WorldWideScience

Sample records for submaximal continuous exercise

  1. The effect of submaximal exercise on fibrinolysis.

    Science.gov (United States)

    Fras, Zlatko; Keber, Dusan; Chandler, Wayne L

    2004-04-01

    We studied the relationship between sustained submaximal exercise, increased tissue plasminogen activator (t-PA) levels and decreased hepatic clearance of t-PA. Six healthy male volunteers exercised for 35 min while receiving constant rate infusions of either saline or two different doses of recombinant t-PA for 90 min (40 min before, 35 min during and 15 min after exercise). Liver blood flow was estimated simultaneously by constant rate indocyanine green infusion. Since t-PA is cleared rapidly by the liver in direct proportion to liver blood flow, it was expected that a significant decrease in liver blood flow during sustained submaximal exercise would be associated with a proportional increase in plasma t-PA. During submaximal exercise with a saline (placebo) infusion, steady-state t-PA antigen increased from a resting baseline of 6.3 +/- 3.1 to 15.1 +/- 5.1 ng/ml; with a 20 microg/min t-PA infusion, t-PA antigen increased from 33 +/- 12 to 84 +/- 25 ng/ml during exercise; and with a 40 microg/min t-PA infusion, t-PA antigen increased from 77 +/- 38 to 166 +/- 42 ng/ml during exercise. During submaximal exercise, liver blood flow fell on average 71, 68 and 70%, respectively, during the three procedures, while calculated t-PA clearance decreased on average 59, 59 and 53%. t-PA concentration versus time curves, displayed in proportional units, were similar. The comparable relative increases in endogenous and exogenous t-PA with simultaneous proportional decreases in liver blood flow suggests that diminished hepatic t-PA clearance is the major cause of increased t-PA concentration and blood fibrinolytic activity enhancement during sustained submaximal exercise.

  2. 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

  3. Reliability of oscillometric central blood pressure responses to submaximal exercise.

    Science.gov (United States)

    Lim, Weijie; Faulkner, James; Lambrick, Danielle; Stoner, Lee

    2016-06-01

    Central blood pressure responses to exercise may provide clinicians with a superior diagnostic and prognostic tool. However, to be of value in a clinical setting these assessments must be simple to conduct and reliable. Using oscillometric pulse wave analysis (PWA), determine the upper limit for between-day reliability of central SBP (cSBP) and central pressure augmentation (AIx) responses to three progressive stages of submaximal exercise in a cohort of young, healthy participants. Fifteen healthy males [25.8 years (SD 5.7), 23.9 kg/m (SD 2.5)] were tested on three different mornings in a fasted state, separated by a maximum of 14 days. Central hemodynamic variables were assessed on the left upper arm. Participants underwent three progressive stages of submaximal cycling at 50 W (low), 100 W (moderate) and 150 W (moderate-hard). During low and moderate-intensity exercise the intra-class correlation coefficient (ICC) values for cSBP (0.79-0.80) and AIx (0.81-0.85) indicated excellent reliability (ICC > 0.75). For the moderate-hard intensity AIx could not be computed, and the ICC for cSBP was adequate (0.72). Findings from this study suggest that, at least in a young, healthy cohort, oscillometric PWA can be used to reliably assess central blood pressure measurements during exercise, up to a moderate intensity. Although further work is required to verify these findings in clinical cohorts, these measurements may potentially provide clinicians with a practical option for obtaining important hemodynamic information beyond that provided by resting peripheral blood pressure.

  4. Acclimatization improves submaximal exercise economy at 5533 m.

    Science.gov (United States)

    Latshang, T D; Turk, A J; Hess, T; Schoch, O D; Bosch, M M; Barthelmes, D; Merz, T M; Hefti, U; Hefti, J Pichler; Maggiorini, M; Bloch, K E

    2013-08-01

    We tested whether the better subjective exercise tolerance perceived by mountaineers after altitude acclimatization relates to enhanced exercise economy. Thirty-two mountaineers performed progressive bicycle exercise to exhaustion at 490 m and twice at 5533 m (days 6-7 and day 11), respectively, during an expedition to Mt. Muztagh Ata. Maximal work rate (W(max)) decreased from mean ± SD 356 ± 73 watts at 490 m to 191 ± 49 watts and 193 ± 45 watts at 5533 m, days 6-7 and day 11, respectively; corresponding maximal oxygen uptakes (VO2max ) were 50.7 ± 9.5, 26.3 ± 5.6, 24.7 ± 7.0 mL/min/kg (P = 0.0001 5533 m vs 490 m). On days 6-7 (5533 m), VO(2) at 75% W(max) (152 ± 37 watts) was 1.75 ± 0.45 L/min, oxygen saturation 68 ± 8%. On day 11 (5533 m), at the same submaximal work rate, VO(2) was lower (1.61 ± 0.47 L/min, P scale 50 ± 15 vs 57 ± 20, P = 0.006) and reduced symptoms of acute mountain sickness. We conclude that the better performance and subjective exercise tolerance after acclimatization were related to regression of acute mountain sickness and improved submaximal exercise economy because of lower metabolic demands for non-external work-performing functions. © 2011 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Cardiac Autonomic Function during Submaximal Treadmill Exercise in Adults with Down Syndrome

    Science.gov (United States)

    Mendonca, Goncalo V.; Pereira, Fernando D.; Fernhall, Bo

    2011-01-01

    This study determined whether the cardiac autonomic function of adults with Down syndrome (DS) differs from that of nondisabled persons during submaximal dynamic exercise. Thirteen participants with DS and 12 nondisabled individuals performed maximal and submaximal treadmill tests with metabolic and heart rate (HR) measurements. Spectral analysis…

  6. Effect of the Canadian Air Force training programme on a submaximal exercise test.

    Science.gov (United States)

    Kappagoda, C T; Linden, R J; Newell, J P

    1979-07-01

    Validation of the submaximal heart rate/oxygen consumption relationship as an index of 'cardiorespiratory fitness' requires the demonstration of systematic alterations in this relationship concomitant with interventions designed to alter physical fitness. To fulfil those criteria a longitudinal training/de-training study was undertaken. Previously sedentary adult subjects undertook the Canadian Airforce 5BX-XBX exercise programme. Submaximal exercise tests were performed before and after training, and following several weeks cessation of training. A regression line of submaximal heart rate on submaximal oxygen consumption was calculated from the data of each submaximal exercise test. Alterations in the regression lines were examined for each subject individually by testing statistically for difference in slope and elevation between any pair of lines. Subjects who undertook the training/de-training study demonstrated significant systematic alterations in the elevation of the regression lines concomitant with periods of training and de-training. The reproducibility of the submaximal heart rate/oxygen consumption relationship was examined in two additional groups of subjects. Group A repeated a submaximal test on 3 or 4 successive days; Group B were tested before and after 16 weeks of normal activity. Subjects in Group A demonstrated non significant, random alterations in the regression lines on repeated testing and subjects in Group B demonstrated random, though on occasion significant, alterations in the regression lines. The elevation of the submaximal heart rate/oxygen consumption relationship is therefore a valid index for detecting sequential changes in 'cardiorespiratory fitness' in individual subjects.

  7. Cardiovascular responses during a submaximal exercise test in patients with Parkinson's disease.

    Science.gov (United States)

    Speelman, Arlène D; Groothuis, Jan T; van Nimwegen, Marlies; van der Scheer, Ellis S; Borm, George F; Bloem, Bastiaan R; Hopman, Maria T E; Munneke, Marten

    2012-01-01

    Patients with Parkinson's disease (PD) are physically less active than controls, and autonomic dysfunction may contribute to this sedentary lifestyle. Specifically, an altered cardiovascular response to physical effort may restrict physical activities. To assess the cardiovascular responses to a submaximal exercise test in PD patients and controls, 546 sedentary PD patients and 29 sedentary healthy controls performed the Åstrand-Rhyming submaximal cycle exercise test. Average heart rate was used to estimate maximal oxygen consumption (VO2max). Variables that may affect submaximal activity in PD patients, including disease severity, fatigue, and level of physical activity in daily life, were recorded. Fewer PD patients (46%) completed the submaximal exercise test successfully than the controls (86%). The estimated VO2max of patients with a successful test was 34% lower than the controls (p physical activities further.

  8. THE INFLUENCE OF OBESITY AND AMBIENT TEMPERATURE ON PHYSIOLOGICAL AND OXIDATIVE RESPONSES TO SUBMAXIMAL EXERCISE

    OpenAIRE

    Ahn, N.; Kim, K.

    2014-01-01

    This study investigated the effects of obesity and ambient temperature on physiological responses and markers of oxidative stress to submaximal exercise in obese and lean people. Sixteen healthy males were divided into an obese group (n=8, %fat: 27.00±3.00%) and a lean group (n=8, %fat: 13.85±2.45%). Study variables were measured during a 60 min submaximal exercise test at 60% VO2max in a neutral (21±1°C) and a cold (4±1°C) environment. Heart rate, blood lactate, rectal temperature, serum lev...

  9. Variation in heart rate during submaximal exercise: Implications for monitoring training : Implications for monitoring training

    NARCIS (Netherlands)

    Lamberts, R.P.; Lemmink, K.A.P.M.; Durandt, J.J.; Lambert, M.I.

    2004-01-01

    A change in heart rate at a controlled submaximal exercise intensity is used as a marker of training status. However, the standard error of measurement has not been studied systematically, and therefore a change in heart rate, which can be considered relevant, has not been determined. Forty-four

  10. Systolic blood pressure reactivity during submaximal exercise and acute psychological stress in youth

    Science.gov (United States)

    Background: Studies in youth show an association between systolic blood-pressure (SBP) reactivity to acute psychological stress and carotid artery intima-media thickness (CIMT). However, it has not yet been determined whether SBP reactivity during submaximal exercise is also associated with CIMT i...

  11. THE INFLUENCE OF OBESITY AND AMBIENT TEMPERATURE ON PHYSIOLOGICAL AND OXIDATIVE RESPONSES TO SUBMAXIMAL EXERCISE

    Directory of Open Access Journals (Sweden)

    N. Ahn

    2014-07-01

    Full Text Available This study investigated the effects of obesity and ambient temperature on physiological responses and markers of oxidative stress to submaximal exercise in obese and lean people. Sixteen healthy males were divided into an obese group (n=8, %fat: 27.00±3.00% and a lean group (n=8, %fat: 13.85±2.45%. Study variables were measured during a 60 min submaximal exercise test at 60% VO2max in a neutral (21±1°C and a cold (4±1°C environment. Heart rate, blood lactate, rectal temperature, serum levels of malondialdehyde (MDA and superoxide dismutase (SOD were measured at rest, during exercise and in recovery. Heart rate of both groups was significantly lower (P<0.05 in the cold than the warm environment, but there were no significant differences between the two groups. Serum SOD activity increased to a significantly greater extent (P<0.05 in the cold than the neutral environment, and remained elevated for longer during exercise in the obese group than the lean group. Serum MDA level during submaximal exercise was not significantly different between conditions or groups. Cold stress in exercise may challenge antioxidant defence mechanisms in obese subjects, but lipid peroxidation remains unchanged.

  12. Normobaric Hypoxia and Submaximal Exercise Effects on Running Memory and Mood State in Women.

    Science.gov (United States)

    Seo, Yongsuk; Gerhart, Hayden D; Stavres, Jon; Fennell, Curtis; Draper, Shane; Glickman, Ellen L

    2017-07-01

    An acute bout of exercise can improve cognitive function in normoxic and hypoxic conditions. However, limited research supports the improvement of cognitive function and mood state in women. The purpose of this study was to examine the effects of hypoxia and exercise on working memory and mood state in women. There were 15 healthy women (age = 22 ± 2 yr) who completed the Automated Neuropsychological Assessment Metrics-4th Edition (ANAM), including the Running Memory Continuous Performance Task (RMCPT) and Total Mood Disturbance (TMD) in normoxia (21% O2), at rest in normoxia and hypoxia (12.5% O2), and during cycling exercise at 60% and 40% Vo2max in hypoxia. RMCPT was not significantly impaired at 30 (100.3 ± 17.2) and 60 (96.6 ± 17.3) min rest in hypoxia compared to baseline in normoxia (97.0 ± 17.0). However, RMCPT was significantly improved during exercise (106.7 ± 20.8) at 60% Vo2max compared to 60 min rest in hypoxia. Following 30 (-89.4 ± 48.3) and 60 min of exposure to hypoxia (-79.8 ± 55.9) at rest, TMD was impaired compared with baseline (-107.1 ± 46.2). TMD was significantly improved during exercise (-108.5 ± 42.7) at 40% Vo2max compared with 30 min rest in hypoxia. Also, RMCPT was significantly improved during exercise (104.0 ± 19.1) at 60% Vo2max compared to 60 min rest in hypoxia (96.6 ± 17.3). Hypoxia and an acute bout of exercise partially influence RMCPT and TMD. Furthermore, a moderate-intensity bout of exercise (60%) may be a more potent stimulant for improving cognitive function than low-intensity (40%) exercise. The present data should be considered by aeromedical personnel performing cognitive tasks in hypoxia.Seo Y, Gerhart HD, Stavres J, Fennell C, Draper S, Glickman EL. Normobaric hypoxia and submaximal exercise effects on running memory and mood state in women. Aerosp Med Hum Perform. 2017; 88(7):627-632.

  13. Prognostic value of treadmill stress echocardiography at extremes of exercise performance: submaximal high exercise capacity ≥ 10 metabolic equivalents.

    Science.gov (United States)

    Yao, Siu-Sun; Agarwal, Vikram; Chaudhry, Farooq A

    2014-03-01

    Submaximal stress testing or achieving High exercise capacity (≥ 10 metabolic equivalents, METS) is a predictor of favorable prognosis. The purpose of this study was to evaluate the prognostic value of submaximal or high exercise capacity stress echocardiography. We evaluated 1781 patients (55 ± 13 years; 59% male) undergoing treadmill stress echocardiography divided into 811 patients with submaximal (high exercise capacity (≥ 10 METS). Resting left ventricular ejection fraction and regional wall motion were assessed. The left ventricle was divided into 16 segments and scored on 5-point scale of wall motion. Abnormal stress echocardiography was defined as stress-induced ischemia (wall-motion score of ≥ 1 grade). Follow-up (3.3 ± 1.5 years) for nonfatal myocardial infarction (MI) (n = 40) and cardiac death (n = 52) were obtained. By univariate analysis, echocardiographic variables of ejection fraction, peak wall-motion score index (WMSI) and number of new ischemic wall-motion abnormalities were significant predictors of cardiac events. Cumulative survival was significantly worse in patients with abnormal (ischemic) versus normal (nonischemic) stress echocardiography in submaximal (4.4%/year vs. 1.3%/year, P high exercise capacity (1.5%/year vs. 0.2%/year, P high exercise capacity studies. © 2013, Wiley Periodicals, Inc.

  14. The Usefulness of Submaximal Exercise Gas Exchange in Pulmonary Arterial Hypertension: A Case Series

    Directory of Open Access Journals (Sweden)

    Paul R. Woods

    2010-04-01

    Full Text Available Introduction Submaximal exercise gas exchange may be a useful tool to track responses to therapy in pulmonary arterial hypertension (PAH patients. Methods Three patients diagnosed with idiopathic PAH, on differing therapies, were included. Standard clinical tests (echocardiography; 6 minute walk were performed pre and 3-5 months after treatment. Gas exchange was measured during 3 minutes of step exercise at both time points. Results Gas exchange variables, end tidal CO 2 (P ET CO 2 and the ratio of ventilation to CO 2 production (V E /VCO 2 , during submaximal exercise were able to track patient responses to therapy over a 3-5 month period. Two patients demonstrated positive improvements, with an increased P ET CO 2 and decreased V E /VCO 2 during light exercise, in response to an altered therapeutic regime. The third patient had a worsening of gas exchange (decreased P ET CO 2 and increased V E /VCO 2 following no changes in the medical regime from the baseline visit. Conclusion Gas exchange variables measured during light submaximal exercise, such as P ET CO 2 and V E /VCO 2 , may be able to better detect small changes in functional status following treatment and could, therefore, be a useful tool to track disease severity in PAH patients. Further study is required to determine the clinical usefulness of these gas exchange variables.

  15. Iron Status in Chronic Heart Failure: Impact on Symptoms, Functional Class and Submaximal Exercise Capacity.

    Science.gov (United States)

    Enjuanes, Cristina; Bruguera, Jordi; Grau, María; Cladellas, Mercé; Gonzalez, Gina; Meroño, Oona; Moliner-Borja, Pedro; Verdú, José M; Farré, Nuria; Comín-Colet, Josep

    2016-03-01

    To evaluate the effect of iron deficiency and anemia on submaximal exercise capacity in patients with chronic heart failure. We undertook a single-center cross-sectional study in a group of stable patients with chronic heart failure. At recruitment, patients provided baseline information and completed a 6-minute walk test to evaluate submaximal exercise capacity and exercise-induced symptoms. At the same time, blood samples were taken for serological evaluation. Iron deficiency was defined as ferritin < 100 ng/mL or transferrin saturation < 20% when ferritin is < 800 ng/mL. Additional markers of iron status were also measured. A total of 538 heart failure patients were eligible for inclusion, with an average age of 71 years and 33% were in New York Heart Association class III/IV. The mean distance walked in the test was 285 ± 101 meters among those with impaired iron status, vs 322 ± 113 meters (P=.002). Symptoms during the test were more frequent in iron deficiency patients (35% vs 27%; P=.028) and the most common symptom reported was fatigue. Multivariate logistic regression analyses showed that increased levels of soluble transferrin receptor indicating abnormal iron status were independently associated with advanced New York Heart Association class (P < .05). Multivariable analysis using generalized additive models, soluble transferrin receptor and ferritin index, both biomarkers measuring iron status, showed a significant, independent and linear association with submaximal exercise capacity (P=.03 for both). In contrast, hemoglobin levels were not significantly associated with 6-minute walk test distance in the multivariable analysis. In patients with chronic heart failure, iron deficiency but not anemia was associated with impaired submaximal exercise capacity and symptomatic functional limitation. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  16. Monitoring Training Progress During Exercise Training in Cancer Survivors : A Submaximal Exercise Test as an Alternative for a Maximal Exercise Test?

    NARCIS (Netherlands)

    May, Anne M.; van Weert, Ellen; Korstjens, Irene; Hoekstra-Weebers, Josette E.; van der Schans, Cees P.; Zonderland, Maria L.; Mesters, Ilse; van den Borne, Bart; Ros, Wynand J.

    May AM, van Weert E, Korstjens 1, Hoekstra-Weebers JE, van der Schans CP, Zonderland ML, Mesters 1, van den Borne B, Ros WJ. Monitoring training progress during exercise training in cancer survivors: a submaximal exercise test as an alternative for a maximal exercise test? Arch Phys Med Rehabil

  17. Effects of submaximal exercise and noise exposure on hearing loss.

    Science.gov (United States)

    Alessio, H M; Hutchinson, K M

    1991-12-01

    A recent Scandinavian study reported that persons cycling at moderate intensity for 10 min suffered hearing loss when the exercise was accompanied by noise. The noise consisted of a 1/3 octave band-filtered noise with a 2000 Hz center frequency at 104 dB SPL. In the present study, adults cycled at 50 rev.min-1 against a force that elicited an oxygen cost equal to 70% of VO2max--an intensity frequently recommended in exercise prescriptions--with and without noise administered via headphones. Repeated measures ANOVA with three factors revealed that although a temporary hearing loss occurred following exercise-and-noise, a similar and slightly greater hearing loss occurred following noise-only. Hearing sensitivity was not significantly altered by exercise-only (p greater than .05). In general, hearing loss values were greatest between 3000 and 4000 Hz. In conclusion, temporary hearing loss was driven by noise exposure, not exercise. However, persons who choose to exercise with personal headphones or in a noisy environment should be aware of potential premature hearing loss.

  18. Altitude Acclimatization Attentuates Plasma Ammonia during Submaximal Exercise,

    Science.gov (United States)

    1986-05-01

    citrulline synthesis in rat liver mitochondria : The effect of ammonia and energy. Int. J. Biochem. 10:235-239, 1979. 14 9. Buono, M.J., T.R. Clancy, and J.R...Mole, P.A., L.B. Oscal, and J.0. Holloszy. Adaptation of muscle to exercise. Increase in levels of palmityl CoA synthetase, carnitine

  19. Haemodynamic changes induced by submaximal exercise before a dive and its consequences on bubble formation

    Science.gov (United States)

    Blatteau, Jean‐Eric; Boussuges, Alain; Gempp, Emmanuel; Pontier, Jean‐Michel; Castagna, Olivier; Robinet, Claude; Galland, Francois‐Michel; Bourdon, Lionel

    2007-01-01

    Objectives To evaluate the effects of a submaximal exercise performed 2 h before a simulated dive on bubble formation and to observe the haemodynamic changes and their influence on bubble formation. Participants and methods 16 trained divers were compressed in a hyperbaric chamber to 400 kPa for 30 min and decompressed at a rate of 100 kPa/min with a 9 min stop at 130 kPa (French Navy MN90 procedure). Each diver performed two dives 3 days apart, one without exercise and one with exercise before the dive. All participants performed a 40 min constant‐load submaximal and calibrated exercise, which consisted of outdoor running 2 h before the dive. Circulating bubbles were detected with a precordial Doppler at 30, 60 and 90 min after surfacing. Haemodynamic changes were evaluated with Doppler echocardiography. Results A single bout of strenuous exercise 2 h before a simulated dive significantly reduced circulating bubbles. Post‐exercise hypotension (PEH) was observed after exercise with reductions in diastolic and mean blood pressure (DBP and MBP), but total peripheral resistance was unchanged. Stroke volume was reduced, whereas cardiac output was unchanged. Simulated diving caused a similar reduction in cardiac output independent of pre‐dive exercise, suggesting that pre‐dive exercise only changed DBP and MBP caused by reduced stroke volume. Conclusion A single bout of strenuous exercise 2 h before a dive significantly reduced the number of bubbles in the right heart of divers and protected them from decompression sickness. Declining stroke volume and moderate dehydration induced by a pre‐dive exercise might influence inert gas load and bubble formation. PMID:17138641

  20. Variation in heart rate during submaximal exercise: implications for monitoring training.

    Science.gov (United States)

    Lamberts, Robert P; Lemmink, Koen A P M; Durandt, Justin J; Lambert, Michael I

    2004-08-01

    A change in heart rate at a controlled submaximal exercise intensity is used as a marker of training status. However, the standard error of measurement has not been studied systematically, and therefore a change in heart rate, which can be considered relevant, has not been determined. Forty-four subjects (26.5 +/- 5.4 years; mean +/- standard deviation) participated in a submaximal running test at the same time of day for 5 consecutive days. Heart rates were determined during each of the 4 exercise intensities (2 minutes each) of increasing intensity and during the 1-minute recovery period after each stage. The repeatability of the heart rate on a day-to-day basis during the stages and recovery periods were high (intraclass correlation coefficient: 95% confidence interval R = 0.94- 0.99). The lowest variation in heart rate occurred in the fourth stage ( approximately 90% maximum heart rate) with heart rate varying 5 +/- 2 b.min(-1) (95% confidence interval for coefficient of variation = 1.1-1.4%). In conclusion, the standard error of measurement of submaximal heart rate is 1.1-1.4%. This magnitude of measurement error needs to be considered when heart rate is used as a marker of training status.

  1. Analysing visual pattern of skin temperature during submaximal and maximal exercises

    Science.gov (United States)

    Balci, Gorkem Aybars; Basaran, Tahsin; Colakoglu, Muzaffer

    2016-01-01

    Aims of this study were to examine our hypotheses assuming that (a) skin temperature patterns would differ between submaximal exercise (SE) and graded maximal exercise test (GXT) and (b) thermal kinetics of Tskin occurring in SE and GXT might be similar in a homogenous cohort. Core temperature (Tcore) also observed in order to evaluate thermoregulatory responses to SE and GXT. Eleven moderately to well-trained male athletes were volunteered for the study (age: 22.2 ± 3.7 years; body mass: 73.8 ± 6.9 kg; height: 181 ± 6.3 cm; body surface area 1.93 ± 0.1 m2; body fat: 12.6% ± 4.2%; V ˙ O2max: 54 ± 9.9 mL min-1 kg-1). Under stabilized environmental conditions in climatic chamber, GXT to volitional exhaustion and 20-min SE at 60% of VO2max were performed on cycle ergometer. Thermal analyses were conducted in 2-min intervals throughout exercise tests. Tskin was monitored by a thermal camera, while Tcore was recorded via an ingestible telemetric temperature sensor. Thermal kinetic analyses showed that Tskin gradually decreased till the 7.58 ± 1.03th minutes, and then initiated to increase till the end of SE (Rsqr = 0.97), while Tskin gradually decreased throughout the GXT (Rsqr = 0.89). Decrease in the level of Tskin during the GXT was significantly below from the SE [F (4, 40) = 2.67, p = 0.07, ηp2 = 0.211]. In the meantime, Tcore continuously increased throughout the SE and GXT (p 0.05). However, total heat energies were calculated as 261.5 kJ/m2 and 416 kJ/m2 for GXT and SE, respectively (p exercises as expected. Tskin curves patterns found to be associated amongst participants at both GXT and SE. Therefore, Tskin kinetics may ensure an important data for monitoring thermoregulation in exercise.

  2. [Submaximal exercise capacity and quality of life in exclusive water-pipe smokers].

    Science.gov (United States)

    Ben Saad, H; Babba, M; Boukamcha, R; Latiri, I; Knani, J; Slama, R; Bougmiza, I; Zbidi, A; Tabka, Z

    2010-05-01

    It is well known that oxidative stress is increased significantly by regular water-pipe smoking (WPS). This could lead to muscle dysfunction and thus to impairments of exercise and quality of life (QOL). Considering the impressive number of WP smokers, we intend to investigate the potential effect of WPS on submaximal exercise capacity and QOL. (1). To evaluate the submaximal exercise capacity by the 6-minutes walking test (6-MWT). (2). To compare the deficiency, incapacity and QOL data of exclusive WPS with those of two control groups (never smokers and exclusive cigarette smokers). (3). To determine the factors influencing the 6-minutes walk distance (6-MWD) of WPS subjects. A multicentre study including 180 exclusive WPS [> or =5 WP-year] men aged > or =40 years. Cigar or cigarette smoking, contraindications to the 6-MWT or cortico-steroid therapy will be exclusion criteria. QOL evaluation, spirometry, electrocardiogram and two 6-MWT will be performed. Signs of exercise impairment will be: 6-MWD or =5/10, haemoglobin saturation fall > or =5 points. Data from WPS subjects will be compared with those from 90 never smoking subjects and 90 exclusives cigarettes smokers. (1). WPS will affect significantly the submaximal exercise capacity. (2). Resting spirometric, 6-MWT and QOL data of exclusive WPS subjects will be significantly reduced compared to never smoking subjects. (3). The 6-MWD's of exclusive WPS subjects will be significantly influenced by cumulative WP consumption, by resting spirometric data, by obesity and by physical activity score. Copyright 2010 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  3. Cognitive Performance Enhancement Induced by Caffeine, Carbohydrate and Guarana Mouth Rinsing during Submaximal Exercise

    Directory of Open Access Journals (Sweden)

    Laura Pomportes

    2017-06-01

    Full Text Available The aim of this study was to investigate the influence of serial mouth rinsing (MR with nutritional supplements on cognitive performance (i.e., cognitive control and time perception during a 40-min submaximal exercise. Twenty-four participants completed 4 counterbalanced experimental sessions, during which they performed MR with either placebo (PL, carbohydrate (CHO: 1.6 g/25 mL, guarana complex (GUAc: 0.4 g/25 mL or caffeine (CAF: 67 mg/25 mL before and twice during exercise. The present study provided some important new insights regarding the specific changes in cognitive performance induced by nutritional supplements. The main results were: (1 CHO, CAF and GUA MR likely led participants to improve temporal performance; (2 CAF MR likely improved cognitive control; and (3 CHO MR led to a likely decrease in subjective perception of effort at the end of the exercise compared to PL, GUA and CAF. Moreover, results have shown that performing 40-min submaximal exercise enhances information processing in terms of both speed and accuracy, improves temporal performance and does not alter cognitive control. The present study opens up new perspectives regarding the use of MR to optimize cognitive performance during physical exercise.

  4. Test retest reliability and minimal detectable change of a novel submaximal graded exercise test in the measurement of graded exercise test duration.

    Science.gov (United States)

    Taylor, James D; Bandy, William D; Whittemore, Joe D

    2011-05-01

    Measurement of graded exercise test duration is clinically important and can be assessed by maximal graded exercise testing. Yet, limitations of maximal graded exercise testing exist. An alternative to maximal graded exercise testing is submaximal graded exercise testing. However, no studies have investigated the reliability of a submaximal graded exercise test in the measurement of graded exercise test duration. The purpose of this study was to determine the test-retest reliability and minimal detectable change (MDC) of a novel submaximal graded exercise test in the measurement of graded exercise test duration. Fifteen people (4 men, 11 women) with a mean age of 26.20 years (SD = 9.04) participated in this study. A novel submaximal graded exercise test was used to measure graded exercise test duration for each participant. Endpoints of the test were either 85% of age-predicted maximum heart rate or voluntarily stopping the test, whichever endpoint occurred first. Heart rate and graded exercise test duration were constantly measured throughout the test. Graded exercise test duration was defined as the total duration (minutes) of the test. For all participants, the submaximal graded exercise test was conducted at baseline and 48-72 hours thereafter. The intraclass correlation coefficient for the test-retest reliability of the test in determining graded exercise test duration was 0.94 (95% CI = 0.83-0.98). The MDC of the test in the measurement of graded exercise test duration was 0.86 minutes. The results suggest that clinicians can use this novel submaximal graded exercise test to reliably measure graded exercise test duration with a measurement error, as expressed by the MDC, of 0.86 minutes.

  5. Evaluation of Exercise Response in a Young, High Risk Population: Submaximal Invasive Cardiopulmonary Exercise Testing (ICPET) in Active Duty Soldiers

    Science.gov (United States)

    2017-03-17

    Submaximal Invasive Cardiopulmonary Exercise Testing iCPET in AD Soldiers presented at/published to American College of Cardiology’s 661h Annual...disclaimer statement for research involving animals . as required by AFMAN 40-401 IP : " The experiments reported herein were conducted according to the...principles set forth in the National Institute of Health Publication No. 80-23, Guide for the Care and Use of Laboratory Animals and the Animal

  6. The physiology of submaximal exercise: The steady state concept.

    Science.gov (United States)

    Ferretti, Guido; Fagoni, Nazzareno; Taboni, Anna; Bruseghini, Paolo; Vinetti, Giovanni

    2017-12-01

    The steady state concept implies that the oxygen flow is invariant and equal at each level along the respiratory system. The same is the case with the carbon dioxide flow. This condition has several physiological consequences, which are analysed. First, we briefly discuss the mechanical efficiency of exercise and the energy cost of human locomotion, as well as the roles played by aerodynamic work and frictional work. Then we analyse the equations describing the oxygen flow in lungs and in blood, the effects of ventilation and of the ventilation - perfusion inequality, and the interaction between diffusion and perfusion in the lungs. The cardiovascular responses sustaining gas flow increase in blood are finally presented. An equation linking ventilation, circulation and metabolism is developed, on the hypothesis of constant oxygen flow in mixed venous blood. This equation tells that, if the pulmonary respiratory quotient stays invariant, any increase in metabolic rate is matched by a proportional increase in ventilation, but by a less than proportional increase in cardiac output. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Human skeletal muscle type 1 fibre distribution and response of stress-sensing proteins along the titin molecule after submaximal exhaustive exercise.

    Science.gov (United States)

    Koskinen, Satu O A; Kyröläinen, Heikki; Flink, Riina; Selänne, Harri P; Gagnon, Sheila S; Ahtiainen, Juha P; Nindl, Bradley C; Lehti, Maarit

    2017-11-01

    Early responses of stress-sensing proteins, muscle LIM protein (MLP), ankyrin repeat proteins (Ankrd1/CARP and Ankrd2/Arpp) and muscle-specific RING finger proteins (MuRF1 and MuRF2), along the titin molecule were investigated in the present experiment after submaximal exhaustive exercise. Ten healthy men performed continuous drop jumping unilaterally on a sledge apparatus with a submaximal height until complete exhaustion. Five stress-sensing proteins were analysed by mRNA measurements from biopsies obtained immediately and 3 h after the exercise from exercised vastus lateralis muscle while control biopsies were obtained from non-exercised legs before the exercise. Decreased maximal jump height and increased serum creatine kinase activities as indirect markers for muscle damage and HSP27 immunostainings on muscle biopsies as a direct marker for muscle damage indicated that the current exercised protocol caused muscle damage. mRNA levels for four (MLP, Ankrd1/CARP, MuRF1 and MuRF2) out of the five studied stress sensors significantly (p exercise. The magnitude of MLP and Ankrd2 responses was related to the proportion of type 1 myofibres. Our data showed that the submaximal exhaustive exercise with subject's own physical fitness level activates titin-based stretch-sensing proteins. These results suggest that both degenerative and regenerative pathways are activated in very early phase after the exercise or probably already during the exercise. Activation of these proteins represents an initial step forward adaptive remodelling of the exercised muscle and may also be involved in the initiation of myofibre repair.

  8. The Impact of a Submaximal Level of Exercise on Balance Performance in Older Persons

    Science.gov (United States)

    2014-01-01

    Objective. The purpose of this study was to determine the impact of a submaximal level of exercise on balance performance under a variety of conditions. Material and Method. Thirteen community-dwelling older persons with intact foot sensation (age = 66.69 ± 8.17 years, BMI = 24.65 ± 4.08 kg/m2, female, n = 6) volunteered to participate. Subjects' balance performances were measured using the Modified Clinical Test of Sensory Integration of Balance (mCTSIB) at baseline and after test, under four conditions of stance: (1) eyes-opened firm-surface (EOF), (2) eyes-closed firm-surface (ECF), (3) eyes-opened soft-surface (EOS), and (4) eyes-closed soft-surface (ECS). The 6-minute walk test (6MWT) protocol was used to induce the submaximal level of exercise. Data was analyzed using the Wilcoxon Signed-Rank Test. Results. Balance changes during EOF (z = 0.00, P = 1.00) and ECF (z = −1.342, P = 0.180) were not significant. However, balance changes during EOS (z = −2.314, P = 0.021) and ECS (z = −3.089, P = 0.02) were significantly dropped after the 6MWT. Conclusion. A submaximal level of exercise may influence sensory integration that in turn affects balance performance, particularly on an unstable surface. Rehabilitation should focus on designing intervention that may improve sensory integration among older individuals with balance deterioration in order to encourage functional activities. PMID:25383386

  9. Hypotension and heart rate variability after resistance exercise performed maximal and submaximal order

    Directory of Open Access Journals (Sweden)

    Victor Gonçalves Corrêa Neto

    2017-06-01

    Full Text Available The aim of the study was verified the blood pressure responses and the cardiac autonomic modulation after the strength exercise in two different conditions (maximal and submaximal. The subjects were divided in three groups, such as: maximal repetitions (age: 20.5 ± 0.6 years, weight: 63.7 ± 14.8, height: 1.7 ± 0.1, body mass index: 22.8 ± 4.5 Kilogram per square meter (kg/m², submaximal repetitions (age: 25 ± 4.1 years, weight: 69.1 ± 12.8, height: 1.8 ± 0.1, body mass index: 22.2 ± 1.7 (kg/m²  and a control group (age: 23.7 ± 3.8 years, weight: 64.2 ± 15, height: 1.7 ± 0.1, body mass index: 21.8 ± 1.9 (kg/m². The blood pressure and the Heart Rate R-R intervals were measured before and during one hour after the session, with 10-minutes intervals length between measurements. The analyze of variance did not showed significant differences between experimental protocols to blood pressure (p > 0.05. However, the effect size was able to show that the most intense training caused a reduction in systolic blood pressure at times. Regarding cardiac autonomic response, the group that exercised the submaximal form exhibited a significant increase in LF / HF (p = 0.022 when 20 minutes’ post-exercise. There was a not significant difference in cardiac autonomic modulation between protocols. The high intensity protocol has caused blood pressure reductions in more moments and it was over safer in relation to cardiac autonomic modulation, since it did not cause increased sympathetic activity during recovery.

  10. Comparison of the YMCA and a Custom Submaximal Exercise Test for Determining VO2max.

    Science.gov (United States)

    Jamnick, Nicholas A; By, Savanny; Pettitt, Cherie D; Pettitt, Robert W

    2016-02-01

    The maximal oxygen uptake (VO2max) is deemed the highest predictor for all-cause mortality, and therefore, an ability to assess VO2max is important. The YMCA submaximal test is one of the most widely used tests to estimate VO2max; however, it has questionable validity. We validated a customized submaximal test that accounts for the nonlinear rise in VO2 relative to power output and compared its accuracy against the YMCA protocol. Fifty-six men and women performed a graded exercise test with a subsequent exhaustive, square wave bout for the verification of "true" VO2max. In counterbalanced order, subjects then completed the YMCA test and our new Mankato submaximal exercise test (MSET). The MSET consisted of a 3-min stage estimated at 35% VO2max and a second 3-min stage estimated at either 65% or 70% VO2max, where VO2max was estimated with a regression equation using sex, body mass index, age, and self-reported PA-R. VO2 values from the graded exercise test and square wave verification bout did not differ with the highest value used to identify "true" VO2max (45.1 ± 8.89 mL · kg(-1) · min(-1)). The MSET (43.6 ± 8.6 mL · kg(-1) · min(-1)) did not differ from "true" VO2max, whereas the YMCA test (41.1 ± 9.6 mL · kg(-1) · min(-1)) yielded an underestimation (P = 0.002). The MSET was moderately correlated with "true" VO2max (ICC = 0.73, CV of 11.3%). The YMCA test was poorly correlated with "true" VO2max (ICC = 0.29, CV of 15.1%). To our knowledge, this is the first study to examine submaximal exercise protocols versus a verified VO2max protocol. The MSET yielded better estimates of VO2max because of the protocol including a stage exceeding gas exchange threshold.

  11. VO2@RER1.0: a novel submaximal cardiopulmonary exercise index.

    Science.gov (United States)

    Chin, Clifford; Kazmucha, Jeffrey; Kim, Nancy; Suryani, Reny; Olson, Inger

    2010-01-01

    Maximal oxygen consumption (VO2max) is the "gold standard" by which to assess functional capacity; however, it is effort dependent. VO2@RER1.0 is defined when VO2 = VCO2. Between December 22, 1997 and November 9, 2004, 305 pediatric subjects underwent cycle ergometer cardiopulmonary exercise testing, exercised to exhaustion, and reached a peak respiratory exchange ratio > or = 1.10. Group 1 subjects achieved a peak VO2 > or = 80% of predicted VO2max; group 2 subjects achieved a peak VO2 subjects achieved a peak VO2 between 61 and 79% of predicted VO2max. Linear regression analysis was performed for VO2@RER1.0 as a function of predicted VO2 for group 1 subjects. A -2 SD regression line and equation was created. VO2@RER1.0 data from groups 2 and 3 were plotted onto the normative graph. Contingency table and relative-risk analysis showed that an abnormal VO2@RER1.0 predicted an abnormal peak VO2(positive-predictive value 83%, negative-predictive value 85%, sensitivity 84%, and specificity 84%). VO2@RER1.0 is a highly sensitive, specific, and predictive submaximal index of functional capacity. This submaximal index is easy to identify without subjectivity. This index may aid in the evaluation of subjects who cannot exercise to maximal parameters.

  12. Brief note about plasma catecholamines kinetics and submaximal exercise in untrained standardbreds

    Directory of Open Access Journals (Sweden)

    Paolo Baragli

    2010-03-01

    Full Text Available Four untrained standardbred horses performed a standardized exercise test on the treadmill and an automated blood collection system programmed to obtain blood samples every 15 s was used for blood collection in order to evaluate the kinetics of adrenaline and noradrenaline. The highest average values obtained for adrenaline and noradrenaline were 15.0 ± 3.0 and 15.8 ± 2.8 nmol/l respectively, with exponential accumulation of adrenaline (r = 0.977 and noradrenaline (r = 0.976 during the test. Analysis of the correlation between noradrenaline and adrenaline for each phase of the test shows that correlation coefficient decreases as the intensity of exercise increases (from r = 0.909 to r = 0.788. This suggests that during submaximal exercise, the process for release, distribution and clearance of adrenaline into blood circulation differs from that of noradrenaline.

  13. Blunted Maximal and Submaximal Responses to Cardiopulmonary Exercise Tests in Patients With Parkinson Disease.

    Science.gov (United States)

    Kanegusuku, Hélcio; Silva-Batista, Carla; Peçanha, Tiago; Nieuwboer, Alice; Silva, Natan D; Costa, Luiz A; de Mello, Marco T; Piemonte, Maria E; Ugrinowitsch, Carlos; Forjaz, Cláudia L

    2016-05-01

    To investigate submaximal and maximal responses during maximal cardiopulmonary exercise tests in subjects with Parkinson disease (PD). Cross-sectional. A PD association. A sample (N=68) of subjects with PD (n=48; mean age, 66±8y; modified Hoehn and Yahr stage between 2 and 3; "on" state of medication) and age-matched controls without PD (n=20; mean age, 64±9y). Maximal cardiopulmonary exercise test on a cycle ergometer. Oxygen uptake (V˙o2), systolic blood pressure (SBP), and heart rate assessed at rest, submaximal intensities (ie, anaerobic threshold [AT] and respiratory compensation point), and maximal intensity (peak exercise). Compared with control subjects, subjects with PD had lower V˙o2, heart rate, and SBP at respiratory compensation point and peak exercise (V˙o2: 14.6±3.6mL⋅kg⋅min vs 17.9±5.5mL⋅kg⋅min and 17.7±4.8mL⋅kg⋅min vs 21.5±6.6mL⋅kg⋅min; heart rate: 119±17beats/min vs 139±12beats/min and 132±20beats/min vs 158±13beats/min; SBP: 151±17mmHg vs 172±20mmHg and 166±21mmHg vs 187±24mmHg; P≤.05). They also had lower heart rate at AT (102±14beats/min vs 110±13beats/min; P≤.05), whereas V˙o2 and SBP at this intensity were similar to those of control subjects. Subjects with PD demonstrated blunted metabolic and cardiovascular responses to submaximal and maximal exercise tests, especially at intensities above AT, which are in line with autonomic disturbances present in patients with PD. Future studies need to determine how this affects performance, participation, and responses of these patients to exercise training at different intensities. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  14. Is the ventilatory threshold coincident with maximal fat oxidation during submaximal exercise in women?

    Science.gov (United States)

    Astorino, T A

    2000-09-01

    The purpose of this study was to detect the fraction of peak oxygen consumption (VO2peak) that elicits maximal rates of fat oxidation during submaximal treadmill exercise. It was hypothesized that this point would appear at a work rate just below the ventilatory threshold. subjects completed a protocol requiring them to exercise for 15 min on a treadmill at six different workloads, 25, 40, 55, 65, 75, and 85% VO2peak, over two separate visits. nine healthy, moderately-trained eumenorrheic females (age = 28.8+/-5.99 yrs, VO2peak = 47.20 +/-2.57 ml x kg(-1) x min(-1)) volunteered for the study. a one-way ANOVA with repeated measures was used to test for differences across exercise intensities in the metabolic variables (i.e. substrate oxidation, blood lactate concentration ([La-]), RER, and the contribution of fat to total energy expenditure). Following significant F ratios, post-hoc tests were used to detect differences between the means for various exercise intensities. Exercise at 75% VO2peak elicited the greatest rate of fat oxidation (4.75+/-0.49 kcal x min(-1)), and this intensity was coincident with the ventilatory threshold (76+/-7.41% VO2peak). Moreover, a significant difference (t(8) = -3.98, ppopulation has application in exercise prescription and refutes the belief that low-intensity exercise is preferred for fat metabolism.

  15. Reliability of heart rate variability threshold and parasympathetic reactivation after a submaximal exercise test

    Directory of Open Access Journals (Sweden)

    Carlos Janssen Gomes da Cruz

    Full Text Available Abstract The objective of this study was to evaluate reproducibility of heart rate variability threshold (HRVT and parasympathetic reactivation in physically active men (n= 16, 24.3 ± 5.1 years. During the test, HRVT was assessed by SD1 and r-MSSD dynamics. Immediately after exercise, r-MSSD was analyzed in segments of 60 seconds for a period of five minutes. High absolute and relatively reproducible analysis of HRVT were observed, as assessed by SD1 and r-MSSD dynamics (ICC = 0.92, CV = 10.8, SEM = 5.8. During the recovery phase, a moderate to high reproducibility was observed for r-MSSD from the first to the fifth minute (ICC = 0.69-0.95, CV = 7.5-14.2, SEM = 0.07-1.35. We conclude that HRVT and r-MSSD analysis after a submaximal stress test are highly reproducible measures that might be used to assess the acute and chronic effects of exercise training on cardiac autonomic modulation during and/or after a submaximal stress test.

