC and CON for changes in biceps brachii muscle oxygenation [tissue oxygenation index (TOI)] and hemodynamics [total hemoglobin volume (tHb)=oxygenated-Hb+deoxygenated-Hb], determined by near-infrared spectroscopy over 10 sets of 6 maximal contractions of the elbow flexors of 10 healthy subjects. This study also compared between ECC and CON for changes in TOI and tHb during a 10-s sustained and 30-repeated maximal isometric contraction (MVC) task measured immediately before and after and 1-3 days following exercise. The torque integral during ECC was greater (P<0.05) than that during CON by approximately 30%, and the decrease in TOI was smaller (P<0.05) by approximately 50% during ECC than CON. Increases in tHb during the relaxation phases were smaller (P<0.05) by approximately 100% for ECC than CON; however, the decreases in tHb during the contraction phases were not significantly different between sessions. These results suggest that ECC utilizes a lower muscle O2 relative to O2 supply compared with CON. Following exercise, greater (P<0.05) decreases in MVC strength and increases in plasma creatine kinase activity and muscle soreness were evident 1-3 days after ECC than CON. Torque integral, TOI, and tHb during the sustained and repeated MVC tasks decreased (P<0.01) only after ECC, suggesting that muscle O2 demand relative to O2 supply during the isometric tasks was decreased after ECC. This could mainly be due to a lower maximal muscle mass activated as a consequence of muscle damage; however, an increase in O2 supply due to microcirculation dysfunction and/or inflammatory vasodilatory responses after ECC is recognized.

LOAD THAT MAXIMIZES POWER OUTPUT IN COUNTERMOVEMENT JUMP

Directory of Open Access Journals (Sweden)

Pedro Jimenez-Reyes

2016-02-01

Full Text Available ABSTRACT Introduction: One of the main problems faced by strength and conditioning coaches is the issue of how to objectively quantify and monitor the actual training load undertaken by athletes in order to maximize performance. It is well known that performance of explosive sports activities is largely determined by mechanical power. Objective: This study analysed the height at which maximal power output is generated and the corresponding load with which is achieved in a group of male-trained track and field athletes in the test of countermovement jump (CMJ with extra loads (CMJEL. Methods: Fifty national level male athletes in sprinting and jumping performed a CMJ test with increasing loads up to a height of 16 cm. The relative load that maximized the mechanical power output (Pmax was determined using a force platform and lineal encoder synchronization and estimating the power by peak power, average power and flight time in CMJ. Results: The load at which the power output no longer existed was at a height of 19.9 ± 2.35, referring to a 99.1 ± 1% of the maximum power output. The load that maximizes power output in all cases has been the load with which an athlete jump a height of approximately 20 cm. Conclusion: These results highlight the importance of considering the height achieved in CMJ with extra load instead of power because maximum power is always attained with the same height. We advise for the preferential use of the height achieved in CMJEL test, since it seems to be a valid indicative of an individual's actual neuromuscular potential providing a valid information for coaches and trainers when assessing the performance status of our athletes and to quantify and monitor training loads, measuring only the height of the jump in the exercise of CMJEL.

Home-based video exercise intervention for community-dwelling frail older women: a randomized controlled trial

DEFF Research Database (Denmark)

Vestergaard, Sonja; Kronborg, Christian; Puggaard, Lis

2008-01-01

and health-related quality of life. METHODS: Communitydwelling frail women >/=75 yrs, receiving public home care, were randomized into a training group (n=30) and a control group (n=31). Participants exercised for 26 minutes, three times per week for five months. Both groups received a bi-weekly telephone...... call. The effect of intervention was evaluated by the physical performance test, mobility-tiredness score, maximal isometric handgrip and biceps strength, lower limb explosive power, repeated chair rise (5 times), 10-m maximal walking-speed, semi-tandem balance, and health-related quality of life......, handgrip, biceps strength, chair rise, and 10-m maximal walking-speed in the training group, and for walking-speed and self-rated health in the control group. CONCLUSIONS: These results suggest that homebased training for frail older women using an exercise video induces lasting health-related quality...