  16. The Effects of Caffeine Supplementation on Physiological Responses to Submaximal Exercise in Endurance-Trained Men.

    Science.gov (United States)

    Glaister, Mark; Williams, Benjamin Henley; Muniz-Pumares, Daniel; Balsalobre-Fernández, Carlos; Foley, Paul

    2016-01-01

    The aim of this study was to evaluate the effects of caffeine on physiological responses to submaximal exercise, with a focus on blood lactate concentration ([BLa]). Using a randomised, single-blind, crossover design; 16 endurance-trained, male cyclists (age: 38 ± 8 years; height: 1.80 ± 0.05 m; body mass: 76.6 ± 7.8 kg; [Formula: see text]: 4.3 ± 0.6 L∙min-1) completed four trials on an electromagnetically-braked cycle ergometer. Each trial consisted of a six-stage incremental test (3 minute stages) followed by 30 minutes of passive recovery. One hour before trials 2-4, participants ingested a capsule containing 5 mg∙kg-1 of either caffeine or placebo (maltodextrin). Trials 2 and 3 were designed to evaluate the effects of caffeine on various physiological responses during exercise and recovery. In contrast, Trial 4 was designed to evaluate the effects of caffeine on [BLa] during passive recovery from an end-exercise concentration of 4 mmol∙L-1. Relative to placebo, caffeine increased [BLa] during exercise, independent of exercise intensity (mean difference: 0.33 ± 0.41 mmol∙L-1; 95% likely range: 0.11 to 0.55 mmol∙L-1), but did not affect the time-course of [BLa] during recovery (p = 0.604). Caffeine reduced ratings of perceived exertion (mean difference: 0.5 ± 0.7; 95% likely range: 0.1 to 0.9) and heart rate (mean difference: 3.6 ± 4.2 b∙min-1; 95% likely range: 1.3 to 5.8 b∙min-1) during exercise, with the effect on the latter dissipating as exercise intensity increased. Supplement × exercise intensity interactions were observed for respiratory exchange ratio (p = 0.004) and minute ventilation (p = 0.034). The results of the present study illustrate the clear, though often subtle, effects of caffeine on physiological responses to submaximal exercise. Researchers should be aware of these responses, particularly when evaluating the physiological effects of various experimental interventions.

  17. Aerobic interval training reduces vascular resistances during submaximal exercise in obese metabolic syndrome individuals.

    Science.gov (United States)

    Mora-Rodriguez, Ricardo; Fernandez-Elias, V E; Morales-Palomo, F; Pallares, J G; Ramirez-Jimenez, M; Ortega, J F

    2017-08-12

    The aim of this study was to determine the effects of high-intensity aerobic interval training (AIT) on exercise hemodynamics in metabolic syndrome (MetS) volunteers. Thirty-eight, MetS participants were randomly assigned to a training (TRAIN) or to a non-training control (CONT) group. TRAIN consisted of stationary interval cycling alternating bouts at 70-90% of maximal heart rate during 45 min day(-1) for 6 months. CONT maintained baseline physical activity and no changes in cardiovascular function or MetS factors were detected. In contrast, TRAIN increased cardiorespiratory fitness (14% in VO2PEAK; 95% CI 9-18%) and improved metabolic syndrome (-42% in Z score; 95% CI 83-1%). After TRAIN, the workload that elicited a VO2 of 1500 ml min(-1) increased 15% (95% CI 5-25%; P < 0.001). After TRAIN when subjects pedaled at an identical submaximal rate of oxygen consumption, cardiac output increased by 8% (95% CI 4-11%; P < 0.01) and stroke volume by 10% (95% CI, 6-14%; P < 0.005) being above the CONT group values at that time point. TRAIN reduced submaximal exercise heart rate (109 ± 15-106 ± 13 beats min(-1); P < 0.05), diastolic blood pressure (83 ± 8-75 ± 8 mmHg; P < 0.001) and systemic vascular resistances (P < 0.01) below CONT values. Double product was reduced only after TRAIN (18.2 ± 3.2-17.4 ± 2.4 bt min(-1) mmHg 10(-3); P < 0.05). The data suggest that intense aerobic interval training improves hemodynamics during submaximal exercise in MetS patients. Specifically, it reduces diastolic blood pressure, systemic vascular resistances, and the double product. The reduction in double product, suggests decreased myocardial oxygen demands which could prevent the occurrence of adverse cardiovascular events during exercise in this population. CLINICALTRIALS. NCT03019796.

  18. The Effect of Acute Sub-Maximal Endurance Exercise on Serum Angiogenic Indices in Sedentary Men

    Directory of Open Access Journals (Sweden)

    Kamal Ranjbar

    2014-06-01

    Full Text Available Background: Endurance training increases capillary density of skeletal muscle, but the molecular mechanism of this process is not yet clear. Therefore, the purpose of this study was to investigate the effect of acute sub maximal endurance exercise on serum levels of vascular endothelial growth factor (VEGF and matrix metaloproteinases 2 and 9 (MMP-2 and MMP-9 in sedentary men. Materials and Methods: Twelve healthy men (22.37±2.30 years, BMI=23.16 ±2.61 kg/mP 2 P participated in this study. Subjects exercised for 1h at 70% of VOR2R max, 3 days after the VOR2R max determination. Antecubital vein blood was collected at rest, immediately and 2h after the exercise. Serum VEGF, MMP-2 and MMP-9 were measured by ELISA methods5T. Results: Serum levels of VEGF and MMP-2 decreased immediately after the exercise. 2 hours after the exercise, serum levels of VEGF remained at a lower level but serum MMP-2 returned to its basal level. Also, serum levels of MMP-9 did not change significantly in response to exercise5T. Conclusion: Acute sub-maximal endurance exercise decreased the main factors involved in development of capillary density in sedentary men. This might to due to the fact that, sub maximal exercise could not provide the two main stimulating factors of angiogenesis, i.e. Shear stress and hypoxia. It could also be explained by the fact that the mechanism of development of capillary network following regular endurance training is different from that following an acute exercise5T.5T

  19. Reduced peripheral arterial blood flow with preserved cardiac output during submaximal bicycle exercise in elderly heart failure

    Directory of Open Access Journals (Sweden)

    Leng Xiaoyan

    2009-11-01

    Full Text Available Abstract Background Older heart failure (HF patients exhibit exercise intolerance during activities of daily living. We hypothesized that reduced lower extremity blood flow (LBF due to reduced forward cardiac output would contribute to submaximal exercise intolerance in older HF patients. Methods and Results Twelve HF patients both with preserved and reduced left ventricular ejection fraction (LVEF (aged 68 ± 10 years without large (aorta or medium sized (iliac or femoral artery vessel atherosclerosis, and 13 age and gender matched healthy volunteers underwent a sophisticated battery of assessments including a peak exercise oxygen consumption (peak VO2, b physical function, c cardiovascular magnetic resonance (CMR submaximal exercise measures of aortic and femoral arterial blood flow, and d determination of thigh muscle area. Peak VO2 was reduced in HF subjects (14 ± 3 ml/kg/min compared to healthy elderly subjects (20 ± 6 ml/kg/min (p = 0.01. Four-meter walk speed was 1.35 ± 0.24 m/sec in healthy elderly verses 0.98 ± 0.15 m/sec in HF subjects (p p ≤ 0.03. Conclusion During CMR submaximal bike exercise in the elderly with heart failure, mechanisms other than low cardiac output are responsible for reduced lower extremity blood flow.

  20. Several submaximal exercise tests are reliable, valid and acceptable in people with chronic pain, fibromyalgia or chronic fatigue: a systematic review

    Directory of Open Access Journals (Sweden)

    Julia Ratter

    2014-09-01

    [Ratter J, Radlinger L, Lucas C (2014 Several submaximal exercise tests are reliable, valid and acceptable in people with chronic pain, fibromyalgia or chronic fatigue: a systematic review. Journal of Physiotherapy 60: 144–150

  1. Substrate utilization during submaximal exercise in children with a severely obese parent

    Directory of Open Access Journals (Sweden)

    Eaves Audrey D

    2012-05-01

    Full Text Available Abstract Background We have reported a reduction in fatty acid oxidation (FAO at the whole-body level and in skeletal muscle in severely obese (BMI ≥ 40 kg/m2 individuals; this defect is retained in cell culture suggesting an inherent component. The purpose of the current study was to determine if an impairment in whole-body fatty acid oxidation (FAO was also evident in children with a severely obese parent. Methods Substrate utilization during submaximal exercise (cycle ergometer was determined in children ages 8–12 y with a severely obese parent (OP, n = 13 or two lean/non-obese (BMI range of 18 to 28 kg/m2 parents (LP, n = 13. A subgroup of subjects (n = 3/group performed 4 weeks of exercise training with substrate utilization measured after the intervention. Results The children did not differ in age (LP vs. OP, respectively (10.7 ± 0.5 vs. 10.2 ± 0.5 y, BMI percentile (65.3 ± 5.2 vs. 75.9 ± 7, Tanner Stage (1.4 ± 0.2 vs. 1.5 ± 0.2, VO2peak (40.3 ± 2.7 vs. 35.6 ± 2.6 ml/kg/min or physical activity levels (accelerometer. At the same absolute workload of 15 W (~38% VO2peak, RER was significantly (P ≤ 0.05 lower in LP vs. OP (0.83 ± 0.02 vs. 0.87 ± 0.01 which was reflected in a reduced reliance on FAO for energy production in the OP group (58.6 ± 5.1 vs. 43.1 ± 4.0% of energy needs during exercise from FAO. At a higher exercise intensity (~65% VO2peak there were no differences in substrate utilization between LP and OP. After exercise training RER tended to decrease (P = 0.06 at the 15 W workload, suggesting an increased reliance on FAO regardless of group. Conclusions These findings suggest that the decrement in FAO with severe obesity has an inherent component that may be overcome with exercise training.

  2. Application of "living high-training low" enhances cardiac function and skeletal muscle oxygenation during submaximal exercises in athletes.

    Science.gov (United States)

    Park, Hun-Young; Nam, Sang-Seok

    2017-03-31

    The aim of this study was to determine the efficiency of the application of living high-training low (LHTL) on cardiac function and skeletal muscle oxygenation during submaximal exercises compared with that of living low-training low (LLTL) in athletes. Male middle- and long-distance runners (n = 20) were randomly assigned into the LLTL group (n = 10, living at 1000-m altitude and training at 700-1330-m altitude) and the LHTL group (n = 10, living at simulated 3000-m altitude and training at 700-1330-m altitude). Their cardiac function and skeletal muscle oxygenation during submaximal exercises at sea level before and after training at each environmental condition were evaluated. There was a significant interaction only in the stroke volume (SV); however, the heart rate (HR), end-diastolic volume (EDV), and end-systolic volume (ESV) showed significant main effects within time; HR and SV significantly increased during training in the LHTL group compared with those in the LLTL group. EDV also significantly increased during training in both groups; however, the LHTL group had a higher increase than the LLTL group. ESV significantly increased during training in the LLTL group. There was no significant difference in the ejection fraction and cardiac output. The skeletal muscle oxygen profiles had no significant differences but improved in the LHTL group compared with those in the LLTL group. LHTL can yield favorable effects on cardiac function by improving the HR, SV, EDV, and ESV during submaximal exercises compared with LLTL in athletes.

  3. TEST-RETEST RELIABILITY OF THE AEROBIC POWER INDEX SUBMAXIMAL EXERCISE TEST IN CANCER PATIENTS

    Directory of Open Access Journals (Sweden)

    Bonnie J. Furzer

    2012-12-01

    Full Text Available The purpose of this study was to investigate the reliability of the Aerobic Power Index (API submaximal cardiorespiratory exercise test, as well as associated variables of oxygen uptake (ml·kg-1·min-1 and ratings of perceived exertion (RPE in cancer patients who are generally unable to complete maximal or lengthy aerobic fitness tests. Twenty male and female participants (11 male; 9 female aged between 18 and 70 y (mean = 53.28 ± 11. 82 y were recruited with medical consent within 4 weeks of completing chemotherapy treatment for a lymphohaematopoietic cancer (LHC. Of the twenty recruited participants' 2 were excluded from analysis due to disease relapse or complications unrelated to testing occurring within the month following testing. Intra-class correlation coefficient (ICC scores for power output (W·kg-1 and oxygen uptake (ml·kg-1·min-1 were highly reliable (R1 = 0.96 and 0.96, respectively and the ICC for RPE was moderately reliable (R1 = 0.83. Technical error of measurement results for power output (W·kg-1, oxygen uptake (ml·kg-1·min-1 and RPE were 0.11W·kg-1, 1.18 ml·kg-1·min-1 and 1.0 respectively. A Pearson's product-moment correlation demonstrated a strong relationship between power output (W·kg-1 and oxygen uptake (ml·kg-1·min-1 for both trials (r = 0.93 and 0.89, respectively. Results demonstrate that the API test is a highly reliable protocol for use with a LHC population and can be considered a clinically feasible, safe and tolerable exercise test

  4. Comparing the Effects of Rest and Massage on Return to Homeostasis Following Submaximal Aerobic Exercise: a Case Study.

    Science.gov (United States)

    Resnick, Portia B

    2016-03-01

    Postexercise massage can be used to help promote recovery from exercise on the cellular level, as well as systemically by increasing parasympathetic activity. No studies to date have been done to assess the effects of massage on postexercise metabolic changes, including excess postexercise oxygen consumption (EPOC). The purpose of this study was to compare the effects of massage recovery and resting recovery on a subject's heart rate variability and selected metabolic effects following a submaximal treadmill exercise session. One healthy 24-year-old female subject performed 30 minutes of submaximal treadmill exercise prior to resting or massage recovery sessions. Metabolic data were collected throughout the exercise sessions and at three 10 minute intervals postexercise. Heart rate variability was evaluated for 10 minutes after each of two 30-minute recovery sessions, either resting or massage. Heart rate returned to below resting levels (73 bpm) with 30 and 60 minutes of massage recovery (72 bpm and 63 bpm, respectively) compared to 30 and 60 minutes of resting recovery (77 bpm and 74 bpm, respectively). Heart rate variability data showed a more immediate shift to the parasympathetic state following 30 minutes of massage (1.152 LF/HF ratio) versus the 30-minute resting recovery (6.91 LF/HF ratio). It took 60 minutes of resting recovery to reach similar heart rate variability levels (1.216 LF/HF) found after 30 minutes of massage. Ventilations after 30 minutes of massage recovery averaged 7.1 bpm compared to 17.9 bpm after 30 minutes of resting recovery. No differences in EPOC were observed through either the resting or massage recovery based on the metabolic data collected. Massage was used to help the subject shift into parasympathetic activity more quickly than rest alone following a submaximal exercise session.

  5. Comparing the Effects of Rest and Massage on Return to Homeostasis Following Submaximal Aerobic Exercise: a Case Study

    Science.gov (United States)

    Resnick, Portia B.

    2016-01-01

    Introduction Postexercise massage can be used to help promote recovery from exercise on the cellular level, as well as systemically by increasing parasympathetic activity. No studies to date have been done to assess the effects of massage on postexercise metabolic changes, including excess postexercise oxygen consumption (EPOC). The purpose of this study was to compare the effects of massage recovery and resting recovery on a subject’s heart rate variability and selected metabolic effects following a submaximal treadmill exercise session. Methods One healthy 24-year-old female subject performed 30 minutes of submaximal treadmill exercise prior to resting or massage recovery sessions. Metabolic data were collected throughout the exercise sessions and at three 10 minute intervals postexercise. Heart rate variability was evaluated for 10 minutes after each of two 30-minute recovery sessions, either resting or massage. Results Heart rate returned to below resting levels (73 bpm) with 30 and 60 minutes of massage recovery (72 bpm and 63 bpm, respectively) compared to 30 and 60 minutes of resting recovery (77 bpm and 74 bpm, respectively). Heart rate variability data showed a more immediate shift to the parasympathetic state following 30 minutes of massage (1.152 LF/HF ratio) versus the 30-minute resting recovery (6.91 LF/HF ratio). It took 60 minutes of resting recovery to reach similar heart rate variability levels (1.216 LF/HF) found after 30 minutes of massage. Ventilations after 30 minutes of massage recovery averaged 7.1 bpm compared to 17.9 bpm after 30 minutes of resting recovery. Conclusions No differences in EPOC were observed through either the resting or massage recovery based on the metabolic data collected. Massage was used to help the subject shift into parasympathetic activity more quickly than rest alone following a submaximal exercise session. PMID:26977215

  6. Oxygen uptake efficiency slope, a new submaximal parameter in evaluating exercise capacity in chronic heart failure patients.

    Science.gov (United States)

    Van Laethem, Christophe; Bartunek, Jozef; Goethals, Marc; Nellens, Paul; Andries, Erik; Vanderheyden, Marc

    2005-01-01

    The oxygen uptake efficiency slope (OUES) is a new submaximal parameter which objectively predicts the maximal exercise capacity in children and healthy subjects. However, the usefulness of OUES in adult patients with and without advanced heart failure remains undetermined. The present study investigates the stability and the usefulness of OUES in adult cardiac patients with and without heart failure. Forty-five patients with advanced heart failure (group A) and 35 patients with ischemic heart disease but normal left ventricular ejection fraction (group B) performed a maximal exercise test. PeakVO2 and percentage of predicted peakVO2 were markers of maximal exercise capacity, whereas OUES, ventilatory anaerobic threshold (VAT), and slope VE/VCO2 were calculated as parameters of submaximal exercise. Group A patients had lower peakVO2 (P slope VE/VCO2 (P slope VE/VCO2, and OUES (all P slope VE/VCO2 (r = -.492, P failure patients unable to perform a maximal exercise test. Further studies are needed to confirm our hypothesis.

  7. Translation of submaximal exercise test responses to exercise prescription using the Talk Test.

    Science.gov (United States)

    Foster, Carl; Porcari, John P; Gibson, Mark; Wright, Glenn; Greany, John; Talati, Neepa; Recalde, Pedro

    2009-12-01

    The exercise intensity at the Talk Test (TT) has been shown to be highly correlated with objective physiological markers, a useful outcome marker in patients with heart disease, a useful tool for avoiding exertional ischemia, and responsive to both positive and negative changes in exercise capacity. This randomized observational study evaluated the ability of the intensity at the TT during exercise testing to define absolute training workloads. Sedentary adults (n = 14) performed an incremental Balke type exercise test (3.0-3.5 mph at 0% grade, +2% grade every 2 minutes). Heart rate (HR), rating of perceived exertion (RPE), and TT were evaluated at each stage. Subsequently, the subjects performed 3 x 20-minute exercise bouts with the workload over the last 10 minutes of each bout equal to the absolute intensity at the stage preceding the LP (LP-1), at the last positive stage of the TT (LP), and at the first equivocal stage of the TT (EQ). During LP-1, LP, and EQ, HR was 140 +/- 23, 151 +/- 20, and 160 +/- 21 bpm, or 73 +/- 11, 79 +/- 9, and 82 +/- 9 % HRmax; RPE (CR scale) was 3.6 +/- 1.5, 4.4 +/- 1.8, and 6.3 +/- 2.2. The TT Score-ranked as 1 = comfortable speech, 2 = slightly uncomfortable speech, and 3 = speech not comfortable-was 1.4 +/- 0.5, 1.8 +/- 0.4, and 2.6 +/- 0.5 LP-1, LP, and at EQ, LP, respectively. The results suggest that to prescribe absolute training intensity from the TT and to get appropriate HR, RPE, and TT responses in sedentary individuals during training, the workload needs to be based on the intensity approximately 1 stage (approximately 1.0-1.2 metabolic equivalents) below the LP stage observed during an incremental test.

  8. Gender differences in substrate utilization during submaximal exercise in endurance-trained subjects.

    Science.gov (United States)

    Roepstorff, Carsten; Steffensen, Charlotte H; Madsen, Marianne; Stallknecht, Bente; Kanstrup, Inge-Lis; Richter, Erik A; Kiens, Bente

    2002-02-01

    Substrate utilization across the leg during 90 min of bicycle exercise at 58% of peak oxygen uptake (VO(2 peak)) was studied in seven endurance-trained males and seven endurance-trained, eumenorrheic females by applying arteriovenous catheterization, stable isotopes, and muscle biopsies. The female and male groups were matched according to VO(2 peak) per kilogram of lean body mass, physical activity level, and training history of the subjects. All subjects consumed the same diet, well controlled in terms of nutrient composition as well as energy content, for 8 days preceding the experiment, and all females were tested in the midfollicular phase of the menstrual cycle. During exercise, respiratory exchange ratio (RER) and leg respiratory quotient (RQ) were similar in females and males. Myocellular triacylglycerol (TG) degradation was negligible in males but amounted to 12.4 +/- 3.2 mmol/kg dry wt in females and corresponded to 25.0 +/- 6.0 and 5.0 +/- 7.3% of total oxygen uptake in females and males, respectively (P < 0.05). Utilization of plasma fatty acids (12.0 +/- 2.5 and 9.6 +/- 1.5%), blood glucose (13.6 +/- 1.5 and 14.3 +/- 1.5%), and glycogen (48.5 +/- 4.9 and 42.8 +/- 2.1%) were similar in females and males. Thus, in females, measured substrate oxidation accounted for 99% of the leg oxygen uptake, whereas in males 28% of leg oxygen uptake was unaccounted for in terms of measured oxidized lipid substrates. These findings may indicate that males utilized additional lipid sources, presumably very low density lipoprotein-TG or TG located between muscle fibers. On the basis of RER and leg RQ, it is concluded that no gender difference existed in the relative contribution from carbohydrate and lipids to the oxidative metabolism across the leg during submaximal exercise at the same relative workload. However, an effect of gender appears to occur in the utilization of the different lipid sources.

  9. Identification of patients at low risk of dying after acute myocardial infarction, by simple clinical and submaximal exercise test criteria.

    Science.gov (United States)

    Campbell, S; A'Hern, R; Quigley, P; Vincent, R; Jewitt, D; Chamberlain, D

    1988-09-01

    A consecutive series of 559 hospital survivors of acute myocardial infarction aged less than 66 years were studied; 93 were designated prospectively as low-risk because they were suitable for early submaximal exercise testing and had none of the following clinical or exercise test 'risk factors': (1) angina for at least one month prior to infarction; (2) symptomatic ventricular arrhythmias, or (3) recurrent ischaemic pain, both after the first 24 h of infarction; (4) cardiac failure; (5) cardiomegaly; and (6) an abnormal exercise test (angina, ST-depression or poor blood pressure response). Altogether 301 patients were exercised; their mortality over a median follow-up of 2.4 years was 10.2%, versus 24.6% in the 258 patients not exercised (P = 0.0005). Absence of clinical 'risk factors' alone, in the exercised patients, identified 156 with a mortality of 5.4% versus 15.6% in the 145 with at least one clinical 'risk factor' (P = 0.004). The fully defined low-risk group comprised 93 of the former patients who had neither clinical nor exercise test 'risk factors'. None of these patients died compared with 19 of those with at least one 'risk factor' (mortality = 14.7%; P = 0.002). Their respective rates of non-fatal reinfarction were similar and never exceeded 5% per annum. Therefore, simple clinical and exercise test criteria can positively identify low-risk patients after infarction in whom secondary prevention may be inappropriate.

  10. Effects of Submaximal Aerobic Exercise on Regulatory T Cell Markers of Male Patients Suffering from Ischemic Heart Disease.

    Science.gov (United States)

    Raygan, Fariba; Sayyah, Mansour; Janesar Qamsari, Seyed Mohammad Reza; Nikoueinejad, Hassan; Sehat, Mojtaba

    2017-02-01

    There are confirmed beneficiary effects of exercise on atherosclerotic inflammation of ischemia-associated heart diseases. The purpose of this study was to evaluate the effect of aerobic exercise on T-regulatory cell markers of IL-35 as well as FoxP3 and T-helper2 marker of IL-33 in patients with ischemic heart disease (IHD). This research was performed on 44 asymptomatic male patients with ischemic heart disease. The participants were randomly assigned into two groups of submaximal aerobic exercise and control group. Blood samples were collected before and after the termination of the exercise protocol. Serum levels of IL-35 and IL-33 as well as the amount of FoxP3 gene expression in peripheral blood mononuclear cells were measured by Elisa and Real time PCR, respectively. Serum levels of IL-35 (p=0.001) as well as the amount of FoxP3 gene expression increased significantly (p=0.012)  in exercise group even after controlling the likely confounding effects of age, length of ischemia, duration of the disease, and the amount of such factors before exercise (p≤0.042). It seems that exercise may yield a better control of atherosclerotic inflammation in patients with ischemic heart disease through the induction of regulatory T cells.

  11. Interaction effects of time of day and sub-maximal treadmill exercise on the main determinants of blood fluidity.

    Science.gov (United States)

    Ahmadizad, Sajad; Bassami, Minoo

    2010-01-01

    The purpose of this study was to investigate the effects of time of day on responses of the main determinants of blood rheology to acute endurance exercise. Ten healthy male subjects (age, 26.9 +/- 5.5 yr) performed two bouts of running at 65% of VO2peak for 45 min on a motorised treadmill in the morning (08:00 h) and evening (20:00 h), which were followed by 30 min recovery. The two exercise trials were performed in two separate days with 7 days intervening. Haemorheological variables were measured before, immediately after exercise and after recovery. Haematocrit, haemoglobin and RBC count were increased significantly (p evening trials and normalised following recovery, irrespective of time of day. Plasma viscosity increased significantly (F2,18 = 12.4, p exercise in both trials and returned to pre-exercise level at the end of recovery. Baseline values (p exercise were significantly affected by time of day. Neither a significant main effect of exercise nor a significant (p > 0.05) time-of-day effect was found for plasma proteins. It was concluded that sub-maximal running at 08:00 or 20:00 h does not induce different responses in the main determinant of blood rheology.

  12. Regadenoson in Europe: first-year experience of regadenoson stress combined with submaximal exercise in patients undergoing myocardial perfusion scintigraphy.

    Science.gov (United States)

    Brinkert, M; Reyes, E; Walker, S; Latus, K; Maenhout, A; Mizumoto, R; Nkomo, C; Standbridge, K; Wechalekar, K; Underwood, S R

    2014-03-01

    Regadenoson was approved for clinical use in Europe in 2011. Since then, it has become the default form of stress at our institution. We have assessed the side-effect profile and tolerability of regadenoson in patients undergoing clinically indicated myocardial perfusion scintigraphy between July 2011 and July 2012. Clinical, stress and imaging data were recorded prospectively. Symptoms during stress were recorded and defined as mild, moderate or severe. An adverse event was defined as any symptom that persisted for more than 30 min or that required investigation or treatment. Of 1,764 consecutive patients, 1,581 (90%) received regadenoson combined with submaximal exercise unless contraindicated. Symptoms were common (63%) but transient and well-tolerated. The severity of symptoms was recorded in most patients as mild (84%). Dyspnoea (36%) and chest discomfort (12%) were the commonest side effects. Adverse events were reported in eight patients (0.5%), thought to be vasovagal in seven of these. All patients recovered fully without sequelae. There were no deaths, myocardial infarction or hospital admissions. Regadenoson stress was performed in 206 patients (12%) with asthma or chronic obstructive pulmonary disease (COPD) without bronchospasm or any other major side effect. We studied the symptom profile of regadenoson in the largest European cohort to date. Regadenoson combined with submaximal exercise was well tolerated, notably also in patients with asthma or COPD. The majority of regadenoson-related adverse events were vasovagal episodes without sequelae.

  13. Estimating Neural Control from Concentric vs. Eccentric Surface Electromyographic Representations during Fatiguing, Cyclic Submaximal Back Extension Exercises

    Directory of Open Access Journals (Sweden)

    Gerold R. Ebenbichler

    2017-05-01

    Full Text Available Purpose: To investigate the differences in neural control of back muscles activated during the eccentric vs. the concentric portions of a cyclic, submaximal, fatiguing trunk extension exercise via the analysis of amplitude and time-frequency parameters derived from surface electromyographic (SEMG data.Methods: Using back dynamometers, 87 healthy volunteers performed three maximum voluntary isometric trunk extensions (MVC's, an isometric trunk extension at 80% MVC, and 25 cyclic, dynamic trunk extensions at 50% MVC. Dynamic testing was performed with the trunk angular displacement ranging from 0° to 40° and the trunk angular velocity set at 20°/s. SEMG data was recorded bilaterally from the iliocostalis lumborum at L1, the longissimus dorsi at L2, and the multifidus muscles at L5. The initial value and slope of the root mean square (RMS-SEMG and the instantaneous median frequency (IMDF-SEMG estimates derived from the SEMG recorded during each exercise cycle were used to investigate the differences in MU control marking the eccentric vs. the concentric portions of the exercise.Results: During the concentric portions of the exercise, the initial RMS-SEMG values were almost twice those observed during the eccentric portions of the exercise. The RMS-SEMG values generally increased during the concentric portions of the exercise while they mostly remained unchanged during the eccentric portions of the exercise with significant differences between contraction types. Neither the initial IMDF-SEMG values nor the time-course of the IMDF-SEMG values significantly differed between the eccentric and the concentric portions of the exercise.Conclusions: The comparison of the investigated SEMG parameters revealed distinct neural control strategies during the eccentric vs. the concentric portions of the cyclic exercise. We explain these differences by relying upon the principles of orderly recruitment and common drive governing motor unit behavior.

  14. Core Temperature Measurement During Submaximal Exercise: Esophageal, Rectal, and Intestinal Temperatures

    Science.gov (United States)

    Lee, Stuart M. C.; Williams, W. Jon; Schneider, Suzanne M.

    2000-01-01

    The purpose of this study was to determine if intestinal temperature (Tin) might be in acceptable alternative to esophageal (Tes) and rectal temperature (Trec) to assess thermoregulation during supine exercise. We hypothesized that Tin would have values similar to Tes and a response time similar to Trec, but the rate of temperature change across time would not be different between measurement sites. Seven subjects completed a continuous supine protocol of 20 min of rest, 20 min of cycle exercise at 40% peak oxygen consumption (VO2pk), 20 min of cycle exercise at 65% V02pk, and 20 min of recovery. Tes, Trec, and Tin were recorded each min throughout the test. Temperatures were not different after 20 min of rest, but Trec was less than the Tes and Tin at the end of the 40% and 65% VO2pk stages. After 20 min of recovery, Tes was less than either Trec or Tin, which were not different from each other. Time to threshold for increased temperature from rest was greater for Trec than Tes but not different from Tin. Time to reach peak temperature was greater for Tin and Trec than Tes. Similarly, time to a decrease in temperature after exercise was greater for Trec than Tes, but not different from Tin. The rate of temperature change from threshold to the end of the 40% VO2pk stage was not different between measurement sites. However, the rate of change during recovery was more negative for Tes than Tin and Trec, which were different from each other. Measurement of Tin may he an acceptable alternative to Tes and Trec with an understanding of its limitations.

  15. Effects of continuous vs interval exercise training on oxygen uptake efficiency slope in patients with coronary artery disease

    OpenAIRE

    Prado, D.M.L.; Rocco,E.A.; SILVA, A. G.; Rocco, D.F.; Pacheco, M.T.; Silva,P.F.; Furlan, V

    2016-01-01

    The oxygen uptake efficiency slope (OUES) is a submaximal index incorporating cardiovascular, peripheral, and pulmonary factors that determine the ventilatory response to exercise. The purpose of this study was to evaluate the effects of continuous exercise training and interval exercise training on the OUES in patients with coronary artery disease. Thirty-five patients (59.3±1.8 years old; 28 men, 7 women) with coronary artery disease were randomly divided into two groups: continuous exercis...

  16. Dichloroacetate therapy attenuates the blood lactate response to submaximal exercise in patients with defects in mitochondrial energy metabolism.

    Science.gov (United States)

    Duncan, G E; Perkins, L A; Theriaque, D W; Neiberger, R E; Stacpoole, P W

    2004-04-01

    We determined acute and chronic effects of dichloroacetate (DCA) on maximal (MAX) and submaximal (SUB) exercise responses in patients with abnormal mitochondrial energetics. Subjects (n = 9) completed a MAX treadmill bout 1 h after ingesting 25 mg/kg DCA or placebo (PL). A 15-min SUB bout was completed the next day while receiving the same treatment. After a 1-d washout, MAX and SUB were repeated while receiving the alternate treatment (acute). Gas exchange and heart rate were measured throughout all tests. Blood lactate (Bla) was measured 0, 3, and 10 min after MAX, and 5, 10, and 15 min during SUB. MAX and SUB were repeated after 3 months of daily DCA or PL. After a 2-wk washout, a final MAX and SUB were completed after 3 months of alternate treatment (chronic). Average Bla during SUB was lower (P abnormal mitochondrial energetics.

  17. Cardiac autonomic dysfunction in chronic stroke women is attenuated after submaximal exercise test, as evaluated by linear and nonlinear analysis.

    Science.gov (United States)

    Francica, Juliana Valente; Bigongiari, Aline; Mochizuki, Luís; Scapini, Kátia Bilhar; Moraes, Oscar Albuquerque; Mostarda, Cristiano; Caperuto, Erico Chagas; Irigoyen, Maria Cláudia; De Angelis, Katia; Rodrigues, Bruno

    2015-09-29

    We evaluated cardiac autonomic modulation in women with chronic ischemic stroke (at least 4 years post-stroke) at rest and in response to submaximal exercise test. Fourteen post-stroke women (S group) and 10 healthy women (C group) participated in this study. Autonomic modulation (using linear and nonlinear analysis), blood pressure and metabolic variables at rest were evaluated immediately after the exercise test and during the recovery period (20 min). All participants underwent submaximal exercise test on cycle ergometer with gas analysis. At rest, the S group displayed higher lactate concentration, systolic (SBP) and diastolic blood pressure (DBP) values when compared to C group. Furthermore, the S group had lower heart rate variability (HRV) in time domain (SDNN: S = 30 ± 5 vs. 40 ± 8 ms; rMSSD: S = 14 ± 2 vs. C = 34 ± 3 ms), decreased high frequency band of pulse interval (S = 8.4 ± 2 vs. 33.1 ± 9 %) and 2V pattern of symbolic analysis (S = 17.3 ± 1 vs. 30 ± 3 %) (both indicators of cardiac vagal modulation) when compared to C group. Immediately after exercise, S group presented higher values of lactate, SBP, DBP and double product when compared to C group, as well as decreased heart rate recovery (HRR) measured at the first, second and third minutes. At recovery time, all HRV parameters in time and frequency domains improved in the S group; however, HF band remained lower when compared to C group. After the exercise test, women with chronic stroke presented reduced heart rate variability, reduced cardiac vagal modulation, as well as reduced HRR, while displayed an improvement of heart rate variability and cardiac vagal modulation when compared to their baseline. These results reinforce the importance of a physically active lifestyle for cardiovascular autonomic disorders observed in chronic stroke women.

  18. Effects of environmental temperature on physiological responses during submaximal and maximal exercises in soccer players

    Directory of Open Access Journals (Sweden)

    MiHyun No

    2016-09-01

    Conclusion: It is concluded that physiological responses and endurance exercise capacity are impaired under cool or hot conditions compared with moderate conditions, suggesting that environmental temperature conditions play an important role for exercise performance.

  19. Met-enkephalin, beta-endorphin and cortisol responses to sub-maximal exercise after sleep disturbances.

    Science.gov (United States)

    Mougin, F; Simon-Rigaud, M L; Mougin, C; Bourdin, H; Jacquier, M C; Henriet, M T; Davenne, D; Kantelip, J P; Magnin, P; Gaillard, R C

    1992-01-01

    The present study compared the effects of partial sleep deprivation and the effects of an intake of a hypnotic compound (zolpidem) prior to bedtime, on sleep and on hormonal and metabolic adaptations to subsequent exercise. Sleep deprivation consisted of a delayed bedtime and an early getting-up time. Eight young subjects, who slept well and were highly trained athletes, were enrolled in this study. Sleep was recorded polygraphically and the following afternoon exercise was performed on a cycle ergometer for 30 min at 75% of maximal oxygen consumption (VO2max) after a 10-min warm up. Met-enkephalin, beta-endorphin, cortisol, and lactate concentrations were measured at rest and during exercise. The data obtained after experimental sleep, with and without medication were compared with those obtained in the reference condition with normal sleep. Both types of sleep reduction decreased the total sleep time, stage 2 sleep, and rapid eye movement sleep, whereas zolpidem administration did not modify either the duration of sleep or the sleep stages. After the reference night, plasma met-enkephalin did not show any significant change at the end of the submaximal exercise, whereas beta-endorphin, cortisol, and lactic acid concentrations increased significantly in all subjects. The changes in concentration in beta-endorphin were significantly related to the changes in cortisol (r = 0.78; P less than 0.01) and to the changes in plasma lactic acid (r = 0.58; P less than 0.05). Cortisol concentrations were also related to lactic acid values (r = 0.94; P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Acute dietary nitrate supplementation does not augment submaximal forearm exercise hyperemia in healthy young men

    National Research Council Canada - National Science Library

    Kim, Jin-Kwang; Moore, David J; Maurer, David G; Kim-Shapiro, Daniel B; Basu, Swati; Flanagan, Michael P; Skulas-Ray, Ann C; Kris-Etherton, Penny; Proctor, David N

    2015-01-01

    ... on exercising limb blood flow in humans. We hypothesized that acute dietary nitrate supplementation from beetroot juice would augment the increases in forearm blood flow, as well as the progressive dilation of the brachial artery...

  1. Prolonged submaximal eccentric exercise is associated with increased levels of plasma IL-6

    DEFF Research Database (Denmark)

    Rohde, Thomas; MacLean, D A; Richter, Erik

    1997-01-01

    To study the relationship between exercise-related muscle proteolysis and the cytokine response, a prolonged eccentric exercise model of one leg was used. Subjects performed two trials [a branched-chain amino acid (BCAA) supplementation and a control trial]. The release of amino acids from muscle...... during and after the eccentric exercise was decreased in the BCAA trial, suggesting a suppression of net muscle protein degradation. The plasma concentrations of interleukin (IL)-6 increased from 0.75 +/- 0.19 (preexercise) to 5.02 +/- 0.96 pg/ml (2 h postexercise) in the control trial and in the BCAA...... supplementation trial from 1.07 +/- 0.41 to 4.15 +/- 1.21 pg/ml. Eccentric exercise had no effect on the concentrations of neutrophils, lymphocytes, CD16+/CD56+, CD4+, CD8+, CD14+/CD38+, lymphocyte proliferative response, or cytotoxic activities. BCAA supplementation reduced the concentration of CD14+/CD38+ cells...

  2. 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

    Cerebral blood flow (CBF) in humans was measured at rest and during dynamic exercise on a cycle ergometer corresponding to 56% (range 27-85) of maximal O2 uptake (VO2max). Exercise bouts were performed by 16 male and female subjects, lasted 15 min each, and were carried out in a semisupine position....... CBF (133Xe clearance) was expressed as the initial slope index (ISI) and as the first compartment flow (F1). CBF at rest [ISI, 58 (range 45-73); F1, 76 (range 55-98) ml.100 g-1.min-1] increased during exercise [ISI to 79 (57-94) and F1 to 118 (75-164) ml.100 g-1.min-1, P less than 0.01]. CBF did...

  3. The Effect of Submaximal Exercise Preceded by Single Whole-Body Cryotherapy on the Markers of Oxidative Stress and Inflammation in Blood of Volleyball Players

    Directory of Open Access Journals (Sweden)

    Celestyna Mila-Kierzenkowska

    2013-01-01

    Full Text Available The aim of the study was to determine the effect of single whole-body cryotherapy (WBC session applied prior to submaximal exercise on the activity of antioxidant enzymes, the concentration of lipid peroxidation products, total oxidative status, and the level of cytokines in blood of volleyball players. The study group consisted of 18 male professional volleyball players, who were subjected to extremely cold air (−130∘C prior to exercise performed on cycloergometer. Blood samples were taken five times: before WBC, after WBC procedure, after exercise preceded by cryotherapy (WBC exercise, and before and after exercise without WBC (control exercise. The activity of catalase statistically significantly increased after control exercise. Moreover, the activity of catalase and superoxide dismutase was lower after WBC exercise than after control exercise (P<0.001. After WBC exercise, the level of IL-6 and IL-1β was also lower (P<0.001 than after control exercise. The obtained results may suggest that cryotherapy prior to exercise may have some antioxidant and anti-inflammatory properties. The relations between the level of studied oxidative stress and inflammatory markers may testify to the contribution of reactive oxygen species in cytokines release into the blood system in response to exercise and WBC.

  4. Responses of Plasma Atrial Natriuretic Peptide to High Intensity Submaximal Exercise in the Heat,

    Science.gov (United States)

    1987-06-01

    been demonstrated that in the rat , cow and human adrenal tumor. ANP decreases ALDO synthesis (Atarashi et al.1984, Delean et al. . 1984, Goodfriend et al...observed in this study (Collins and Weiner. 1986). It has recently been demonstrated that hypothyroidism is characterized by decreased plasma levels of...anesthetized rats . Can J. Physiol. Pharmacol. 62: 819-826. Armstrong LE. Dziados JE (1986). Effects of heat exposure on the exercising adult. In: Bernhardt

  5. Pulmonary and leg VO2 during submaximal exercise: implications for muscular efficiency

    Science.gov (United States)

    Poole, D. C.; Gaesser, G. A.; Hogan, M. C.; Knight, D. R.; Wagner, P. D.

    1992-01-01

    Insights into muscle energetics during exercise (e.g., muscular efficiency) are often inferred from measurements of pulmonary gas exchange. This procedure presupposes that changes of pulmonary O2 (VO2) associated with increases of external work reflect accurately the increased muscle VO2. The present investigation addressed this issue directly by making simultaneous determinations of pulmonary and leg VO2 over a range of work rates calculated to elicit 20-90% of maximum VO2 on the basis of prior incremental (25 or 30 W/min) cycle ergometry. VO2 for both legs was calculated as the product of twice one-leg blood flow (constant-infusion thermodilution) and arteriovenous O2 content difference across the leg. Measurements were made 3-5 min after each work rate imposition to avoid incorporation of the VO2 slow component above the lactate threshold. For all 17 subjects, the slope of pulmonary VO2 (9.9 +/- 0.2 ml O2.W-1.min-1) was not different (P greater than 0.05) from that for leg VO2 (9.2 +/- 0.6 ml O2.W-1.min-1). Estimation of "delta" efficiency (i.e., delta work accomplished divided by delta energy expended, calculated from slope of VO2 vs. work rate and a caloric equivalent for O2 of 4.985 cal/ml) using pulmonary VO2 measurements (29.1 +/- 0.6%) was likewise not significantly different (P greater than 0.05) from that made using leg VO2 measurements (33.7 +/- 2.4%). These data suggest that the net VO2 cost of metabolic "support" processes outside the exercising legs changes little over a relatively broad range of exercise intensities. Thus, under the conditions of this investigation, changes of VO2 measured from expired gas reflected closely those occurring within the exercising legs.

  6. Ramadan fasting and the GH/IGF-1 axis of trained men during submaximal exercise.

    Science.gov (United States)

    Bouhlel, Ezzedine; Zaouali, Monia; Miled, Abdelhedi; Tabka, Zouhair; Bigard, Xavier; Shephard, Roy

    2008-01-01

    The aim of this study was to explore possible changes in body composition, blood glucose regulation, plasma growth hormone (GH), insulin-like growth factor 1 (IGF-1), insulin-like growth factor-binding protein-3 (IGFBP-3), and insulin concentrations of trained athletes in response to the intermittent fasting and dehydration of Ramadan observance. Nine trained male rugby players (age 19 +/- 2 years, height 1.78 +/- 0.74 m) were tested 3 times: before Ramadan (C), at the end of the first week (R1), and during the fourth week (R2). They performed a progressive cycle ergometer test at each visit. The work rate was increased in 6-min stages corresponding to 20, 30, 40, 50 and 60% of W max. Substrate oxidation was evaluated by indirect calorimetry. On each occasion, substrate and plasma hormone concentrations were measured at rest and at the end of the exercise. Ramadan fasting induced a significant decrease in body mass and body fat (R2 vs. C, p < 0.001). Plasma concentrations of glucose, insulin, GH, IGF-1 and IGFBP-3 did not change significantly between C and R2, either at rest or following exercise. Ramadan fasting induces positive changes in body composition without disturbing glucose regulation or activity of the GH/IGF-1 system. 2008 S. Karger AG, Basel.

  7. The Effect of Submaximal Exercise Preceded by Single Whole-Body Cryotherapy on the Markers of Oxidative Stress and Inflammation in Blood of Volleyball Players

    Science.gov (United States)

    Mila-Kierzenkowska, Celestyna; Szpinda, Michał; Augustyńska, Beata; Woźniak, Bartosz

    2013-01-01

    The aim of the study was to determine the effect of single whole-body cryotherapy (WBC) session applied prior to submaximal exercise on the activity of antioxidant enzymes, the concentration of lipid peroxidation products, total oxidative status, and the level of cytokines in blood of volleyball players. The study group consisted of 18 male professional volleyball players, who were subjected to extremely cold air (−130°C) prior to exercise performed on cycloergometer. Blood samples were taken five times: before WBC, after WBC procedure, after exercise preceded by cryotherapy (WBC exercise), and before and after exercise without WBC (control exercise). The activity of catalase statistically significantly increased after control exercise. Moreover, the activity of catalase and superoxide dismutase was lower after WBC exercise than after control exercise (P cryotherapy prior to exercise may have some antioxidant and anti-inflammatory properties. The relations between the level of studied oxidative stress and inflammatory markers may testify to the contribution of reactive oxygen species in cytokines release into the blood system in response to exercise and WBC. PMID:24489985

  8. Effects of a helium/oxygen mixture on individuals' lung function and metabolic cost during submaximal exercise for participants with obstructive lung diseases.

    Science.gov (United States)

    Häussermann, Sabine; Schulze, Anja; Katz, Ira M; Martin, Andrew R; Herpich, Christiane; Hunger, Theresa; Texereau, Joëlle

    2015-01-01

    Helium/oxygen therapies have been studied as a means to reduce the symptoms of obstructive lung diseases with inconclusive results in clinical trials. To better understand this variability in results, an exploratory physiological study was performed comparing the effects of helium/oxygen mixture (78%/22%) to that of medical air. The gas mixtures were administered to healthy, asthmatic, and chronic obstructive pulmonary disease (COPD) participants, both moderate and severe (6 participants in each disease group, a total of 30); at rest and during submaximal cycling exercise with equivalent work rates. Measurements of ventilatory parameters, forced spirometry, and ergospirometry were obtained. There was no statistical difference in ventilatory and cardiac responses to breathing helium/oxygen during submaximal exercise. For asthmatics, but not for the COPD participants, there was a statistically significant benefit in reduced metabolic cost, determined through measurement of oxygen uptake, for the same exercise work rate. However, the individual data show that there were a mixture of responders and nonresponders to helium/oxygen in all of the groups. The inconsistent response to helium/oxygen between individuals is perhaps the key drawback to the more effective and widespread use of helium/oxygen to increase exercise capacity and for other therapeutic applications.

  9. Effects of a helium/oxygen mixture on individuals’ lung function and metabolic cost during submaximal exercise for participants with obstructive lung diseases

    Science.gov (United States)

    Häussermann, Sabine; Schulze, Anja; Katz, Ira M; Martin, Andrew R; Herpich, Christiane; Hunger, Theresa; Texereau, Joëlle

    2015-01-01

    Background Helium/oxygen therapies have been studied as a means to reduce the symptoms of obstructive lung diseases with inconclusive results in clinical trials. To better understand this variability in results, an exploratory physiological study was performed comparing the effects of helium/oxygen mixture (78%/22%) to that of medical air. Methods The gas mixtures were administered to healthy, asthmatic, and chronic obstructive pulmonary disease (COPD) participants, both moderate and severe (6 participants in each disease group, a total of 30); at rest and during submaximal cycling exercise with equivalent work rates. Measurements of ventilatory parameters, forced spirometry, and ergospirometry were obtained. Results There was no statistical difference in ventilatory and cardiac responses to breathing helium/oxygen during submaximal exercise. For asthmatics, but not for the COPD participants, there was a statistically significant benefit in reduced metabolic cost, determined through measurement of oxygen uptake, for the same exercise work rate. However, the individual data show that there were a mixture of responders and nonresponders to helium/oxygen in all of the groups. Conclusion The inconsistent response to helium/oxygen between individuals is perhaps the key drawback to the more effective and widespread use of helium/oxygen to increase exercise capacity and for other therapeutic applications. PMID:26451096

  10. 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

  11. Evaluation of respiratory dynamics by volumetric capnography during submaximal exercise protocol of six minutes on treadmill in cystic fibrosis patients.

    Science.gov (United States)

    Parazzi, Paloma L F; Marson, Fernando A L; Ribeiro, Maria A G O; Schivinski, Camila I S; Ribeiro, José D

    2017-11-29

    Volumetric capnography provides the standard CO2 elimination by the volume expired per respiratory cycle and is a measure to assess pulmonary involvement. Thus, the objective of this study was to evaluate the respiratory dynamics of healthy control subjects and those with cystic fibrosis in a submaximal exercise protocol for six minutes on the treadmill, using volumetric capnography parameters (slope 3 [Slp3], Slp3/tidal volume [Slp3/TV], and slope 2 [Slp2]). This was a cross-sectional study with 128 subjects (cystic fibrosis, 64 subjects; controls, 64 subjects]. Participants underwent volumetric capnography before, during, and after six minutes on the treadmill. Statistical analysis was performed using the Friedman, Mann-Whitney, and Kruskal-Wallis tests, considering age and sex. An alpha=0.05 was considered. Six minutes on the treadmill evaluation: in cystic fibrosis, volumetric capnography parameters were different before, during, and after six minutes on the treadmill; the same was observed for the controls, except for Slp2. Regarding age, an Slp3 difference was observed in cystic fibrosis patients regardless of age, at all moments, and in controls for age≥12 years; a difference in Slp3/TV was observed in cystic fibrosis and controls, regardless of age; and an Slp2 difference in the cystic fibrosis, regardless of age. Regarding sex, Slp3 and Slp3/TV differences were observed in cystic fibrosis regardless of sex, and in controls in male participants; an Slp2 difference was observed in the cystic fibrosis and female participants. The analysis between groups (cystic fibrosis and controls) indicated that Slp3 and Slp3/TV has identified the CF, regardless of age and sex, while the Slp2 showed the CF considering age. Cystic fibrosis showed greater values of the parameters before, during, and after exercise, even when stratified by age and sex, which may indicate ventilation inhomogeneity in the peripheral pathways in the cystic fibrosis. Copyright © 2017 Sociedade

  12. Effects of a helium/oxygen mixture on individuals’ lung function and metabolic cost during submaximal exercise for participants with obstructive lung diseases

    Directory of Open Access Journals (Sweden)

    Häussermann S

    2015-09-01

    Full Text Available Sabine Häussermann,1 Anja Schulze,1 Ira M Katz,2,3 Andrew R Martin,4 Christiane Herpich,1 Theresa Hunger,1 Joëlle Texereau2 1Inamed GmbH, Gauting, Germany; 2Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, Les Loges-en-Josas, France; 3Department of Mechanical Engineering, Lafayette College, Easton, PA, USA; 4Department of Mechanical Engineering, University of Alberta, Edmonton, AB, CanadaBackground: Helium/oxygen therapies have been studied as a means to reduce the symptoms of obstructive lung diseases with inconclusive results in clinical trials. To better understand this variability in results, an exploratory physiological study was performed comparing the effects of helium/oxygen mixture (78%/22% to that of medical air.Methods: The gas mixtures were administered to healthy, asthmatic, and chronic obstructive pulmonary disease (COPD participants, both moderate and severe (6 participants in each disease group, a total of 30; at rest and during submaximal cycling exercise with equivalent work rates. Measurements of ventilatory parameters, forced spirometry, and ergospirometry were obtained.Results: There was no statistical difference in ventilatory and cardiac responses to breathing helium/oxygen during submaximal exercise. For asthmatics, but not for the COPD participants, there was a statistically significant benefit in reduced metabolic cost, determined through measurement of oxygen uptake, for the same exercise work rate. However, the individual data show that there were a mixture of responders and nonresponders to helium/oxygen in all of the groups.Conclusion: The inconsistent response to helium/oxygen between individuals is perhaps the key drawback to the more effective and widespread use of helium/oxygen to increase exercise capacity and for other therapeutic applications. Keywords: helium/oxygen, inspiratory capacity, oxygen uptake, COPD, asthma, obstructive airway diseases, exercise, heliox

  13. Submaximal exercise testing with near-infrared spectroscopy in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome patients compared to healthy controls: a case-control study.

    Science.gov (United States)

    Miller, Ruth R; Reid, W Darlene; Mattman, Andre; Yamabayashi, Cristiane; Steiner, Theodore; Parker, Shoshana; Gardy, Jennifer; Tang, Patrick; Patrick, David M

    2015-05-20

    Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating illness. Symptoms include profound fatigue and distinctive post-exertional malaise (PEM). We asked whether a submaximal exercise test would prove useful for identifying different patterns of tissue oxygen utilization in individuals with ME/CFS versus healthy subjects. Such a test has potential to aid with ME/CFS diagnosis, or to characterize patients' illness. A case-control study of 16 patients with ME/CFS compared to 16 healthy controls completing a 3-min handgrip protocol was performed. Response was measured using near-infrared spectroscopy, resulting in measurements of oxygenated (O2Hb) and deoxygenated hemoglobin (HHb) over wrist extensors and flexors. Changes in O2Hb (delta (d)O2Hb) and HHb (dHHb) absorbance between the first and last contraction were calculated, as were the force-time product of all contractions, measured as tension-time index (TTI), and ratings of perceived exertion (RPE). Individuals with ME/CFS demonstrated smaller dO2Hb and dHHb than controls. However, after adjusting for TTI and change in total hemoglobin (delta (d)tHb), differences in dO2Hb and dHHb were reduced, with large overlapping variances. RPE was significantly higher for cases than controls, particularly at rest. Relative to controls, participants with ME/CFS demonstrated higher RPE, lower TTI, and reduced dO2Hb and dHHb during repetitive handgrip exercise, although considerable variance was observed. With further study, submaximal exercise testing may prove useful for stratifying patients with a lower propensity for inducing PEM, and have the ability to establish baseline intensities for exercise prescription.

  14. Coconut Water Does Not Improve Markers of Hydration During Sub-maximal Exercise and Performance in a Subsequent Time Trial Compared with Water Alone.

    Science.gov (United States)

    Peart, Daniel J; Hensby, Andy; Shaw, Matthew P

    2017-06-01

    The purpose of this study was to compare markers of hydration during submaximal exercise and subsequent time trial performance when consuming water (PW) or coconut water (CW). There was also a secondary aim to assess the palatability of CW during exercise and voluntary intake during intense exercise. 10 males (age 27.9 ± 4.9 years, body mass 78.1 ± 10.1kg, average max minute power 300.2 ± 28.2W) completed 60-min of submaximal cycling followed by a 10-km time trial on two occasions. During these trials participants consumed either PW or CW in a randomized manner, drinking a 250 ml of the assigned drink between 10-15 min, 25-30 min and 40-45 min, and then drinking ad libitum from 55-min until the end of the time trial. Body mass and urine osmolality were recorded preexercise and then after 30-min, 60-min, and post time trial. Blood glucose, lactate, heart rate, rate of perceived exertion (RPE; 6-20) and ratings of thirst, sweetness, nausea, fullness and stomach upset (1 =very low/none, 5= very high) were recorded during each drink period. CW did not significantly improve time trial performance compared with PW (971.4 ± 50.5 and 966.6 ± 44.8 s respectively; p = .698) and there was also no significant differences between trials for any of the physiological variables measured. However there were subjective differences between the beverages for taste, resulting in a significantly reduced volume of voluntary intake in the CW trial (115 ± 95.41 ml and 208.7 ± 86.22 ml; p < .001).

  15. Vascular endothelial growth factor mRNA expression and arteriovenous balance in resonse to prolonged, submaximal exercise in humans

    DEFF Research Database (Denmark)

    Hiscock, N.; Fischer, C.P.; Pilegaard, Henriette

    2003-01-01

    VEGF, regulation of gene expression, exercise, angiogensis, skeletal muscle, peripheral vascular function......VEGF, regulation of gene expression, exercise, angiogensis, skeletal muscle, peripheral vascular function...

  16. The Effect of Lower-Body Positive Pressure on the Cardiorespiratory Response at Rest and during Submaximal Running Exercise

    Directory of Open Access Journals (Sweden)

    Frédéric Stucky

    2018-01-01

    Full Text Available Anti-gravity treadmills facilitate locomotion by lower-body positive pressure (LBPP. Effects on cardiorespiratory regulation are unknown. Healthy men (30 ± 8 y, 178.3 ± 5.7 cm, 70.3 ± 8.0 kg; mean ± SD stood upright (n = 10 or ran (n = 9 at 9, 11, 13, and 15 km.h−1 (5 min stages with LBPP (0, 15, 40 mmHg. Cardiac output (CO, stroke volume (SV, heart rate (HR, blood pressure (BP, peripheral resistance (PR, and oxygen uptake (VO2 were monitored continuously. During standing, LBPP increased SV [by +29 ± 13 (+41% and +42 ± 15 (+60% ml, at 15 and 40 mmHg, respectively (p < 0.05] and decreased HR [by −15 ± 6 (−20% and −22 ± 9 (−29% bpm (p < 0.05] resulting in a transitory increase in CO [by +1.6 ± 1.0 (+32% and +2.0 ± 1.0 (+39% l.min−1 (p < 0.05] within the first seconds of LBPP. This was accompanied by a transitory decrease in end-tidal PO2 [by −5 ± 3 (−5% and −10 ± 4 (−10% mmHg (p < 0.05] and increase in VO2 [by +66 ± 53 (+26% and +116 ± 64 (+46% ml.min−1 (p < 0.05], suggesting increased venous return and pulmonary blood flow. The application of LBPP increased baroreflex sensitivity (BRS [by +1.8 ± 1.6 (+18% and +4.6 ± 3.7 (+47% at 15 and 40 mmHg LBPP, respectively P < 0.05]. After reaching steady-state exercise CO vs. VO2 relationships remained linear with similar slope and intercept for each participant (mean R2 = 0.84 ± 0.13 while MAP remained unchanged. It follows that (1 LBPP affects cardiorespiratory integration at the onset of exercise; (2 at a given LBPP, once reaching steady-state exercise, the cardiorespiratory load is reduced proportionally to the lower metabolic demand resulting from the body weight support; (3 the balance between cardiovascular response, oxygen delivery to the exercising muscles and blood pressure regulation is maintained at exercise steady-state; and (4 changes in baroreflex sensitivity may be involved in the regulation of cardiovascular parameters during LBPP.

  17. Effects of acute caffeinated coffee consumption on energy utilization related to glucose and lipid oxidation from short submaximal treadmill exercise in sedentary men.

    Science.gov (United States)

    Leelarungrayub, Donrawee; Sallepan, Maliwan; Charoenwattana, Sukanya

    2011-01-01

    Aim of this study was to evaluate the short term effect of coffee drinking on energy utilization in sedentary men. This study was performed in healthy sedentary men, who were randomized into three groups, control (n = 6), decaffeinated (n = 10), and caffeine (n = 10). The caffeine dose in coffee was rechecked and calculated for individual volunteers at 5 mg/kg. Baseline before drinking, complete blood count (CBC), glucose, antioxidant capacity, lipid peroxide, and caffeine in blood was evaluated. After drinking coffee for 1 hr, the submaximal exercise test with a modified Bruce protocol was carried out, and the VO2 and RER were analyzed individually at 80% maximal heart rate, then the blood was repeat evaluated. Three groups showed a nonsignificant difference in CBC results and physical characteristics. The caffeine group showed significant changes in all parameters; higher VO2 levels, (P = 0.037) and lower RER (P = 0.047), when compared to the baseline. Furthermore, the glucose level after exercise test increased significantly (P = 0.033) as well as lipid peroxide levels (P = 0.005), whereas antioxidant capacity did not change significantly (P = 0.759), when compared to the before exercise testing. In addition, the blood caffeine level also increased only in the caffeine group (P = 0.008). Short consumption of caffeinated coffee (5 mg/kg of caffeine), improves energy utilization and relates to glucose derivation and lipid oxidation.

  18. Beta2-adrenergic stimulation increases energy expenditure at rest, but not during submaximal exercise in active overweight men

    DEFF Research Database (Denmark)

    Onslev, Johan; Jacobson, Glenn A; Narkowicz, Christian K

    2017-01-01

    percentage and rac-formoterol-induced change in energy expenditure. During exercise, energy expenditure was not different between treatments, although carbohydrate oxidation was 15% higher (P = 0.021) for rac-formoterol than placebo. Rac-formoterol-induced shift in substrate choice from rest to exercise...

  19. Effect of acute exercise-induced fatigue on maximal rate of heart rate increase during submaximal cycling.

    Science.gov (United States)

    Thomson, Rebecca L; Rogers, Daniel K; Howe, Peter R C; Buckley, Jonathan D

    2016-01-01

    Different mathematical models were used to evaluate if the maximal rate of heart rate (HR) increase (rHRI) was related to reductions in exercise performance resulting from acute fatigue. Fourteen triathletes completed testing before and after a 2-h run. rHRI was assessed during 5 min of 100-W cycling and a sigmoidal (rHRIsig) and exponential (rHRIexp) model were applied. Exercise performance was assessed using a 5-min cycling time-trial. The run elicited reductions in time-trial performance (1.34 ± 0.19 to 1.25 ± 0.18 kJ · kg(-1), P exercise HR (73.0 ± 8.4 to 90.5 ± 11.4 beats · min(-1), P exercise and steady-state HR. rHRIsig was reduced following acute exercise-induced fatigue, and correlated with difference in performance.

  20. Neuromuscular blockade of slow twitch muscle fibres elevates muscle oxygen uptake and energy turnover during submaximal exercise in humans

    DEFF Research Database (Denmark)

    Krustrup, Peter; Secher, Niels; Relu, Mihai U.

    2008-01-01

    We tested the hypothesis that a greater activation of fast-twitch (FT) fibres during dynamic exercise leads to a higher muscle oxygen uptake (VO2 ) and energy turnover as well as a slower muscle on-kinetics. Subjects performed one-legged knee-extensor exercise for 10 min at an intensity of 30 W...... fibres, respectively. From 127 s of exercise, muscle VO2 was higher (P muscle VO2 response...... was slower (P muscle homogenate CP was lowered (P muscle lactate production was similar in CUR and CON (37.8 +/- 4.1 versus 35.2 +/- 6.2 mmol). Estimated total muscle ATP turnover was 19...

  1. The Effect of 4 Weeks Fixed and Mixed Intermittent Hypoxic Training (IHT) on Respiratory Metabolic and Acid-base Response of Capillary Blood During Submaximal Bicycle Exercise in Male Elite Taekwondo Players.

    Science.gov (United States)

    Park, Hun-Young; Sunoo, Sub; Nam, Sang-Seok

    2016-12-31

    The purpose of our study was to determine the effectiveness of 4 weeks fixed and mixed intermittent hypoxic training (IHT) and its difference from exercise training at sea-level on exercise load, respiratory metabolic and acid-base response of capillary blood during 80% maximal heart rate (HRmax) bicycle exercise in male elite Taekwondo players. Male elite Taekwondo players (n = 25 out of 33) were randomly assigned to training at sea-level (n = 8, control group), training at 16.5%O 2 (2000 m) simulated hypoxic condition (n = 9, fixed IHT group), and training at 14.5%O 2 (3000 m) up to 2 weeks and 16.5%O 2 (2000 m) simulated hypoxic condition (n = 8, mixed IHT group) for 3 weeks. We compared their average exercise load, respiratory metabolic, and acid-base response of the capillary blood during 80% HRmax submaximal bicycle exercise before and after 4 weeks training. Fixed and mixed IHT groups showed positive improvement in respiratory metabolic and acid-base response of the capillary blood during 80% HRmax submaximal bicycle exercise after 4 weeks training. However, all dependent variables showed no significant difference between fixed IHT and mix IHT. Results suggested that mixed and fixed IHT is effective in improving respiratory metabolic and acid-base response of capillary blood in male elite Taekwondo players. Thus, IHT could be a novel and effective method for improving exercise performance through respiratory metabolic and acid-base response.

  2. Acute citrulline malate supplementation improves upper- and lower-body submaximal weightlifting exercise performance in resistance-trained females.

    Science.gov (United States)

    Glenn, Jordan M; Gray, Michelle; Wethington, Lauren N; Stone, Matthew S; Stewart, Rodger W; Moyen, Nicole E

    2017-03-01

    Citrulline malate (CM) is a nonessential amino acid that increases exercise performance in males. However, based on physiological differences between genders, these results cannot be extrapolated to females. Therefore, the purpose of this investigation was to evaluate effects of acute CM supplementation on upper- and lower-body weightlifting performance in resistance-trained females. Fifteen females (23 ± 3 years) completed two randomized, double-blind trials consuming either CM (8 g dextrose + 8 g CM) or a placebo (8 g dextrose). One hour after supplement consumption, participants performed six sets each of upper- (i.e., bench press) and lower-body (i.e., leg press) exercises to failure at 80 % of previously established one-repetition maximum. Immediately after each set, repetitions completed, heart rate and rating of perceived exertion (RPE) were recorded. Repeated-measures analysis of variance indicated that subjects completed significantly (p = .045) more repetitions throughout upper-body exercise when consuming CM versus placebo (34.1 ± 5.7 vs. 32.9 ± 6.0, respectively). When consuming CM, similar significant (p = .03) improvements in total repetitions completed were observed for lower-body exercise (66.7 ± 30.5 vs. 55.13 ± 20.64, respectively). Overall RPE score was significantly lower (p = .02) in upper-body exercise when subjects consumed CM versus placebo (7.9 ± 0.3 and 8.6 ± 0.2, respectively). The supplement consumed exhibited no significant effects on heart rate at any time point. Acute CM supplementation in females increased upper- and lower-body resistance exercise performance and decreased RPE during upper-body exercise. These data indicate that athletes competing in sports with muscular endurance-based requirements may potentially improve performance by acutely supplementing CM.

  3. Heat storage in Asian elephants during submaximal exercise: behavioral regulation of thermoregulatory constraints on activity in endothermic gigantotherms.

    Science.gov (United States)

    Rowe, M F; Bakken, G S; Ratliff, J J; Langman, V A

    2013-05-15

    Gigantic size presents both opportunities and challenges in thermoregulation. Allometric scaling relationships suggest that gigantic animals have difficulty dissipating metabolic heat. Large body size permits the maintenance of fairly constant core body temperatures in ectothermic animals by means of gigantothermy. Conversely, gigantothermy combined with endothermic metabolic rate and activity likely results in heat production rates that exceed heat loss rates. In tropical environments, it has been suggested that a substantial rate of heat storage might result in a potentially lethal rise in core body temperature in both elephants and endothermic dinosaurs. However, the behavioral choice of nocturnal activity might reduce heat storage. We sought to test the hypothesis that there is a functionally significant relationship between heat storage and locomotion in Asian elephants (Elephas maximus), and model the thermoregulatory constraints on activity in elephants and a similarly sized migratory dinosaur, Edmontosaurus. Pre- and post-exercise (N=37 trials) measurements of core body temperature and skin temperature, using thermography were made in two adult female Asian elephants at the Audubon Zoo in New Orleans, LA, USA. Over ambient air temperatures ranging from 8 to 34.5°C, when elephants exercised in full sun, ~56 to 100% of active metabolic heat production was stored in core body tissues. We estimate that during nocturnal activity, in the absence of solar radiation, between 5 and 64% of metabolic heat production would be stored in core tissues. Potentially lethal rates of heat storage in active elephants and Edmontosaurus could be behaviorally regulated by nocturnal activity.

  4. Exercise-induced hypoalgesia - interval versus continuous mode.

    Science.gov (United States)

    Kodesh, Einat; Weissman-Fogel, Irit

    2014-07-01

    Aerobic exercise at approximately 70% of maximal aerobic capacity moderately reduces pain sensitivity and attenuates pain, even after a single session. If the analgesic effects depend on exercise intensity, then high-intensity interval exercise at 85% of maximal aerobic capacity should further reduce pain. The aim of this study was to explore the exercise-induced analgesic effects of high-intensity interval aerobic exercise and to compare them with the analgesic effects of moderate continuous aerobic exercise. Twenty-nine young untrained healthy males were randomly assigned to aerobic-continuous (70% heart rate reserve (HRR)) and interval (4 × 4 min at 85% HRR and 2 min at 60% HRR between cycles) exercise modes, each lasting 30 min. Psychophysical pain tests, pressure and heat pain thresholds (HPT), and tonic heat pain (THP) were conducted before and after exercise sessions. Repeated measures ANOVA was used for data analysis. HPT increased (p = 0.056) and THP decreased (p = 0.013) following exercise unrelated to exercise type. However, the main time effect (pre-/postexercise) was a trend of increased HPT (45.6 ± 1.9 °C to 46.2 ± 1.8 °C; p = 0.082) and a significant reduction in THP (from 50.7 ± 25 to 45.9 ± 25.4 numeric pain scale; p = 0.043) following interval exercise. No significant change was found for the pressure pain threshold following either exercise type. In conclusion, interval exercise (85% HRR) has analgesic effects on experimental pain perception. This, in addition to its cardiovascular, muscular, and metabolic advantages may promote its inclusion in pain management programs.

  5. Myocardial oxygen consumption at rest and during submaximal ...

    African Journals Online (AJOL)

    olayemitoyin

    2008-11-26

    Nov 26, 2008 ... Department of Physiology, JSS Medical College, Constituent College of JSS University, Mysore – 570015, ... determine the effect of increased adiposity on myocardial oxygen consumption at rest and during submaximal exercise in ... during exercise suggesting higher hemodynamic stress to the heart.

  6. Myocardial oxygen consumption at rest and during submaximal ...

    African Journals Online (AJOL)

    olayemitoyin

    2008-11-26

    Nov 26, 2008 ... and myocardial fatty acid utilization has been showed to decrease after weight loss from gastric bypass surgery or diet in obese persons (Fei ho et al., 1995,). During submaximal exercise and immediately after exercise, all three groups showed an increase in. RPP. The percentage increase in RPP was.

  7. Efeitos cardiovasculares da abstinência do fumo no repouso e durante o exercício submáximo em mulheres jovens fumantes Cardiovascular effects of smoking abstinence at rest and during submaximal exercise in young female smokers

    Directory of Open Access Journals (Sweden)

    Demilto Yamaguchi da Pureza

    2007-10-01

    Full Text Available OBJETIVO: O objetivo do presente estudo foi verificar o efeito da abstinência do fumo nas respostas cardiovasculares ao exercício físico progressivo submáximo em mulheres sedentárias fumantes. MÉTODOS: A pressão arterial sistólica (PAS e diastólica (PAD e a freqüência cardíaca (FC foram medidas de forma não invasiva em mulheres jovens não fumantes (MNF, n = 7 e fumantes (MF, n = 7, sem e com abstinência do fumo por 24 horas, em repouso, durante a realização do teste submáximo em bicicleta ergométrica e na recuperação. RESULTADOS: Em repouso, a PAD e a FC foram maiores nas MF (76 ± 1mmHg e 86 ± 5bpm quando comparadas com as MNF (68 ± 2mmHg e 72 ± 2bpm. Após 24 horas sem o tabaco essas medidas foram normalizadas. Durante o exercício, a PAS e a FC aumentaram nos grupos estudados. A PAD foi maior nas MF (~15% em relação às MNF em todos os estágios do exercício. Na situação de abstinência, a PAD aumentou somente no último estágio de exercício. Na recuperação tanto a PAD quanto a FC foram maiores nas MF, na situação basal e com abstinência de 24h, quando comparadas as MNF. CONCLUSÃO: Estes resultados demonstram que mulheres jovens fumantes apresentam prejuízo em parâmetros hemodinâmicos em repouso e em resposta ao exercício submáximo, os quais, podem ser em parte revertidos pela abstinência em curto prazo do uso do tabaco.OBJECTIVE: The objective of the present study was to verify the effect of tobacco smoking abstinence on cardiovascular responses to progressive submaximal physical exercise in sedentary female smokers. METHODS: Systolic blood pressure (SBP, diastolic blood pressure (DBP and heart rate (HR were non-invasively measured in young non-smoking women (NSW, n = 7 and smoking women (SW, n = 7, with and without tobacco abstinence for 24 hours, at rest, during the accomplishment of a submaximal bicycle ergometric test and recovery period. RESULTS: At rest, DBP and HR were higher in the SW group

  8. EFFECTIVENESS OF INTERVAL EXERCISE VERSUS CONTINUOUS EXERCISE TO IMPROVE EXERCISE TOLERANCE IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE SUBJECTS

    Directory of Open Access Journals (Sweden)

    G. Swathi

    2015-12-01

    Full Text Available Background: COPD is characterized by chronic airflow limitation and a range of pathological changes in the lung. Chronic inflammation causes structural changes and narrowing of the small airways and destruction of lung parenchyma, leads to the loss of alveolar attachments to the small airways and decreases lung elastic recoil; in turn these changes diminish the expiration and the work of breathing is increased. Scarcity of evidence on continuous and interval exercises is forcing researchers conduct studies on effectiveness of interval exercise with continuous exercise on exercise tolerance in subjects with COPD. Methods: 60 subjects were selected by lottery method. All the subjects were explained about the condition and mode of assessment and written informed consent were obtained from them and divided into 2 groups interval training group and continuous exercise training group and subjects were scheduled to attend exercise session 5 days a week for 4 weeks with exercise duration 20 min’s with cycle ergometer. Outcome measure: six minute walk test and heart rate. Results: On observing the means of post test parameters of experimental group A and experimental group B Independent t-test was done and the P- value is >0.05 .It shows a no significant difference between the two groups. Conclusion: The results had shown that both interval exercise group and continuous exercise group who received four weeks of therapy has improved significantly on pre and post test values within the groups but when compared between these groups there is no statistical significance noted. So this study concluded that there is no significant difference between interval exercise group and continuous exercise group in improving exercise tolerance among COPD subjects.

  9. therapeutic effect of continuous exercise training program on serum ...

    African Journals Online (AJOL)

    2014-09-01

    Sep 1, 2014 ... THERAPEUTIC EFFECT OF CONTINUOUS EXERCISE TRAINING. PROGRAM ON SERUM CREATININE CONCENTRATION IN MEN. WITH HYPERTENSION: A RANDOMIZED CONTROLLED TRIAL. L. SIKIRU1and G. C. OKOYE2. 1Biomedical Technology Dept., School of Health Technology, Federal ...

  10. Therapeutic effect of continuous exercise training program on serum ...

    African Journals Online (AJOL)

    Background: Creatinine (Cr) has been implicated as an independent predictor of hypertension and exercise has been reported as adjunct therapy for hypertension. The purpose of the present study was to investigate the effect of continuous training programme on blood pressure and serum creatinine concentration in black ...

  11. Lactate Kinetics After Intermittent and Continuous Exercise Training

    OpenAIRE

    Gharbi, Adnene; Chamari, Karim; Kallel, Amjad; Ahmaidi, Saîd; Tabka, Zouhair; Abdelkarim, Zbidi

    2008-01-01

    The purpose of this study was to assess, the effects of continuous and intermittent exercise training on lactate kinetic parameters and maximal aerobic speed (MAS) using field tests. Twenty-four male sport students were equally divided into continuous (CT) and intermittent (IT) physically trained groups. Another six participants acted as non-trained controls (CG). The trained participants practiced 6-days per week for 6 weeks. Before and after training, all participants completed an increment...

  12. [Hormonal changes during continuous exercise in athletic women].

    Science.gov (United States)

    Mesaki, N; Sasaki, J; Shoji, M; Iwasaki, H; Asano, K; Eda, M

    1987-01-01

    Recently, the number of women who participate in strenuous exercise has increased significantly. The relationship between delayed menarche and early onset of sports training, and increased incidence of menstrual dysfunction related to athletic activity had led to increased interest. Five basketball players who are among the best players in Japan were subjected to an investigation of endocrinological responses effected by 60 minutes continuous exercise cycle ergometer. The VO2max value was previously examined. Then, the level of load during exercise was established at 60% VO2max in this study. The serum level of estradiol increased significantly in the luteal phase but not so significantly in the follicular phase. Progesterone did not show a significant change during exercise. FSH increased slightly in both phases. However, LH showed a slight increase in the follicular phase and a slight decrease in the luteal phase. On the other hand, prolactin showed a continuous significant increase during exercise in both phases. These data suggested that strenuous daily training leads to a frequent significant increase in prolactin in athletic women and this frequent increase in prolactin may be one of the major factors causing menstrual dysfunction in athletic women. The specialized physician should be more concerned about the managing of athletes who are suffering from menstrual dysfunction.

  13. Myocardial oxygen consumption at rest and during submaximal ...

    African Journals Online (AJOL)

    Overweight and obesity are major risk factors for cardiovascular diseases. The objective of this study was to determine the effect of increased adiposity on myocardial oxygen consumption at rest and during submaximal exercise in young adults. The study consisted of 85 young adults (18-22years) grouped into 3 based on ...

  14. Influence of menstrual phase on ventilatory response to submaximal ...

    African Journals Online (AJOL)

    Objectives. To determine whether an increase in respiratory drive, due to elevated progesterone and oestrogen concentration during various menstrual phases, persists throughout prolonged submaximal exercise and potentially contributes to fatigue. Furthermore, to determine whether the difference in the ventilatory ...

  15. Lactate Kinetics After Intermittent and Continuous Exercise Training

    Science.gov (United States)

    Gharbi, Adnene; Chamari, Karim; Kallel, Amjad; Ahmaidi, Saîd; Tabka, Zouhair; Abdelkarim, Zbidi

    2008-01-01

    The purpose of this study was to assess, the effects of continuous and intermittent exercise training on lactate kinetic parameters and maximal aerobic speed (MAS) using field tests. Twenty-four male sport students were equally divided into continuous (CT) and intermittent (IT) physically trained groups. Another six participants acted as non-trained controls (CG). The trained participants practiced 6-days per week for 6 weeks. Before and after training, all participants completed an incremental exercise test to assess their MAS, and a 30- second supra-maximal exercise followed by 30 minutes of active recovery to determine the individual blood lactate recovery curve. It was found that exercise training has significantly increased MAS (p < 0.001), the lactate exchange and removal abilities as well as the lactate concentrations at the beginning of the recovery ([La]-(0)); for both CT and IT groups; this was accompanied by a significant reduction of the time to lactate-peak. Nevertheless, the improvement in MAS was significantly higher (p < 0.001) post-intermittent (15.1 % ± 2.4) than post-continuous (10.3 % ± 3.2) training. The lactate-exchange and removal abilities were also significantly higher for IT than for CT-group (P<0.05). Moreover, IT-group showed a significantly shorter half-time of the blood lactate (t-½-[La]) than CT-group (7.2 ± 0.5 min vs 7.7 ± 0.3 min, respectively) (p < 0.05). However, no significant differences were observed in peak blood lactate concentration ([La]peak), time to reach [La]peak (t-[La]peak), and [La]-(0) between the two physically-trained groups. We conclude that both continuous and intermittent training exercises were equally effective in improving t-[La]peak and [La]peak, although intermittent training was more beneficial in elevating MAS and in raising the lactate exchange (γ1) and removal (γ2) indexes. Key points Coaches and athletes need to be aware of the potentiality positive effects of exercise intensity. Improvements

  16. Addition of atropine to submaximal exercise stress testing in patients evaluated for suspected ischaemia with SPECT imaging: a randomized, placebo-controlled trial

    Energy Technology Data Exchange (ETDEWEB)

    Manganelli, Fiore; Sauro, Rosario; Di Lorenzo, Emilio; Rosato, Giuseppe [San Giuseppe Moscati Hospital, Department of Cardiology and Heart Surgery, Avellino (Italy); Spadafora, Marco; Varrella, Paola; Peluso, Giuseppina [San Giuseppe Moscati Hospital, Nuclear Medicine Unit, Avellino (Italy); Daniele, Stefania [Institute of Diagnostic and Nuclear Development (SDN), Naples (Italy); Cuocolo, Alberto [Institute of Diagnostic and Nuclear Development (SDN), Naples (Italy); University Federico II, Department of Biomorphological and Functional Sciences, Naples (Italy); National Council of Research, Institute of Biostructures and Bioimages, Naples (Italy)

    2011-02-15

    To evaluate the effects of the addition of atropine to exercise testing in patients who failed to achieve their target heart rate (HR) during stress myocardial perfusion imaging with single-photon emission computed tomography (SPECT). The study was a prospective, randomized, placebo-controlled design. Patients with suspected or known coronary artery disease who failed to achieve a target HR ({>=}85% of maximal predicted HR) during exercise SPECT imaging were randomized to receive intravenous atropine (n = 100) or placebo (n = 101). The two groups of patients did not differ with respect to demographic or clinical characteristics. A higher proportion of patients in the atropine group achieved the target HR compared to the placebo group (60% versus 3%, p < 0.0001). SPECT imaging was abnormal in a higher proportion of patients in the atropine group as compared to the placebo group (57% versus 42%, p < 0.05). Stress-induced myocardial ischaemia was present in more patients in the atropine group as compared to placebo (47% versus 29%, p < 0.01). In both groups of patients, no major side effects occurred. The addition of atropine at the end of exercise testing is more effective than placebo in raising HR to adequate levels, without additional risks of complications. The use of atropine in patients who initially failed to achieve their maximal predicted HR is associated with a higher probability of achieving a diagnostic myocardial perfusion study. (orig.)

  17. Hypotensive Response Magnitude and Duration in Hypertensives: Continuous and Interval Exercise

    Directory of Open Access Journals (Sweden)

    Raphael Santos Teodoro de Carvalho

    2015-03-01

    Full Text Available Background: Although exercise training is known to promote post-exercise hypotension, there is currently no consistent argument about the effects of manipulating its various components (intensity, duration, rest periods, types of exercise, training methods on the magnitude and duration of hypotensive response. Objective: To compare the effect of continuous and interval exercises on hypotensive response magnitude and duration in hypertensive patients by using ambulatory blood pressure monitoring (ABPM. Methods: The sample consisted of 20 elderly hypertensives. Each participant underwent three ABPM sessions: one control ABPM, without exercise; one ABPM after continuous exercise; and one ABPM after interval exercise. Systolic blood pressure (SBP, diastolic blood pressure (DBP, mean arterial pressure (MAP, heart rate (HR and double product (DP were monitored to check post-exercise hypotension and for comparison between each ABPM. Results: ABPM after continuous exercise and after interval exercise showed post-exercise hypotension and a significant reduction (p < 0.05 in SBP, DBP, MAP and DP for 20 hours as compared with control ABPM. Comparing ABPM after continuous and ABPM after interval exercise, a significant reduction (p < 0.05 in SBP, DBP, MAP and DP was observed in the latter. Conclusion: Continuous and interval exercise trainings promote post-exercise hypotension with reduction in SBP, DBP, MAP and DP in the 20 hours following exercise. Interval exercise training causes greater post-exercise hypotension and lower cardiovascular overload as compared with continuous exercise.

  18. LACTATE KINETICS AFTER INTERMITTENT AND CONTINUOUS EXERCISE TRAINING

    Directory of Open Access Journals (Sweden)

    Adnene Gharbi

    2008-06-01

    Full Text Available The purpose of this study was to assess, the effects of continuous and intermittent exercise training on lactate kinetic parameters and maximal aerobic speed (MAS using field tests. Twenty-four male sport students were equally divided into continuous (CT and intermittent (IT physically trained groups. Another six participants acted as non-trained controls (CG. The trained participants practiced 6-days per week for 6 weeks. Before and after training, all participants completed an incremental exercise test to assess their MAS, and a 30- second supra-maximal exercise followed by 30 minutes of active recovery to determine the individual blood lactate recovery curve. It was found that exercise training has significantly increased MAS (p < 0.001, the lactate exchange and removal abilities as well as the lactate concentrations at the beginning of the recovery ([La]-(0; for both CT and IT groups; this was accompanied by a significant reduction of the time to lactate-peak. Nevertheless, the improvement in MAS was significantly higher (p < 0.001 post-intermittent (15.1 % ± 2.4 than post-continuous (10.3 % ± 3.2 training. The lactate-exchange and removal abilities were also significantly higher for IT than for CT-group (P<0.05. Moreover, IT-group showed a significantly shorter half-time of the blood lactate (t-½-[La] than CT-group (7.2 ± 0.5 min vs 7.7 ± 0.3 min, respectively (p < 0.05. However, no significant differences were observed in peak blood lactate concentration ([La]peak, time to reach [La]peak (t-[La]peak, and [La]-(0 between the two physically-trained groups. We conclude that both continuous and intermittent training exercises were equally effective in improving t-[La]peak and [La]peak, although intermittent training was more beneficial in elevating MAS and in raising the lactate exchange (γ1 and removal (γ2 indexes

  19. Muscular and pulmonary O2 uptake kinetics during moderate- and high-intensity sub-maximal knee-extensor exercise in humans

    DEFF Research Database (Denmark)

    Krustrup, Peter; Jones, Andrew M.; Wilkerson, Daryl P.

    2009-01-01

    The purpose of this investigation was to determine the contribution of muscle O2 consumption (m O2) to pulmonary O2 uptake (p O2) during both low-intensity (LI) and high-intensity (HI) knee extension exercise, and during subsequent recovery, in humans. Seven healthy male subjects (age 20-25 years...... kinetics for LI (30 +/- 3 vs. 30 +/- 3 s) but was slightly higher (Pintensities. In recovery, agreement between the responses was more limited both for LI (36 +/- 4 vs. 18 +/- 4 s, P

  20. Submaximal arm crank ergometry : Effects of crank axis positioning on mechanical efficiency, physiological strain and perceived discomfort

    NARCIS (Netherlands)

    van Drongelen, S; Maas, J C; Scheel-Sailer, A; Van Der Woude, L H V

    2009-01-01

    PURPOSE: To evaluate the effect of the spatial orientation of the crank axis on mechanical efficiency, physiological strain and perceived discomfort in submaximal synchronous arm crank ergometry. METHODS: Twelve able-bodied individuals performed 12 submaximal exercise bouts of 3 minutes (women: 20

  1. EFFECTIVENESS OF INTERVAL EXERCISE VERSUS CONTINUOUS EXERCISE TO IMPROVE EXERCISE TOLERANCE IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE SUBJECTS

    OpenAIRE

    G.Swathi; A.Chaturvedi.P; P.Apparao; P.Kiranprakash; A.Nityal

    2015-01-01

    Background: COPD is characterized by chronic airflow limitation and a range of pathological changes in the lung. Chronic inflammation causes structural changes and narrowing of the small airways and destruction of lung parenchyma, leads to the loss of alveolar attachments to the small airways and decreases lung elastic recoil; in turn these changes diminish the expiration and the work of breathing is increased. Scarcity of evidence on continuous and interval exercises is forcing researchers c...

  2. Hypotensive Response Magnitude and Duration in Hypertensives: Continuous and Interval Exercise

    OpenAIRE

    Raphael Santos Teodoro de Carvalho; Cássio Mascarenhas Robert Pires; Gustavo Cardoso Junqueira; Dayana Freitas; Leila Maria Marchi-Alves

    2015-01-01

    Background: Although exercise training is known to promote post-exercise hypotension, there is currently no consistent argument about the effects of manipulating its various components (intensity, duration, rest periods, types of exercise, training methods) on the magnitude and duration of hypotensive response. Objective: To compare the effect of continuous and interval exercises on hypotensive response magnitude and duration in hypertensive patients by using ambulatory blood pressure monitor...

  3. Intense Exercise in Type 1 Diabetes: Exploring the Role of Continuous Glucose Monitoring

    OpenAIRE

    Chassin, Ludovic Jean; Wilinska, Malgorzata E.; Hovorka, Roman

    2007-01-01

    Development of the external artificial pancreas (AP) is anticipated to be incremental, starting with simple and progressing to more complex applications incorporating exercise periods of various duration and intensity. Most studies investigating the effect of exercise on glucose excursions in subjects with type 1 diabetes either explored moderate exercise, which exerts different effects compared to intense exercise, or did not adopt continuous glucose monitoring combined with frequent plasma ...

  4. Similar expression of oxidative genes after interval and continuous exercise

    DEFF Research Database (Denmark)

    Wang, Li; Psilander, Niklas; Tonkonogi, Michail

    2009-01-01

    in mitochondrial biogenesis and lipid metabolism. METHODS: Nine sedentary subjects cycled for 90 min with two protocols: CE (at 67% VO2max) and IE (12 s at 120% and 18 s at 20% of VO2max). The duration of exercise and work performed with CE and IE was identical. Muscle biopsies were taken before and 3 h after...... exercise. RESULTS: There were no significant differences between the two exercise protocols in the increases in VO2 and HR, the reduction in muscle glycogen (35%-40% with both protocols) or the changes in blood metabolites (lactate, glucose, and fatty acids). The mRNA content for major regulators...... and CE. However, the mRNA content for several downstream targets of PGC-1alpha increased significantly only after CE, and mRNA content for nuclear respiratory factor 2 was significantly higher after CE (P exercise...

  5. Menopausal women: perceiving continuous power through the experience of regular exercise.

    Science.gov (United States)

    Jeng, Chii; Yang, Shun-Hsuan; Chang, Pi-Chen; Tsao, Lee-Ing

    2004-05-01

    Menopausal women are at high risk for cardiovascular diseases and osteoporosis. However, for so long, women have devoted much of their time and energy to family, children, and work such that they could not regularly exercise. There are few studies addressing the experiences of Taiwanese women who regularly exercise. The aim of this study was to explore the experiences of regularly exercising, defined as thoughts or actions by menopausal women who did not regularly exercise before menopause, but who now exercise regularly. A grounded theory research design was used. In-depth interviews were undertaken with a purposive sampling of 12 menopausal women who began to do regular exercises after menopause and who have continued exercising for more than 6 months. The constant comparative method was used to analyse the interview data. 'Perceiving Continuous Power' was the core category during the process of regularly exercising. Every participating woman perceived that her body and mind were filled with continuous power including the subcategories of 'Overcoming the initial discomfort', 'Experiencing Benefits to Body and Mind' and 'Broadening' during the process. 'Awareness of Health Crisis', which included the subcategories of 'Cureless Chronic Disease', 'Mood Swings', and 'Conflict on Medication', was identified as occurring when these women first began regularly exercising. Throughout the process of perceiving continuous power, women experienced the following interactive behaviour categories: 'Exercise Selection' with subcategories of 'Self-Evaluation', 'Seeking and Fitting', 'Comparing' and 'Health Becoming' with the subcategories of 'Releasing Health Crisis', 'Regaining Flowering Life', and 'Self-Fulfilling'. Regular exercises provided continuous power for menopausal women. The experiences with exercise we uncovered in this study can provide a reference for nurses to guide menopausal women with their regular exercise plans.