Physical exercise in type 1 diabetes: recommendations and care

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Luis Paulo Gomes Mascarenhas

Full Text Available Abstract The management of type 1 diabetes mellitus (T1DM is based on three pillars: insulin therapy, nutrition, and regular practice of physical activity. Physical exercises are associated with metabolic demands that depend on the individual's energy stores and level of physical conditioning, and vary according to environmental conditions and intensity, duration, and type of exercise. All these factors, added to eventual distress with competitions, exert influence on glucose metabolism. The athletic career of diabetic individuals is often hindered by a risk of hypoglycemia during and after the exercise, frequent hyperglycemia before, during, and after certain physical activities, occurrence of ketoacidosis, and presence of chronic microvascular and macrovascular complications. Aerobic exercises reduce the levels of blood glucose while anaerobic exercise may promote transient hyperglycemia. Although diabetic individuals may achieve excellence in sport, their physical performance should be maximized by strict blood glucose control, adequate modifications in insulin dose on the day of the exercise, and appropriate nutritional intake. This review discusses the impact of physical exercise on glucose metabolism, as well as nutritional considerations and strategies appropriate to the practice of physical exercises by patients with T1DM.

The slope of the oxygen pulse curve does not depend on the maximal heart rate in elite soccer players

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Raphael Rodrigues Perim

2011-01-01

Full Text Available INTRODUCTION: It is unknown whether an extremely high heart rate can affect oxygen pulse profile during progressive maximal exercise in healthy subjects. OBJECTIVE: Our aim was to compare relative oxygen pulse (adjusted for body weight curves in athletes at their maximal heart rate during treadmill cardiopulmonary exercise testing. METHODS: A total of 180 elite soccer players were categorized in quartiles according to their maximum heart rate values (n = 45. Oxygen consumption, maximum heart rate and relative oxygen pulse curves in the extreme quartiles, Q1 and Q4, were compared at intervals corresponding to 10% of the total duration of a cardiopulmonary exercise testing. RESULTS: Oxygen consumption was similar among all subjects during cardiopulmonary exercise testing; however subjects in Q1 started to exhibit lower maximum heart rate values when 20% of the test was complete. Conversely, the relative oxygen pulse was higher in this group when cardiopulmonary exercise testing was 40% complete (p<.01. Although the slopes of the lines were similar (p = .25, the regression intercepts differed (p<.01 between Q1 and Q4. During the last two minutes of testing, a flat or decreasing oxygen pulse was identified in 20% of the soccer players, and this trend was similar between subjects in Q1 and Q4. CONCLUSION: Relative oxygen pulse curve slopes, which serve as an indirect and non-invasive surrogate for stroke volume, suggest that the stroke volume is similar in young and aerobically fit subjects regardless of the maximum heart rate reached.

Glucagon and plasma catecholamines during beta-receptor blockade in exercising man

DEFF Research Database (Denmark)

Galbo, H; Holst, Janett; Christensen, N J

1976-01-01

Seven men ran at 60% of individual maximal oxygen uptake to exhaustion during beta-adrenergic blockade with propranolol (P), during lipolytic blockade with nicotinic acid (N), or without drugs (C). The total work times (83 +/- 9 (P), 122 +/- 8 (N), 166 +/- 10 (C) min, mean and SE) differed signif...... determinants for the exercise-induced glucagon secretion in man. It is suggested that decreased glucose availability enhances the secretion of glucagon and epinephrine during prolonged exercise....

The importance of O – level grades in medical school admission: the ...

African Journals Online (AJOL)

grades in Physics, Chemistry, Biology and Mathematics. In the latter group, the JAMB scores and O' level grades were given equal weighting (50% of mark ... were given a written interview test and an oral interview. At the end of the exercise, 40 candidates were admitted. Eventually, 31 of this group and four out of the five ...

Treatment of subclinical fluid retention in patients with symptomatic heart failure: effect on exercise performance.