  6. Differing response of asthmatics to sulfur dioxide exposure with continuous and intermittent exercise

    Energy Technology Data Exchange (ETDEWEB)

    Kehrl, H.R.; Roger, L.J.; Hazucha, M.J.; Horstman, D.H.

    1986-08-29

    Ten mild asthmatics were initially exposed in an environmental chamber (26 C, 70% RH) to clean air and 1.0 ppm sulfur dioxide while performing three sets of 10 minutes treadmill exercise (ventilation = 41 1/min) and 15 minutes rest. To evaluate the effects of the pattern and duration of exercise on the response to sulfur dioxide exposure, the subjects were then exposed to the same environmental conditions, while exercising continuously for 30 minutes. Specific airways resistance (SRaw) was measured by body plethysmography prior to exposures and after each exercise. All SRaw responses with sulfur dioxide exposure were significantly different than the clean air responses. It appears that asthmatics show an attenuated response to repetitive exercise in a 1.00 ppm sulfur dioxide atmosphere and that the response to sulfur dioxide exposure develops rapidly and is maintained during 30 minutes continuous exercise.

  7. Effects of preferred and nonpreferred music on continuous cycling exercise performance.

    Science.gov (United States)

    Nakamura, Priscila M; Pereira, Gleber; Papini, Camila B; Nakamura, Fábio Y; Kokubun, Eduardo

    2010-02-01

    The aim of this study was to investigate the effects of preferred and nonpreferred music on exercise distance, Heart Rate (HR), and Rating of Perceived Exertion (RPE) during continuous cycling exercise performed at high intensity. Fifteen participants performed five test sessions. During two sessions, they cycled with fixed workload on ergometer to determine the Critical Power (CP) intensity. Then, they performed three more sessions cycling at CP intensity: listening to Preferred Music, listening to Nonpreferred Music, and No Music. The HR responses in the exercise sessions did not differ among all conditions. However, the RPE was higher for Nonpreferred Music than in the other conditions. The performance under Preferred Music (9.8 +/- 4.6 km) was greater than under Nonpreferred Music (7.1 +/- 3.5 km) conditions. Therefore, listening to Preferred Music during continuous cycling exercise at high intensity can increase the exercise distance, and individuals listening to Nonpreferred Music can perceive more discomfort caused by the exercise.

  8. Aging and exercise performance.

    Science.gov (United States)

    Mahler, D A; Cunningham, L N; Curfman, G D

    1986-05-01

    Diverse physiologic changes occur in the oxygen transport system during the aging process. Physical performance and VO2max decline with age, but the changes may be attenuated by exercise training. Increased ventilation is required during exercise in order to compensate for reduced efficiency of gas exchange. Cardiovascular alterations include prolonged duration of myocardial contraction, a slightly reduced left ventricular ejection fraction during exercise, decreased heart rate during both submaximal and maximal exercise, and attenuation of myocardial response to beta-adrenergic stimulation. Cardiac output during exercise can be maintained in the elderly owing to a greater dependence on ventricular filling. Appropriate exercise training leads to enhanced efficiency of the lungs, heart, and skeletal muscles. These physiologic benefits contribute to an increase in functional capacity and an enhanced sense of well-being. Exercise testing is recommended for individuals who have cardiorespiratory symptoms and for those at risk for the development of coronary artery disease. Reasonable goals for an aerobic training program are continuous activity for 30 minutes at a moderate intensity of exertion at least 3 days per week. The intensity of exercise should be based on a prescribed training heart rate. The exercise prescription should be individualized and should incorporate one or more activities for optimal enjoyment and compliance. Opportunities and facilities for indoor exercise are important during inclement weather. Regular physical exercise is important at any age!

  9. Intermittent versus continuous exercise training in chronic heart failure: a meta-analysis.

    Science.gov (United States)

    Smart, Neil A; Dieberg, Gudrun; Giallauria, Francesco

    2013-06-20

    We conducted a meta-analysis of randomized, controlled trials of combined strength and intermittent aerobic training, intermittent aerobic training only and continuous exercise training in heart failure patients. A systematic search was conducted of Medline (Ovid) (1950-September 2011), Embase.com (1974-September 2011), Cochrane Central Register of Controlled Trials and CINAHL (1981-September 19 2011). The search strategy included a mix of MeSH and free text terms for the key concepts heart failure, exercise training, interval training and intermittent exercise training. The included studies contained an aggregate of 446 patients, 212 completed intermittent exercise training, 66 only continuous exercise training, 59 completed combined intermittent and strength training and 109 sedentary controls. Weighted mean difference (MD) in Peak VO2 was 1.04mlkg(-1)min(-1) and (95% C.I.) was 0.42-1.66 (p=0.0009) in intermittent versus continuous exercise training respectively. Weighted mean difference in Peak VO2 was -1.10mlkg(-1)min(-1) (95% C.I.) was -1.83-0.37 p=0.003 for intermittent only versus intermittent and strength (combined) training respectively. In studies reporting VE/VCO2 for intermittent versus control groups, MD was -1.50 [(95% C.I. -2.64, -0.37), p=0.01] and for intermittent versus continuous exercise training MD was -1.35 [(95% C.I. -2.15, -0.55), p=0.001]. Change in peak VO2 was positively correlated with weekly exercise energy expenditure for intermittent exercise groups (r=0.48, p=0.05). Combined strength and intermittent exercise appears superior for peak VO2 changes when compared to intermittent exercise of similar exercise energy expenditure. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. Effect of orthostatic stress on exercise performance after bedrest

    Science.gov (United States)

    Convertino, V. A.; Goldwater, D. J.; Sandler, H.

    1982-01-01

    The cardiorespiratory responses to supine against upright exercise were compared to determine the orthostatic effects of gravity on exercise performance following bedrest. Five healthy male subjects underwent seven days of continuous bedrest. A deconditioning effect was manifested by significant increases in ventilation volume, carbon dioxide production, respiratory exchange ratio, heart rate, heart rate-pressure product, and diastolic blood pressure during submaximal exercise following bedrest. The major finding from this study was that bedrest resulted in a general decrease in exercise tolerance, which was more stressful in the upright posture compared to the supine position, judging from specific submaximal cardiorespiratory responses to cycle ergometry. The data support the hypothesis that there is an orthostatic factor to the reduction in work tolerance following bedrest deconditioning, in addition to the effects caused by increased physical activity.

  11. Health promotion: the impact of beliefs of health benefits, social relations and enjoyment on exercise continuation.

    Science.gov (United States)

    Nielsen, G; Wikman, J M; Jensen, C J; Schmidt, J F; Gliemann, L; Andersen, T R

    2014-08-01

    The aim of this study was to explore how and why participants in structured exercise intervention programs continue or stop exercising after the program is finished. We conducted four focus group interviews with four groups of middle-aged and elderly men (total n = 28) who had participated in exercise interventions involving playing either a team sport (football) or a more individually focused activity (spinning and crossfit). Our results show that different social, organizational and material structures inherent in the different activities shape the subjects' enjoyment of exercise participation, as well as their intention and ability to continue being active. In conclusion, team sport activities seem to be intrinsically motivating to the participants through positive social interaction and play. They are therefore more likely to result in exercise continuation than activities that rely primarily on extrinsic motivation such as the expectation of improved health and well-being. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Effects of exercise continued until anaerobic threshold on balance performance in male basketball players.

    Science.gov (United States)

    Erkmen, Nurtekin; Suveren, Sibel; Göktepe, Ahmet Salim

    2012-06-01

    The objective of the present study was to determine the effects of exercise continued until the anaerobic threshold on balance performance in basketball players. Twelve male basketball players (age = 20.92 ± 2.81 years, body height = 192.72 ± 7.61 cm, body mass = 88.09 ± 8.41 kg, training experience = 7.17 ± 3.10 years) volunteered to participate in this study. A Kinesthetic Ability Trainer (KAT 2000 stabilometer) was used to measure the balance performance. Balance tests consisted of static tests on dominant, nondominant and double leg stance. The Bruce Protocol was performed by means of a treadmill. The exercise protocol was terminated when the subject passed the anaerobic threshold. After the exercise protocol, balance measurements were immediately repeated. Statistical differences between pre and post-exercise for dominant, nondominant and double leg stance were determined by the paired samples t-test according to the results of the test of normality. The post-exercise balance score on the dominant leg was significantly higher than pre-exercise (t = -2.758, p exercise in the balance scores of the nondominant leg after the exercise protocol (t = 0.428, p > 0.05). A significant difference was found between pre and post-exercise balance scores in the double leg stance (t = -2.354, p exercise continued until the anaerobic threshold decreased balance performance on the dominant leg in basketball players, but did not alter it in the nondominant leg.

  13. Effect of Carbohydrate Ingestion on Sprint Performance Following Continuous Exercise

    Science.gov (United States)

    Siahkohian, M.; Farhadi, H.; Naghizadeh Baghi, A.; Valizadeh, A.

    The purpose of this study was to determine the effect of 5% carbohydrate ingestion on the sprint performance immediately following 90 min of running at 70-80% of maximal heart rate reserve. Thirty young active men were selected as subjects and allocated randomly to two carbohydrate (CHO, N = 15) and placebo (PL, N = 15) groups. Pre-test 200 m dash, 90 min running and post-test 200 m dash took place, respectively. Exercise heart rate monitored during 90 min running by a cardio frequency meter. Significant differences were found between the CHO and PL post-test 200 m dash records (pBlood glucose was found to be significantly higher at the end of the 90 min running for the CHO group than for the PL group (p<0.01). The results suggest that carbohydrate ingestion during endurance exercise inhibits failing of Sprint performance of young active men.

  14. Is an elevated submaximal heart rate associated with psychomotor slowness in young elite soccer players?

    NARCIS (Netherlands)

    Brink, Michel S.; Visscher, Chris; Schmikli, Sandor L.; Nederhof, E.; Lemmink, Koen A. P. M.

    2013-01-01

    The aim of the present study was to find early markers for overreaching that are applicable in sport practice. In a group of elite soccer players aged 1518, the stressrecovery balance and reaction times before and after exercise were assessed. Overreaching was indicated by an elevated submaximal

  15. The influence of intense intermittent versus moderate continuous exercise on postprandial lipemia.

    Science.gov (United States)

    Ferreira, Aparecido Pimentel; Ferreira, Cristiane Batisti; Souza, Vinícius Carolino de; Córdova, Cláudio Olavo de Almeida; Silva, Glauber Castelo Branco; Nóbrega, Otávio de Toledo; França, Nancí Maria de

    2011-01-01

    Postprandial lipemia is characterized by an increased concentration of circulating lipids after fat intake and is an independent risk factor for cardiovascular disease. Exercise is known to reduce postprandial lipemia and its negative clinical outcomes. This study investigated the effect of intense intermittent versus moderate continuous exercise using the same energy expenditure in postprandial lipemia. Twenty healthy men (aged 21.5 ± 3.5 years) performed a random sequence of either rest or 500 Kcal tests separated by a minimum 48 h interval as follows: (a) no exercise (control), (b) intense intermittent exercise, or (c) moderate continuous exercise. Each test series was completed 30 min before ingestion of a high-fat meal (1 g fat/kg). Venous blood was collected before and at 1, 2, 3 and 4 hours after the high-fat meal. Postprandial lipemia was assessed using the area under the curve approach as well as a kinetic profile of mean lipid variables. Statistical significance was tested at the p<0.05 level. With both statistical approaches, intense intermittent and moderate continuous exercises were both effective in reducing postprandial triglycerides; however, only intense intermittent exercise reduced the levels of postprandial very low density lipoprotein. Intense intermittent and continuous exercise produced lower levels of insulinemia using the area under the curve analysis only. Intense intermittent or continuous exercise with an energy expenditure of 500 kcal completed 30 min before ingestion of high-fat meal reduced postprandial lipid levels to different levels in physically active men. Understanding these relevant differences will enable clinicians to provide the best exercise prescription for patients.

  16. The influence of intense intermittent versus moderate continuous exercise on postprandial lipemia

    Directory of Open Access Journals (Sweden)

    Aparecido Pimentel Ferreira

    2011-01-01

    Full Text Available INTRODUCTION: Postprandial lipemia is characterized by an increased concentration of circulating lipids after fat intake and is an independent risk factor for cardiovascular disease. Exercise is known to reduce postprandial lipemia and its negative clinical outcomes. OBJECTIVE: This study investigated the effect of intense intermittent versus moderate continuous exercise using the same energy expenditure in postprandial lipemia. MATERIALS AND METHODS: Twenty healthy men (aged 21.5 + 3.5 years performed a random sequence of either rest or 500 Kcal tests separated by a minimum 48 h interval as follows: (a no exercise (control, (b intense intermittent exercise, or (c moderate continuous exercise. Each test series was completed 30 min before ingestion of a high-fat meal (1 g fat/kg. Venous blood was collected before and at 1, 2, 3 and 4 hours after the high-fat meal. Postprandial lipemia was assessed using the area under the curve approach as well as a kinetic profile of mean lipid variables. Statistical significance was tested at the p<0.05 level. RESULTS: With both statistical approaches, intense intermittent and moderate continuous exercises were both effective in reducing postprandial triglycerides; however, only intense intermittent exercise reduced the levels of postprandial very low density lipoprotein. Intense intermittent and continuous exercise produced lower levels of insulinemia using the area under the curve analysis only. CONCLUSION: Intense intermittent or continuous exercise with an energy expenditure of 500 kcal completed 30 min before ingestion of high-fat meal reduced postprandial lipid levels to different levels in physically active men. Understanding these relevant differences will enable clinicians to provide the best exercise prescription for patients.

  17. Interval and continuous aerobic exercise training similarly increase cardiac function and autonomic modulation in infarcted mice

    OpenAIRE

    Abad,Cesar Cavinato Cal; do Nascimento, Ademir Manuel; dos Santos, Leandro Eziquiel; Figueroa, Diego; Ramona, Pamella; Sartori, Michele; Scapini, Katia B.; Albuquerque, Oscar; Moraes-Silva,Ivana Cinthya; Coelho-J?nior, H?lio Jos?; Rodrigues,Bruno; Mostarda,Cristiano Teixeira; De Angelis, K?tia; Irigoyen, Maria Cl?udia

    2017-01-01

    The present study aimed to compare the effects of moderate-intensity continuous and high-intensity interval exercise training (ET) on exercise tolerance, cardiac morphometry and function, hemodynamic, and cardiac autonomic modulation in myocardial infarcted mice. Wild-type mice (WT) were divided into four groups: sedentary WT (S); WT myocardium infarction sedentary (IS); WT myocardium infarction underwent to moderate-intensity continuous ET (MICT), and WT myocardium infarction underwent to hi...

  18. THE EFFECTS OF INTERMITTENT EXERCISE ON PHYSIOLOGICAL OUTCOMES IN AN OBESE POPULATION: CONTINUOUS VERSUS INTERVAL WALKING

    Directory of Open Access Journals (Sweden)

    Karen Wallman

    2010-03-01

    Full Text Available This study compared the effects of 12 weeks of caloric restriction and interval exercise (INT and caloric restriction and continuous aerobic exercise (CON on physiological outcomes in an obese population. Forty-four individuals (BMI > 30 kg·m-2 were randomised into the INT or CON group. Participant withdrawal resulted in 12 and 14 participants in the INT and CON groups, respectively. All participants were on a strict monitored diet. Exercise involved two 15-min bouts of walking performed on five days per week. Interval exercise consisted of a 2:1 min ratio of low-intensity (40-45% VO2peak and high- intensity (70-75% VO2peak exercise, while the CON group exercised between 50-55% VO2peak. Exercise duration and average intensity (%VO2peak were similar between groups. There were no significant differences (p > 0.05 between the two groups for any variable assessed apart from very low density lipoprotein (VLDL-C, which significantly decreased over time in the INT group only (p < 0.05, d = 1.03. Caloric restriction and interval exercise compared to caloric restriction and continuous aerobic exercise resulted in similar outcome measures apart from VLDL-C levels, which significantly improved in the INT group only

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

    Science.gov (United States)

    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 high intensity 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.

  20. Do continuous and intermittent exercises sets induce similar cardiovascular responses in the elderly women?

    Directory of Open Access Journals (Sweden)

    Veloso Úrsula

    2003-01-01

    Full Text Available There is a lack of information about elderly acute cardiovascular responses in the elderly during exercise involving different muscle groups and strategies of load/repetition interaction (LRI in continuous and intermittent sets. The purpose of this study was to compare heart rate (HR, systolic blood pressure (SBP, rate-pressure product (RPP and quality of exercise performance (QEx of upper and lower body exercises (arms abduction and hip flexion in different situations of LRI. Twelve healthy women aged 65 to 85 years old volunteered to this study. The subjects performed both exercises at 12 maximal repetitions workload, continuously (2 sets of 12 reps and alternately (4 sets of 6 reps. HR was measured with a cardiotachometer and SBP through auscultation technique at the end of the last repetition of each set. The exercises were recorded in video to evaluate QEx. At least for the selected exercises, LRI did not influence QEx. However, SBP and RPP values for the intermittent sets were significantly higher than for continuous situations (p < 0.05. The authors concluded that continuous sets seem to be associated to greater cardiovascular stress in elder subjects, mainly because of SBP responses during the exercise.

  1. Hemodynamic responses to single sessions of aerobic exercise and resistance exercise in pregnancy.

    Science.gov (United States)

    Petrov Fieril, Karolina; Glantz, Anna; Fagevik Olsen, Monika

    2016-09-01

    Previous research on maternal hemodynamic responses to a single exercise session during pregnancy is sparse, especially considering immediate responses to resistance exercise. The aim of the study was to examine blood pressure, heart rate, body temperature, and Rating of Perceived Exertion in healthy pregnant women during single sessions of continuous submaximal exercise in pregnancy week 21. A cross-over design was used. Twenty healthy pregnant women from four prenatal clinics in Gothenburg, Sweden, were included. On day 1, the women did 30 min of aerobic exercise and on day 3 they did 30 min of resistance exercise. Blood pressure, heart rate, and Rating of Perceived Exertion were measured after 15 and 30 min of exercise. After 15 and 30 min of exercise, there was a significant increase in systolic blood pressure and heart rate (p exercise (p = 0.01) than resistance exercise (p = 0.03). Resistance exercise was perceived as more intense than aerobic exercise after 15 min (p = 0.02) and 30 min (p = 0.001) of exercise. Five minutes after completing the exercise, blood pressure quickly reverted to normal although heart rate was still increased (p = 0.001). There was no correlation between heart rate and Rating of Perceived Exertion (rs  = 0.05-0.43). Maternal hemodynamic responses were essentially the same, regardless of whether the exercise was submaximal aerobic or resistance exercise, although resistance exercise was perceived as more intense. Aerobic and resistance exercise corresponding to "somewhat hard" seems to have no adverse effect with regard to maternal hemodynamic responses in healthy pregnancy. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.

  2. Erythrocyte membrane fluidity and indices of plasmatic oxidative damage after acute physical exercise in humans.

    Science.gov (United States)

    Berzosa, C; Gómez-Trullén, E M; Piedrafita, E; Cebrián, I; Martínez-Ballarín, E; Miana-Mena, F J; Fuentes-Broto, L; García, J J

    2011-06-01

    Optimal levels of membrane fluidity are essential for numerous cell functions including cell growth, solute transport and signal transduction. Since exercise enhances free radical production, our aim was to evaluate in healthy male subjects the effects of an acute bout of maximal and submaximal exercise on the erythrocyte membrane fluidity and its possible relation to the oxidative damage overproduction due to exercise. Subjects (n = 34) performed three cycloergometric tests: a continuous progressive exercise, a strenuous exercise until exhaustion and an acute bout of exercise at an intensity corresponding to 70% of maximal work capacity for 30 min. Venous blood samples were collected before and immediately after these exercises. Erythrocyte membrane fluidity was assessed by fluorescence spectroscopy. Plasma malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA) concentrations and carbonyl content of plasmatic proteins were used as an index of lipid and protein oxidation, respectively. Exercise produced a dramatic drop in the erythrocyte membrane fluidity as compared to resting time, but this was not accompanied by significant changes in the plasmatic MDA and 4-HDA concentrations. The highest erythrocyte membrane rigidity was detected immediately after strenuous exercise until exhaustion was performed. Protein carbonyl levels were higher after exhaustive exercises than at rest. Continuous progressive and strenuous exercises until exhaustion, but not submaximal workload, resulted in a significant enhanced accumulation of carbonylated proteins in the plasma. These findings are consistent with the idea that exercise exaggerates oxidative damage, which may contribute, at least partially, to explain the rigidity in the membrane of the erythrocytes due to acute exercise.

  3. Therapeutic role of continuous exercise training programme on the ...

    African Journals Online (AJOL)

    Results: Findings of the study revealed significant decreased effect of continuous training programme on SBP, DBP, TC and significant increased effects on VO2max and HDL level at p< 0.05. Also there was a significant negative and positive correlation between changes in VO2max and changes in TC and HDL ...

  4. Assessment of cardiorespiratory fitness using submaximal protocol in older adults with mood disorder and Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Natacha Alves de Oliveira

    2013-01-01

    Full Text Available BACKGROUND: Evidence has shown benefits for mental health through aerobic training oriented in percentage of VO2max, indicating the importance of this variable for clinical practice. OBJECTIVE: To validate a method for estimating VO2max using a submaximal protocol in elderly patients with clinically diagnosis as major depressive disorder (MDD and Parkinson's disease (PD. METHODS: The sample comprised 18 patients (64.22 ± 9.92 years with MDD (n = 7 and with PD (n = 11. Three evaluations were performed: I disease staging, II direct measurement of VO2max and III submaximal exercise test. Linear regression was performed to verify the accuracy of estimation in VO2max established in ergospirometry and the predicted VO2max from the submaximal test measurement. We also analyzed the correlation between the Bland-Altman procedures. RESULTS: The regression analysis showed that VO2max values estimated by submaximal protocol associated with the VO2max measured, both in absolute values (R² = 0.65; SEE = 0.26; p < 0.001 and the relative (R² = 0.56; SEE = 3.70; p < 0.001. The Bland-Altman plots for analysis of agreement of showed a good correlation between the two measures. DISCUSSION: The VO2max predicted by submaximal protocol demonstrated satisfactory criterion validity and simple execution compared to ergospirometry.

  5. Training effects on endurance capacity in maximal intermittent exercise: comparison between continuous and interval training.

    Science.gov (United States)

    Tanisho, Kei; Hirakawa, Kazufumi

    2009-11-01

    The purpose of this study was to examine the effects of 2 different training regimens, continuous (CT) and interval (IT), on endurance capacity in maximal intermittent exercise. Eighteen lacrosse players were divided into CT (n = 6), IT (n = 6), and nontraining (n = 6) groups. Both training groups trained for 3 days per week for 15 weeks using bicycle ergometers. Continuous training performed continuous aerobic training for 20-25 minutes, and IT performed high-intensity pedaling comprising 10 sets of 10-second maximal pedaling with 20-second recovery periods. Maximal anaerobic power, maximal oxygen uptake (V(O2max)), and intermittent power output were measured before and after the training period. The intermittent exercise test consisted of a set of ten 10-second maximal sprints with 40-second intervals. Maximal anaerobic power significantly increased in IT (p training groups (p intermittent exercise test, the average of the total mean power output (1-10 sets) increased in both training groups (p training reduced lactate production and increased the mean power output, but there was little effect on high-power endurance capacity in maximal intermittent exercise. In contrast, although lactate production did not decrease, IT improved fatigability and mean power output in the last stage. These results indicated that the endurance capacities for maximal intermittent and continuous exercises were not identical. Ball game players should therefore improve their endurance capacity with high-intensity intermittent exercise, and it is insufficient to assess their capacity with only V(O2max) or continuous exercise tests.

  6. Myocardial damage after continuous aerobic and anaerobic exercise in rats

    Directory of Open Access Journals (Sweden)

    Rostika Flora

    2013-12-01

    Full Text Available Background: Regular physical activity is highly recommended in preventive, curative, and rehabilitative programs in order to promote health, especially cardiovascular health. However, physical activity can also cause sudden death. In athletes, sudden death may occur during sport competitions, with myocardial infarction as the most common etiology. It is suspected that continuous training without any rest-day play a role in cardiac muscle damage and sudden death during competition. Our study was aimed to learn about cardiac muscle adaptation on continuous aerobic and anaerobic physical activity without any rest-day. Methods: The specimens in our study were cardiac muscle tissue obtained from rats that had performed aerobic and anaerobic physical activity on treadmill for 1, 3, 7, and 10 days without any rest-day. Blood gas analysis and hematological assessment were used as parameters of systemic adaptation to hypoxia during physical activity. Moreover, histopathology of cardiac muscle tissue was performed as parameter for cardiac muscle damage.Results: The results showed that aerobic and anaerobic physical activity caused a systemic hypoxic condition and triggered adaptation responses. Cardiac muscle damage occurred on the 10th day in both treatment groups, with more severe damage observed in the group with anaerobic physical activity. The tissue protein level in the anaerobic group increased progressively on the 10th day.Conclusion: Physical activity may result in hypoxia and systemic adaptation. Aerobic and anaerobic physical activities performed for 10 days without any rest-day may cause cardiac muscle damage. (Med J Indones. 2013;22:209-14. doi: 10.13181/mji.v22i4.601Keywords: Cardiac muscle, cardiac muscle damage, histopathology, physical activity

  7. Absence of Respiratory Muscle Fatigue in High-Intensity Continuous or Interval Cycling Exercise.

    Science.gov (United States)

    Kurti, Stephanie P; Smith, Joshua R; Emerson, Sam R; Castinado, Kenneth M; Harms, Craig A

    2015-11-01

    Respiratory muscle fatigue (RMF) occurs during prolonged exercise (∼15-20 minutes) at >85% V[Combining Dot Above]O2max. However, RMF has been reported to occur in ∼3-6 minutes in various modes of exercise at a high intensity. It is not known if continuous cycling exercise vs. repeated bouts of high-intensity interval training (HIT) at >85% V[Combining Dot Above]O2max will lead to RMF. We hypothesized that RMF would occur after a constant load test and would be present before end exercise in an HIT protocol. Eight moderately active healthy men (21.7 ± 1.7 years; 181.3 ± 5.2 cm; 81.3 ± 2.3 kg) completed a V[Combining Dot Above]O2max test on a cycle ergometer. Subjects then completed 2 bouts of HIT (7 × 1 minute, 2-minute recovery between intervals) and 3 bouts of continuous exercise (CE) tests at 90% of peak power (determined from an incremental exercise test to exhaustion). Maximal inspiratory pressure (PIMAX) and expiratory pressure (PEMAX) were measured pre- and post-exercise for both HIT and CE and after each interval during HIT. Decreases in postexercise PIMAX and PEMAX compared with baseline were used to determine RMF. There were no differences (p > 0.05) in PIMAX or PEMAX pre- to post-exercise for HIT (PIMAX pre: 134 ± 51, post: 135 ± 50 cmH2O; PEMAX pre: 143 ± 41, post: 148 ± 46 cmH2O) or CE (PIMAX pre: 135 ± 54, post: 133 ± 52 cmH2O; PEMAX pre: 146 ± 46, post: 148 ± 46 cmH2O) indicating RMF was not present following CE and HIT. These data suggest that repeated high-intensity cycling exercise at 90% peak power in a CE or HIT protocol does not lead to RMF.

  8. Effect of continuous and interval exercise training on the PETCO2 response during a graded exercise test in patients with coronary artery disease

    OpenAIRE

    Enéas A. Rocco; Prado, Danilo M L; Silva, Alexandre G.; Lazzari, Jaqueline M. A.; Bortz, Pedro C; Rocco,Débora F. M.; Carla G. Rosa; Valter Furlan

    2012-01-01

    OBJECTIVE: The purpose of this study was to evaluate the following: 1) the effects of continuous exercise training and interval exercise training on the end-tidal carbon dioxide pressure (PETCO2) response during a graded exercise test in patients with coronary artery disease; and 2) the effects of exercise training modalities on the association between PETCO2 at the ventilatory anaerobic threshold (VAT) and indicators of ventilatory efficiency and cardiorespiratory fitness in patients with co...

  9. Which factors determine the freely chosen cadence during submaximal cycling?

    Science.gov (United States)

    Vercruyssen, Fabrice; Brisswalter, Jeanick

    2010-03-01

    The present review of cycling science focuses on the identification of criteria that affect the freely chosen cadence (FCC) during submaximal exercise of short and prolonged durations. Cadence selection during submaximal cycling constitutes a potential parameter affecting the endurance performance in subjects of varying aerobic fitness level and experience. The activity constraints such as specificity (e.g. cycle bout of triathlon) and exercise duration may play an important role in the selection of cadence and must be taken into consideration in the task description. The 'holistic' approach of this review is based on a multifactorial analysis considering the cycling constraints, and the physiological and biomechanical factors of cadence selection so as to establish any interrelationships between these factors. During cycle bouts of short duration (<15 min), it has been well argued that experienced cyclists, trained runners and triathletes adopt high cadences (80-100 rpm) systematically above the energetically optimal cadence (EOC) at which the oxygen uptake is minimal (55-65 rpm). The choice of a high cadence has been shown to be dependent upon several factors, such as the aerobic fitness level, the reduction in forces applied to the cranks, the lower extremity net joint moments and minimal neuromuscular fatigue. However, with increasing exercise duration the FCC has been reported to be close to the EOC exclusively in endurance athletes practising a variety of activities, suggesting an impact of training mode on the muscular adaptations and the organisation of the movement pattern. Copyright 2009 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  10. Eight weeks of intermittent hypoxic training improves submaximal physiological variables in highly trained runners.

    Science.gov (United States)

    Holliss, Ben A; Burden, Richard J; Jones, Andrew M; Pedlar, Charles R

    2014-08-01

    It is unclear whether intermittent hypoxic training (IHT) results in improvements in physiological variables associated with endurance running. Twelve highly trained runners (VO2peak 70.0 ± 3.5 ml·kg-1·min-1) performed incremental treadmill tests to exhaustion in normobaric normoxia and hypoxia (16.0% FIO2) to assess submaximal and maximal physiological variables and the limit of tolerance (T-Lim). Participants then completed 8 weeks of moderate to heavy intensity normoxic training (control [CONT]) or IHT (twice weekly 40 minutes runs, in combination with habitual training), in a single blinded manner, before repeating the treadmill tests. Submaximal heart rate decreased significantly more after IHT (-5 ± 5 b·min-1; p = 0.001) than after CONT ( -1 ± 5 b·min-1; p = 0.021). Changes in submaximal V[Combining Dot Above]O2 were significantly different between groups (p ≤ 0.05); decreasing in the IHT group in hypoxia (-2.6 ± 1.7 ml·kg-1·min-1; p = 0.001) and increasing in the CONT group in normoxia (+1.1 ± 2.1 ml·kg-1·min-1; p = 0.012). There were no VO2peak changes within either group, and while T-Lim improved post-IHT in hypoxia (p = 0.031), there were no significant differences between groups. Intermittent hypoxic training resulted in a degree of enhanced cardiovascular fitness that was evident during submaximal, but not maximal intensity exercise. These results suggest that moderate to heavy intensity IHT provides a mean of improving the capacity for submaximal exercise and may be useful for pre-acclimatization for subsequent exercise in hypoxia, but additional research is required to establish its efficacy for athletic performance at sea level.

  11. Evaluation of the American College of Sports Medicine submaximal treadmill running test for predicting VO2max.

    Science.gov (United States)

    Marsh, Clare E

    2012-02-01

    The purpose of this study was to assess the validity of the American College of Sports Medicine's (ACSM's) submaximal treadmill running test in predicting VO2max. Twenty-one moderately well-trained men aged 18-34 years performed 1 maximal treadmill test to determine maximal oxygen uptake (M VO2max) and 2 submaximal treadmill tests using 4 stages of continuous submaximal exercise. Estimated VO2max was predicted by extrapolation to age-predicted maximal heart rate (HRmax) and calculated in 2 ways: using data from all submaximal stages between 110 b·min(-1) and 85% HRmax (P VO2max-All), and using data from the last 2 stages only (P VO2max-2). The measured VO2max was overestimated by 3% on average for the group but was not significantly different to predicted VO2max (1-way analysis of variance [ANOVA] p = 0.695; M VO2max = 53.01 ± 5.38; P VO2max-All = 54.27 ± 7.16; P VO2max-2 = 54.99 ± 7.69 ml·kg(-1)·min(-1)), although M VO2max was not overestimated in all the participants--it was underestimated in 30% of observations. Pearson's correlation, standard error of estimate (SEE), and total error (E) between measured and predicted VO2max were r = 0.646, 4.35, 4.08 ml·kg(-1)·min(-1) (P VO2max-All) and r = 0.642, 4.21, 3.98 ml·kg(-1)·min(-1) (P VO2max-2) indicating that the accuracy in prediction (error) was very similar whether using P VO2max-All or P VO2max-2, with up to 70% of the participants predicted scores within 1 SEE (∼4 ml·kg(-1)·min(-1)) of M VO2max. In conclusion, the ACSM equation provides a reasonably good estimation of VO2max with no difference in predictive accuracy between P VO2max-2 and P VO2max-All, and hence, either approach may be equally useful in tracking an individual's aerobic fitness over time. However, if a precise knowledge of VO2max is required, then it is recommended that this be measured directly.

  12. Heterogeneous recruitment of quadriceps muscle portions and fibre types during moderate intensity knee-extensor exercise: effect of thigh occlusion

    DEFF Research Database (Denmark)

    Krustrup, Peter; Söderlund, Karin; Relu, Mihai U.

    2009-01-01

    The involvement of quadriceps femoris muscle portions and fibre type recruitment was studied during submaximal knee-extensor exercise without and with thigh occlusion (OCC) and compared with responses during intense exercise. Six healthy male subjects performed 90-s of moderate exercise without...... (MOD; 29+/-4 W) and with thigh OCC, and moderate exercise followed by 90-s of intense exercise (HI; 65+/-8 W). Temperatures were continuously measured in m. vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) and successive muscle biopsies were obtained from VL. During MOD, muscle...

  13. Sweat Rates During Continuous and Interval Aerobic Exercise: Implications for NASA Multipurpose Crew Vehicle (MPCV) Missions

    Science.gov (United States)

    Ryder, Jeffrey W.; Scott, Jessica; Ploutz-Snyder, Robert; Ploutz-Snyder, Lori L.

    2016-01-01

    Aerobic deconditioning is one of the effects spaceflight. Impaired crewmember performance due to loss of aerobic conditioning is one of the risks identified for mitigation by the NASA Human Research Program. Missions longer than 8 days will involve exercise countermeasures including those aimed at preventing the loss of aerobic capacity. The NASA Multipurpose Crew Vehicle (MPCV) will be NASA's centerpiece architecture for human space exploration beyond low Earth orbit. Aerobic exercise within the small habitable volume of the MPCV is expected to challenge the ability of the environmental control systems, especially in terms of moisture control. Exercising humans contribute moisture to the environment by increased respiratory rate (exhaling air at 100% humidity) and sweat. Current acceptable values are based on theoretical models that rely on an "average" crew member working continuously at 75% of their aerobic capacity (Human Systems Integration Requirements Document). Evidence suggests that high intensity interval exercise for much shorter durations are equally effective or better in building and maintaining aerobic capacity. This investigation will examine sweat and respiratory rates for operationally relevant continuous and interval aerobic exercise protocols using a variety of different individuals. The results will directly inform what types of aerobic exercise countermeasures will be feasible to prescribe for crewmembers aboard the MPCV.

  14. Mood and selective attention in the cold: the effect of interval versus continuous exercise.

    Science.gov (United States)

    Muller, Matthew D; Muller, Sarah M; Kim, Chul-Ho; Ryan, Edward J; Gunstad, John; Glickman, Ellen L

    2011-07-01

    Both mood and cognitive function are altered in cold environments. Body warming through exercise may improve Stroop interference score and lessen total negative mood. The purpose of this study was to determine the effect of equal caloric bouts of interval (INT) and continuous (CONT) exercise on mood and selective attention in the cold. Eleven young men underwent two experimental trials in 5°C air. Both trials consisted of 90 min acute cold exposure (ACE), 30 min exercise (INT vs. CONT), and 60 min recovery (REC). The Profile of Mood States (POMS) and Stroop Color Word Test (SCWT) were administered at four time points. Mean body temperature decreased during ACE, increased during exercise, and decreased during REC. Repeated measures analysis of variance revealed a main effect for time for several of the POMS sub scores. In particular, negative mood was significantly decreased after exercise relative to ACE and then significantly increased during REC. Further, CONT appears to be more effective than INT at decreasing negative mood. Components of the SCWT supported both the arousal and distraction theories for simple perception, but no significant effects were shown for the interference score. In the cold, exercise decreases negative mood but does not appear to affect selective attention. Further mechanistic studies could determine the best mode and intensity of exercise for improving cognitive function in the cold.

  15. The effects of interval- vs. continuous exercise on excess post-exercise oxygen consumption and substrate oxidation rates in subjects with type 2 diabetes

    DEFF Research Database (Denmark)

    Karstoft, Kristian; Wallis, Gareth A.; Pedersen, Bente K.

    2016-01-01

    ), substrate oxidation rates and lipid metabolism in the hours following exercise in subjects with type 2 diabetes (T2D). Methods Following an overnight fast, ten T2D subjects (M/F: 7/3; age = 60.3 ± 2.3 years; body mass index (BMI) = 28.3 ± 1.1 kg/m2) completed three 60-min interventions in a counterbalanced......, free fatty acids and glycerol concentrations, and glycerol kinetics were increased comparably during and after IW and CW compared to CON. Conclusions Interval exercise results in greater EPOC than oxygen-consumption matched continuous exercise during a post-exercise MMTT in subjects with T2D, whereas......Background For unknown reasons, interval training often reduces body weight more than energy-expenditure matched continuous training. We compared the acute effects of time-duration and oxygen-consumption matched interval- vs. continuous exercise on excess post-exercise oxygen consumption (EPOC...

  16. Physical Education Teachers' Continuing Professional Development in Health-Related Exercise: A Figurational Analysis

    Science.gov (United States)

    Alfrey, Laura; Webb, Louisa; Cale, Lorraine

    2012-01-01

    This paper uses figurational sociology to explain why Secondary Physical Education teachers' engagement with Health Related Exercise (HRE) is often limited. Historically-rooted concerns surround the teaching of HRE, and these have recently been linked to teachers' limited continuing professional development (CPD) in HRE (HRE-CPD). A two-phase,…

  17. Interval versus continuous aerobic exercise training in breast cancer survivors--a pilot RCT.

    Science.gov (United States)

    Dolan, Lianne B; Campbell, Kristin; Gelmon, Karen; Neil-Sztramko, Sarah; Holmes, Daniel; McKenzie, Donald C

    2016-01-01

    Exercise therapy is being explored in a variety of cancer populations to counteract treatment-related deconditioning. Higher intensity interval protocols are being prescribed to improve physical function and attenuate surrogates of comorbidity in non-cancer populations. The purpose of this study is to explore the safety of higher intensity exercise stimuli on cardiorespiratory fitness (VO2peak) in breast cancer survivors. Postmenopausal breast cancer survivors were randomized into three groups: supervised aerobic interval training (AIT), supervised continuous moderate exercise training (CMT), and an unsupervised control group (CON). For 6 weeks, AIT exercised between 70 and 100% VO2peak, while CMT exercised between 60 and 70% VO2peak. Both groups followed a matched-work design. Thirty-three participants completed the study (age, 57.2 (9) years; weight, 67.6 (12) kg) with no adverse advents. Between-group baseline values were non-significant. VO2peak at baseline (25.3 (5.4) mL·kg(-1)·min(-1)) was below population norms. Compared to CON, cardiorespiratory fitness improved in AIT and CMT by 12% (P exercise groups. AIT had a greater influence on lower extremity strength (P = 0.026) and body weight (P = 0.031). This pilot study provides evidence that similar to CMT, AIT can safely increase VO2peak in a small group of breast cancer survivors. Further exploration of the benefits of implementing higher intensity training protocols is warranted.

  18. Sleep depth and continuity before and after chronic exercise in older men: electrophysiological evidence.

    Science.gov (United States)

    Melancon, Michel O; Lorrain, Dominique; Dionne, Isabelle J

    2015-03-01

    During later life sleep depth (slow-wave sleep, SWS) and maintenance exhibit deleterious changes, with possible negative effects on daytime function. This study assessed the effect of chronic, supervised exercise on sleep using laboratory-based polysomnography (PSG) and repeated measures in older adults. Thirteen men aged 64±3served as their own controls and had their sleep measured for a total of 6 nights: 3 before and 3 after the 16-week training intervention. Each sequence involved 1 familiarization trial followed by 2 experimental nights (exercise night; nonexercise night) measured using 13-channel PSG (combined electroencephalography, electromyography, and electro-oculography). The exercise challenges consisted of inclined treadmill brisk walking (60min, 68-69% V˙O2peak). The intervention successfully improved some parameters of aerobic fitness, i.e. ventilatory thresholds 1 and 2 (Pexercise triggered increases in circulating free fatty acids and lactate levels both at baseline and after the intervention (Pexercise following training resulted in a 71% increase in SWS during subsequent sleep in comparison with the nonexercise condition before training, respectively 2.4% and 1.4% (Pexercise reduced total wake time by 30% and REM onset latency by 14% (Pexercise improved sleep continuity by decreasing total wake time. These results show that aerobic training could increase sleep depth and continuity, during active days, in elderly men. In habitual exercisers, these effects of aerobic exercise on sleep, although modest, might counteract those resulting from aging. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. High-Intensity Interval Training Elicits Higher Enjoyment than Moderate Intensity Continuous Exercise.

    Directory of Open Access Journals (Sweden)

    Jacob S Thum

    Full Text Available Exercise adherence is affected by factors including perceptions of enjoyment, time availability, and intrinsic motivation. Approximately 50% of individuals withdraw from an exercise program within the first 6 mo of initiation, citing lack of time as a main influence. Time efficient exercise such as high intensity interval training (HIIT may provide an alternative to moderate intensity continuous exercise (MICT to elicit substantial health benefits. This study examined differences in enjoyment, affect, and perceived exertion between MICT and HIIT. Twelve recreationally active men and women (age = 29.5 ± 10.7 yr, VO2max = 41.4 ± 4.1 mL/kg/min, BMI = 23.1 ± 2.1 kg/m2 initially performed a VO2max test on a cycle ergometer to determine appropriate workloads for subsequent exercise bouts. Each subject returned for two additional exercise trials, performing either HIIT (eight 1 min bouts of cycling at 85% maximal workload (Wmax with 1 min of active recovery between bouts or MICT (20 min of cycling at 45% Wmax in randomized order. During exercise, rating of perceived exertion (RPE, affect, and blood lactate concentration (BLa were measured. Additionally, the Physical Activity Enjoyment Scale (PACES was completed after exercise. Results showed higher enjoyment (p = 0.013 in response to HIIT (103.8 ± 9.4 versus MICT (84.2 ± 19.1. Eleven of 12 participants (92% preferred HIIT to MICT. However, affect was lower (p<0.05 and HR, RPE, and BLa were higher (p<0.05 in HIIT versus MICT. Although HIIT is more physically demanding than MICT, individuals report greater enjoyment due to its time efficiency and constantly changing stimulus.NCT:02981667.

  20. High-Intensity Interval Training Elicits Higher Enjoyment than Moderate Intensity Continuous Exercise

    Science.gov (United States)

    Thum, Jacob S.; Parsons, Gregory; Whittle, Taylor

    2017-01-01

    Exercise adherence is affected by factors including perceptions of enjoyment, time availability, and intrinsic motivation. Approximately 50% of individuals withdraw from an exercise program within the first 6 mo of initiation, citing lack of time as a main influence. Time efficient exercise such as high intensity interval training (HIIT) may provide an alternative to moderate intensity continuous exercise (MICT) to elicit substantial health benefits. This study examined differences in enjoyment, affect, and perceived exertion between MICT and HIIT. Twelve recreationally active men and women (age = 29.5 ± 10.7 yr, VO2max = 41.4 ± 4.1 mL/kg/min, BMI = 23.1 ± 2.1 kg/m2) initially performed a VO2max test on a cycle ergometer to determine appropriate workloads for subsequent exercise bouts. Each subject returned for two additional exercise trials, performing either HIIT (eight 1 min bouts of cycling at 85% maximal workload (Wmax) with 1 min of active recovery between bouts) or MICT (20 min of cycling at 45% Wmax) in randomized order. During exercise, rating of perceived exertion (RPE), affect, and blood lactate concentration (BLa) were measured. Additionally, the Physical Activity Enjoyment Scale (PACES) was completed after exercise. Results showed higher enjoyment (p = 0.013) in response to HIIT (103.8 ± 9.4) versus MICT (84.2 ± 19.1). Eleven of 12 participants (92%) preferred HIIT to MICT. However, affect was lower (pHIIT versus MICT. Although HIIT is more physically demanding than MICT, individuals report greater enjoyment due to its time efficiency and constantly changing stimulus. Trial Registration: NCT:02981667. PMID:28076352

  1. Prolonged administration of recombinant human erythropoietin increases submaximal performance more than maximal aerobic capacity

    DEFF Research Database (Denmark)

    Thomsen, J J; Rentsch, R L; Robach, P

    2007-01-01

    The effects of recombinant human erythropoietin (rHuEpo) treatment on aerobic power (VO2max) are well documented, but little is known about the effects of rHuEpo on submaximal exercise performance. The present study investigated the effect on performance (ergometer cycling, 20-30 min at 80......HuEpo treatment VO2max increased (PVO2max) was increased by 54.0 and 54.3% (P... week 11), TTE was decreased by 26.8% as compared to pre rHuEpo administration. In conclusion, in healthy non-athlete subjects rHuEpo administration prolongs submaximal exercise performance by about 54% independently of the approximately 12% increase in VO2max....

  2. A Java-based enterprise system architecture for implementing a continuously supported and entirely Web-based exercise solution.

    Science.gov (United States)

    Wang, Zhihui; Kiryu, Tohru

    2006-04-01

    Since machine-based exercise still uses local facilities, it is affected by time and place. We designed a web-based system architecture based on the Java 2 Enterprise Edition that can accomplish continuously supported machine-based exercise. In this system, exercise programs and machines are loosely coupled and dynamically integrated on the site of exercise via the Internet. We then extended the conventional health promotion model, which contains three types of players (users, exercise trainers, and manufacturers), by adding a new player: exercise program creators. Moreover, we developed a self-describing strategy to accommodate a variety of exercise programs and provide ease of use to users on the web. We illustrate our novel design with examples taken from our feasibility study on a web-based cycle ergometer exercise system. A biosignal-based workload control approach was introduced to ensure that users performed appropriate exercise alone.

  3. Participation in water-exercising long-term after breast cancer surgery: Experiences of significant factors for continuing exercising as a part of cancer rehabilitation.

    Science.gov (United States)

    Enblom, A; Lindquist, H; Bergmark, K

    2017-08-15

    Although physical exercising has great benefits, little is known regarding factors of significance for cancer survivors to continue exercising within their rehabilitation. The objective was to describe factors experienced to be of significance for cancer survivors to continue with water-exercising long-term after breast cancer surgery. Women (n = 29) who had undergone breast cancer surgery (mastectomy 79%, axillary surgery 86%, and radiotherapy 86%) for median (md) 13 (25th-75th percentile 3-21.5) was followed up regarding their rehabilitation, arm function Disabilities of Arm Shoulder and Hand (md 14, IQR 7-32), EQ-5D score (md 0.8, IQR 0.73-1.0) and quality of life EQ health barometer (md 80, IQR 64-95). We performed qualitative focus-group interviews regarding the women's views (n = 24). The women had participated in water-exercising 1-46 semesters, md 8 (25th-75th percentile 3-21.5) semesters. Nearly all, 97%, participated in the water-exercising group every week, and 21 (72%) had participated in the water-exercising group at least half of the time since their breast cancer surgery, without complications. The women experienced that factors of significance to continue with water-exercising were the convenience of easily modified weightless exercising in the water, social interaction, and access to a private dressing room. These factors would be important to consider to encourage continuing in exercising. © 2017 John Wiley & Sons Ltd.

  4. Effect of continuous and intermittent bouts of isocaloric cycling and running exercise on excess postexercise oxygen consumption.

    Science.gov (United States)

    Cunha, Felipe A; Midgley, Adrian W; McNaughton, Lars R; Farinatti, Paulo T V

    2016-02-01

    The purpose of this study was to investigate excess postexercise oxygen consumption (EPOC) induced by isocaloric bouts of continuous and intermittent running and cycling exercise. This was a counterbalanced randomized cross-over study. Ten healthy men, aged 23-34yr, performed six bouts of exercise: (a) two maximal cardiopulmonary exercise tests for running and cycling to determine exercise modality-specific peak oxygen uptake (VO2peak); and (b) four isocaloric exercise bouts (two continuous bouts expending 400kcal and two intermittent bouts split into 2×200kcal) performed at 75% of the running and cycling oxygen uptake reserve. Exercise bouts were separated by 72h and performed in a randomized, counter-balanced order. The VO2 was monitored for 60-min postexercise and for 60-min during a control non-exercise day. The VO2 was significantly greater in all exercise conditions compared to the control session (PEPOC from the two intermittent bouts was significantly greater than that of the continuous cycling (mean difference=3.5L, P=0.001) and running (mean difference=6.4L, PEPOC, where running elicited a higher net EPOC than cycling (mean difference=2.2L, PEPOC compared to a continuous exercise bout of equivalent energy expenditure. Furthermore, the magnitude of EPOC was influenced by exercise modality, with the greatest EPOC occurring with isocaloric exercise involving larger muscle mass (i.e., treadmill running vs. cycling). Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  5. Growth hormone responses to continuous and intermittent exercise in females under oral contraceptive therapy.

    Science.gov (United States)

    Bernardes, R P; Radomski, M W

    1998-12-01

    In this study we investigated the effect of oral contraceptive (OC) use (OCU) and non-use (OCNU) on growth hormone (GH) responses to exercise in the same females (n = 7, age 22-31 years) during the normal course of OC therapy. Continuous (60% maximum oxygen consumption, VO2max for 20 min) and intermittent exercise (>80% VO2max) protocols of equal total duration, and similar external work were performed during phases of OCNU (days 3-5 of the menstrual cycle) and OCU (days 7-11). Levels of GH, lactate, 17 beta-estradiol, and progesterone were measured. Lactate responses were significantly greater (Pmenstrual cycle to benefit from an increased GH response to exercise during phases of OC use or the luteal phase of women not on OC therapy.

  6. A modified exercise protocol may promote continuance of exercise after the intervention in lung cancer patients—a pragmatic uncontrolled trial

    DEFF Research Database (Denmark)

    Andersen, Andreas H; Vinther, Anders; Poulsen, Lise-Lotte

    2013-01-01

    A previous study investigated the effects of a well-documented COPD exercise protocol in lung cancer patients. The study showed improvements in physical fitness, but poor adherence to continued exercise after intervention. The aim of the present study was to investigate the effect of a modified...... exercise intervention on post-intervention adherence, and physical fitness in a broad group of lung cancer patients....

  7. RELATIONSHIP BETWEEN THE MTI ACCELEROMETER (ACTIGRAPH COUNTS AND RUNNING SPEED DURING CONTINUOUS AND INTERMITTENT EXERCISE

    Directory of Open Access Journals (Sweden)

    Alain Durocher

    2005-12-01

    Full Text Available This study was designed to investigate the relationship between Actigraph counts and running speed; and to describe differences due to accelerometer position on the body and due to exercise modality. Eleven physical education students (age, 25.1 ± 3.7 years; height, 1.73 ± 0.10 m; body mass, 70.8 ± 10.8 kg completed two exhaustive exercise tests (continuous and intermittent, with MTI accelerometers mounted both at the hip and ankle. Exercise consisted of running for 3-min at incremental speeds until volitional exhaustion. During both exercise tests, the relationship between the ActiGraph outputs worn at the hip and speed was linear in the range 1.1 - 3.3 m·s-1 (r2 = 0.94 and 0.95, p 0.05. The ActiGraph seems to be a reliable tool for estimating a wide range of activity or exercise intensities. An ActiGraph worn at the ankle may be more appropriate to reflect normal human movement.

  8. Impaired Muscle Oxygenation and Elevated Exercise Blood Pressure in Hypertensive Patients: Links With Vascular Stiffness.

    Science.gov (United States)

    Dipla, Konstantina; Triantafyllou, Areti; Koletsos, Nikolaos; Papadopoulos, Stavros; Sachpekidis, Vasileios; Vrabas, Ioannis S; Gkaliagkousi, Eugenia; Zafeiridis, Andreas; Douma, Stella

    2017-08-01

    This study examined in vivo (1) skeletal muscle oxygenation and microvascular function, at rest and during handgrip exercise, and (2) their association with macrovascular function and exercise blood pressure (BP), in newly diagnosed, never-treated patients with hypertension and normotensive individuals. Ninety-one individuals (51 hypertensives and 40 normotensives) underwent office and 24-hour ambulatory BP, arterial stiffness, and central aortic BP assessment, followed by a 5-minute arterial occlusion and a 3-minute submaximal handgrip exercise. Changes in muscle oxygenated and deoxygenated hemoglobin and tissue oxygen saturation were continuously monitored by near-infrared spectroscopy and beat-by-beat BP by Finapres. Hypertensives had higher (Pexercising at the same submaximal intensity, hypertensives required a significantly greater (Pexercise. © 2017 American Heart Association, Inc.

  9. Short-term high-intensity interval and continuous moderate-intensity training improve maximal aerobic power and diastolic filling during exercise.

    Science.gov (United States)

    Esfandiari, Sam; Sasson, Zion; Goodman, Jack M

    2014-02-01

    This study examined the effects of short-term high-intensity interval training (HIT) and continuous moderate-intensity training (CMT) on cardiac function in young, healthy men. Sixteen previously untrained men (mean age of 25.1 ± 4.1 years) were randomly assigned to HIT and CMT (n = 8 each) and assessed before and after six sessions over a 12-day training period. HIT consisted of 8-12 intervals of cycling for 60 s at 95-100% of pre-training maximal aerobic power (VO(2max)), interspersed by 75 s of cycling at 10% VO(2max). CMT involved 90-120 min of cycling at 65% pre-training VO(2max). Left ventricular (LV) function was determined at rest and during submaximal exercise (heart rate ~105 bpm) using two-dimensional and Doppler echocardiography. Training resulted in increased calculated plasma volume (PV) in both groups, accompanied by improved VO(2max) in HIT (HIT: from 39.5 ± 7.1 to 43.9 ± 5.5 mL kg(-1) min(-1); CMT: from 39.9 ± 5.9 to 41.7 ± 5.3 mL kg(-1) min(-1); P volume (P = 0.02) and cardiac output (P = 0.02) were observed, secondary to increases in end-diastolic volume (P training groups and were related to changes in PV. Short-term HIT and CMT elicit rapid improvements in VO2max and LV filling without global changes in cardiac performance at rest.

  10. Interval and continuous exercise enhances aerobic capacity and hemodynamic function in CHF rats.

    Science.gov (United States)

    Nunes, Ramiro B; Alves, Jadson P; Kessler, Luíza P; Dornelles, André Z; Stefani, Giuseppe P; Lago, Pedro D

    2015-09-01

    The aim of the present study was to compare the effects of continuous versus interval aerobic exercise training on hemodynamic parameters, cardiac remodeling, and maximal exercise capacity (MEC) in chronic heart failure (CHF) rats. Twenty-four male Wistar rats were subjected to myocardial infarction (MI) surgery. Five weeks post MI, the animals were assigned to one of three groups: sedentary group (CHF-Sed, n=8), aerobic continuous training group (CHF-ACT, n=8), and aerobic interval training group (CHF-AIT, n=8). Treadmill training was performed five times a week for 8 weeks (ACT: 50 min/day at 15 m/min and AIT: 40 min/day with 8 min of warm-up at 10 m/min and exercise at 15 m/min 4×4 min interspersed with 4×4 min at 23 m/min). MEC was evaluated pre and post exercise program. Left ventricular end-diastolic pressure (LVEDP), left ventricular mass/body mass ratio (LVM:BM), and total collagen volume fraction were lower in the trained groups compared with the sedentary group, but no difference was found between the trained groups. Systolic ventricular pressure (SVP) and maximum positive derivative of LV pressure (+dP/dtmax) were higher in the trained groups, but CHF-ACT showed higher +dP/dtmax compared to CHF-AIT. Both training regimens were able to increase MEC. However, the aerobic interval training was superior for improving MEC. Aerobic training is an important intervention to improve cardiac function and remodeling and physical capacity in CHF rats. Interval training is a potential strategy to maximize the results, but exercise type and intensity are still topics to be explored.

  11. Interval and continuous exercise enhances aerobic capacity and hemodynamic function in CHF rats

    Directory of Open Access Journals (Sweden)

    Ramiro B. Nunes

    2015-08-01

    Full Text Available OBJECTIVE: The aim of the present study was to compare the effects of continuous versus interval aerobic exercise training on hemodynamic parameters, cardiac remodeling, and maximal exercise capacity (MEC in chronic heart failure (CHF rats.METHOD: Twenty-four male Wistar rats were subjected to myocardial infarction (MI surgery. Five weeks post MI, the animals were assigned to one of three groups: sedentary group (CHF-Sed, n=8, aerobic continuous training group (CHF-ACT, n=8, and aerobic interval training group (CHF-AIT, n=8. Treadmill training was performed five times a week for 8 weeks (ACT: 50 min/day at 15 m/min and AIT: 40 min/day with 8 min of warm-up at 10 m/min and exercise at 15 m/min 4×4 min interspersed with 4×4 min at 23 m/min. MEC was evaluated pre and post exercise program.RESULTS: Left ventricular end-diastolic pressure (LVEDP, left ventricular mass/body mass ratio (LVM:BM, and total collagen volume fraction were lower in the trained groups compared with the sedentary group, but no difference was found between the trained groups. Systolic ventricular pressure (SVP and maximum positive derivative of LV pressure (+dP/dtmax were higher in the trained groups, but CHF-ACT showed higher +dP/dtmax compared to CHF-AIT. Both training regimens were able to increase MEC. However, the aerobic interval training was superior for improving MEC.CONCLUSION: Aerobic training is an important intervention to improve cardiac function and remodeling and physical capacity in CHF rats. Interval training is a potential strategy to maximize the results, but exercise type and intensity are still topics to be explored.

  12. Hybrid diffuse optical techniques for continuous hemodynamic measurement in gastrocnemius during plantar flexion exercise

    Science.gov (United States)

    Henry, Brad; Zhao, Mingjun; Shang, Yu; Uhl, Timothy; Thomas, D. Travis; Xenos, Eleftherios S.; Saha, Sibu P.; Yu, Guoqiang

    2015-12-01

    Occlusion calibrations and gating techniques have been recently applied by our laboratory for continuous and absolute diffuse optical measurements of forearm muscle hemodynamics during handgrip exercises. The translation of these techniques from the forearm to the lower limb is the goal of this study as various diseases preferentially affect muscles in the lower extremity. This study adapted a hybrid near-infrared spectroscopy and diffuse correlation spectroscopy system with a gating algorithm to continuously quantify hemodynamic responses of medial gastrocnemius during plantar flexion exercises in 10 healthy subjects. The outcomes from optical measurement include oxy-, deoxy-, and total hemoglobin concentrations, blood oxygen saturation, and relative changes in blood flow (rBF) and oxygen consumption rate (rV˙O2). We calibrated rBF and rV˙O2 profiles with absolute baseline values of BF and V˙O2 obtained by venous and arterial occlusions, respectively. Results from this investigation were comparable to values from similar studies. Additionally, significant correlation was observed between resting local muscle BF measured by the optical technique and whole limb BF measured concurrently by a strain gauge venous plethysmography. The extensive hemodynamic and metabolic profiles during exercise will allow for future comparison studies to investigate the diagnostic value of hybrid technologies in muscles affected by disease.

  13. Accuracy of continuous glucose monitoring during exercise in type 1 diabetes pregnancy.

    Science.gov (United States)

    Kumareswaran, Kavita; Elleri, Daniela; Allen, Janet M; Caldwell, Karen; Nodale, Marianna; Wilinska, Malgorzata E; Amiel, Stephanie A; Hovorka, Roman; Murphy, Helen R

    2013-03-01

    Performance of continuous glucose monitors (CGMs) may be lower when glucose levels are changing rapidly, such as occurs during physical activity. Our aim was to evaluate accuracy of a current-generation CGM during moderate-intensity exercise in type 1 diabetes (T1D) pregnancy. As part of a study of 24-h closed-loop insulin delivery in 12 women with T1D (disease duration, 17.6 years; glycosylated hemoglobin, 6.4%) during pregnancy (gestation, 21 weeks), we evaluated the Freestyle Navigator(®) sensor (Abbott Diabetes Care, Alameda, CA) during afternoon (15:00-18:00 h) and morning (09:30-12:30 h) exercise (55 min of brisk walking on a treadmill followed by a 2-h recovery), compared with sedentary conditions (18:00-09:00 h). Plasma (reference) glucose, measured at regular 15-30-min intervals with the YSI Ltd. (Fleet, United Kingdom) model YSI 2300 analyzer, was used to assess CGM performance. Sensor accuracy, as indicated by the larger relative absolute difference (RAD) between paired sensor and reference glucose values, was lower during exercise compared with rest (median RAD, 11.8% vs. 18.4%; Pexercise (median RAD, 32.1%) conditions. Using Clarke error grid analysis, 96% of CGM values were clinically safe under resting conditions compared with only 87% during exercise. Compared with sedentary conditions, accuracy of the Freestyle Navigator CGM was lower during moderate-intensity exercise in pregnant women with T1D. This difference was particularly marked in hypoglycemia and could not be solely explained by the glucose rate of change associated with physical activity.

  14. Effects of interval and continuous exercise training on autonomic cardiac function in COPD patients.

    Science.gov (United States)

    Rodríguez, Diego A; Arbillaga, Ane; Barberan-Garcia, Anael; Ramirez-Sarmiento, Alba; Torralba, Yolanda; Vilaró, Jordi; Gimeno-Santos, Elena; Gea, Joaquim; Orozco-Levi, Mauricio; Roca, Josep; Marco, Ester

    2016-01-01

    Both interval (IT) and continuous (CT) exercise training results in an improvement of aerobic capacity in patients with chronic obstructive pulmonary disease (COPD); however, their effects on cardiac autonomic function remains unclear. The aim of our study was to evaluate the effect of a supervised CT vs IT on autonomic cardiac function in COPD patients. COPD patients were divided into two different groups according to training modality (IT or CT). Autonomic cardiac dysfunction (ACD) was defined as a heart rate recovery lower than 12 bpm heart rate after the first minute of maximal exercise (HRR1 ) and an abnormal chronotropic response (CR) to exercise (age: 68 (8) years, %FEV1 : 42 (13) predicted} were trained (15 subjects in the CT group, 14 subjects in the IT group). After training, both groups increased peak oxygen consumption [mean difference ΔVO2 peak: 156 mL/min (P = 0.04) on IT; and 210 mL/min (P = 0.01) on CT], HRR1 [IT, from 10.4 (5) to 13.8 (5) bpm (P = 0.04); and CT, from 14.3 (5) to 17.7 (5) bpm (P = 0.04)] and CR [IT, from 57% (22) to 81% (9) (P = 0.001); and CT, from 48% (28) to 73% (17) (P = 0.001)]. Sixteen patients showed ACD. Among these patients, HRR1 (P = 0.01 for IT and P = 0.04 for CT) and CR (P = 0.001 for IT and P = 0.002 for CT) were enhanced after training. Both IT and CT exercise training improve heart rate recovery and CR in COPD patients. These benefits could help to individualize exercise training. © 2014 John Wiley & Sons Ltd.

  15. Global Metabolic Stress of Isoeffort Continuous and High Intensity Interval Aerobic Exercise: A Comparative (1)H NMR Metabonomic Study.

    Science.gov (United States)

    Zafeiridis, Andreas; Chatziioannou, Anastasia Chrysovalantou; Sarivasiliou, Haralambos; Kyparos, Antonios; Nikolaidis, Michalis G; Vrabas, Ioannis S; Pechlivanis, Alexandros; Zoumpoulakis, Panagiotis; Baskakis, Constantinos; Dipla, Konstantina; Theodoridis, Georgios A

    2016-12-02

    The overall metabolic/energetic stress that occurs during an acute bout of exercise is proposed to be the main driving force for long-term training adaptations. Continuous and high-intensity interval exercise protocols (HIIE) are currently prescribed to acquire the muscular and metabolic benefits of aerobic training. We applied (1)H NMR-based metabonomics to compare the overall metabolic perturbation and activation of individual bioenergetic pathways of three popular aerobic exercises matched for effort/strain. Nine men performed continuous, long-interval (3 min), and short-interval (30 s) bouts of exercise under isoeffort conditions. Blood was collected before and after exercise. The multivariate PCA and OPLS-DA models showed a distinct separation of pre- and postexercise samples in three protocols. The two models did not discriminate the postexercise overall metabolic profiles of the three exercise types. Analysis focused on muscle bioenergetic pathways revealed an extensive upregulation of carbohydrate-lipid metabolism and the TCA cycle in all three protocols; there were only a few differences among protocols in the postexercise abundance of molecules when long-interval bouts were performed. In conclusion, continuous and HIIE exercise protocols, when performed with similar effort/strain, induce comparable global metabolic response/stress despite their marked differences in work-bout intensities. This study highlights the importance of NMR metabonomics in comprehensive monitoring of metabolic consequences of exercise training in the blood of athletes and exercising individuals.

  16. The effect of continuous aerobic exercise on premenstrual syndrome: a randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Mosallanejad Z

    2007-11-01

    Full Text Available Background: Premenstrual syndrome is one of the most incidencial problems in women's during reproductive age. That effect personal performance in family and society status. Varied therapeutic treatment has been studied for its promotion. The main attention was to find a method without complications. This study performed with aim of assessing effect of one period of continuous aerobic exercise on premenstrual syndrome in 18-25 years female students in jahrom medical school."nMethods: This study was a kind of semi experimental study with two group plane. Forty students were assessed for premenstrual syndrome with regular mense, without previous history of Diabetes mellitus and Thyroid, Gynecologic and psychological disease. Twenty subjects (with similar VO2 MAX were selected and randomly divided to two experimental and control groups. Data gathering was from ILPDD questionnaire concluded 11 question about signs and symptoms of mental and physical complain related to premenstrual syndrome that filled by samples. All samples have positive five complain that four of them depend on mental symptoms of premenstrual syndrome. Intensity of quantity of premenstrual syndrome and levels of estrogen and progesterone were measured. Then, exercise regime including continuous aerobic exercise, were performed for eight weeks, with frequency of three sessions every week. At the end of 8th week, posttests were repeated in the situation similar to pretest. Analytic statistic as a Nonparametric Mann-whitney test, and nonparametric Wilcoxon signed ranks test was used for comparing variables."nResults: This study showed that after two method of aerobic exercise, somatic and effective complain was decrease in case group (p>0.05. Hormonal change in two groups was not significant."nConclusion: Releaving aerobic experiences is effective for somatic and affective complains secondary to premenstrual syndrome and this plan can be replace by other methods of medical

  17. The Effect of One Session Continuous and Intermittent Aerobic Exercise on Blood Responses of HSP72 , Cortisol and Creatine Kinase

    Directory of Open Access Journals (Sweden)

    M. Amani

    2013-10-01

    Full Text Available Introduction & Objective: Heat shock proteins help the cells’ ability to keep their structures against different stresses. The purpose of this study was to investigate the effect of one ses-sion continuous and intermittent aerobic exercise on blood responses of HSP72, cortisol and creatine kinase (CK. Materials & Methods: This study is semi-experimental in which 21 male student athletes were divided in continuous group (n=7, intermittent group (n=7 and control group (n=7. Exer-cise protocol of continuous group included 1 hour running with 80% maximum heart rate in-tensity and that of intermittent group was 3 stages of 20 minute running with the same inten-sity as of continuous group . Blood sampling of basal, pre exercise, immediately after exer-cise and 90 minutes after exercise were gathered and the amounts of HSP72, cortisol and CK, were measured by ELISA, RIA and Enzymatic methods respectively. The data was analyzed with one way ANOVA and repeated measure analysis of variance at P?0.05 significance level. Results: HSP72 levels in the continuous group and intermittent group despite an increase in the average did not show a statistically significant difference. Changes between the groups were significant in immediately after exercise and 90 minutes after exercise (P.values respectively 0.017 and 0.002. CK changes in continuous group were significant but cortisol changes in different stages hadn’t significant difference Conclusion: Exercise with its role associated with cortisol and CK will stimulate HSP72 and continuous exercise will make further increase in HSP72 and CK increasing leads to a greater HSP72 response. (Sci J Hamadan Univ Med Sci 2013; 20 (3:223-231

  18. Continuous Exercise but Not High Intensity Interval Training Improves Fat Distribution in Overweight Adults

    Directory of Open Access Journals (Sweden)

    Shelley E. Keating

    2014-01-01

    Full Text Available Objective. The purpose of this study was to assess the effect of high intensity interval training (HIIT versus continuous aerobic exercise training (CONT or placebo (PLA on body composition by randomized controlled design. Methods. Work capacity and body composition (dual-energy X-ray absorptiometry were measured before and after 12 weeks of intervention in 38 previously inactive overweight adults. Results. There was a significant group × time interaction for change in work capacity (P<0.001, which increased significantly in CONT (23.8±3.0% and HIIT (22.3±3.5% but not PLA (3.1±5.0%. There was a near-significant main effect for percentage trunk fat, with trunk fat reducing in CONT by 3.1±1.6% and in PLA by 1.1±0.4%, but not in HIIT (increase of 0.7±1.0% (P=0.07. There was a significant reduction in android fat percentage in CONT (2.7±1.3% and PLA (1.4±0.8% but not HIIT (increase of 0.8±0.7% (P=0.04. Conclusion. These data suggest that HIIT may be advocated as a time-efficient strategy for eliciting comparable fitness benefits to traditional continuous exercise in inactive, overweight adults. However, in this population HIIT does not confer the same benefit to body fat levels as continuous exercise training.

  19. Hypotensive effects of resistance exercise with continuous and intermittent blood flow restriction

    Directory of Open Access Journals (Sweden)

    Gabriel Rodrigues Neto

    Full Text Available Abstract The aim of this study was to compare the acute effects of low-intensity (LI resistance exercise (RE with continuous blood flow restriction (CBFR and intermittent blood flow restriction (IBFR on systolic blood pressure (SBP, diastolic blood pressure (DBP, and mean arterial pressure (MAP. After a one-repetition maximum test, 10 normotensive recreationally trained men performed three experimental protocols. In the three RE protocols, increases in SBP, DBP, and MAP were observed immediately after exercise, but the effect sizes (ESs were greater for the LI + CBFR and high-intensity protocols. There were hypotensive effects on SBP, DBP, and MAP in all three protocols; however, the effects on MAP lasted longer for the LI + IBFR and LI + CBFR protocols. These long-lasting hypotensive effects on DBP and MAP occurred in all three protocols. Thus, we conclude that the post exercise hypotensive effects on SBP, DBP, and MAP appear to occur in all three RE protocols, with the effect on SBP being longer in the LI + IBFR and LI + CBFR protocols.

  20. Low doses of caffeine reduce heart rate during submaximal cycle ergometry

    Directory of Open Access Journals (Sweden)

    Wetter Thomas J

    2007-10-01

    Full Text Available Abstract Background The purpose of this study was to examine the cardiovascular effects of two low-levels of caffeine ingestion in non habitual caffeine users at various submaximal and maximal exercise intensities. Methods Nine male subjects (19–25 yr; 83.3 ± 3.1 kg; 184 ± 2 cm, underwent three testing sessions administered in a randomized and double-blind fashion. During each session, subjects were provided 4 oz of water and a gelatin capsule containing a placebo, 1.5 mg/kg caffeine, or 3.0 mg/kg caffeine. After thirty minutes of rest, a warm-up (30 Watts for 2 min the pedal rate of 60 rpm was maintained at a steady-state output of 60 watts for five minutes; increased to 120 watts for five minutes and to 180 watts for five minutes. After a 2 min rest the workload was 180 watts for one minute and increased by 30 watts every minute until exhaustion. Heart rate (HR was measured during the last 15-seconds of each minute of submaximal exercise. Systolic blood pressure (BP was measured at rest and during each of the three sub-maximal steady state power outputs. Minute ventilation (VE, Tidal volume (VT, Breathing frequency (Bf, Rating of perceived exertion (RPE, Respiratory exchange ratio (RER, and Oxygen consumption (VO2 were measured at rest and during each minute of exercise. Results Caffeine at 1.5 and 3.0 mg/kg body weight significantly lowered (p E, VT, VO2, RPE, maximal power output or time to exhaustion. Conclusion In non habitual caffeine users it appears that consuming a caffeine pill (1.5 & 3.0 mg/kg at a dose comparable to 1–3 cups of coffee lowers heart rate during submaximal exercise but not at near maximal and maximal exercise. In addition, this caffeine dose also only appears to affect systolic blood pressure at rest but not during cycling exercise.

  1. Effects of Dietary Acid Load on Exercise Metabolism and Anaerobic Exercise Performance

    Directory of Open Access Journals (Sweden)

    Susan L. Caciano, Cynthia L. Inman, Elizabeth E. Gockel-Blessing, Edward P. Weiss

    2015-06-01

    Full Text Available Dietary acid load, quantified as the potential renal acid load (PRAL of the diet, affects systemic pH and acid-base regulation. In a previous cross-sectional study, we reported that a low dietary PRAL (i.e. alkaline promoting diet is associated with higher respiratory exchange ratio (RER values during maximal exercise. The purpose of the present study was to confirm the previous findings with a short-term dietary intervention study. Additionally, we sought to determine if changes in PRAL affects submaximal exercise RER (as a reflection of substrate utilization and anaerobic exercise performance. Subjects underwent a graded treadmill exercise test (GXT to exhaustion and an anaerobic exercise performance test on two occasions, once after following a low-PRAL diet and on a separate occasion, after a high-PRAL diet. The diets were continued as long as needed to achieve an alkaline or acid fasted morning urine pH, respectively, with all being 4-9 days in duration. RER was measured during the GXT with indirect calorimetry. The anaerobic performance test was a running time-to-exhaustion test lasting 1-4 min. Maximal exercise RER was lower in the low-PRAL trial compared to the high-PRAL trial (1.10 ± 0.02 vs. 1.20 ± 0.05, p = 0.037. The low-PRAL diet also resulted in a 21% greater time to exhaustion during anaerobic exercise (2.56 ± 0.36 vs. 2.11 ± 0.31 sec, p = 0.044 and a strong tendency for lower RER values during submaximal exercise at 70% VO2max (0.88 ± 0.02 vs. 0.96 ± 0.04, p = 0.060. Contrary to our expectations, a short-term low-PRAL (alkaline promoting diet resulted in lower RER values during maximal-intensity exercise. However, the low-PRAL diet also increased anaerobic exercise time to exhaustion and appears to have shifted submaximal exercise substrate utilization to favor lipid oxidation and spare carbohydrate, both of which would be considered favorable effects in the context of exercise performance.

  2. [Comparison of submaximal front crawl and breast stroke swimming in relation to energy expenditure].

    Science.gov (United States)

    Sugiyama, K; Katamoto, S

    1992-11-01

    The purpose of this study was to compare the energy expenditure during submaximal front crawl (Fr) and breast stroke (Br) swimming. Six male college swimmers performed submaximal and maximal exercise tests in both styles in a swimming flume. In submaximal exercise tests, they swam at the following given velocities for 5 min, Br: 0.3, 0.5 and 0.7 m/sec; Fr: 0.3, 0.5, 0.7 and 0.9 m/sec. In maximal exercise tests, following submaximal swimming at 0.9 m/sec in Br and 1.1 m/sec in Fr, swimming velocity was increased progressively by 0.1 m/sec every 1 min until the subjects reached to voluntary exhaustion. VO2max obtained from the maximal swimming tests in Br and Fr were 4.27 and 4.18 l/min, respectively. And there was no significant difference between these two values. VO2 during Br and Fr swimming at four and five submaximal velocities were 1.06, 1.30, 1.79, 2.65 l/min and 1.17, 1.34, 1.63, 2.04, 3.05 l/min, respectively. And, it was found that VO2 at 0.3 and 0.9 m/sec were significantly different (p styles curvilinearly increased with swimming velocity, and these relationships were well fitted for the regression equation of the second order (Br: y = 3.84625x2 - 1.95914x + 1.310463,r2 = 0.999 (p < 0.05), Fr: y = 3.233446x2 - 2.28136x + 1.611524, r2 = 0.979 (p < 0.05)). It was calculated that the two curves crossed at a point on 0.49 m/sec, and that VO2 at this point was 1.27 l/min. This value equivalented to 30.4% VO2max in Br and 29.7% VO2max in Fr.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Exercises

    Science.gov (United States)

    ... exercising. Count out loud as you do the exercises. View Chronic Obstructive Pulmonary Disease (COPD) Home Techniques to ... Intimacy Importance of Being Together Body Changes with Age Communicating with Your Partner Exercise and Sexual Activity Less Strenuous Positions for Sexual ...

  4. The Effect of an Acute Bout of Moderate-Intensity Aerobic Exercise on Motor Learning of a Continuous Tracking Task.

    Science.gov (United States)

    Snow, Nicholas J; Mang, Cameron S; Roig, Marc; McDonnell, Michelle N; Campbell, Kristin L; Boyd, Lara A

    2016-01-01

    There is evidence for beneficial effects of acute and long-term exercise interventions on several forms of memory, including procedural motor learning. In the present study we examined how performing a single bout of continuous moderate intensity aerobic exercise would impact motor skill acquisition and retention in young healthy adults, compared to a period of rest. We hypothesized that exercise would improve motor skill acquisition and retention, compared to motor practice alone. Sixteen healthy adults completed sessions of aerobic exercise or seated rest that were immediately followed by practice of a novel motor task (practice). Exercise consisted of 30 minutes of continuous cycling at 60% peak O2 uptake. Twenty-four hours after practice, we assessed motor learning with a no-exercise retention test (retention). We also quantified changes in offline motor memory consolidation, which occurred between practice and retention (offline). Tracking error was separated into indices of temporal precision and spatial accuracy. There were no differences between conditions in the timing of movements during practice (p = 0.066), at retention (p = 0.761), or offline (p = 0.966). However, the exercise condition enabled participants to maintain spatial accuracy during practice (p = 0.477); whereas, following rest performance diminished (p = 0.050). There were no significant differences between conditions at retention (p = 0.532) or offline (p = 0.246). An acute bout of moderate-intensity aerobic exercise facilitated the maintenance of motor performance during skill acquisition, but did not influence motor learning. Given past work showing that pairing high intensity exercise with skilled motor practice benefits learning, it seems plausible that intensity is a key modulator of the effects of acute aerobic exercise on changes in complex motor behavior. Further work is necessary to establish a dose-response relationship between aerobic exercise and motor learning.

  5. Effects of music tempo upon submaximal cycling performance.

    Science.gov (United States)

    Waterhouse, J; Hudson, P; Edwards, B

    2010-08-01

    In an in vivo laboratory controlled study, 12 healthy male students cycled at self-chosen work-rates while listening to a program of six popular music tracks of different tempi. The program lasted about 25 min and was performed on three occasions--unknown to the participants, its tempo was normal, increased by 10% or decreased by 10%. Work done, distance covered and cadence were measured at the end of each track, as were heart rate and subjective measures of exertion, thermal comfort and how much the music was liked. Speeding up the music program increased distance covered/unit time, power and pedal cadence by 2.1%, 3.5% and 0.7%, respectively; slowing the program produced falls of 3.8%, 9.8% and 5.9%. Average heart rate changes were +0.1% (faster program) and -2.2% (slower program). Perceived exertion and how much the music was liked increased (faster program) by 2.4% and 1.3%, respectively, and decreased (slower program) by 3.6% and 35.4%. That is, healthy individuals performing submaximal exercise not only worked harder with faster music but also chose to do so and enjoyed the music more when it was played at a faster tempo. Implications of these findings for improving training regimens are discussed.

  6. Effects of Continuous and Accumulated Exercise on Endothelial Function in Rat Aorta.

    Science.gov (United States)

    Martinez, Juliana Edwiges; Taipeiro, Elane de Fátima; Chies, Agnaldo Bruno

    2017-04-01

    The practice of exercise in short bouts repeated throughout the day may be an alternative strategy to lift people out of physical inactivity. to evaluate if accumulated exercise, as occurs in continuous exercise training, improve endothelial function in rat aorta. Wistar male rats were divided into three groups: continuous exercise (CEx, 1 hour on the treadmill) or accumulated exercise (AEx, 4 bouts of 15 minutes / day) for 5 days/week for 8 weeks, or sedentary (SED). During the training period, body weight gain and increase in exercise performance were recorded. On sacrifice day, aorta was dissected into rings (3-5 mm) and mounted on the organ bath. Fitness was significantly greater in CEx and AEx rats as compared with SED animals. In addition, compared with the SED group, CEx animals had a lower body mass gain, and the aorta obtained from these animals had reduced contractile response to norepinephrine and greater acetylcholine-induced relaxation. These results were not observed in ACEx animals. Both CEx and AEx improved fitness, but only CEx led to reduced body weight gain and improved endothelial function. A prática de exercícios em sessões curtas que se repetem ao longo do dia pode ser uma alternativa para tirar as pessoas da inatividade física. Verificar se o exercício acumulado, tal como ocorre com o treinamento com exercício contínuo, melhora a função endotelial na aorta de ratos. Ratos Wistar machos foram divididos em 3 grupos: treinamento com exercício contínuo (ExC; 1 hora em esteira) ou com exercício acumulado (ExA; 4 sessões de 15 minutos ao longo do dia) por 5 dias/semana, durante 8 semanas, ou grupo sedentário (SED). Durante o treinamento, foram registrados o ganho de peso corporal e desempenho na esteira. No dia do sacrifício, anéis (3-5 mm) da aorta foram obtidos e montados em banho de órgãos. Animais ExC e ExA mostraram aptidão física significativamente maior em comparação com os SED. Paralelamente, em comparação com SED

  7. Effect of inspiratory muscle warm-up on submaximal rowing performance.

    Science.gov (United States)

    Arend, Mati; Mäestu, Jarek; Kivastik, Jana; Rämson, Raul; Jürimäe, Jaak

    2015-01-01

    Performing inspiratory muscle warm-up might increase exercise performance. The aim of this study was to investigate the impact of inspiratory muscle warm-up to submaximal rowing performance and to find if there is an effect on lactic acid accumulation and breathing parameters. Ten competitive male rowers aged between 19 and 27 years (age, 23.1 ± 3.8 years; height, 188.1 ± 6.3 cm; body mass, 85.6 ± 6.6 kg) were tested 3 times. During the first visit, maximal inspiratory pressure (MIP) assessment and the incremental rowing test were performed to measure maximal oxygen consumption and maximal aerobic power (Pamax). A submaximal intensity (90% Pamax) rowing test was performed twice with the standard rowing warm-up as test 1 and with the standard rowing warm-up and specific inspiratory muscle warm-up as test 2. During the 2 experimental tests, distance, duration, heart rate, breathing frequency, ventilation, peak oxygen consumption, and blood lactate concentration were measured. The only value that showed a significant difference between the test 1 and test 2 was breathing frequency (52.2 ± 6.8 vs. 53.1 ± 6.8, respectively). Heart rate and ventilation showed a tendency to decrease and increase, respectively, after the inspiratory muscle warm-up (p < 0.1). Despite some changes in respiratory parameters, the use of 40% MIP intensity warm-up is not suggested if the mean intensity of the competition is at submaximal level (at approximately 90% maximal oxygen consumption). In conclusion, the warm-up protocol of the respiratory muscles used in this study does not have a significant influence on submaximal endurance performance in highly trained male rowers.

  8. Effect of task-related continuous auditory feedback during learning of tracking motion exercises

    Directory of Open Access Journals (Sweden)

    Rosati Giulio

    2012-10-01

    Full Text Available Abstract Background This paper presents the results of a set of experiments in which we used continuous auditory feedback to augment motor training exercises. This feedback modality is mostly underexploited in current robotic rehabilitation systems, which usually implement only very basic auditory interfaces. Our hypothesis is that properly designed continuous auditory feedback could be used to represent temporal and spatial information that could in turn, improve performance and motor learning. Methods We implemented three different experiments on healthy subjects, who were asked to track a target on a screen by moving an input device (controller with their hand. Different visual and auditory feedback modalities were envisaged. The first experiment investigated whether continuous task-related auditory feedback can help improve performance to a greater extent than error-related audio feedback, or visual feedback alone. In the second experiment we used sensory substitution to compare different types of auditory feedback with equivalent visual feedback, in order to find out whether mapping the same information on a different sensory channel (the visual channel yielded comparable effects with those gained in the first experiment. The final experiment applied a continuously changing visuomotor transformation between the controller and the screen and mapped kinematic information, computed in either coordinate system (controller or video, to the audio channel, in order to investigate which information was more relevant to the user. Results Task-related audio feedback significantly improved performance with respect to visual feedback alone, whilst error-related feedback did not. Secondly, performance in audio tasks was significantly better with respect to the equivalent sensory-substituted visual tasks. Finally, with respect to visual feedback alone, video-task-related sound feedback decreased the tracking error during the learning of a novel

  9. Effect of task-related continuous auditory feedback during learning of tracking motion exercises

    Science.gov (United States)

    2012-01-01

    Background This paper presents the results of a set of experiments in which we used continuous auditory feedback to augment motor training exercises. This feedback modality is mostly underexploited in current robotic rehabilitation systems, which usually implement only very basic auditory interfaces. Our hypothesis is that properly designed continuous auditory feedback could be used to represent temporal and spatial information that could in turn, improve performance and motor learning. Methods We implemented three different experiments on healthy subjects, who were asked to track a target on a screen by moving an input device (controller) with their hand. Different visual and auditory feedback modalities were envisaged. The first experiment investigated whether continuous task-related auditory feedback can help improve performance to a greater extent than error-related audio feedback, or visual feedback alone. In the second experiment we used sensory substitution to compare different types of auditory feedback with equivalent visual feedback, in order to find out whether mapping the same information on a different sensory channel (the visual channel) yielded comparable effects with those gained in the first experiment. The final experiment applied a continuously changing visuomotor transformation between the controller and the screen and mapped kinematic information, computed in either coordinate system (controller or video), to the audio channel, in order to investigate which information was more relevant to the user. Results Task-related audio feedback significantly improved performance with respect to visual feedback alone, whilst error-related feedback did not. Secondly, performance in audio tasks was significantly better with respect to the equivalent sensory-substituted visual tasks. Finally, with respect to visual feedback alone, video-task-related sound feedback decreased the tracking error during the learning of a novel visuomotor perturbation, whereas

  10. Cardiovascular adaptation in people with multiple sclerosis following a twelve week exercise programme suggest deconditioning rather than autonomic dysfunction caused by the disease. Results from a randomized controlled trial.

    Science.gov (United States)

    Feltham, M G; Collett, J; Izadi, H; Wade, D T; Morris, M G; Meaney, A J; Howells, K; Sackley, C; Dawes, H

    2013-12-01

    Guidelines for optimal exercise doses in people with multiple sclerosis (MS) have to be established. We need to ascertain the basic physiological and perceptual response and adaptation to different exercise doses in this clinical population. The aim of this paper was to explore the response during maximal and sub-maximal exercise in people with MS prior to and following two different twelve week exercise programmes. Sub-analysis of per protocol exercise data of a two group, single blinded, randomised control trial. Multicentre (community leisure and rehabilitation centres). Participants with MS assigned to a continuous (N.=12; mean±SE age=52.3±2.08; Barthel index median & range=19&13-20) or interval (N.=9; mean±SE age=49.3±3.5; Barthel index median & range=19&18-20) exercise programme. Cardiovascular, respiratory and perceptual exercise response and adaption was measured at maximal and sub-maximal levels of physical exercise prior to and following a twelve week exercise programme, delivered at different intensities. Irrespective of the type of exercise programme followed, there was a significant increase in peak power (z=-1.98; P=0.05) and normalised oxygen uptake during unloaded cycling (z =-2.00; P=0.05). At discharge from the exercise programmes, the cardiovascular response to sub-maximal exercise had significantly changed (t(360) =-4.62; pphysical exercise following a twelve week programme is analogous to non-diseased adults. Cardiovascular adaptation in people with MS following a twelve week exercise programme suggests deconditioning rather than autonomic dysfunction caused by the disease.

  11. The effects of interval- vs. continuous exercise on excess post-exercise oxygen consumption and substrate oxidation rates in subjects with type 2 diabetes.