Science.gov (United States)

Chomsky, D B; Lang, C C; Rayos, G; Wilson, J R

1997-08-01

Patients with heart failure frequently have elevated intracardiac diastolic pressures but no clinical evidence of excess fluid retention. We speculated that such pressure elevations may indicate subclinical fluid retention and that removal of this fluid could improve exercise intolerance. To test this hypothesis, we studied 10 patients with right atrial pressure > or = 8 mm Hg but without rales, edema, or apparent jugular venous distension. Right-sided heart catheterization was performed, after which patients underwent maximal treadmill cardiopulmonary testing. Patients were then hospitalized and underwent maximal diuresis, after which exercise was repeated. Before diuresis, right atrial pressure averaged 16 +/- 5 mm Hg (+/-standard deviation), pulmonary capillary wedge pressure 30 +/- 6 mm Hg, and peak exercise Vo2 11.2 +/- 2.3 ml/min/ kg. Patients underwent diuresis of 4.5 +/- 2.2 kg over 4 +/- 2 days to a resting right atrial pressure of 6 +/- 4 and wedge pressure of 19 +/- 7 mm Hg. After diuresis, all patients reported overall symptomatic improvement. Maximal exercise duration increased significantly from 9.2 +/- 4.2 to 12.5 +/- 4.7 minutes. At matched peak workloads, significant improvements were also seen in minute ventilation (45 +/- 12 to 35 +/- 9 L/min), lactate levels (42 +/- 16 to 29 +/- 9 mg/dl), and Borg dyspnea scores (15 +/- 3 to 12 +/- 4) (all p < 0.05). Invasive hemodynamic monitoring allows the identification of excess fluid retention in patients with heart failure when there are no clinical signs of fluid overload. Removal of this subclinical excess fluid improves exercise performance and exertional dyspnea.

Excessive Exercise Habits in Marathoners as Novel Indicators of Masked Hypertension

OpenAIRE

Kim, Young-Joo; Park, Yongbum; Kang, Duk-Ho; Kim, Chul-Hyun

2017-01-01

Background. Excessive exercise such as marathon running increases the risk of cardiovascular events that may be related to myocardial infarction and sudden death. We aimed to investigate that the exercise characteristics can be used as a novel indicator of masked hypertension. Methods. A total of 571 middle-aged recreational male marathoners were assigned to a high blood pressure group (HBPG; n = 214) or a normal blood pressure group (NBPG; n = 357). A graded exercise test was used to examine...

Intraspecific correlations of basal and maximal metabolic rates in birds and the aerobic capacity model for the evolution of endothermy.

Science.gov (United States)

Swanson, David L; Thomas, Nathan E; Liknes, Eric T; Cooper, Sheldon J

2012-01-01

The underlying assumption of the aerobic capacity model for the evolution of endothermy is that basal (BMR) and maximal aerobic metabolic rates are phenotypically linked. However, because BMR is largely a function of central organs whereas maximal metabolic output is largely a function of skeletal muscles, the mechanistic underpinnings for their linkage are not obvious. Interspecific studies in birds generally support a phenotypic correlation between BMR and maximal metabolic output. If the aerobic capacity model is valid, these phenotypic correlations should also extend to intraspecific comparisons. We measured BMR, M(sum) (maximum thermoregulatory metabolic rate) and MMR (maximum exercise metabolic rate in a hop-flutter chamber) in winter for dark-eyed juncos (Junco hyemalis), American goldfinches (Carduelis tristis; M(sum) and MMR only), and black-capped chickadees (Poecile atricapillus; BMR and M(sum) only) and examined correlations among these variables. We also measured BMR and M(sum) in individual house sparrows (Passer domesticus) in both summer, winter and spring. For both raw metabolic rates and residuals from allometric regressions, BMR was not significantly correlated with either M(sum) or MMR in juncos. Moreover, no significant correlation between M(sum) and MMR or their mass-independent residuals occurred for juncos or goldfinches. Raw BMR and M(sum) were significantly positively correlated for black-capped chickadees and house sparrows, but mass-independent residuals of BMR and M(sum) were not. These data suggest that central organ and exercise organ metabolic levels are not inextricably linked and that muscular capacities for exercise and shivering do not necessarily vary in tandem in individual birds. Why intraspecific and interspecific avian studies show differing results and the significance of these differences to the aerobic capacity model are unknown, and resolution of these questions will require additional studies of potential mechanistic

Intraspecific correlations of basal and maximal metabolic rates in birds and the aerobic capacity model for the evolution of endothermy.

Directory of Open Access Journals (Sweden)

David L Swanson

Full Text Available The underlying assumption of the aerobic capacity model for the evolution of endothermy is that basal (BMR and maximal aerobic metabolic rates are phenotypically linked. However, because BMR is largely a function of central organs whereas maximal metabolic output is largely a function of skeletal muscles, the mechanistic underpinnings for their linkage are not obvious. Interspecific studies in birds generally support a phenotypic correlation between BMR and maximal metabolic output. If the aerobic capacity model is valid, these phenotypic correlations should also extend to intraspecific comparisons. We measured BMR, M(sum (maximum thermoregulatory metabolic rate and MMR (maximum exercise metabolic rate in a hop-flutter chamber in winter for dark-eyed juncos (Junco hyemalis, American goldfinches (Carduelis tristis; M(sum and MMR only, and black-capped chickadees (Poecile atricapillus; BMR and M(sum only and examined correlations among these variables. We also measured BMR and M(sum in individual house sparrows (Passer domesticus in both summer, winter and spring. For both raw metabolic rates and residuals from allometric regressions, BMR was not significantly correlated with either M(sum or MMR in juncos. Moreover, no significant correlation between M(sum and MMR or their mass-independent residuals occurred for juncos or goldfinches. Raw BMR and M(sum were significantly positively correlated for black-capped chickadees and house sparrows, but mass-independent residuals of BMR and M(sum were not. These data suggest that central organ and exercise organ metabolic levels are not inextricably linked and that muscular capacities for exercise and shivering do not necessarily vary in tandem in individual birds. Why intraspecific and interspecific avian studies show differing results and the significance of these differences to the aerobic capacity model are unknown, and resolution of these questions will require additional studies of potential

Effects of contraction duration on low-frequency fatigue in voluntary and electrically induced exercise of quadriceps muscle in humans.

Science.gov (United States)

Ratkevicius, A; Skurvydas, A; Povilonis, E; Quistorff, B; Lexell, J

1998-04-01

The aims of this study were to investigate if low-frequency fatigue (LFF) dependent on the duration of repeated muscle contractions and to compare LFF in voluntary and electrically induced exercise. Male subjects performed three 9-min periods of repeated isometric knee extensions at 40% maximal voluntary contraction with contraction plus relaxation periods of 30 plus 60 s, 15 plus 30 s and 5 plus 10 s in protocols 1, 2 and 3, respectively. The same exercise protocols were repeated using feedback-controlled electrical stimulation at 40% maximal tetanic torque. Before and 15 min after each exercise period, knee extension torque at 1, 7, 10, 15, 20, 50 and 100 Hz was assessed. During voluntary exercise, electromyogram root mean square (EMGrms) of the vastus lateralis muscle was evaluated. The 20-Hz torque:100-Hz torque (20:100 Hz torque) ratio was reduced more after electrically induced than after voluntary exercise (P exercise, the decrease in 20:100 Hz torque ratio was gradually (P exercise, the decrease in 20:100 Hz torque ratio and the increase in EMGrms were greater in protocol 1 (P exercise and that the electrically induced exercise produced a more pronounced LFF compared to voluntary exercise of submaximal intensity. It is suggested that compensatory recruitment of faster-contracting motor units is an additional factor affecting the severity of LFF during voluntary exercise.

Does chronic smoking affect induced-exercise catecholamine release?

Directory of Open Access Journals (Sweden)

Gökhan İpekoğlu

2017-04-01

Full Text Available This study was performed to investigate the acute effect of the submaximal aerobic exercise upon epinephrine and nor-epinephrine levels in chronic smokers and non-smoker.  The study was carried out upon 10 regular (15> cigarettes/day smoker untrained male along five years and 10 never smoker untrained male. Subjects performed an endurance exercise that continues 40 minutes at 70% maximal heart rate. There were 15cc venous blood samples extracted from the forearm pre-exercise (PRE, post-exercise (POST, post-exercise 2 hours (2h, post-exercise 24 hours (24h to measure of epinephrine and nor-epinephrine levels. The plasma level of each hormone increased after exercise and the tendency of rise was similar between groups as it seen in which 55,6% and 54,68% for epinephrine and 27,1% and 35,7% for norepinephrine. In this respect no group-time relationship has been found (p>0,05.  But in between-group analyses, basal and after exercise levels were different (p<0,05. The study revealed the fact that, smokers have higher plasma levels of epinephrine and norepinephrine before and after exercise. The results demonstrate that long-term smoking induces elevate baseline and post-aerobic submaximal exercise plasma epinephrine and nor-epinephrine levels.  The sympatho-adrenal activity appears to be disrupt with long-term smoking which effect the glycolytic and fat metabolism during exercise.