    Science.gov (United States)

    Karstoft, Kristian; Wallis, Gareth A; Pedersen, Bente K; Solomon, Thomas P J

    2016-09-01

    For unknown reasons, interval training often reduces body weight more than energy-expenditure matched continuous training. We compared the acute effects of time-duration and oxygen-consumption matched interval- vs. continuous exercise on excess post-exercise oxygen consumption (EPOC), substrate oxidation rates and lipid metabolism in the hours following exercise in subjects with type 2 diabetes (T2D). Following an overnight fast, ten T2D subjects (M/F: 7/3; age=60.3±2.3years; body mass index (BMI)=28.3±1.1kg/m(2)) completed three 60-min interventions in a counterbalanced, randomized order: 1) control (CON), 2) continuous walking (CW), 3) interval-walking (IW - repeated cycles of 3min of fast and 3min of slow walking). Indirect calorimetry was applied during each intervention and repeatedly for 30min per hour during the following 5h. A liquid mixed meal tolerance test (MMTT, 450kcal) was consumed by the subjects 45min after completion of the intervention with blood samples taken regularly. Exercise interventions were successfully matched for total oxygen consumption (CW=1641±133mL/min; IW=1634±126mL/min, P>0.05). EPOC was higher after IW (8.4±1.3l) compared to CW (3.7±1.4l, PEPOC than oxygen-consumption matched continuous exercise during a post-exercise MMTT in subjects with T2D, whereas effects on substrate oxidation and lipid metabolism are comparable. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Comparing interval and continuous exercise training regimens on neurotrophic factors in rat brain.

    Science.gov (United States)

    Afzalpour, Mohammad Esmaiel; Chadorneshin, Hossein Taheri; Foadoddini, Mohsen; Eivari, Hossein Abtahi

    2015-08-01

    The research literature suggests that oxidative stress and pro-inflammatory factors influence neurotrophins in vitro. However, there is insufficient information about their effects on exercise training conditions, especially during high intensity trainings. This study aimed to compare the effects of 6weeks of high intensity interval and continuous training regimens on brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), hydrogen peroxide (H2O2), and tumor necrosis factor alpha (TNF-α) in the rat brain. For this purpose, twenty-four Albino Wistar rats were divided into sedentary control (SC), high intensity interval training (HIIT), and continuous training (CT) groups. Both HIIT and CT regimens increased H2O2 level and TNF-α concentration in the brain, and the alterations made were greater following HIIT than CT. In addition, both HIIT and CT regimens increased BDNF and GDNF concentrations significantly, with a higher elevation following HIIT than CT. Furthermore, H2O2 level and TNF-α concentration correlated positively with both BDNF and GDNF concentrations. Generally, high intensity interval training regimen, rather than continuous training regimen, is highly potential to improve BDNF and GDNF through a greater increase in H2O2 and TNF-α as oxidative stress and pro-inflammatory factors. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Neuromuscular function of the quadriceps muscle during isometric maximal, submaximal and submaximal fatiguing voluntary contractions in knee osteoarthrosis patients.

    Directory of Open Access Journals (Sweden)

    Anett Mau-Moeller

    and neuromuscular activation, but also with an impaired position and torque control at submaximal torque levels, an altered EMG-torque relationship and a higher performance fatigability of the quadriceps muscle. It is recommended that the rehabilitation includes strengthening and fatiguing exercises at maximal and submaximal force levels.

  14. Comparison of the effects of continuous positive airway pressure, oral appliance and exercise training in obstructive sleep apnea syndrome.

    Science.gov (United States)

    Schütz, Teresa Cristina Barros; Cunha, Thays Crosara Abrahão; Moura-Guimaraes, Thais; Luz, Gabriela Pontes; Ackel-D'Elia, Carolina; Alves, Eduardo da Silva; Pantiga, Gilberto; Mello, Marco Tulio de; Tufik, Sergio; Bittencourt, Lia

    2013-01-01

    There are several treatments for obstructive sleep apnea syndrome, such as weight loss, use of an oral appliance and continuous positive airway pressure, that can be used to reduce the signs and symptoms of obstructive sleep apnea syndrome. Few studies have evaluated the effectiveness of a physical training program compared with other treatments. The aim of this study was to assess the effects of physical exercise on subjective and objective sleep parameters, quality of life and mood in obstructive sleep apnea patients and to compare these effects with the effects of continuous positive airway pressure and oral appliance treatments. Male patients with moderate to severe obstructive sleep apnea and body mass indices less than 30 kg/m2 were randomly assigned to three groups: continuous positive airway pressure (n = 9), oral appliance (n = 9) and physical exercise (n = 7). Polysomnographic recordings, blood samples and daytime sleepiness measurements were obtained prior to and after two months of physical exercise or treatment with continuous positive airway pressure or an oral appliance. Clinicaltrials.gov: NCT01289392 RESULTS: After treatment with continuous positive airway pressure or an oral appliance, the patients presented with a significant reduction in the apnea-hypopnea index. We did not observe changes in the sleep parameters studied in the physical exercise group. However, this group presented reductions in the following parameters: T leukocytes, very-low-density lipoprotein and triglycerides. Two months of exercise training also had a positive impact on subjective daytime sleepiness. Our results suggest that isolated physical exercise training was able to modify only subjective daytime sleepiness and some blood measures. Continuous positive airway pressure and oral appliances modified the apnea-hypopnea index.

  15. Comparison of the effects of continuous positive airway pressure, oral appliance and exercise training in obstructive sleep apnea syndrome

    Directory of Open Access Journals (Sweden)

    Teresa Cristina Barros Schutz

    2013-01-01

    Full Text Available OBJECTIVE: There are several treatments for obstructive sleep apnea syndrome, such as weight loss, use of an oral appliance and continuous positive airway pressure, that can be used to reduce the signs and symptoms of obstructive sleep apnea syndrome. Few studies have evaluated the effectiveness of a physical training program compared with other treatments. The aim of this study was to assess the effects of physical exercise on subjective and objective sleep parameters, quality of life and mood in obstructive sleep apnea patients and to compare these effects with the effects of continuous positive airway pressure and oral appliance treatments. METHODS: Male patients with moderate to severe obstructive sleep apnea and body mass indices less than 30 kg/m2 were randomly assigned to three groups: continuous positive airway pressure (n = 9, oral appliance (n = 9 and physical exercise (n = 7. Polysomnographic recordings, blood samples and daytime sleepiness measurements were obtained prior to and after two months of physical exercise or treatment with continuous positive airway pressure or an oral appliance. Clinicaltrials.gov: NCT01289392 RESULTS: After treatment with continuous positive airway pressure or an oral appliance, the patients presented with a significant reduction in the apnea-hypopnea index. We did not observe changes in the sleep parameters studied in the physical exercise group. However, this group presented reductions in the following parameters: T leukocytes, very-low-density lipoprotein and triglycerides. Two months of exercise training also had a positive impact on subjective daytime sleepiness. CONCLUSIONS: Our results suggest that isolated physical exercise training was able to modify only subjective daytime sleepiness and some blood measures. Continuous positive airway pressure and oral appliances modified the apnea-hypopnea index.

  16. Where does HIT fit? An examination of the affective response to high-intensity intervals in comparison to continuous moderate- and continuous vigorous-intensity exercise in the exercise intensity-affect continuum.

    Directory of Open Access Journals (Sweden)

    Mary E Jung

    Full Text Available Affect experienced during an exercise session is purported to predict future exercise behaviour. Compared to continuous moderate-intensity exercise (CMI, the affective response to continuous vigorous-intensity exercise (CVI has consistently been shown to be more aversive. The affective response, and overall tolerability to high-intensity interval training (HIT, is less studied. To date, there has yet to be a comparison between HIT, CVI, and CMI. The purpose of this study was to compare the tolerability and affective responses during HIT to CVI and CMI. This study utilized a repeated measures, randomized, counter-balanced design. Forty-four participants visited the laboratory on four occasions. Baseline fitness testing was conducted to establish peak power output in Watts (W peak. Three subsequent visits involved a single bout of a HIT, corresponding to 1-minute at ∼ 100% W peak and 1-minute at ∼ 20% W peak for 20 minutes, b CMI, corresponding to ∼ 40% W peak for 40 minutes, and c CVI, corresponding to ∼ 80% W peak for 20 minutes. The order of the sessions was randomized. Affective responses were measured before, during and after each session. Task self-efficacy, intentions, enjoyment and preference were measured after sessions. Participants reported greater enjoyment of HIT as compared to CMI and CVI, with over 50% of participants reporting a preference to engage in HIT as opposed to either CMI or CVI. HIT was considered more pleasurable than CVI after exercise, but less pleasurable than CMI at these times. Despite this participants reported being just as confident to engage in HIT as they were CMI, but less confident to engage in CVI. This study highlights the utility of HIT in inactive individuals, and suggests that it may be a viable alternative to traditionally prescribed continuous modalities of exercise for promoting self-efficacy and enjoyment of exercise.

  17. Effect of music on submaximal cycling

    African Journals Online (AJOL)

    Boutcher SH, Trenske M. The effects of sensory deprivation and music on perceived exertion and affect during exercise. Journal of Sport and Exercise. Psychology 1990; 12: 167-76. 4. Grant S, Aitchison T, Henderson E, et al. A comparison of the reproduc- ibility and the sensitivity to change of visual analogue scales, Borg ...

  18. Low dose of dichloroacetate infusion reduces blood lactate after submaximal exercise in horses Baixa dose de infusão de dicloroacetato reduz o lactato sanguíneo após exercício submáximo em cavalos

    Directory of Open Access Journals (Sweden)

    Guilherme C. Ferraz

    2013-01-01

    Full Text Available The acute administration of an indirect activator of the enzyme pyruvate dehydrogenase (PDH in human athletes causes a reduction in blood lactate level during and after exercise. A single IV dose (2.5m.kg-1 of dichloroacetate (DCA was administered before a submaximal incremental exercise test (IET with five velocity steps, from 5.0 m.s-1 for 1 min to 6.0, 6.5, 7.0 and 7.5m.s-1 every 30s in four untrained mares. The blood collections were done in the period after exercise, at times 1, 3, 5, 10, 15 and 20 min. Blood lactate and glucose (mM were determined electro-enzymatically utilizing a YSI 2300 automated analyzer. There was a 15.3% decrease in mean total blood lactate determined from the values obtained at all assessment times in both trials after the exercise. There was a decrease in blood lactate 1, 3, 5, 10, 15 and 20 min after exercise for the mares that received prior DCA treatment, with respective mean values of 6.31±0.90 vs 5.81±0.50, 6.45±1.19 vs 5.58±1.06, 6.07±1.56 vs 5.26±1.12, 4.88±1.61 vs 3.95±1.00, 3.66±1.41 vs 2.86±0.75 and 2.75±0.51 vs 2.04±0.30. There was no difference in glucose concentrations. By means of linear regression analysis, V140, V160, V180 and V200 were determined (velocity at which the rate heart is 140, 160, 180, and 200 beats/minute, respectively. The velocities related to heart rate did not differ, indicating that there was no ergogenic effect, but prior administration of a relatively low dose of DCA in mares reduced lactatemia after an IET.A administração aguda de um ativador indireto da enzima piruvato desidrogenase (PD em atletas da espécie humana provoca redução na concentração de lactato sanguíneo durante e após exercício. Uma dose única, intravenosa de 2.5m.kg-1 de dicloroacetato (DCA foi administrada antes de um exercício teste incremental submáximo (ETI com cinco etapas de velocidade sendo 5,0 ms-1 por 1 minuto e 6,0, 6,5, 7,0, e 7,5 ms-1 a cada 30 segundos em quatro

  19. Effects of dietary Acid load on exercise metabolism and anaerobic exercise performance.

    Science.gov (United States)

    Caciano, Susan L; Inman, Cynthia L; Gockel-Blessing, Elizabeth E; Weiss, Edward P

    2015-06-01

    Dietary acid load, quantified as the potential renal acid load (PRAL) of the diet, affects systemic pH and acid-base regulation. In a previous cross-sectional study, we reported that a low dietary PRAL (i.e. alkaline promoting diet) is associated with higher respiratory exchange ratio (RER) values during maximal exercise. The purpose of the present study was to confirm the previous findings with a short-term dietary intervention study. Additionally, we sought to determine if changes in PRAL affects submaximal exercise RER (as a reflection of substrate utilization) and anaerobic exercise performance. Subjects underwent a graded treadmill exercise test (GXT) to exhaustion and an anaerobic exercise performance test on two occasions, once after following a low-PRAL diet and on a separate occasion, after a high-PRAL diet. The diets were continued as long as needed to achieve an alkaline or acid fasted morning urine pH, respectively, with all being 4-9 days in duration. RER was measured during the GXT with indirect calorimetry. The anaerobic performance test was a running time-to-exhaustion test lasting 1-4 min. Maximal exercise RER was lower in the low-PRAL trial compared to the high-PRAL trial (1.10 ± 0.02 vs. 1.20 ± 0.05, p = 0.037). The low-PRAL diet also resulted in a 21% greater time to exhaustion during anaerobic exercise (2.56 ± 0.36 vs. 2.11 ± 0.31 sec, p = 0.044) and a strong tendency for lower RER values during submaximal exercise at 70% VO2max (0.88 ± 0.02 vs. 0.96 ± 0.04, p = 0.060). Contrary to our expectations, a short-term low-PRAL (alkaline promoting) diet resulted in lower RER values during maximal-intensity exercise. However, the low-PRAL diet also increased anaerobic exercise time to exhaustion and appears to have shifted submaximal exercise substrate utilization to favor lipid oxidation and spare carbohydrate, both of which would be considered favorable effects in the context of exercise performance. Key pointsShort-term (4-9 days) changes in

  20. Skeletal muscle metabolism during prolonged exercise in Pompe disease

    Directory of Open Access Journals (Sweden)

    Nicolai Preisler

    2017-07-01

    Full Text Available Objective: Pompe disease (glycogenosis type II is caused by lysosomal alpha-glucosidase deficiency, which leads to a block in intra-lysosomal glycogen breakdown. In spite of enzyme replacement therapy, Pompe disease continues to be a progressive metabolic myopathy. Considering the health benefits of exercise, it is important in Pompe disease to acquire more information about muscle substrate use during exercise. Methods: Seven adults with Pompe disease were matched to a healthy control group (1:1. We determined (1 peak oxidative capacity (VO2peak and (2 carbohydrate and fatty acid metabolism during submaximal exercise (33 W for 1 h, using cycle-ergometer exercise, indirect calorimetry and stable isotopes. Results: In the patients, VO2peak was less than half of average control values; mean difference −1659 mL/min (CI: −2450 to −867, P = 0.001. However, the respiratory exchange ratio increased to >1.0 and lactate levels rose 5-fold in the patients, indicating significant glycolytic flux. In line with this, during submaximal exercise, the rates of oxidation (ROX of carbohydrates and palmitate were similar between patients and controls (mean difference 0.226 g/min (CI: 0.611 to −0.078, P = 0.318 and mean difference 0.016 μmol/kg/min (CI: 1.287 to −1.255, P = 0.710, respectively. Conclusion: Reflecting muscle weakness and wasting, Pompe disease is associated with markedly reduced maximal exercise capacity. However, glycogenolysis is not impaired in exercise. Unlike in other metabolic myopathies, skeletal muscle substrate use during exercise is normal in Pompe disease rendering exercise less complicated for e.g. medical or recreational purposes.

  1. Skeletal muscle metabolism during prolonged exercise in Pompe disease.

    Science.gov (United States)

    Preisler, Nicolai; Laforêt, Pascal; Madsen, Karen Lindhardt; Husu, Edith; Vissing, Christoffer Rasmus; Hedermann, Gitte; Galbo, Henrik; Lindberg, Christopher; Vissing, John

    2017-08-01

    Pompe disease (glycogenosis type II) is caused by lysosomal alpha-glucosidase deficiency, which leads to a block in intra-lysosomal glycogen breakdown. In spite of enzyme replacement therapy, Pompe disease continues to be a progressive metabolic myopathy. Considering the health benefits of exercise, it is important in Pompe disease to acquire more information about muscle substrate use during exercise. Seven adults with Pompe disease were matched to a healthy control group (1:1). We determined (1) peak oxidative capacity (VO2peak) and (2) carbohydrate and fatty acid metabolism during submaximal exercise (33 W) for 1 h, using cycle-ergometer exercise, indirect calorimetry and stable isotopes. In the patients, VO2peak was less than half of average control values; mean difference -1659 mL/min (CI: -2450 to -867, P = 0.001). However, the respiratory exchange ratio increased to >1.0 and lactate levels rose 5-fold in the patients, indicating significant glycolytic flux. In line with this, during submaximal exercise, the rates of oxidation (ROX) of carbohydrates and palmitate were similar between patients and controls (mean difference 0.226 g/min (CI: 0.611 to -0.078, P = 0.318) and mean difference 0.016 µmol/kg/min (CI: 1.287 to -1.255, P = 0.710), respectively). Reflecting muscle weakness and wasting, Pompe disease is associated with markedly reduced maximal exercise capacity. However, glycogenolysis is not impaired in exercise. Unlike in other metabolic myopathies, skeletal muscle substrate use during exercise is normal in Pompe disease rendering exercise less complicated for e.g. medical or recreational purposes. © 2017 The authors.

  2. Effects of high-intensity interval versus continuous exercise training on post-exercise heart rate recovery in coronary heart-disease patients.

    Science.gov (United States)

    Villelabeitia-Jaureguizar, Koldobika; Vicente-Campos, Davinia; Senen, Alejandro Berenguel; Jiménez, Verónica Hernández; Garrido-Lestache, María Elvira Barrios; Chicharro, Jose López

    2017-10-01

    Heart rate recovery (HRR) has been considered a prognostic and mortality indicator in both healthy and coronary patients. Physical exercise prescription has shown improvements in VO2peak and HRR, but most of the studies have been carried out applying continuous training at a moderate intensity, being very limited the use of protocols of high intensity interval training in coronary patients. We aimed to compare the effects of a moderate continuous training (MCT) versus a high intensity interval training (HIIT) programme on VO2peak and HRR. Seventy three coronary patients were assigned to either HIIT or MCT groups for 8weeks. Incremental exercise tests in a cycloergometer were performed to obtain VO2peak data and heart rate was monitored during and after the exercise test to obtain heart rate recovery data. Both exercise programmes significantly increase VO2peak with a higher increase in the HIIT group (HIIT: 4.5±4.46ml/kg/min vs MCT: 2.46±3.57ml/kg/min; p=0.039). High intensity interval training resulted in a significantly increase in HRR at the first and second minute of the recovery phase (15,44±7,04 vs 21,22±6,62, ptraining. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Exercise hemodynamics during extended continuous flow left ventricular assist device support: the response of systemic cardiovascular parameters and pump performance

    NARCIS (Netherlands)

    Martina, Jerson; Jonge, Nicolaas; Rutten, Marcel; Kirkels, J. Hans; Klöpping, Corinne; Rodermans, Ben; Sukkel, Eveline; Hulstein, Nelienke; Mol, Bas; Lahpor, Jaap

    2013-01-01

    Patients on continuous flow left ventricular assist devices (cf-LVADs) are able to return to an active lifestyle and perform all sorts of physical activities. This study aims to evaluate exercise hemodynamics in patients with a HeartMate II cf-LVAD (HM II). Thirty (30) patients underwent a bicycle

  4. Accuracy of Continuous Glucose Monitoring (CGM during Continuous and High-Intensity Interval Exercise in Patients with Type 1 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Othmar Moser

    2016-08-01

    Full Text Available Continuous exercise (CON and high-intensity interval exercise (HIIE can be safely performed with type 1 diabetes mellitus (T1DM. Additionally, continuous glucose monitoring (CGM systems may serve as a tool to reduce the risk of exercise-induced hypoglycemia. It is unclear if CGM is accurate during CON and HIIE at different mean workloads. Seven T1DM patients performed CON and HIIE at 5% below (L and above (M the first lactate turn point (LTP1, and 5% below the second lactate turn point (LTP2 (H on a cycle ergometer. Glucose was measured via CGM and in capillary blood (BG. Differences were found in comparison of CGM vs. BG in three out of the six tests (p < 0.05. In CON, bias and levels of agreement for L, M, and H were found at: 0.85 (−3.44, 5.15 mmol·L−1, −0.45 (−3.95, 3.05 mmol·L−1, −0.31 (−8.83, 8.20 mmol·L−1 and at 1.17 (−2.06, 4.40 mmol·L−1, 0.11 (−5.79, 6.01 mmol·L−1, 1.48 (−2.60, 5.57 mmol·L−1 in HIIE for the same intensities. Clinically-acceptable results (except for CON H were found. CGM estimated BG to be clinically acceptable, except for CON H. Additionally, using CGM may increase avoidance of exercise-induced hypoglycemia, but usual BG control should be performed during intense exercise.

  5. Cardiac troponin T and echocardiographic dimensions after repeated sprint vs. moderate intensity continuous exercise in healthy young males.

    Science.gov (United States)

    Weippert, Matthias; Divchev, Dimitar; Schmidt, Paul; Gettel, Hannes; Neugebauer, Antina; Behrens, Kristin; Wolfarth, Bernd; Braumann, Klaus-Michael; Nienaber, Christoph A

    2016-04-19

    Regular physical exercise can positively influence cardiac function; however, investigations have shown an increase of myocardial damage biomarkers after acute prolonged endurance exercises. We investigated the effect of repeated sprint vs. moderate long duration exercise on markers of myocardial necrosis, as well as cardiac dimensions and functions. Thirteen healthy males performed two different running sessions (randomized, single blinded cross-over design): 60 minutes moderate intensity continuous training (MCT, at 70% of peak heart rate (HRpeak)) and two series of 12 × 30-second sprints with set recovery periods in-between (RST, at 90% HRpeak). Venous blood samples for cardiac troponin T (cTnT), creatine kinase (CK) and MB isoenzyme (CK-MB) were taken 1 and 4 hours after exercise sessions. After each session electrocardiographic (ECG) and transthoracic echocardiographic (TTE) data were recorded. Results showed that all variables - average heart rate, serum lactate concentration during RST, subjective exertion and cTnT after RST - were significantly higher compared to MCT. CK and CK-MB significantly increased regardless of exercise protocol, while ECG and TTE indicated normal cardiac function. Our results provide evidence that RST contributes significantly to cTnT and CK release. This biomarker increase seems to reflect a physiological rather than a pathological phenomenon in healthy, exercising subjects.

  6. The influence of interval versus continuous exercise on thermoregulation, torso hemodynamics, and finger dexterity in the cold.

    Science.gov (United States)

    Muller, Matthew D; Ryan, Edward J; Bellar, David M; Kim, Chul-Ho; Blankfield, Robert P; Muller, Sarah M; Glickman, Ellen L

    2010-07-01

    The purpose of this study was to evaluate how interval (INT) and continuous (CONT) exercise alter body temperatures and manual dexterity in the cold (5 degrees C). Fourteen young men underwent two trials consisting of a 90-min period of acute cold exposure (ACE), 30 min of exercise (INT or CONT), and a 60-min recovery period (REC). Participants donned approximately 1 clo but the hands remained bare for the entire protocol so that a steep decline in dexterity performance occurred prior to the initiation of exercise. INT and CONT were isoenergetic, reflecting 50 +/- 1% of each individual's VO(2) peak. Rectal (Tre) and skin temperatures were monitored continuously and dexterity testing was conducted at ten time points throughout each 3-h trial. In addition, oxygen consumption (VO(2)) and torso hemodynamics were assessed via indirect calorimetry and impedance cardiography (ICG), respectively. As expected, finger temperature and dexterity declined during ACE, relative to baseline. Both modes of exercise increased finger temperature and dexterity, relative to ACE. However, CONT was more effective than INT at increasing finger temperature on the dominant hand, which was associated with better dexterity scores during REC. Tre was not different between trials but a significant increase in stroke volume was found following CONT. Perhaps elevated stroke volume during post-exercise REC plays a role in finger rewarming and dexterity performance. Further mechanistic studies are needed to confirm the role of cardiovascular function in the enhancement of manual performance in the cold.

  7. Walking the Talk: Continuous Improvement of a Quality Management Field Exercise

    Science.gov (United States)

    Coy, Steven; Adams, Jeffery

    2012-01-01

    This article provides results from a three semester case study of the pedagogical efficacy of an innovative quality management field exercise. A series of direct and indirect measures were used to assess the extent to which the field exercise met a set of learning objectives. The results indicate that the assessment framework is useful in…

  8. Effect of oxygen on postoperative cardiovascular response to exercise

    DEFF Research Database (Denmark)

    Kjaersgaard, M; Lie, C; Bisgaard, T

    2000-01-01

    OBJECTIVE: To evaluate the effect of supplemental oxygen on postoperative cardiovascular response to submaximal exercise. DESIGN: Randomised, controlled study. SETTING: University hospital, Denmark. SUBJECTS: 16 patients having major abdominal operations. INTERVENTIONS: A submaximal exercise test...... in non-surgical patients and surgical patients not taking exercise. These findings do not suggest that decreased peripheral tissue oxygenation is responsible for the impaired cardiovascular response to exercise in postoperative patients....... oximeter. MAIN OUTCOME MEASURES: Heart rate during exercise. RESULTS: At similar workloads there were significantly lower heart rates (median decrease 3 min(-1)) during exercise tests with oxygen compared with air (p

  9. Intermittent and continuous high-intensity exercise training induce similar acute but different chronic muscle adaptations.

    Science.gov (United States)

    Cochran, Andrew J R; Percival, Michael E; Tricarico, Steven; Little, Jonathan P; Cermak, Naomi; Gillen, Jenna B; Tarnopolsky, Mark A; Gibala, Martin J

    2014-05-01

    High-intensity interval training (HIIT) performed in an 'all-out' manner (e.g. repeated Wingate tests) is a time-efficient strategy to induce skeletal muscle remodelling towards a more oxidative phenotype. A fundamental question that remains unclear, however, is whether the intermittent or 'pulsed' nature of the stimulus is critical to the adaptive response. In study 1, we examined whether the activation of signalling cascades linked to mitochondrial biogenesis was dependent on the manner in which an acute high-intensity exercise stimulus was applied. Subjects performed either four 30 s Wingate tests interspersed with 4 min of rest (INT) or a bout of continuous exercise (CONT) that was matched for total work (67 ± 7 kJ) and which required ∼4 min to complete as fast as possible. Both protocols elicited similar increases in markers of adenosine monophosphate-activated protein kinase (AMPK) and p38 mitogen-activated protein kinase activation, as well as Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) mRNA expression (main effects for time, P ≤ 0.05). In study 2, we determined whether 6 weeks of the CONT protocol (3 days per week) would increase skeletal muscle mitochondrial content to a similar extent to what we have previously reported after 6 weeks of INT. Despite similar acute signalling responses to the CONT and INT protocols, training with CONT did not increase the maximal activity or protein content of a range of mitochondrial markers. However, peak oxygen uptake was higher after CONT training (from 45.7 ± 5.4 to 48.3 ± 6.5 ml kg(-1) min(-1); P < 0.05) and 250 kJ time trial performance was improved (from 26:32 ± 4:48 to 23:55 ± 4:16 min:s; P < 0.001) in our recreationally active participants. We conclude that the intermittent nature of the stimulus is important for maximizing skeletal muscle adaptations to low-volume, all-out HIIT. Despite the lack of skeletal muscle mitochondrial adaptations

  10. The acute effects of interval- vs. continuous-walking exercise on glycemic control in subjects with type 2 diabetes

    DEFF Research Database (Denmark)

    Karstoft, Kristian; Christensen, Camilla S; Pedersen, Bente K

    2014-01-01

    . Design: Cross-over, controlled with trials performed in randomized order. Setting: Hospitalized and ambulatory care. Patients: Diagnosed with type 2 diabetes (T2DM; n=10, no withdrawels). Interventions: Subjects performed three 1-hour interventions: 1) interval-walking (IW; repeated cycles of 3 minutes...... of slow and fast walking); 2) continuous-walking (CW); 3) Control (CON). Oxygen consumption (VO2) was measured continuously to match mean VO2 between exercise sessions (∼75% VO2peak). Main Outcome Measures: A mixed meal tolerance test (MMTT; 450 kcal, 55% carbohydrate) with stable glucose isotopic tracers...... was provided after each intervention and glucose kinetics were measured during the following 4 hours. Free-living glycemic control was assessed for ∼32 hours following the MMTT using continuous glucose monitoring (CGM). Results: VO2 was well-matched between the exercise interventions. IW decreased mean...

  11. Understanding Why Undergraduate Students Declare and Continue to Study an Exercise Science-Related Major.

    Science.gov (United States)

    Vaartstra, Matthew B; Kercher, Vanessa M; Start, Amanda; Brown, Amber N; Peterson, Mark D; McGrath, Ryan

    2017-01-01

    Understanding factors that contribute to a student's selection of an exercise science-related major is important to student success, higher education and industry. This study sought to 1) better understand why undergraduate students study an exercise science-related major, 2) determine whether positive influences to study an exercise science-related major differ by academic classification, and 3) identify what student's aspirations are after graduation. Department administrators from four-year colleges and universities offering an exercise science-related major in the Northwest Region of the United States (i.e., Idaho, Montana, Oregon, and Washington) were contacted. Cooperating department administrators were given self-reported questionnaires for students to complete using a snowball sampling method. A total of 388 participants completed the questionnaire. Interest in the subject and potential job opportunities were the most common reasons to study an exercise science-related major. Self-reported Holland's codes identified that realistic and social personalities were most prevalent among participants. Seniors rated a friend's influence and college advisors as stronger influences to study an exercise science-related major compared to freshmen. Pay in the field was a stronger influence for freshmen to study an exercise science-related major than for fifth-year seniors, whereas freshmen were less influenced by introductory courses to study an exercise-science related major than fifth-year seniors. The majority of undergraduate students studying an exercise science-related major planned on attending graduate school after completing their baccalaureate degree. These findings can be used to help guide undeclared students and better serve undergraduates enrolled in an exercise science-related major.

  12. Prediction of Maximum Oxygen Uptake Using Both Exercise and Non-Exercise Data

    Science.gov (United States)

    George, James D.; Paul, Samantha L.; Hyde, Annette; Bradshaw, Danielle I.; Vehrs, Pat R.; Hager, Ronald L.; Yanowitz, Frank G.

    2009-01-01

    This study sought to develop a regression model to predict maximal oxygen uptake (VO[subscript 2max]) based on submaximal treadmill exercise (EX) and non-exercise (N-EX) data involving 116 participants, ages 18-65 years. The EX data included the participants' self-selected treadmill speed (at a level grade) when exercise heart rate first reached…

  13. Effects of submaximal and supramaximal interval training on determinants of endurance performance in endurance athletes.

    Science.gov (United States)

    Paquette, M; Le Blanc, O; Lucas, S J E; Thibault, G; Bailey, D M; Brassard, P

    2017-03-01

    We compared the effects of submaximal and supramaximal cycling interval training on determinants of exercise performance in moderately endurance-trained men. Maximal oxygen consumption (VO2max ), peak power output (Ppeak ), and peak and mean anaerobic power were measured before and after 6 weeks (3 sessions/week) of submaximal (85% maximal aerobic power [MP], HIIT85 , n = 8) or supramaximal (115% MP, HIIT115 , n = 9) interval training to exhaustion in moderately endurance-trained men. High-intensity training volume was 47% lower in HIIT115 vs HIIT85 (304 ± 77 vs 571 ± 200 min; P training was generally associated with increased VO2max (HIIT85 : +3.3 ± 3.1 mL/kg/min; HIIT115 : +3.3 ± 3.6 ml/kg/min; Time effect P = 0.002; Group effect: P = 0.95), Ppeak (HIIT85 : +18 ± 9 W; HIIT115 : +16 ± 27 W; Time effect P = 0.045; Group effect: P = 0.49), and mean anaerobic power (HIIT85 : +0.42 ± 0.69 W/kg; HIIT115 : +0.55 ± 0.65 W/kg; Time effect P = 0.01; Group effect: P = 0.18). Six weeks of submaximal and supramaximal interval training performed to exhaustion seems to equally improve VO2max and anaerobic power in endurance-trained men, despite half the accumulated time spent at the target intensity. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Similar Anti-Inflammatory Acute Responses from Moderate-Intensity Continuous and High-Intensity Intermittent Exercise.

    Science.gov (United States)

    Cabral-Santos, Carolina; Gerosa-Neto, José; Inoue, Daniela Sayuri; Panissa, Valéria Leme Gonçalves; Gobbo, Luís Alberto; Zagatto, Alessandro Moura; Campos, Eduardo Zapaterra; Lira, Fábio Santos

    2015-12-01

    The purpose of this study was to compare the effect of high-intensity intermittent exercise (HIIE) versus volume matched steady state exercise (SSE) on inflammatory and metabolic responses. Eight physically active male subjects completed two experimental sessions, a 5-km run on a treadmill either continuously (70% vVO2max) or intermittently (1:1 min at vVO2max). Blood samples were collected at rest, immediately, 30 and 60 minutes after the exercise session. Blood was analyzed for glucose, non-ester fatty acid (NEFA), uric acid, lactate, cortisol, and cytokines (IL-6, IL-10 and TNF-α) levels. The lactate levels exhibited higher values immediately post-exercise than at rest (HIIE 1.34 ± 0.24 to 7.11 ± 2.85, and SSE 1.35 ± 0.14 to 4.06±1.60 mmol·L(-1), p 0.05). Cortisol, IL-6, IL-10 and TNF-α levels showed time-dependent changes under the different conditions (p < 0.05), however, the area under the curve of TNF-α in the SSE were higher than HIIE (p < 0.05), and the area under the curve of IL-6 in the HIIE showed higher values than SSE (p < 0.05). In addition, both exercise conditions promote increased IL-10 levels and IL-10/TNF-α ratio (p < 0.05). In conclusion, our results demonstrated that both exercise protocols, when volume is matched, promote similar inflammatory responses, leading to an anti-inflammatory status; however, the metabolic responses are different. Key pointsMetabolic contribution of both exercise, HIIE and SSE, was different.Both protocols leading to an anti-inflammatory status.HIIE induce a higher energy expenditure take into account total session duration.

  15. Exercise during Short-Term and Long-Term Continuous Exposure to Hypoxia Exacerbates Sleep-Related Periodic Breathing.

    Science.gov (United States)

    Tellez, Helio Fernandez; Morrison, Shawnda A; Neyt, Xavier; Mairesse, Olivier; Piacentini, Maria Francesca; Macdonald-Nethercott, Eoin; Pangerc, Andrej; Dolenc-Groselj, Leja; Eiken, Ola; Pattyn, Nathalie; Mekjavic, Igor B; Meeusen, Romain

    2016-04-01

    Exposure to hypoxia elevates chemosensitivity, which can lead to periodic breathing. Exercise impacts gas exchange, altering chemosensitivity; however, interactions between sleep, exercise and chronic hypoxic exposure have not been examined. This study investigated whether exercise exacerbates sleep-related periodic breathing in hypoxia. Two experimental phases. Short-Term Phase: a laboratory controlled, group-design study in which 16 active, healthy men (age: 25 ± 3 y, height: 1.79 ± 0.06 m, mass: 74 ± 8 kg) were confined to a normobaric hypoxic environment (FIO2 = 0.139 ± 0.003, 4,000 m) for 10 days, after random assignment to a sedentary (control, CON) or cycle-exercise group (EX). Long-Term Phase: conducted at the Concordia Antarctic Research Station (3,800 m equivalent at the Equator) where 14 men (age: 36 ± 9 y, height: 1.77 ± 0.09 m, mass: 75 ± 10 kg) lived for 12-14 months, continuously confined. Participants were stratified post hoc based on self-reported physical activity levels. We quantified apnea-hypopnea index (AHI) and physical activity variables. Short-Term Phase: mean AHI scores were significantly elevated in the EX group compared to CON (Night1 = CON: 39 ± 51, EX: 91 ± 59; Night10 = CON: 32 ± 32, EX: 92 ± 48; P = 0.046). Long-Term Phase: AHI was correlated to mean exercise time (R(2) = 0.4857; P = 0.008) and the coefficient of variation in night oxyhemoglobin saturation (SpO2; R(2) = 0.3062; P = 0.049). Data indicate that exercise (physical activity) per se affects night SpO2 concentrations and AHI after a minimum of two bouts of moderate-intensity hypoxic exercise, while habitual physical activity in hypobaric hypoxic confinement affects breathing during sleep, up to 13+ months' duration. © 2016 Associated Professional Sleep Societies, LLC.

  16. Motivational aspects that influence the elderly to enroll on and continue participating in physical exercise programs

    Directory of Open Access Journals (Sweden)

    Carmen Freyre

    2007-03-01

    Full Text Available Currently, there is a growing demand for physical exercise in programs promoting health; however, the elderly are still under-represented in such programs. This study aims to identify, classify and discuss social, cultural and educational factors relating to the health and quality of life of the elderly, establishing relationships with the motives for which they join and adhere to regular physical exercise programs in public areas. This was a field study employing descriptive quantitative and qualitative methodology and for which 120 participants from two physical exercise programs in Recife were interviewed. The results indicate that the most important motives for participation were as follows: to improve health (84.2%, to improve physical performance (70.8%, to adopt a healthy lifestyle (62.5%, to reduce stress (60.8%, to comply with doctor’s orders (56.7%, to recover from injury (55%, to improve self-image (50.8% and to enhance self-esteem and relax (47.5%. The most important motives for continuing to attend such programs were: to improve posture (75%; to promote a feeling of wellbeing (74.2%; to keep fi t (70.8%; to experience pleasure (66.7%; to become stronger and be motivated by the instructor (62.5%; to experience a feeling of well-being produced by the social environment (60%; and to experience self-realization and receive attention from the instructor (57.5%. For the men (35.1%, the habit of performing physical exercise in their youth had no bearing on their joining such programs. On the basis of these indicators, universities can make a valuable contribution by offering socio-educational health-related projects encouraging the elderly population to avoid a sedentary lifestyle. RESUMO Atualmente, a busca pela prática de exercícios físicos em programas para promoção de saúde vem crescendo; porém a procura pelos idosos é insuficiente. Esta investigação identifica, classifica e discute os aspectos socioculturais e educativos

  17. F-door spaces and F-submaximal spaces

    Directory of Open Access Journals (Sweden)

    Lobna Dridi

    2013-04-01

    Full Text Available Submaximal spaces and door spaces play an enigmatic role in topology. In this paper, reinforcing this role, we are concerned with reaching two main goals: The first one is to characterize topological spaces X such that F(X is a submaximal space (resp., door space for some covariant functor Ff rom the category Top to itself. T0, and FH functors are completely studied. Secondly, our interest is directed towards the characterization of maps f given by a flow (X, f in the category Set, such that (X,P(f is submaximal (resp., door where P(f is a topology on X whose closed sets are exactly the f-invariant sets.

  18. Effect of continuing repeated passive and active exercises on knee's position senses in patients with hemiplegia.

    Science.gov (United States)

    Kwon, Oh Sung; Lee, Seung Won

    2013-01-01

    To determine the repeated passive movement (RPM) and repeated active movement (RAM) exercise on position sense of the knee joint in patients with hemiplegia. 45 hemiplegia patients were randomly allocated to either the control group(no exercise), RPM group, or RAM group, with 15 subjects in each group. The exercise was repeated 60 times on the angle 10 to 100 degrees of the knee joint with an angle speed of 120°/s, with three sets for 15 minutes. Evaluation was performed using Passive Angle Repositioning (PAR) and Active Angle Repositioning (AAR). Error of positioning sense showed a decrease in PAR and AAR in the RPM group (p hemiplegia; however, RAM exercise that causes fatigue can decrease proprioception.

  19. Interval and Continuous Exercise Training Produce Similar Increases in Skeletal Muscle and Left Ventricle Microvascular Density in Rats

    Directory of Open Access Journals (Sweden)

    Flávio Pereira

    2013-01-01

    Full Text Available Interval training (IT, consisting of alternated periods of high and low intensity exercise, has been proposed as a strategy to induce more marked biological adaptations than continuous exercise training (CT. The purpose of this study was to assess the effects of IT and CT with equivalent total energy expenditure on capillary skeletal and cardiac muscles in rats. Wistar rats ran on a treadmill for 30 min per day with no slope (0%, 4 times/week for 13 weeks. CT has constant load of 70% max; IT has cycles of 90% max for 1 min followed by 1 min at 50% max. CT and IT increased endurance and muscle oxidative capacity and attenuated body weight gain to a similar extent (P>0.05. In addition, CT and IT similarly increased functional capillary density of skeletal muscle (CT: 30.6±11.7%; IT: 28.7±11.9% and the capillary-to-fiber ratio in skeletal muscle (CT: 28.7±14.4%; IT: 40.1±17.2% and in the left ventricle (CT: 57.3±53.1%; IT: 54.3±40.5%. In conclusion, at equivalent total work volumes, interval exercise training induced similar functional and structural alterations in the microcirculation of skeletal muscle and myocardium in healthy rats compared to continuous exercise training.

  20. The validity of submaximal ratings of perceived exertion to predict one repetition maximum.

    Science.gov (United States)

    Eston, Roger; Evans, Harrison James Llewelyn

    2009-01-01

    The One Repetition Maximum (1-RM) test is commonly used to assess strength. However, direct assessments of 1-RM are time consuming and unsafe for novice lifters. Whilst various equations exist to predict 1-RM, there is limited research on the validity of these equations. The purpose of this study was to assess the validity of using sub-maximal ratings of perceived exertion (RPE) to predict 1-RM in young adults, using the Borg 6-20 RPE Scale. Twenty healthy participants (ten male (Mean ± SD, 20.8 ± 0.6 y, 75.7 ± 9.3 kg, 1.8 ± 0.07 m) and ten female (20.3 ± 0.7 y, 68.4 ± 10.0 kg, 1.68 ± 0.03 m)) completed two trials involving resistance exercises for both the upper and lower body. In the first trial the 1-RM for the bilateral biceps curl (BC) and the bilateral knee extension (KE) were determined for each participant. In the second trial, participants performed blinded repetitions which were equivalent to 20, 40 and 60 % of 1-RM for both exercises. The RPE was recorded immediately after two repetitions had been completed at each intensity. The order of intensity of the repetitions was randomly assigned with participants wearing blindfolds to exclude the possibility of pre-determined judgments about load and RPE. Individual RPE recorded at each intensity was subjected to linear regression analysis and the line of best fit was extrapolated to RPE 20 to predict 1-RM in both exercises. There was no significant difference (p > 0.05) between the 1-RM predicted from RPE 20 and measured 1-RM for both exercises for the men and women. Measured and predicted values for men were 46.0 ± 4.6 and 45.2 ± 6. 1 kg for biceps curl, and 46.3 ± 3.8 and 43.0 ± 7.1 kg for knee extension, respectively. Measured and predicted values for women were 18.6 ± 5.7 and 19.3 ± 5.6 kg for biceps curl, and 25.5 ± 9.6 and 27.2 ± 12.6 kg for knee extension, respectively. Pearson product-moment correlation coefficients between actual and predicted 1-RM for the BC and KE were 0.97 and 0

  1. Therapeutic effect of continuous exercise training program on serum creatinine concentration in men with hypertension: a randomized controlled trial.

    Science.gov (United States)

    Sikiru, L; Okoye, G C

    2014-09-01

    Creatinine (Cr) has been implicated as an independent predictor of hypertension and exercise has been reported as adjunct therapy for hypertension. The purpose of the present study was to investigate the effect of continuous training programme on blood pressure and serum creatinine concentration in black African subjects with hypertension. Three hundred and fifty seven male patients with mild to moderate (systolic blood pressure [SBP] between 140-180 & diastolic blood pressure [DBP] between 90-109 mmHg) essential hypertension were age matched and randomly grouped into continuous & control groups. The continuous group involved in an 8 weeks continuous training (60-79% HR reserve) of between 45 minutes to 60 minutes, 3 times per week, while the control group remain sedentary. SBP, DBP, VO2max, serum Cr, body mass index (BMI), waist hip ratio (WHR) and percent (%) body fat. Analysis of covariance (ANCOVA) and Pearson correlation tests were used in data analysis. Findings of the study revealed significant decreased effects of continuous training programme on SBP, DBP, Cr, BMI, WHR, % body fat and significant increase in VO2max at ptherapeutic role of moderate intensity continuous exercise training as a multi-therapy in the down regulation of blood pressure, serum Cr, body size and body fat in hypertension.

  2. Exercise

    Science.gov (United States)

    ... it can lead to weakness of muscles, decreased bone density with an increased risk of fracture, and shallow, inefficient breathing. An exercise program needs to fit the capabilities and limitations ...

  3. Similar Anti-Inflammatory Acute Responses from Moderate-Intensity Continuous and High-Intensity Intermittent Exercise

    Directory of Open Access Journals (Sweden)

    Carolina Cabral-Santos, José Gerosa-Neto, Daniela Sayuri Inoue, Valéria Leme Gonçalves Panissa, Luís Alberto Gobbo, Alessandro Moura Zagatto, Eduardo Zapaterra Campos, Fábio Santos Lira

    2015-12-01

    Full Text Available The purpose of this study was to compare the effect of high-intensity intermittent exercise (HIIE versus volume matched steady state exercise (SSE on inflammatory and metabolic responses. Eight physically active male subjects completed two experimental sessions, a 5-km run on a treadmill either continuously (70% vVO2max or intermittently (1:1 min at vVO2max. Blood samples were collected at rest, immediately, 30 and 60 minutes after the exercise session. Blood was analyzed for glucose, non-ester fatty acid (NEFA, uric acid, lactate, cortisol, and cytokines (IL-6, IL-10 and TNF-α levels. The lactate levels exhibited higher values immediately post-exercise than at rest (HIIE 1.34 ± 0.24 to 7.11 ± 2.85, and SSE 1.35 ± 0.14 to 4.06±1.60 mmol·L-1, p 0.05. Cortisol, IL-6, IL-10 and TNF-α levels showed time-dependent changes under the different conditions (p < 0.05, however, the area under the curve of TNF-α in the SSE were higher than HIIE (p < 0.05, and the area under the curve of IL-6 in the HIIE showed higher values than SSE (p < 0.05. In addition, both exercise conditions promote increased IL-10 levels and IL-10/TNF-α ratio (p < 0.05. In conclusion, our results demonstrated that both exercise protocols, when volume is matched, promote similar inflammatory responses, leading to an anti-inflammatory status; however, the metabolic responses are different.

  4. Mental fatigue does not affect maximal anaerobic exercise performance.

    Science.gov (United States)

    Martin, Kristy; Thompson, Kevin G; Keegan, Richard; Ball, Nick; Rattray, Ben

    2015-04-01

    Mental fatigue can negatively impact on submaximal endurance exercise and has been attributed to changes in perceived exertion rather than changes in physiological variables. The impact of mental fatigue on maximal anaerobic performance is, however, unclear. Therefore, the aim of the present study was to induce a state of mental fatigue to examine the effects on performance, physiological and perceptual variables from subsequent tests of power, strength and anaerobic capacity. Twelve participants took part in the single-blind, randomised, crossover design study. Mental fatigue was induced by 90 min of the computer-based Continuous Performance Task AX version. Control treatment consisted of 90 min of watching emotionally neutral documentaries. Participants consequently completed countermovement jump, isometric leg extension and a 3-min all-out cycling tests. Results of repeated measures analysis of variance and paired t tests revealed no difference in any performance or physiological variable. Rating of perceived exertion tended to be greater when mentally fatigued (mental fatigue = 19 ± 1 vs control = 18 ± 1, p = 0.096, [Formula: see text] = .232) and intrinsic motivation reduced (mental fatigue = 11 ± 4 vs control = 13 ± 6, p = 0.063, d = 0.597) in the mental fatigue condition. Near identical responses in performance and physiological parameters between mental fatigue and control conditions suggest that peripheral mechanisms primarily regulate maximal anaerobic exercise. Whereas mental fatigue can negatively impact submaximal endurance exercise, it appears that explosive power, voluntary maximal strength and anaerobic work capacity are unaffected.

  5. Submaximal cardiopulmonary thresholds on a robotics-assisted tilt table, a cycle and a treadmill: a comparative analysis.

    Science.gov (United States)

    Saengsuwan, Jittima; Nef, Tobias; Laubacher, Marco; Hunt, Kenneth J

    2015-11-10

    The robotics-assisted tilt table (RATT), including actuators for tilting and cyclical leg movement, is used for rehabilitation of severely disabled neurological patients. Following further engineering development of the system, i.e. the addition of force sensors and visual bio-feedback, patients can actively participate in exercise testing and training on the device. Peak cardiopulmonary performance parameters were previously investigated, but it also important to compare submaximal parameters with standard devices. The aim of this study was to evaluate the feasibility of the RATT for estimation of submaximal exercise thresholds by comparison with a cycle ergometer and a treadmill. 17 healthy subjects randomly performed six maximal individualized incremental exercise tests, with two tests on each of the three exercise modalities. The ventilatory anaerobic threshold (VAT) and respiratory compensation point (RCP) were determined from breath-by-breath data. VAT and RCP on the RATT were lower than the cycle ergometer and the treadmill: oxygen uptake (V'O2) at VAT was [mean (SD)] 1.2 (0.3), 1.5 (0.4) and 1.6 (0.5) L/min, respectively (p < 0.001); V'O2 at RCP was 1.7 (0.4), 2.3 (0.8) and 2.6 (0.9) L/min, respectively (p = 0.001). High correlations for VAT and RCP were found between the RATT vs the cycle ergometer and RATT vs the treadmill (R on the range 0.69-0.80). VAT and RCP demonstrated excellent test-retest reliability for all three devices (ICC from 0.81 to 0.98). Mean differences between the test and retest values on each device were close to zero. The ventilatory equivalent for O2 at VAT for the RATT and cycle ergometer were similar and both were higher than the treadmill. The ventilatory equivalent for CO2 at RCP was similar for all devices. Ventilatory equivalent parameters demonstrated fair-to-excellent reliability and repeatability. It is feasible to use the RATT for estimation of submaximal exercise thresholds: VAT and RCP on the RATT were lower than the

  6. Differential contributions of ankle plantarflexors during submaximal isometric muscle action

    DEFF Research Database (Denmark)

    Masood, Tahir; Bojsen-Møller, Jens; Kalliokoski, Kari K

    2014-01-01

    The objective of this study was to investigate the relative contributions of superficial and deep ankle plantarflexors during repetitive submaximal isometric contractions using surface electromyography (SEMG) and positron emission tomography (PET). Myoelectric signals were obtained from twelve....... The findings of this study provide valuable reference for studies where individual muscle contributions are estimated using models and simulations....

  7. An Investigation into Submaximal Endurance in Children with Motor ...

    African Journals Online (AJOL)

    This study investigated the submaximal endurance levels of children with motor difficulties, using the six-minute walk test (6MWT). A prospective, cross-sectional study was conducted. Forty-eight children between ages seven and ten years were enrolled. They came from similar socio-economic backgrounds and attended ...

  8. VO2 kinetics of constant-load exercise following bed-rest-induced deconditioning

    Science.gov (United States)

    Convertino, V. A.; Goldwater, D. J.; Sandler, H.

    1984-01-01

    Previous studies have shown that the oxygen uptake kinetics during exercise and recovery may be changed by alterations in work intensity, prior exercise, muscle group involvement, ambient conditions, posture, disease state, and level of physical conditioning. However, the effects of detraining on oxygen uptake kinetics have not been determined. The present investigation has the objective to determine the effects of deconditioning following seven days of continuous head-down bed rest on changes in steady-state oxygen uptake, O2 deficit, and recovery oxygen uptake during the performance of constant-load exercise. The obtained results may provide support for previous proposals that submaximal oxygen uptake was significantly reduced following bed rest. The major finding was that bed-rest deconditioning resulted in a reduction of total O2 transport/utilization capacity during the transient phase of upright but not supine exercise.

  9. Cardiorespiratory response to exercise on a large therapeutic roll.

    Science.gov (United States)

    Gappmaier, Eduard; Tavazoie, Sima F; Jacketta, Michael G

    2013-09-01

    Large therapeutic rolls (LTR) and balls are popular rehabilitation tools and have also been advertised as cardiovascular training devices. The aim of this study was to determine if individuals of varying fitness levels would reach aerobic training levels by evidence-based standards as described in American College of Sports Medicine (ACSM) publications. Fourteen volunteers performed a maximal exercise test and on subsequent days, two submaximal exercise tests on the LTR (LTR-A and -B). LTR-A consisted of four 5-minute stages of exercise at progressive intensity levels. LTR-B included 20 minutes of continuous exercise. Oxygen consumption (VO2) and heart rate (HR) during exercise on the LTR were compared with ACSM recommended standards. The average (range) peak intensity achieved during LTR-A was 66.8% (51.7-82.7%) of maximal VO2 reserve (VO2R) and 82.9% (70.7%-91.2%) of maximal heart rate (HRmax). During LTR-B, HR and VO2 of all participants was maintained at moderate exercise intensity and averaged 56% of VO2R and 78% of HRmax during the 20 minute exercise period. These findings suggest that individuals with a wide range of aerobic fitness are able to reach and maintain aerobic training levels with appropriate exercise on a large therapeutic roll or ball.

  10. Physical Education Teachers' Continuing Professional Development in Health-Related Exercise

    Science.gov (United States)

    Alfrey, Laura; Cale, Lorraine; Webb, Louisa A.

    2012-01-01

    Background: As a component of the physical education curriculum, Health-Related Exercise (HRE) has been subject to intensive critique in terms of its status, organisation and expression in schools. Concerns and questions have also been raised about physical education teachers' professional knowledge of health and the extent to which HRE features…

  11. Enhancing energy expenditure and enjoyment of exercise during pregnancy through the addition of brief higher intensity intervals to traditional continuous moderate intensity cycling

    OpenAIRE

    Ong, Ming Jing; Wallman, Karen E.; Fournier, Paul A.; Newnham, John P.; Guelfi, Kym J.

    2016-01-01

    Background Current guidelines recommend that pregnant women without contraindications should engage in 30?min or more of moderate intensity exercise on most days of the week, however, many women fail to achieve this goal. This study examined the effect of adding brief higher intensity intervals to traditional continuous moderate intensity exercise on energy expenditure and the enjoyment of exercise in late pregnancy. This is important to determine given that any additional energy expenditure ...

  12. The extent of aerobic system activation during continuous and interval exercise protocols in young adolescents and men.

    Science.gov (United States)

    Zafeiridis, Andreas; Rizos, Stylianos; Sarivasiliou, Haralampos; Kazias, Anastassios; Dipla, Konstantina; Vrabas, Ioannis S

    2011-02-01

    This study assessed the extent of aerobic system activation in young adolescents and men during heavy continuous (HC), short-interval (SI), and long-interval (LI) aerobic exercise protocols, and compared this response between the 2 age groups in the 3 protocols. Ten young adolescents (aged 13.2 ± 0.3 years) and 10 men (aged 21.0 ± 1.6 years) completed a maximal incremental test, an HC exercise protocol (83% of maximal aerobic velocity; MAV), an SI exercise protocol (30 s at 110% MAV with 30 s at 50%), and an LI exercise protocol (3 min at 95% MAV with 3 min at 35%). Oxygen consumption and heart rate were measured continuously, and blood samples were obtained for lactate determination. Men completed more runs and distance in the SI protocol (p age differences in the number of LI runs and in the duration of HC protocol. In both age groups, more time was spent above 90% and 95% of maximal oxygen consumption (p differences between the HC and SI protocols. Although within each protocol the percentage of maximal oxygen consumption achieved and time spent above 90% and 95% of maximal oxygen consumption was not different between age groups, the time spent at 80% maximal oxygen consumption was longer for adolescents than men in the HC protocol, and longer for men than boys in the SI protocol (p age groups. The LI protocol taxed the aerobic system at 90%-100% of maximal oxygen consumption for a longer time when compared with the HC and SI protocols in young adolescents and in men. However, differences were observed between groups in taxing the aerobic system at 80% maximal oxygen consumption: in young adolescents, the HC protocol allowed longer running time than the LI and SI protocols, while in men there were no differences among protocols.

  13. Exercise

    DEFF Research Database (Denmark)

    Idorn, Manja; thor Straten, Eivind Per

    2016-01-01

    We recently demonstrated that voluntary exercise leads to an influx of immune cells in tumors and a greater than 60% reduction in tumor incidence and growth across several mouse models. Improved immunological control of tumor progression may have important clinical implications in the prevention...... and treatment of cancer in humans....

  14. Comparison of Acute Physiological and Psychological Responses Between Moderate Intensity Continuous Exercise and three Regimes of High Intensity Training.

    Science.gov (United States)

    Green, Nicole; Wertz, Timothy; LaPorta, Zachary; Mora, Adam; Serbas, Jasmine; Astorino, Todd A

    2017-07-19

    High intensity interval training (HIIT) elicits similar physiological adaptations as moderate intensity continuous training (MICT) despite less time commitment. However, there is debate whether HIIT is more aversive than MICT. This study compared physiological and perceptual responses between MICT and three regimes of HIIT. Nineteen active adults (age = 24.0 ± 3.3 yr) unfamiliar with HIIT initially performed ramp exercise to exhaustion to measure maximal oxygen uptake (VO2 max) and determine workload for subsequent sessions, whose order was randomized. Sprint interval training (SIT) consisted of six 20 s bouts of "all-out" cycling at 140% of maximum watts (Wmax). Low volume (HIITLV) and high volume HIIT (HIITHV) consisted of eight 60 s bouts at 85% Wmax and six 2 min bouts at 70% Wmax, respectively. MICT consisted of 25 min at 40% Wmax. Across regimes, work was not matched. Heart rate, VO2, blood lactate concentration (BLa), affect, and rating of perceived exertion (RPE) were assessed during exercise. Ten minutes post-exercise, Physical Activity Enjoyment (PACES) was measured via a survey. Results revealed significantly higher (pregimes versus MICT at 50, 75, and 100 % of session duration, PACES was similar across regimes (p=0.65) although it was higher in women (p=0.03). Findings from healthy adults unaccustomed to interval training demonstrate that HIIT and SIT are perceived as enjoyable as MICT despite being more aversive.

  15. Effects of Submaximal Endurance Training and Vitamin D3 Supplementation on Pain Threshold in Diabetic Rats

    Directory of Open Access Journals (Sweden)

    S. Jalal Taherabadi

    2013-07-01

    Full Text Available Background: According to beneficial effects of endurance training and vitamin D3 in diabetes mellitus, purpose of this study is effects submaximal endurance training and vitamin D3 supplementation on pain threshold in streptozotocin induced diabetic rats.Materials and Methods: Male Wistar rats (250±20 g, N=40 were made diabetic by streptozotocin (60 mg/kg, subcutaneously. 72 h after injection diabetes induction was confirmed by tail vein blood glucose concentration (>300 mg/dl. Then animals were divided to five groups: diabetic control (DC, diabetic trained (DT, diabetic -vitamin D (DD, diabetic trained and vitamin D (DTD, and control (C. Animals were submitted to endurance training by treadmill and vitamin D3 treatment (twice aweek, intrapretonally for 4 weeks. 48 h after at the end of exercise and treatment protocol, we used tail-flick to assess the effects of training and vitamin D3 on thermal pain threshold. We used one way ANOVA statistical analysis to compare differences between groups, significance level of p<0.05 was considered.Results: Diabetic induced hyperalgesia were decreased significantly by vitamin D but not 4 weeks endurance exercise training. Concurrent effects of training and vitamin D on thermal pain threshold were not significantly higher than vitamin D effects alone.Conclusion: It is concluded that vitamin D administration given at the time of diabetes induction may be able to restore thermal hyperalgesia. But effects of endurance exercise training needs to more investigation in diabetic rats.

  16. Live high:train low increases muscle buffer capacity and submaximal cycling efficiency.

    Science.gov (United States)

    Gore, C J; Hahn, A G; Aughey, R J; Martin, D T; Ashenden, M J; Clark, S A; Garnham, A P; Roberts, A D; Slater, G J; McKenna, M J

    2001-11-01

    This study investigated whether hypoxic exposure increased muscle buffer capacity (beta(m)) and mechanical efficiency during exercise in male athletes. A control (CON, n=7) and a live high:train low group (LHTL, n=6) trained at near sea level (600 m), with the LHTL group sleeping for 23 nights in simulated moderate altitude (3000 m). Whole body oxygen consumption (VO2) was measured under normoxia before, during and after 23 nights of sleeping in hypoxia, during cycle ergometry comprising 4 x 4-min submaximal stages, 2-min at 5.6 +/- 0.4 W kg(-1), and 2-min 'all-out' to determine total work and VO(2peak). A vastus lateralis muscle biopsy was taken at rest and after a standardized 2-min 5.6 +/- 0.4 W kg(-1) bout, before and after LHTL, and analysed for beta(m) and metabolites. After LHTL, beta(m) was increased (18%, P buffer capacity. Further, reduced VO2 during normoxic exercise after LHTL suggests that improved exercise efficiency is a fundamental adaptation to LHTL.

  17. Stability Ball Sitting versus Chair Sitting During Sub-maximal Arm Ergometry.

    Science.gov (United States)

    Marks, Charles R C; Hylland, Kristina E; Terrell, Jacob

    It was predicted that sitting on a stability ball during arm ergometry would elevate cardiovascular parameters when compared to sitting on a chair and that this would be associated with greater recruitment of trunk and leg skeletal muscles. Open-circuit spirometry, videotaping, blood pressure, heart rate, and EMG were conducted during rest and four minute stages of 15 W, 30 W, and 45 W using a Monark arm ergometer. Twenty-six apparently healthy adults exercised twice, once sitting on a stability ball and the other sitting on a chair (order randomized), with 45 to 60 minutes of rest between. ANOVA for repeated measures and paired-t testing were used for analysis. Oxygen consumption was significantly 10 to 16% higher during exercise while sitting on the stability ball. There were no significant differences between sitting modes for heart rate, SBP, and DBP. Also, resting and exercise rectus femoris and 45 W external oblique EMGs were significantly higher on the stability ball. Finally, the knee was significantly more extended with the feet farther apart and more forward on the stability ball. The stability ball significantly elevates oxygen consumption during sub-maximal arm cranking without significantly increasing heart rate or blood pressure and this is associated with increased thigh muscle activation and lower leg repositioning.

  18. Adjunctive Use of Noninvasive Ventilation During Exercise in Patients With Decompensated Heart Failure.

    Science.gov (United States)

    Moraes, Igor Gutierrez; Kimoto, Karen Mota; Fernandes, Marcos Brandmuller; Grams, Samantha Torres; Yamaguti, Wellington Pereira

    2017-02-01

    Noninvasive ventilation (NIV) as an adjunct strategy for increasing exercise tolerance has been widely investigated in patients with pulmonary diseases. To our knowledge, there are no studies that have used NIV during exercise in patients with decompensated heart failure (HF). The aim of this study was to evaluate the effects of NIV on exercise tolerance in hospitalized patients with decompensated HF. Thirteen patients (77 ± 15 years) with a mean left ventricular ejection fraction of 35 ± 15% were included. Patients underwent 2 submaximal exercise tests with constant load for lower limbs using a portable cycle ergometer. Tests were performed on the same day with a 60-minute interval between each one, using a randomized crossover design: sham ventilation (continuous positive airway pressure mode, 4 cm H2O) and intervention situation (NIV in bilevel mode). Primary outcome was the endurance time performed during exercise tests with constant load. Submaximal exercise with NIV in bilevel mode improved endurance time (7.2 ± 2.7 minutes) compared to the tests performed with continuous positive airway pressure (5.1 ± 1.5 minutes; p = 0.008). Increase in endurance time (Δ time) with bilevel test showed a significant correlation with reduction in the slope of dyspnea (Δ Borg) over time (r = -0.73; p = 0.004). There was a significant correlation between endurance time in bilevel tests and maximum inspiratory pressure % predicted (r = 0.68; p = 0.02). In conclusion, NIV was effective in increasing exercise tolerance in hospitalized patients with decompensated HF. (ClinicalTrials.gov registration NCT02122848). Copyright © 2016 Elsevier Inc. All rights reserved.

  19. THE VALIDITY OF SUBMAXIMAL RATINGS OF PERCEIVED EXERTION TO PREDICT ONE REPETITION MAXIMUM

    Directory of Open Access Journals (Sweden)

    Harrison James Llewelyn Evans

    2009-12-01

    Full Text Available The One Repetition Maximum (1-RM test is commonly used to assess strength. However, direct assessments of 1-RM are time consuming and unsafe for novice lifters. Whilst various equations exist to predict 1-RM, there is limited research on the validity of these equations. The purpose of this study was to assess the validity of using sub-maximal ratings of perceived exertion (RPE to predict 1-RM in young adults, using the Borg 6-20 RPE Scale. Twenty healthy participants (ten male (Mean ± SD, 20.8 ± 0.6 y, 75.7 ± 9.3 kg, 1.8 ± 0.07 m and ten female (20.3 ± 0.7 y, 68.4 ± 10.0 kg, 1.68 ± 0.03 m completed two trials involving resistance exercises for both the upper and lower body. In the first trial the 1-RM for the bilateral biceps curl (BC and the bilateral knee extension (KE were determined for each participant. In the second trial, participants performed blinded repetitions which were equivalent to 20, 40 and 60 % of 1-RM for both exercises. The RPE was recorded immediately after two repetitions had been completed at each intensity. The order of intensity of the repetitions was randomly assigned with participants wearing blindfolds to exclude the possibility of pre-determined judgments about load and RPE. Individual RPE recorded at each intensity was subjected to linear regression analysis and the line of best fit was extrapolated to RPE 20 to predict 1-RM in both exercises. There was no significant difference (p > 0.05 between the 1-RM predicted from RPE 20 and measured 1-RM for both exercises for the men and women. Measured and predicted values for men were 46.0 ± 4.6 and 45.2 ± 6. 1 kg for biceps curl, and 46.3 ± 3.8 and 43.0 ± 7.1 kg for knee extension, respectively. Measured and predicted values for women were 18.6 ± 5.7 and 19.3 ± 5.6 kg for biceps curl, and 25.5 ± 9.6 and 27.2 ± 12.6 kg for knee extension, respectively. Pearson product-moment correlation coefficients between actual and predicted 1-RM for the BC and KE were 0

  20. A new submaximal cycle ergometer test for prediction of VO2max.

    Science.gov (United States)

    Ekblom-Bak, E; Björkman, F; Hellenius, M-L; Ekblom, B

    2014-04-01

    Maximal oxygen uptake (VO2max) is an important, independent predictor of cardiovascular health and mortality. Despite this, it is rarely measured in clinical practice. The aim of this study was to create and evaluate a submaximal cycle ergometry test based on change in heart rate (HR) between a lower standard work rate and an individually chosen higher work rate. In a mixed population (n = 143) with regard to sex (55% women), age (21-65 years), and activity status (inactive to highly active), a model included change in HR per unit change in power, sex, and age for the best estimate of VO2max. The association between estimated and observed VO2max for the mixed sample was r = 0.91, standard error of estimate = 0.302 L/min, and mean measured VO2max = 3.23 L/min. The corresponding coefficient of variation was 9.3%, a significantly improved precision compared with one of the most commonly used submaximal exercise tests, the Åstrand test, which in the present study was estimated to be 18.1%. Test-retest reliability analysis over 1 week revealed no mean difference in the estimated VO2max (-0.02 L/min, 95% confidence interval: -0.07-0.03). The new test is low-risk, easily administered, and valid for a wide capacity range, and is therefore suitable in situations as health evaluations in the general population. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Beyond Scale Correspondence: A Comparison of Continuous Open Scaling and Fixed Graded Scaling when Using Social Cognitive Constructs in the Exercise Domain

    Science.gov (United States)

    Rhodes, Ryan E.; Matheson, Deborah H.; Blanchard, Chris M.

    2006-01-01

    The standard response format for self-reported exercise-behavior measurement is the continuous open scale, but popular social cognitive theories use fixed graded scales, a noncorrespondent format. Benefits of using continuous open scales for social cognitive constructs include scale correspondence with the behavior measure, the potential of…

  2. Effect of pre-exercise carbohydrate ingestion on plasma cytokine, stress hormone, and neutrophil degranulation responses to continuous, high-intensity exercise.

    Science.gov (United States)

    Lancaster, Graeme I; Jentjens, Roy L P G; Moseley, Luke; Jeukendrup, Asker E; Gleeson, Michael

    2003-12-01

    The purpose of the present study was to examine the effect of pre-exercise carbohydrate (CHO) ingestion on circulating leukocyte numbers, plasma interleukin (IL)-6, plasma cortisol, and lipopolysaccharide (LPS)-stimulated neutrophil degranulation responses in moderately trained male cyclists who completed approximately 1-h of high-intensity cycling. The influence of the timing of pre-exercise CHO ingestion was investigated in 8 subjects who consumed 75 g CHO as a glucose solution at either 15 (-15 trial), or 75 (-75 trial) min before the onset of exercise. The influence of the amount of pre-exercise CHO ingestion was investigated in a further 10 subjects who consumed either 25 g or 200 g CHO as a glucose solution or a placebo 45 min before the onset of exercise. At the onset of exercise in the timing experiment, the plasma glucose concentration was significantly (p exercise period. In the -15 trial, plasma glucose level was well maintained, and the plasma cortisol concentration and N/L ratio were not significantly elevated above resting levels. However, LPS-stimulated neutrophil degranulation was similar in the -15 and -75 trials. The amount of CHO ingested had no effect on the magnitude of the rise in the N/L ratio compared with placebo when consumed 45 min pre-exercise. Finally, although an exercise-induced increase in the plasma IL-6 concentration was observed, this effect was independent of pre-exercise CHO ingestion.

  3. Enhancing energy expenditure and enjoyment of exercise during pregnancy through the addition of brief higher intensity intervals to traditional continuous moderate intensity cycling.

    Science.gov (United States)

    Ong, Ming Jing; Wallman, Karen E; Fournier, Paul A; Newnham, John P; Guelfi, Kym J

    2016-07-15

    Current guidelines recommend that pregnant women without contraindications should engage in 30 min or more of moderate intensity exercise on most days of the week, however, many women fail to achieve this goal. This study examined the effect of adding brief higher intensity intervals to traditional continuous moderate intensity exercise on energy expenditure and the enjoyment of exercise in late pregnancy. This is important to determine given that any additional energy expenditure resulting from higher intensity intervals may be meaningless if enjoyment is compromised, since long-term adherence will likely be low. In this study, 12 healthy pregnant women at 30 ± 1 weeks gestation, aged 35 ± 6 years with a BMI of 27.1 ± 4.3 kg/m(2) performed either 30 min of continuous cycling exercise (CONT) at a steady power output equivalent to 65 % age-predicted heart rate maximum or an equivalent period of interval cycling (INTV) consisting of continuous cycling at the same power output as CONT, but with the addition of six 15-s self-paced higher intensity efforts throughout, performed at regular intervals, on separate occasions in a counterbalanced order. Mean cycling power output, heart rate, oxygen consumption and energy expenditure were higher during INTV compared with CONT (P exercise was higher with INTV (P = 0.01). The addition of six 15-s higher intensity intervals to continuous moderate intensity exercise effectively increased energy expenditure by 28 %, at the same time as enhancing the enjoyment of exercise in late pregnancy. While these findings may be specific to recreationally active women, this study provides a rationale for future studies to examine the physiological and psychological responses to regular interval training during pregnancy to optimise exercise prescription. Australian New Zealand Clinical Trials Registry ACTRN12616000680460 . 25 May 2016 (Registered retrospectively).

  4. Continuation of exercise is necessary to inhibit high fat diet-induced β-amyloid deposition and memory deficit in amyloid precursor protein transgenic mice.

    Directory of Open Access Journals (Sweden)

    Masato Maesako

    Full Text Available High fat diet (HFD is prevalent in many modern societies and HFD-induced metabolic condition is a growing concern worldwide. It has been previously reported that HFD clearly worsens cognitive function in amyloid precursor protein (APP transgenic mice. On the other hand, we have demonstrated that voluntary exercise in an enriched environment is an effective intervention to rescue HFD-induced β-amyloid (Aβ deposition and memory deficit. However, it had been unclear whether consumption of HFD after exercising abolished the beneficial effect of exercise on the inhibition of Alzheimer's disease (AD pathology. To examine this question, we exposed wild type (WT and APP mice fed with HFD to exercise conditions at different time periods. In our previous experiment, we gave HFD to mice for 20 weeks and subjected them to exercise during weeks 10-20. In the present study, mice were subjected to exercise conditions during weeks 0-10 or weeks 5-15 while being on HFD. Interestingly, we found that the effect of exercise during weeks 0-10 or weeks 5-15 on memory function was not abolished in WT mice even if they kept having HFD after finishing exercise. However, in APP transgenic mice, HFD clearly disrupted the effect of exercise during weeks 0-10 or weeks 5-15 on memory function. Importantly, we observed that the level of Aβ oligomer was significantly elevated in the APP mice that exercised during weeks 0-10: this might have been caused by the up-regulation of Aβ production. These results provide solid evidence that continuation of exercise is necessary to rescue HFD-induced aggravation of cognitive decline in the pathological setting of AD.

  5. Self-Monitoring Using Continuous Glucose Monitors with Real-Time Feedback Improves Exercise Adherence in Individuals with Impaired Blood Glucose: A Pilot Study.

    Science.gov (United States)

    Bailey, Kaitlyn J; Little, Jonathan P; Jung, Mary E

    2016-03-01

    Exercise helps individuals with prediabetes or type 2 diabetes (T2D) manage their blood glucose (BG); however, exercise adherence in this population is dismal. In this pilot study we tested the efficacy of a self-monitoring group-based intervention using continuous glucose monitors (CGMs) at increasing exercise adherence in individuals with impaired BG. Thirteen participants with prediabetes or T2D were randomized to an 8-week standard care exercise program (CON condition) (n = 7) or self-monitoring exercise intervention (SM condition) (n = 6). Participants in the SM condition were taught how to self-monitor their exercise and BG, to goal set, and to use CGM to observe how exercise influences BG. We hypothesized that compared with the CON condition, using a real-time CGM would facilitate self-monitoring behavior, resulting in increased exercise adherence. Repeated-measures analysis of variance revealed significant Condition × Time interactions for self-monitoring (P self-efficacy to self-monitor (P = 0.01), such that the SM condition showed greater increases in these outcomes immediately after the program and at the 1-month follow-up compared with the CON condition. The SM condition had higher program attendance rates (P = 0.03), and a greater proportion of participants reregistered for additional exercise programs (P = 0.048) compared with the CON condition. Participants in both conditions experienced improvements in health-related quality of life, waist circumference, and fitness (P values self-monitoring and exercise behavior in individuals living with prediabetes or T2D.

  6. A submaximal test for the assessment of knee extensor endurance capacity.

    Science.gov (United States)

    De Ruiter, Cornelis J; Mallee, Max I P; Leloup, Lara E C; De Haan, Arnold

    2014-02-01

    We aimed to develop an undemanding test for endurance capacity of the knee extensor muscles, which can also be applied to frail participants. We hypothesized 1) that the first objective indications for peripheral fatigue during incremental unilateral repetitive isometric knee extensor contractions could be used to assess a fatigue threshold (FT), 2) that torque at FT would depend on training status, and 3) that this torque could easily be sustained for 30 min. Five trained and five untrained participants performed 5-min bouts of 60 repetitive contractions (3-s on and 2-s off). Torque, set at 25% maximal voluntary contraction (MVC), was increased by 5% MVC in subsequent bouts. The highest torque for which rectified surface EMG remained stable during the bout was defined as the FT. On separate occasions, 30-min bouts were performed at and above the FT to assess sustainable torque. Changes in gas exchange parameters, HR, and RPE were monitored to corroborate FT. At FT (RPE = 5.7 ± 1.7), torque was higher (P MVC) than in untrained participants (30.5% ± 1.8% MVC). Sustainable torque was ∼4% higher than (P MVC, significant increases in rectified surface EMG and V˙O2 were found. During incremental knee extensor contractions, FT could be assessed at a submaximal exercise intensity. FT was higher in trained than in untrained participants and was related to exercise sustainability. With the use of FT, changes in endurance capacity of single muscle groups can potentially also be determined in frail participants for whom exercise performed until exhaustion is unwarranted.

  7. Is energy expenditure taken into account in human sub-maximal jumping? - a simulation study

    NARCIS (Netherlands)

    Vanrenterghem, J.; Bobbert, M.F.; Casius, L.J.R.; de Clercq, D.

    2008-01-01

    This paper presents a simulation study that was conducted to investigate whether the stereotyped motion pattern observed in human sub-maximal jumping can be interpreted from the perspective of energy expenditure. Human sub-maximal vertical countermovement jumps were compared to jumps simulated with

  8. A New Submaximal Rowing Test to Predict 2,000-m Rowing Ergometer Performance

    NARCIS (Netherlands)

    Otter, Ruby T. A.; Brink, Michel S.; Lamberts, Robert P.; Lemmink, Koen A. P. M.

    Otter, RTA, Brink, MS, Lamberts, RP, and Lemmink, KAPM. A new submaximal rowing test to predict 2,000-m rowing ergometer performance. J Strength Cond Res 29(9): 2426-2433, 2015-The purpose of this study was to assess predictive value of a new submaximal rowing test (SmRT) on 2,000-m ergometer rowing

  9. Comparing VO2max determined by using the relation between heart rate and accelerometry with submaximal estimated VO2max.

    Science.gov (United States)

    Tönis, T M; Gorter, K; Vollenbroek-Hutten, M M R; Hermens, H

    2012-08-01

    An exploratory study to identify parameters that can be used for estimating a subject's cardio-respiratory physical fitness level, expressed as VO2max, from a combination of heart rate and 3D accelerometer data. Data were gathered from 41 healthy subjects (23 male, 18 female) aged between 20 and 29 years. The measurement protocol consisted of a sub-maximal single stage treadmill walking test for VO2max estimation followed by a walking test at two different speeds (4 and 5.5 kmh-1) for parameter determination. The relation between measured heart rate and accelerometer output at different walking speeds was used to get an indication of exercise intensity and the corresponding heart rate at that intensity. Regression analysis was performed using general subject measures (age, gender, weight, length, BMI) and intercept and slope of the relation between heart rate and accelerometer output during walking as independent variables to estimate the VO2max. A linear regression model using a combination of the slope and intercept parameters, together with gender revealed the highest percentage of explained variance (R2 = 0.90) and had a standard error of the estimate (SEE) of 2.052 mL O2kg-1min-1 with VO2max. Results are comparable with current commonly used sub-maximal laboratory tests to estimate VO2max. The combination of heart rate and accelerometer data seems promising for ambulant estimation of VO2max-.

  10. Exposure to a combination of heat and hyperoxia during cycling at submaximal intensity does not alter thermoregulatory responses

    Directory of Open Access Journals (Sweden)

    C Zinner

    2016-02-01

    Full Text Available In this study, we tested the hypothesis that breathing hyperoxic air (FinO2 = 0.40 while exercising in a hot environment exerts negative effects on the total tissue level of haemoglobin concentration (tHb; core (Tcore and skin (Tskin temperatures; muscle activity; heart rate; blood concentration of lactate; pH; partial pressure of oxygen (PaO2 and carbon dioxide; arterial oxygen saturation (SaO2; and perceptual responses. Ten well-trained male athletes cycled at submaximal intensity at 21°C or 33°C in randomized order: first for 20 min while breathing normal air (FinO2 = 0.21 and then 10 min with FinO2 = 0.40 (HOX. At both temperatures, SaO2 and PaO2, but not tHb, were increased by HOX. Tskin and perception of exertion and thermal discomfort were higher at 33°C than 21°C (p 0.07. Blood lactate and heart rate were higher at 33°C than 21°C. In conclusion, during 30 min of submaximal cycling at 21°C or 33°C, Tcore, Tskin and Tbody, tHb, muscle activity and ratings of perceived exertion and thermal discomfort were the same under normoxic and hyperoxic conditions. Accordingly, breathing hyperoxic air (FinO2 = 0.40 did not affect thermoregulation under these conditions.

  11. The Effect of Two Different Modes of Exercise Swimming and Vitamin C Supplementation on Anemia Indices in Male Wistar Rat

    OpenAIRE

    Fatemeh Lashkari; Mohammad Ali Samavati Sharif; Kamal Ranjbar

    2015-01-01

    Introduction: It has been shown that long term swimming exercise leads to anemia. Therefore the aim of the present study was the effect of vitamin C supplement and maximal and submaximal swimming exercise on anemia in without iron deficiency rats.Methods: For this purpose, 60 male wistar rats (6-8 week age and 170 -190 g weight) were divided into 6 groups: 1: Control rats (Con, n=10) 2: Vitamin C supplementation (Con+C, n=10) 3: Submaximal swimming (S, n=10) 4: Submaximal swimming + Vitamin C...

  12. The Impact of Central and Peripheral Cyclooxygenase Enzyme Inhibition on Exercise-Induced Elevations in Core Body Temperature.

    Science.gov (United States)

    Veltmeijer, Matthijs T W; Veeneman, Dineke; Bongers, Coen C C W; Netea, Mihai G; van der Meer, Jos W; Eijsvogels, Thijs M H; Hopman, Maria T E

    2017-05-01

    Exercise increases core body temperature (TC) due to metabolic heat production. However, the exercise-induced release of inflammatory cytokines including interleukin-6 (IL-6) may also contribute to the rise in TC by increasing the hypothalamic temperature set point. This study investigated whether the exercise-induced increase in TC is partly caused by an altered hypothalamic temperature set point. Fifteen healthy, active men age 36 ± 14 y were recruited. Subjects performed submaximal treadmill exercise in 3 randomized test conditions: (1) 400 mg ibuprofen and 1000 mg acetaminophen (IBU/APAP), (2) 1000 mg acetaminophen (APAP), and (3) a control condition (CTRL). Acetaminophen and ibuprofen were used to block the effect of IL-6 at a central and peripheral level, respectively. TC, skin temperature, and heart rate were measured continuously during the submaximal exercise tests. Baseline values of TC, skin temperature, and heart rate did not differ across conditions. Serum IL-6 concentrations increased in all 3 conditions. A significantly lower peak TC was observed in IBU/APAP (38.8°C ± 0.4°C) vs CTRL (39.2°C ± 0.5°C, P = .02) but not in APAP (38.9°C ± 0.4°C) vs CTRL. Similarly, a lower ΔTC was observed in IBU/APAP (1.7°C ± 0.3°C) vs CTRL (2.0°C ± 0.5°C, P skin temperature and heart-rate responses across conditions. The combined administration of acetaminophen and ibuprofen resulted in an attenuated increase in TC during exercise compared with a CTRL. This observation suggests that a prostaglandin-E2-induced elevated hypothalamic temperature set point may contribute to the exercise-induced rise in TC.

  13. Achievement of VO2max criteria during a continuous graded exercise test and a verification stage performed by college athletes.

    Science.gov (United States)

    Mier, Constance M; Alexander, Ryan P; Mageean, Amanda L

    2012-10-01

    The purpose of this study was to determine the incidence of meeting specific VO2max criteria and to test the effectiveness of a VO2max verification stage in college athletes. Thirty-five subjects completed a continuous graded exercise test (GXT) to volitional exhaustion. The frequency of achieving various respiratory exchange ratio (RER) and age-predicted maximum heart rate (HRmax) criteria and a VO2 plateau within 2 and 2.2 ml·kg(-1)·min(-1) (VO2max plateau was 5 (≤2 ml·kg(-1)·min(-1)) and 7 (≤2.2 ml·kg(-1)·min(-1)), RER criteria 34 (≥1.05), 32 (≥1.10), and 24 (≥1.15), HRmax criteria, 35 (VO2max and HRmax did not differ between GXT and the verification stage (53.6 ± 5.6 vs. 55.5 ± 5.6 ml·kg(-1)·min(-1) and 187 ± 7 vs. 187 ± 6 b·min(-1)); however, the RER was lower during the verification stage (1.15 ± 0.06 vs. 1.07 ± 0.07, p = 0.004). Six subjects achieved a similar VO2 (within 2.2 ml·kg(-1)·min(-1)), whereas 4 achieved a higher VO2 compared with the GXT. These data demonstrate that a continuous GXT limits the college athlete's ability to achieve VO2max plateau and certain RER and HR criteria. The use of a verification stage increases the frequency of VO2max achievement and may be an effective method to improve the accuracy of VO2max measurements in college athletes.

  14. The effect of maximal vs submaximal exertion on postprandial lipid levels in individuals with and without coronary heart disease.

    Science.gov (United States)

    Aronov, David M; Bubnova, Marina G; Perova, Natalia V; Orekhov, Alexander N; Bobryshev, Yuri V

    Decisions about fat consumption and levels of physical activity are among the everyday choices we make in life and risk of coronary heart disease (CHD) can be affected by those choices. The purpose of this study was to investigate the influence of a standard fat load combined with physical exertion of different intensities on the plasma lipid profile of CHD patients and CHD-free individuals. This study looked at the influence of different intensities of physical exercise on postprandial lipid metabolism in 20 healthy men and 36 men with diagnosis of CHD. Venous blood samples were obtained after overnight fasting, 3 hours after standard fat load (before the physical load), and immediately after maximal or submaximal physical exercise on bicycle ergometer. After fat load total cholesterol (TC) concentration did not change in either group. However, after the addition of maximal exercise, TC, triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and apolipoprotein (Apo) B increased significantly (P < .01) in both groups. After fat load and maximal exercise, there was no change in high-density lipoprotein cholesterol (HDL-C) in healthy men, but in men with CHD, HDL-C fell significantly (P < .01); and Apo AI rose in healthy men (P < .01) but dropped significantly (P < .01) in men with CHD. Submaximal physical exercise (60% of max VO2 load for 40 minutes) after fat load decreased TG level in CHD patients (P < .01) and improved other lipid parameters in both groups significantly (↓LDL-C, ↑HDL-C, ↑Apo AI, ↓Apo B, P < .01). We observed a worsening of physical work capacity in men with CHD (significant reduction of duration and total amount of work performed, maximal VO2, oxygen pulse), during maximal stress test performed 3 hours after fat load. There was a doubling of the number of abnormal stress test results (P < .01). Healthy persons showed an increase in respiratory parameters (ventilation, CO2 production, maximal VO2, and oxygen

  15. Prescription of aerobic exercise during pregnancy.

    Science.gov (United States)

    Wolfe, L A; Hall, P; Webb, K A; Goodman, L; Monga, M; McGrath, M J

    1989-11-01

    Available evidence supports the existence of both risks and benefits of aerobic conditioning during human pregnancy. During intensive exertion, maternal skeletal muscle and the fetus may compete for blood flow, oxygen delivery and essential fuel substrates. Hence, the most important hypothetical risks include acute fetal hypoxia, hyperthermia and malnutrition. If exercise is repeated on a chronic basis, teratogenic effects, fetal growth retardation or altered fetal development may result if maternal/fetal adaptive reserve is exceeded. A dose-response relationship for such effects has been demonstrated in laboratory animals, but specific findings may have limited applicability to voluntary exercise in pregnant women. Although further investigation is needed, the majority of published studies suggest that fitness-type conditioning does not jeopardise fetal well-being in healthy well-nourished women. Benefits of such exercise appear to include increases in maximal aerobic power (VO2max, L/min) and enhanced cardiopulmonary reserve. It has also been proposed that exercise prevents accumulation of excess body fat, promotes psychological well-being, helps to prevent gestational diabetes and low back pain and may facilitate labour. However, these benefits remain to be confirmed by objective scientific study. Due primarily to a lack of scientific data, existing medical guidelines for exercise during pregnancy are conservative and follow a common sense approach. Good agreement exists on the need for preparticipation medical screening and continuing surveillance to verify the existence of maternal/fetal adaptive reserve. Women are advised to select safe, non-ballistic exercise modalities and to avoid thermal or hyperbaric environmental stress during exercise. Exercise in the supine position is also prudent to avoid, particularly in late gestation. The usefulness of heart rate in prescribing and monitoring exercise intensity has been questioned, with use of conventional

  16. Developing new VO2max prediction models from maximal, submaximal and questionnaire variables using support vector machines combined with feature selection.

    Science.gov (United States)

    Abut, Fatih; Akay, Mehmet Fatih; George, James

    2016-12-01

    Maximal oxygen uptake (VO2max) is an essential part of health and physical fitness, and refers to the highest rate of oxygen consumption an individual can attain during exhaustive exercise. In this study, for the first time in the literature, we combine the triple of maximal, submaximal and questionnaire variables to propose new VO2max prediction models using Support Vector Machines (SVM's) combined with the Relief-F feature selector to predict and reveal the distinct predictors of VO2max. For comparison purposes, hybrid models based on double combinations of maximal, submaximal and questionnaire variables have also been developed. By utilizing 10-fold cross-validation, the performance of the models has been calculated using multiple correlation coefficient (R) and root mean square error (RMSE). The results show that the best values of R and RMSE, with 0.94 and 2.92mLkg-1min-1 respectively, have been obtained by combining the triple of relevantly identified maximal, submaximal and questionnaire variables. Compared with the results of the rest of hybrid models in this study and the other prediction models in literature, the reported values of R and RMSE have been found to be considerably more accurate. The predictor variables gender, age, maximal heart rate (MX-HR), submaximal ending speed (SM-ES) of the treadmill and Perceived Functional Ability (Q-PFA) questionnaire have been found to be the most relevant variables in predicting VO2max. The results have also been compared with that of Multilayer Perceptron (MLP) and Tree Boost (TB), and it is seen that SVM significantly outperforms other regression methods for prediction of VO2max. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Dynamic cerebral autoregulation changes during sub-maximal handgrip maneuver.

    Directory of Open Access Journals (Sweden)

    Ricardo C Nogueira

    Full Text Available PURPOSE: We investigated the effect of handgrip (HG maneuver on time-varying estimates of dynamic cerebral autoregulation (CA using the autoregressive moving average technique. METHODS: Twelve healthy subjects were recruited to perform HG maneuver during 3 minutes with 30% of maximum contraction force. Cerebral blood flow velocity, end-tidal CO₂ pressure (PETCO₂, and noninvasive arterial blood pressure (ABP were continuously recorded during baseline, HG and recovery. Critical closing pressure (CrCP, resistance area-product (RAP, and time-varying autoregulation index (ARI were obtained. RESULTS: PETCO₂ did not show significant changes during HG maneuver. Whilst ABP increased continuously during the maneuver, to 27% above its baseline value, CBFV raised to a plateau approximately 15% above baseline. This was sustained by a parallel increase in RAP, suggestive of myogenic vasoconstriction, and a reduction in CrCP that could be associated with metabolic vasodilation. The time-varying ARI index dropped at the beginning and end of the maneuver (p<0.005, which could be related to corresponding alert reactions or to different time constants of the myogenic, metabolic and/or neurogenic mechanisms. CONCLUSION: Changes in dynamic CA during HG suggest a complex interplay of regulatory mechanisms during static exercise that should be considered when assessing the determinants of cerebral blood flow and metabolism.

  18. Design and testing of an MRI-compatible cycle ergometer for non-invasive cardiac assessments during exercise

    Directory of Open Access Journals (Sweden)

    Gusso Silmara

    2012-03-01

    Full Text Available Abstract Background Magnetic resonance imaging (MRI is an important tool for cardiac research, and it is frequently used for resting cardiac assessments. However, research into non-pharmacological stress cardiac evaluation is limited. Methods We aimed to design a portable and relatively inexpensive MRI cycle ergometer capable of continuously measuring pedalling workload while patients exercise to maintain target heart rates. Results We constructed and tested an MRI-compatible cycle ergometer for a 1.5 T MRI scanner. Resting and sub-maximal exercise images (at 110 beats per minute were successfully obtained in 8 healthy adults. Conclusions The MRI-compatible cycle ergometer constructed by our research group enabled cardiac assessments at fixed heart rates, while continuously recording power output by directly measuring pedal force and crank rotation.

  19. Reliability and Seasonal Changes of Submaximal Variables to Evaluate Professional Cyclists.

    Science.gov (United States)

    Rodríguez-Marroyo, Jose A; Pernía, Raúl; Villa, José G; Foster, Carl

    2017-11-01

    The aim of this study was to determine the reliability and validity of several submaximal variables that can be easily obtained by monitoring cyclists' performances. Eighteen professional cyclists participated in this study. In a first part (n = 15) the test-retest reliability of heart rate (HR) and rating of perceived exertion (RPE) during a progressive maximal test was measured. Derived submaximal variables based on HR, RPE, and power output (PO) responses were analyzed. In a second part (n = 7) the pattern of the submaximal variables according to cyclists' training status was analyzed. Cyclists were assessed 3 times during the season: at the beginning of the season, before the Vuelta a España, and the day after this Grand Tour. Part 1: No significant differences in maximal and submaximal variables between test-retest were found. Excellent ICCs (0.81-0.98) were obtained in all variables. Part 2: The HR and RPE showed a rightward shift from early to peak season. In addition, RPE showed a left shift after the Vuelta a España. Submaximal variables based on RPE had the best relationship with both performance and changes in performance. The present study showed the reliability of different maximal and submaximal variables used to assess cyclists' performances. Submaximal variables based on RPE seem to be the best to monitor changes in training status over a season.

  20. A Systematic Review of Submaximal Cycle Tests to Predict, Monitor, and Optimize Cycling Performance.

    Science.gov (United States)

    Capostagno, Benoit; Lambert, Michael I; Lamberts, Robert P

    2016-09-01

    Finding the optimal balance between high training loads and recovery is a constant challenge for cyclists and their coaches. Monitoring improvements in performance and levels of fatigue is recommended to correctly adjust training to ensure optimal adaptation. However, many performance tests require a maximal or exhaustive effort, which reduces their real-world application. The purpose of this review was to investigate the development and use of submaximal cycling tests that can be used to predict and monitor cycling performance and training status. Twelve studies met the inclusion criteria, and 3 separate submaximal cycling tests were identified from within those 12. Submaximal variables including gross mechanical efficiency, oxygen uptake (VO2), heart rate, lactate, predicted time to exhaustion (pTE), rating of perceived exertion (RPE), power output, and heart-rate recovery (HRR) were the components of the 3 tests. pTE, submaximal power output, RPE, and HRR appear to have the most value for monitoring improvements in performance and indicate a state of fatigue. This literature review shows that several submaximal cycle tests have been developed over the last decade with the aim to predict, monitor, and optimize cycling performance. To be able to conduct a submaximal test on a regular basis, the test needs to be short in duration and as noninvasive as possible. In addition, a test should capture multiple variables and use multivariate analyses to interpret the submaximal outcomes correctly and alter training prescription if needed.

  1. Thermal perceptions and skin temperatures during continuous and intermittent ventilation of the torso throughout and after exercise in the heat.

    Science.gov (United States)

    Davey, Sarah L; Barwood, Martin J; Tipton, Michael J

    2013-11-01

    This study tested the hypothesis that intermittent cooling in air-perfused vests (APV) will not only maintain thermal balance but, due to cyclical activations of cutaneous thermoreceptors, also enhance thermal perceptions. Ten physically active males completed four conditions where they exercised (walking: 5 km h(-1), 2 % gradient) in a hot environment (~34.0 °C, 50 % RH) for 72 min, followed by a 33-min period of rest. They wore an APV throughout. The four conditions differed in respect to the profile of ambient air that was perfused through the APV: continuous perfusion (CP); intermittent perfusion of 6 min ON/OFF periods (IPonoff); a steady increase and decrease in flow rate in equal increments (IPramp); and an initial step-increase in the flow rate followed by an incremental decrease to zero flow rate (IPtriang). Whole body and torso thermal comfort (TC, TTC), whole body and torso temperature sensation (TS, TTS), whole body and torso skin temperature ([Formula: see text], [Formula: see text]), local relative humidity ([Formula: see text]) and rectal temperature (T re) were measured. There were no significant differences in T re, absolute whole body and local [Formula: see text], TC, TTC and TS between the cooling profiles. However, TTS was cooler in CP and IPramp than IPonoff and IPtriang. Even though intermittent cooling did not significantly enhance thermal perceptions in CP, a trend existed for TC (P = 0.063) to become less favourable over time. To reduce the power consumption and extend the battery life of an APV, it is recommended that an intermittent cooling profile should be adopted.

  2. The influence of evaluation protocol on time spent exercising at a high level of oxygen uptake during continuous cycling

    OpenAIRE

    Merry, KL; Glaister, Mark; Howatson, Glyn; Van Someren, Ken A.

    2015-01-01

    AIM: This study evaluated the effects of protocol variation on the time spent exercising at ≥95% .VO2max during cycle ergometer trials performed at the exercise intensity associated with .VO2max (i .VO2max).\\ud METHODS: Nine male triathletes (age: 32±10 years; body mass: 73.3±6.1 kg; stature: 1.79±0.07 m; .VO2max: 3.58±0.45 L.min-1) performed four exercise tests. During tests 1 and 2, participants performed a maximal incremental cycle ergometer test using different stage durations (1 min and ...

  3. Does continuous endurance exercise in water elicit a higher release of ANP and BNP and a higher plasma concentration of FFAs in pre-obese and obese men than high intensity intermittent endurance exercise? - study protocol for a randomized controlled trial.

    Science.gov (United States)

    Karner-Rezek, Klaus; Knechtle, Beat; Fenzl, Matthias; Gredig, Joeri; Rosemann, Thomas

    2013-10-10

    Atrial natriuretic peptides (ANP) and Brain natriuretic peptides (BNP) stimulate fat cell plasma membrane receptors. They are potent lipolytic agents on isolated fat cells from subcutaneous adipose tissue. The physiological effects of continuous endurance exercise on ANP release and plasma free fatty acids (FFA) concentrations have been well described. The enhancement of fat metabolism using high intensity intermittent exercise protocols has been assessed in more recent investigations. The combined effects of endurance exercise and water immersion on ANP and FFA plasma concentration and the magnitude of excess post-exercise oxygen consumption (EPOC) might be further enhanced by choosing the most effective exercise protocol. Exercise modalities may play a significant role in the future prevention and treatment of obesity. The two testing trials will be performed according to a randomized and cross-over design. Twenty healthy sedentary pre-obese and obese class-1 men will be scrutinized with regard to their metabolic responses to continuous exercise in water and to high intensity endurance exercise in water. Both trials will be matched for energy expenditure. After preliminary testing, the tests will be conducted as repeated measurements. The two different exercise protocols will be compared. The aims of the study are to investigate (1) whether continuous endurance exercise or high intensity intermittent endurance exercise in water elicits both a higher release of ANP and BNP and a higher plasma concentration of glycerol and (2) to determine whether continuous endurance exercise in water or a high intensity intermittent endurance exercise in water would lead to a more pronounced short term (two hours) EPOC effect. If our hypothesis would be confirmed, the most effective exercise protocol based on the combined effects of high intensity endurance exercise and water immersion on ANP and BNP release and glycerol plasma concentrations can be identified. Moreover, the

  4. Long term effects of a continuous and intermittent aerobic exercise on weight changes and body fat percentage in overweight and obese women

    Directory of Open Access Journals (Sweden)

    Alizadeh Z

    2013-01-01

    Full Text Available Background: Obesity and sedentary lifestyle are growing problem. The global community's concern is to find the best strategy to obtain a more efficient process of weight reduction, increase physical activity, and minimize weight regain level. The purpose of this study was to evaluate the long-term effects of a short-term intervention on weight changes.Methods: The present study is a one-year follow-up study of a 12-week intervention during which the 15 individuals in the intermittent group performed 40 minutes exercise in three bouts per day; however, the 15 participants of the continuous group did the same but 40 minutes continuously. The 15 participants in the control group had no exercise prescription. After one year, weight changes, body fat percentage, and BMI were re-evaluated in the groups.Results: After adjusting the baseline weight, patterns of change in the mean weights from the end of the third month to the twelfth month were different across groups (P=0.02. After significant weight loss in the intermittent group, the mean weight in this group increased by 2.32 kilograms during the period, although not statistically significant. No increase was observed in the control group’s mean weight (P=1.00. In the continuous group, the mean weight increased statistically (P=0.048, 3.63 kilograms.Conclusion: It seems that long-term effects of moderate intensity intermittent aerobic exercise in overweight and obese women on weight control are more efficient than those of continuous exercise. However, for a change in lifestyle and prevention of weight regain, longer follow-ups are required.

  5. Effect of high-intensity interval versus continuous exercise training on functional capacity and quality of life in patients with coronary artery disease.

    OpenAIRE

    Villelabeitia Jaureguizar, Koldobika; Vicente Campos, Davinia; Ruiz Bautista, Lorena; Hernández de la Peña, César; Arriaza Gómez, María José; Calero Rueda, María José; Mahillo Fernández, Ignacio

    2015-01-01

    There is strong evidence that exercise training has beneficial health effects in patients with cardiovascular disease. Most studies have focused on moderate continuous training (MCT); however, a body of evidence has begun to emerge demonstrating that highintensity interval training (HIIT) has significantly better results in terms of morbidity and mortality. The aim of this study was to compare the effects of MCT versus HIIT on functional capacity and quality of life and t...

  6. Effects of Three-Day Bed Rest on Physiological Responses to Graded Exercise in Endurance Athletes, Body Builders and Sedentary Men

    Science.gov (United States)

    Smorawinski, J.; Nazar, K.; Kaciuza-Uscilko, H.; Kaminska, E.; Cybulski, G.; Kodrzycka, A.; Bice, B.; Greenleaf, J. E.; Sun, Sid (Technical Monitor)

    2001-01-01

    To test the hypotheses that short-term bed rest (BR) deconditioning influences metabolic, cardiorespiratory and neurohormonal responses to exercise and that these effects depend on the subjects' training status 12 sedentary men, and 10 endurance- and 10 strength-trained athletes were submitted to three-day BR. Before and after BR they performed incremental exercise test until volitional exhaustion. Respiratory gas exchange and HR were recorded continuously and stroke volume (SV) was measured at submaximal loads. Blood was taken for lactate [LA], adrenaline [A], noradrenaline, [NA], renting activity (PRA), growth hormone [hGH], testosterone and cortisol determination. Reduction of peak oxygen uptake (VO2peak) after BR was greater in the endurance athletes (than in the remaining groups (17 % vs. 100%). Decrements in VO2peak correlated positively with the initial values (r = 0.73, p less than 0.001). Resting and exercise respiratory exchange ratios were increased in athletes. Cardiac output was unchanged by BR in all groups, but exercise HR was increased and SV diminished in the sedentary subjects. The submaximal [LA] and [LA] thresholds were decreased the in endurance athletes from 71 to 60 %VO2 peak (p less than 0.001); they also had an earlier increase in [NA], and an attenuated increase in [hGH), and accentuated PRA and cortisol elevations during exercise. These effects were insignificant in the remaining subjects. In conclusion: reduction of exercise performance and modifications in neurohormonal response to exercise after BR depend on the previous level and mode of physical training, being the most pronounced in the endurance athletes.

  7. Inflight Exercise Regimen for the 2-Hour Prebreathe Protocol

    Science.gov (United States)

    Foster, Philip P.; Gernhardt, Michael L.; Woodruff, Kristin K.; Schneider, Susan M.; Homick, Jerry L. (Technical Monitor)

    2000-01-01

    A 10 min aerobic prebreathe exercise up to 75% V-O2(sub max) on a dual-cycle ergometer, included in the 2-hour prebreathe protocol, has been shown to dramatically reduce the incidence of decompression sickness (DCS) at altitude. In-flight only leg ergometry will be available. A balanced exercise was developed using surgical tubing with the ergometer on-orbit. We hypothesize that a 75% V02max workload, individually prescribed, would be achieved using a target heart rate to regulate the intensity of the arm exercise. VO2, heart rate (HR) / ECG, V-CO2 /V-O2, V(sub E), and V(sub T), and rate of perceived exertion (Borg scale) were measured in eleven healthy subjects who passed a US Air Force Class III Physical examination. A V-O2 peak test was performed to assess the sub-maximal exercise prescription. Two series of sub-maximal tests were performed: (1) leg ergometer/hand ergometer and (2) leg ergometer/surgical tubes. We found no significant differences (P > 0.05) in comparing the means for V-O2 and HR between the predicted and measured values during the final 4 minute-stage at "75% V-O2 workload" or between the two types of sub-maximal tests. The prescribed prebreathe sub-maximal exercise performed with flight certified surgical tubes was achieved using the target HR.

  8. Validated Predictions of Metabolic Energy Consumption for Submaximal Effort Movement.

    Directory of Open Access Journals (Sweden)

    George A Tsianos

    2016-06-01

    Full Text Available Physical performance emerges from complex interactions among many physiological systems that are largely driven by the metabolic energy demanded. Quantifying metabolic demand is an essential step for revealing the many mechanisms of physical performance decrement, but accurate predictive models do not exist. The goal of this study was to investigate if a recently developed model of muscle energetics and force could be extended to reproduce the kinematics, kinetics, and metabolic demand of submaximal effort movement. Upright dynamic knee extension against various levels of ergometer load was simulated. Task energetics were estimated by combining the model of muscle contraction with validated models of lower limb musculotendon paths and segment dynamics. A genetic algorithm was used to compute the muscle excitations that reproduced the movement with the lowest energetic cost, which was determined to be an appropriate criterion for this task. Model predictions of oxygen uptake rate (VO2 were well within experimental variability for the range over which the model parameters were confidently known. The model's accurate estimates of metabolic demand make it useful for assessing the likelihood and severity of physical performance decrement for a given task as well as investigating underlying physiologic mechanisms.

  9. Modelling the Effect of Exercise on Insulin Pharmacokinetics in "Continuous Subcutaneous Insulin Infusion" Treated Type 1 Diabetes Patients

    DEFF Research Database (Denmark)

    Duun-Henriksen, Anne Katrine; Juhl, Rune; Schmidt, Signe

    infusion (CSII) treated patients by modelling the absorption rate as a function of exercise. Methods: Three models are estimated from 17 data sequences. All of them are based on a linear three-compartment base model. The models are based on stochastic differential equations to allow noise to enter...... the dynamics. In the first model, the insulin absorption rate parameter is replaced by a random walk. In the second model, the relationship between the absorption rate and exercise is modelled as a linear dependency, while in the third model this linear relationship depends on the intensity. A Lamperti...

  10. Effects of menstrual phase and amenorrhea on exercise performance in runners.

    Science.gov (United States)

    De Souza, M J; Maguire, M S; Rubin, K R; Maresh, C M

    1990-10-01

    There are few well controlled studies in terms of subject selection, menstrual classification, and exercise protocol that have examined both maximal and submaximal exercise responses during different phases of the menstrual cycle in eumenorrheic runners and compared these runners to amenorrheic runners. Thus, the purpose of this study was to measure selected physiological and metabolic responses to maximal and submaximal exercise during two phases of the menstrual cycle in eumenorrheic runners and amenorrheic runners. Eight eumenorrheic runners (29.0 +/- 4.2 yr) and eight amenorrheic runners (24.5 +/- 5.7 yr) matched for physical, gynecological, and training characteristics were studied. The eumenorrheic runners performed one maximal and one submaximal (40 min at 80% VO2max) treadmill run during both the early follicular (days 2-4) and midluteal (6-8 d from LH surge) phases. The amenorrheic runners performed one maximal and one submaximal (40 min at 80% VO2max) treadmill run. Cycle phases were documented by urinary luteinizing hormone and progesterone assays and by plasma estradiol and progesterone assays. No differences were observed in oxygen uptake, minute ventilation, heart rate, respiratory exchange ratio, rating of perceived exertion, time to fatigue (maximal), and plasma lactate (following the maximal and submaximal exercise tests) between the follicular and luteal phases in the eumenorrheic runners and the amenorrheic runners. We conclude that neither menstrual phase (follicular vs luteal) nor menstrual status (eumenorrheic vs amenorrheic) alters or limits exercise performance in female athletes.

  11. The Gravity-Loading countermeasure Skinsuit (GLCS) and its effect upon aerobic exercise performance

    Science.gov (United States)

    Attias, Julia; Philip, A. T. Carvil; Waldie, James; Russomano, Thais; Simon, N. Evetts; David, A. Green

    2017-03-01

    The Russian Pingvin suit is employed as a countermeasure to musculoskeletal atrophy in microgravity, though its 2-stage loading regime is poorly tolerated. The Gravity-Loading Countermeasure Skinsuit (GLCS) has been devised to comfortably compress the body via incrementally increasing longitudinal elastic-fibre tensions from the shoulders to the feet. We tested whether the Mk III GLCS was a feasible adjunct to sub-maximal aerobic exercise and resulting VO2Max predictions. Eight healthy subjects (5♂, 28±6 yr) performed cycle ergometry at 75% VO2Max (derived from an Astrand-Rhyming protocol) whilst wearing a GLCS and gym clothing (GYM). Ventilatory parameters, heart rate (HR), core temperature (TC), and blood lactate (BL) were recorded along with subjective perceived exertion, thermal comfort, movement discomfort and body control. Physiological and subjective responses were compared over TIME and between GYM and GLCS (ATTIRE) with 2-way repeated measures ANOVA and Wilcoxon tests respectively. Resultant VO2Max predictions were compared with paired t-tests between ATTIRE. The GLCS induced greater initial exercise ventilatory responses which stabilised by 20 min. HR and TC continued to rise from 5 min irrespective of ATTIRE, whereas BL was greater in the GLCS at 20 min. Predicted V O2Max did not differ with ATTIRE, though some observed differences in HR were noteworthy. All subjective ratings were exacerbated in the GLCS. Despite increased perception of workload and initial ventilatory augmentations, submaximal exercise performance was not impeded. Whilst predicted VO2Max did not differ, determination of actual VO2Max in the GLCS is warranted due to apparent modulation of the linear HR-VO2 relationship. The GLCS may be a feasible adjunct to exercise and potential countermeasure to unloaded-induced physiological deconditioning on Earth or in space.

  12. Effects of 3-day bed rest on physiological responses to graded exercise in athletes and sedentary men

    Science.gov (United States)

    Smorawinski, J.; Nazar, K.; Kaciuba-Uscilko, H.; Kaminska, E.; Cybulski, G.; Kodrzycka, A.; Bicz, B.; Greenleaf, J. E.

    2001-01-01

    To test the hypotheses that short-term bed-rest (BR) deconditioning influences metabolic, cardiorespiratory, and neurohormonal responses to exercise and that these effects depend on the subjects' training status, 12 sedentary men and 10 endurance- and 10 strength-trained athletes were submitted to 3-day BR. Before and after BR they performed incremental exercise test until volitional exhaustion. Respiratory gas exchange and heart rate (HR) were recorded continuously, and stroke volume (SV) was measured at submaximal loads. Blood was taken for lactate concentration ([LA]), epinephrine concentration ([Epi]), norepinephrine concentration ([NE]), plasma renin activity (PRA), human growth hormone concentration ([hGH]), testosterone, and cortisol determination. Reduction of peak oxygen uptake (VO(2 peak)) after BR was greater in the endurance athletes than in the remaining groups (17 vs. 10%). Decrements in VO(2 peak) correlated positively with the initial values (r = 0.73, P physical training, being the most pronounced in the endurance athletes.

  13. Acute Warm-up Effects in Submaximal Athletes: An EMG Study of Skilled Violinists.

    Science.gov (United States)

    McCrary, J Matt; Halaki, Mark; Sorkin, Evgeny; Ackermann, Bronwen J

    2016-02-01

    Warm-up is commonly recommended for injury prevention and performance enhancement across all activities, yet this recommendation is not supported by evidence for repetitive submaximal activities such as instrumental music performance. The objective of this study is to quantify the effects of cardiovascular, core muscle, and musical warm-ups on muscle activity levels, musical performance, and subjective experience in skilled violinists. Fifty-five undergraduate, postgraduate, or professional violinists performed five randomly ordered 45-s musical excerpts of varying physical demands both before and after a randomly assigned 15-min, moderate-intensity cardiovascular, core muscle, musical (technical violin exercises), or inactive control warm-up protocol. Surface EMG data were obtained for 16 muscles of the trunk, shoulders, and right arm during each musical performance. Sound recording and perceived exertion (RPE) data were also obtained. Sound recordings were randomly ordered and rated for performance quality by blinded adjudicators. Questionnaire data regarding participant pain sites and fitness levels were used to stratify participants according to pain and fitness levels. Data were analyzed using two- and three-factor ANCOVA (surface EMG and sound recording) and Wilcoxon matched pairs tests (RPE). None of the three warm-up protocols had significant effects on muscle activity levels (P ≥ 0.10). Performance quality did not significantly increase (P ≥ 0.21). RPE significantly decreased (P 0.23). Acute physiological and musical benefits from cardiovascular, core muscle, and musical warm-ups in skilled violinists are limited to decreases in RPE. This investigation provides data from the performing arts in support of sports medical evidence suggesting that warm-up only effectively enhances maximal strength and power performance.

  14. Dissociation between lactate and proton exchange in muscle during intense exercise in man

    DEFF Research Database (Denmark)

    Bangsbo, Jens; Juel, Carsten; Hellsten, Ylva

    1997-01-01

    , the difference between net proton and lactate release was positive throughout exercise and of similar magnitude in N and H. 5. The present data suggest that (1) H+ exchange in muscle during submaximal exercise can to a large extent occur through mechanisms other than via coupling to lactate; (2) muscle transport...

  15. Ethnic differences in vascular responses to aerobic exercise.

    Science.gov (United States)

    Foulds, Heather J A; Bredin, Shannon S D; Warburton, Darren E R

    2015-02-01

    Indigenous populations currently experience greater rates of cardiovascular disease. Although ethnic differences in cardiovascular responses to exercise have previously been identified, these responses among indigenous populations are unknown. This investigation aimed to evaluate the vascular responses to aerobic exercise of Canadian indigenous and European adults. Twelve age- and sex-matched indigenous and European adults completed a cycle ergometer maximal aerobic power test and submaximal 30 min of 60% maximal aerobic capacity on two separate days. Blood pressure, pulse wave velocity, baroreceptor sensitivity, arterial compliance, vascular resistance, and intima-media thickness were directly measured before and after aerobic exercises. Vascular responses to exercise were generally similar between indigenous and European adults including decreases in baroreceptor sensitivity and vascular resistance after maximal exercise. No changes in intima-media thickness, pulse wave velocity, and arterial compliance were observed after exercise in either group. However, after submaximal exercise, only European adults demonstrated reductions in baroreceptor sensitivity (spectral: 9.2 ± 4.3 to 11.5 ± 6.7 ms·mm Hg, P = 0.41, vs 15.8 ± 8.3 m·s to 8.9 ± 5.7 ms·mm Hg, P = 0.02; sequence: 14.6 ± 5.4 to 16.5 ± 11.0 ms·mm Hg, P = 0.48, vs 26.2 ± 10.5 m·s to 15.4 ± 9.4 ms·mm Hg, P = 0.02). Similarly, decreases in blood pressure after exercise were observed only among European adults. Indigenous adults demonstrated vascular responses similar to those demonstrated by European adults, although blood pressure was only observed to decrease among European adults after maximal and submaximal exercise, and baroreceptor sensitivity, after submaximal exercise.

  16. Exercise performance, core temperature, and metabolism after prolonged restricted activity and retraining in dogs

    Science.gov (United States)

    Nazar, K.; Greenleaf, J. E.; Pohoska, E.; Turlejska, E.; Kaciuba-Uscilko, H.; Kozlowski, S.

    1992-01-01

    Physiological effects of restricted activity (RA) and subsequent retraining have been studied. Ten male mongrel dogs performed a submaximal exercise endurance test on a treadmill during kennel control, after 8 weeks of cage confinement and after eight weeks of retraining using the same treadmill protocol 1 h/d for 6 d/week. Data obtained show that RA reduces exercise endurance, the effectiveness of exercise thermoregulation, muscle glycogen stores, and the lipolytic response to exercise and to noradrenaline stimulation.

  17. Actual Versus Predicted Cardiovascular Demands in Submaximal Cycle Ergometer Testing.

    Science.gov (United States)

    Hoehn, Amanda M; Mullenbach, Megan J; Fountaine, Charles J

    The Astrand-Rhyming cycle ergometer test (ARCET) is a commonly administered submaximal test for estimating aerobic capacity. Whereas typically utilized in clinical populations, the validity of the ARCET to predict VO 2max in a non-clinical population, especially female, is less clear. Therefore, the purpose of this study was to determine the accuracy of the ARCET in a sample of healthy and physically active college students. Subjects (13 females, 10 males) performed a maximal cycle ergometer test to volitional exhaustion to determine VO 2max . At least 48 hours later, subjects performed the ARCET protocol. Predicted VO 2max was calculated following the ARCET format using the age corrected factor. There was no significant difference (p=.045) between actual (41.0±7.97 ml/kg/min) and predicted VO 2max (40.3±7.58 ml/kg/min). When split for gender there was a significant difference between actual and predicted VO 2 for males, (45.1±7.74 vs. 42.7±8.26 ml/kg/min, p=0.029) but no significant difference observed for females, (37.9±6.9 vs. 38.5±6.77 ml/kg/min, p=0.675). The correlation between actual and predicted VO 2 was r=0.84, phealthy college population of both male and female subjects. Implications of this study suggest the ARCET can be used to assess aerobic capacity in both fitness and clinical settings where measurement via open-circuit spirometry is either unavailable or impractical.

  18. Efficacy of single-hormone and dual-hormone artificial pancreas during continuous and interval exercise in adult patients with type 1 diabetes: randomised controlled crossover trial.

    Science.gov (United States)

    Taleb, Nadine; Emami, Ali; Suppere, Corinne; Messier, Virginie; Legault, Laurent; Ladouceur, Martin; Chiasson, Jean-Louis; Haidar, Ahmad; Rabasa-Lhoret, Rémi

    2016-12-01

    The aim of this study was to assess whether the dual-hormone (insulin and glucagon) artificial pancreas reduces hypoglycaemia compared with the single-hormone (insulin alone) artificial pancreas during two types of exercise. An open-label randomised crossover study comparing both systems in 17 adults with type 1 diabetes (age, 37.2 ± 13.6 years; HbA1c, 8.0 ± 1.0% [63.9 ± 10.2 mmol/mol]) during two exercise types on an ergocycle and matched for energy expenditure: continuous (60% [Formula: see text] for 60 min) and interval (2 min alternating periods at 85% and 50% [Formula: see text] for 40 min, with two 10 min periods at 45% [Formula: see text] at the start and end of the session). Blocked randomisation (size of four) with a 1:1:1:1 allocation ratio was computer generated. The artificial pancreas was applied from 15:30 hours until 19:30 hours; exercise was started at 18:00 hours and announced 20 min earlier to the systems. The study was conducted at the Institut de recherches cliniques de Montréal. During single-hormone control compared with dual-hormone control, exercise-induced hypoglycaemia (plasma glucose artificial pancreas outperformed the single-hormone artificial pancreas in regulating glucose levels during announced exercise in adults with type 1 diabetes. ClinicalTrials.gov NCT01930110 FUNDING: : Société Francophone du Diabète and Diabète Québec.

  19. Cardiac rehabilitation in chronic heart failure: effect of an 8-week, high-intensity interval training versus continuous training.

    Science.gov (United States)

    Freyssin, Céline; Verkindt, Chantal; Prieur, Fabrice; Benaich, Philippe; Maunier, Sébastien; Blanc, Philippe

    2012-08-01

    To compare the effects of an 8-week, high-intensity interval training protocol versus continuous training. Randomized controlled trial. Cardiac rehabilitation center. Patients (N=26; mean age ± SD, 54±12y) with chronic heart failure were enrolled in a cardiac rehabilitation program for 8 weeks. Patients were randomly assigned into 2 groups that performed either interval training (IT) or continuous training (CT). IT consisted of 3 sessions of 12 repetitions of 30 seconds of exercise at very high intensity, followed by 60 seconds of complete rest. The CT group performed CT exercises, which consisted of 45 minutes of aerobic exercise. Parameters of gas exchanges: peak oxygen consumption (Vo(2)peak), first ventilator threshold (VT1), distance at six-minute walk test (6MWT), and level of anxiety and depression were measured. The IT group increased significantly their Vo(2)peak, the duration of the exercise test, the oxygen pulse, oxygen consumption at the VT1, and the distance walked during the 6MWT. The CT group only increased the time at the VT1 and the distance performed at the 6MWT. The improvement in the time at the VT1 was significantly higher for the IT group than for the CT group. This study shows that IT at very high intensity for patients with heart failure appears to be more effective than CT in improving indices of submaximal exercise capacity. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  20. Effects of music during exercise on RPE, heart rate and the autonomic nervous system.

    Science.gov (United States)

    Yamashita, S; Iwai, K; Akimoto, T; Sugawara, J; Kono, I

    2006-09-01

    The purpose of this study was to investigate the relationship between the influence of music on RPE during sub-maximal exercise and on the autonomic nervous system before and after sub-maximal exercise. Heart rate (HR), HR variability (HRV) and rates of physical fatigue (RPE) during exercise at 60% and at 40% VO2max with and without music were measured. The exercise protocol consisted of a 30-min seated rest (control) period followed by a 30-min submaximal cycling exercise and a 35-min recovery period. Autonomic-nervous activity was measured before and after exercise. During exercise, RPE was recorded every 3 min and HR was recorded for every minute. Although RPE did not differ during exercise at 60% VO2max, this value was lower during exercise at 40% VO2max in the presence, than in the absence of a favorite piece music (P music. These findings suggested that music evokes a ''distraction effect'' during low intensity exercise, but might not influence the autonomic nervous system. Therefore, when jogging or walking at comparatively low exercise intensity, listening to a favorite piece of music might decrease the influence of stress caused by fatigue, thus increasing the ''comfort'' level of performing the exercise.

  1. Effect of chain wheel shape on crank torque, freely chosen pedal rate, and physiological responses during submaximal cycling

    DEFF Research Database (Denmark)

    Hansen, Ernst Albin; Jensen, Kurt; Hallén, Jostein

    2009-01-01

    . A musculoskeletal simulation model supported the idea that a contributing factor to the observed difference in blood lactate concentration may be slightly reduced muscle activity around the phase where peak crank torque occurs during cycling with the Biopace chain wheel. In that particular phase of the crank......The development of noncircular chain wheels for the enhancement of cycling performance has been in progress for a long time and continues apace. In this study we tested whether submaximal cycling using a non-circular (Biopace) versus a circular chain wheel resulted in lower peak crank torque...... chain wheel at 180 W at 65 and 90 rpm for recording of crank torque profiles, and at their freely chosen pedal rate for recording of pedal rate and metabolic response, including oxygen uptake and blood lactate concentration. Crank torque profiles were similar between the two chain wheels during cycling...

  2. Concentrically trained cyclists are not more susceptible to eccentric exercise-induced muscle damage than are stretch-shortening exercise-trained runners.

    Science.gov (United States)

    Snieckus, Audrius; Kamandulis, Sigitas; Venckūnas, Tomas; Brazaitis, Marius; Volungevičius, Gintautas; Skurvydas, Albertas

    2013-03-01

    Here, we test the hypothesis that continuous concentric exercise training renders skeletal muscles more susceptible to damage in response to eccentric exercise. Elite road cyclists (CYC; n = 10, training experience 8.1 ± 2.0 years, age 22.9 ± 3.7 years), long-distance runners (LDR; n = 10, 9.9 ± 2.3 years, 24.4 ± 2.5 years), and healthy untrained (UT) men (n = 10; 22.4 ± 1.7 years) performed 100 submaximal eccentric contractions at constant angular velocity of 60° s(-1). Concentric isokinetic peak torque, isometric maximal voluntary contraction (MVC), and electrically induced knee extension torque were measured at baseline and immediately and 48 h after an eccentric exercise bout. Muscle soreness was assessed and plasma creatine kinase (CK) activity was measured at baseline and 48 h after exercise. Voluntary and electrically stimulated knee extension torque reduction were significantly greater (p < 0.05) in UT than in LDR and CYC. Immediately and 48 h after exercise, MVC decreased by 32 % and 20 % in UT, 20 % and 5 % in LDR, and 25 % and 6 % in CYC. Electrically induced 20 Hz torque decreased at the same times by 61 and 29 % in UT, 40 and 17 % in LDR, and 26 and 14 % in CYC. Muscle soreness and plasma CK activity 48 h after exercise did not differ significantly between athletes and UT subjects. In conclusion, even though elite endurance athletes are more resistant to eccentric exercise-induced muscle damage than are UT people, stretch-shortening exercise-trained LDR have no advantage over concentrically trained CYC.

  3. Similar mitochondrial signaling responses to a single bout of continuous or small-sided-games-based exercise in sedentary men.

    Science.gov (United States)

    Mendham, Amy E; Duffield, Rob; Coutts, Aaron J; Marino, Frank E; Boyko, Andriy; McAinch, Andrew J; Bishop, David John

    2016-12-01

    This study assessed the mitochondrial related signaling responses to a single bout of noncontact, modified football (touch rugby), played as small-sided games (SSG), or cycling (CYC) exercise in sedentary, obese, middle-aged men. In a randomized, crossover design, nine middle-aged, sedentary, obese men completed two, 40-min exercise conditions (CYC and SSG) separated by a 21-day recovery period. Heart rate (HR) and ratings of perceived exertion (RPE) were collected during each bout. Needle biopsies from the vastus lateralis muscle were collected at rest and 30 and 240 min postexercise for analysis of protein content and phosphorylation (PGC-1α, SIRT1, p53, p53(Ser15), AMPK, AMPK(Thr172), CAMKII, CAMKII(Thr286), p38MAPK, and p38MAPK(Thr180/Tyr182)) and mRNA expression (PGC-1α, p53, NRF1, NRF2, Tfam, and cytochrome c). A main effect of time effect for both conditions was evident for HR, RPE, and blood lactate (P 0.05). Both conditions increased PGC1-α protein and mRNA expression at 240 min (P 0.05). CYC increased p53 protein content at 240 min to a greater extent than SSG (P < 0.05). mRNA expression of NRF2 decreased in both conditions (P < 0.05). No condition by time interactions were evident for mRNA expression of Tfam, NRF1, cytochrome c, and p53. The similar PGC-1α response between intensity-matched conditions suggests both conditions are of similar benefit for stimulating mitochondrial biogenesis. Differences between conditions regarding fluctuation in exercise intensity and type of muscle contraction may explain the increase of p53 and AMPK within CYC and not SSG (noncontact, modified football). Copyright © 2016 the American Physiological Society.

  4. Independent effect of type 2 diabetes beyond characteristic comorbidities and medications on immediate but not continued knee extensor exercise hyperemia.

    Science.gov (United States)

    Poitras, Veronica J; Bentley, Robert F; Hopkins-Rosseel, Diana H; LaHaye, Stephen A; Tschakovsky, Michael E

    2015-08-01

    We tested the hypothesis that type 2 diabetes (T2D), when present in the characteristic constellation of comorbidities (obesity, hypertension, dyslipidemia) and medications, slows the dynamic adjustment of exercising muscle perfusion and blunts the steady state relative to that of controls matched for age, body mass index, fitness, comorbidities, and non-T2D medications. Thirteen persons with T2D and 11 who served as controls performed rhythmic single-leg isometric quadriceps exercise (rest-to-6 kg and 6-to-12 kg transitions, 5 min at each intensity). Measurements included leg blood flow (LBF, femoral artery ultrasound), mean arterial pressure (MAP, finger photoplethysmography), and leg vascular conductance (LVK, calculated). Dynamics were quantified using mean response time (MRT). Measures of amplitude were also used to compare response adjustment: the change from baseline to 1) the peak initial response (greatest 1-s average in the first 10 s; ΔLBFPIR, ΔLVKPIR) and 2) the on-transient (average from curve fit at 15, 45, and 75 s; ΔLBFON, ΔLVKON). ΔLBFPIR was significantly blunted in T2D vs. control individuals (P = 0.037); this was due to a tendency for reduced ΔLVKPIR (P = 0.063). In contrast, the overall response speed was not different between groups (MRT P = 0.856, ΔLBFON P = 0.150) nor was the change from baseline to steady state (P = 0.204). ΔLBFPIR, ΔLBFON, and LBF MRT did not differ between rest-to-6 kg and 6-to-12 kg workload transitions (all P > 0.05). Despite a transient amplitude impairment at the onset of exercise, there is no robust or consistent effect of T2D on top of the comorbidities and medications typical of this population on the overall dynamic adjustment of LBF, or the steady-state levels achieved during low- or moderate-intensity exercise. Copyright © 2015 the American Physiological Society.

  5. Acute effect of intermittent and continuous aerobic exercise on release of cardiac troponin T in sedentary men

    DEFF Research Database (Denmark)

    Ranjbar, Rouhollah; Ahmadi, Mohammad Amin; Zar, Abdossaleh

    2017-01-01

    in sedentary men. METHODS: Eleven sedentary healthy men aged 22.3±1.9years completed the study. The subjects were divided into two groups and performed, in random order, IE (intensity alternating between 50% (2min) and 80% (1min) HRreserve) or CE (60% HRreserve). The study was designed as a single...... and RPP increased significantly following both exercise protocols (P=0.001). CONCLUSIONS: In summary, both CE and IE results in increased serum concentrations of hs-cTnT in sedentary men. However, this increase does not seem to be caused by the irreversible death of cardiomyocytes. CE resulted...

  6. Effect of music on submaximal cycling | Schie | South African Journal ...

    African Journals Online (AJOL)

    Objective. Athletes frequently report training to music, yet there have been relatively few studies that have addressed the benefit of exercising with music. Design. Volunteer men and women (N=30), aged between 18 and 40 years, performed an initial familiarisation session. Part of this session involved the measurement of ...

  7. Effects of aerobic interval training versus continuous moderate exercise programme on aerobic and anaerobic capacity, somatic features and blood lipid profile in collegate females.

    Science.gov (United States)

    Mazurek, Krzystof; Krawczyk, Krzysztof; Zmijewski, Piotr; Norkowski, Henryk; Czajkowska, Anna

    2014-01-01

    Regular physical activity has many positive health benefits, including reducing the risk of cardiovascular diseases, metabolic diseases and some cancers, as well as improving the quality of life. objectives. The aim of the study was to examine the effects of 8-week aerobic interval cycle exercise training (AIT) compared to continuous cycle exercises of moderate intensity (CME) on the aerobic and anaerobic capacity, somatic features and lipid profile. The research was conducted in 88 volunteers aged 19.5±0.6 years, who were randomized to three groups of organized physical activity (OPA), who exercised 3 times per week in 47 min sessions: (I) AIT (n=24) comprising 2 series of 6x10 s sprinting with maximal pedalling cadence and active rest pedalling with intensity 65%-75% HRmax, (II) CME (n=22) corresponding to 65%-75% HRmax, (III) regular collegiate physical education classes of programmed exercises (CON; n=42). Before and after OPA anthropometrics, aero- and anaerobic capacity and lipid profile indices were measured. In AIT, a significantly greater decrease of waist circumference and WHR was noted when compared to CON, and a significantly greater reduction of sum of skinfolds than in CON and CME. Improvement in relative and absolute VO2max (L/min and ml/kg/min) was significantly higher in AIT than CON. Work output and peak power output in the anaerobic test improved significantly in AIT, CME and CON, but independently of training type. OPA was effective only in reducing triglyceride concentrations in CME and CON groups, without interaction effects in relation to training type. It was found that 8 weeks of OPA was beneficial in improving somatic and aerobic capacity indices, but AIT resulted in the greatest improvement in somatic indices (waist circumference, WHR, sum of skinfolds) and in VO2max, compared to CME and CON programmes.

  8. Effects of aerobic interval training versus continuous moderate exercise programme on aerobic and anaerobic capacity, somatic features and blood lipid profile in collegate females

    Directory of Open Access Journals (Sweden)

    Krzystof Mazurek

    2014-11-01

    Full Text Available introduction. Regular physical activity has many positive health benefits, including reducing the risk of cardiovascular diseases, metabolic diseases and some cancers, as well as improving the quality of life. objectives. The aim of the study was to examine the effects of 8-week aerobic interval cycle exercise training (AIT compared to continuous cycle exercises of moderate intensity (CME on the aerobic and anaerobic capacity, somatic features and lipid profile. material and methods. The research was conducted in 88 volunteers aged 19.5±0.6 years, who were randomized to three groups of organized physical activity (OPA, who exercised 3 times per week in 47 min sessions: (I AIT (n=24 comprising 2 series of 6x10 s sprinting with maximal pedalling cadence and active rest pedalling with intensity 65%–75% HRmax, (II CME (n=22 corresponding to 65%-75% HRmax, (III regular collegiate physical education classes of programmed exercises (CON; n=42. Before and after OPA anthropometrics, aero- and anaerobic capacity and lipid profile indices were measured. results. In AIT, a significantly greater decrease of waist circumference and WHR was noted when compared to CON, and a significantly greater reduction of sum of skinfolds than in CON and CME. Improvement in relative and absolute VO2max (L/min and ml/kg/min was significantly higher in AIT than CON. Work output and peak power output in the anaerobic test improved significantly in AIT, CME and CON, but independently of training type. OPA was effective only in reducing triglyceride concentrations in CME and CON groups, without interaction effects in relation to training type. conclusion. It was found that 8 weeks of OPA was beneficial in improving somatic and aerobic capacity indices, but AIT resulted in the greatest improvement in somatic indices (waist circumference, WHR, sum of skinfolds and in VO[sub]2[/sub]max, compared to CME and CON programmes.

  9. Neurohormonal activation and exercise tolerance in patients supported with a continuous-flow left ventricular assist device

    DEFF Research Database (Denmark)

    Jung, Mette Holme; Goetze, Jens Peter; Boesgaard, Soeren

    2016-01-01

    . The aim of this study was to assess the relation between neurohormonal activation patterns in CF-LVAD patients and exercise capacity. METHODS: Plasma concentrations of the C-terminal portion of pro-arginine vasopressin precursor (copeptin), pro-adrenomedullin (proADM), pro-B-type (proBNP) and pro.......0±5.3ml/kg/min and exhibited strong negative correlations with copeptin, r=-0.61 (p=0.001) and proADM, r=-0.56 (p=0.005). Additionally comparing patients with peak VO2copeptin and proADM concentrations, 2.8±0.8 vs 2.1±0.7pmol/l (p=0.03) and 1.......0±0.5 vs 0.7±0.2nmol/l (p=0.01), respectively. In contrast natriuretic peptides were not associated with maximal exercise capacity. Lower QOL correlated with increasing proBNP. CONCLUSION: Resting plasma levels of proADM and copeptin are significantly correlated with peak VO2 in CF-LVAD patients. Future...

  10. Aerobic exercise supplemented with muscular endurance training improves onset of blood lactate accumulation.

    Science.gov (United States)

    Farrell, John W; Lantis, David J; Ade, Carl J; Cantrell, Greg S; Larson, Rebecca D

    2017-05-05

    Studies have shown that when aerobic exercise is supplemented with muscular endurance training metabolic adaptions occur that result in the delay of the onset of blood lactate accumulation (OBLA). However, previous studies have not explored any submaximal cardiorespiratory adaptations that may result from this training protocol. The aim of the current investigation was to evaluate the effect of supplementing an aerobic exercise training program with a muscular endurance training program on various cardiorespiratory and metabolic measurements. Fourteen aerobically active men performed an incremental exercise test to determine the OBLA, gas exchange threshold (GET), and maximal oxygen uptake (VO2max). Maximal strength was measured using 1-repetition max (1-RM) for leg press (LP), leg curl (LC), and leg extension (LE). Eight subjects supplemented their aerobic activity (EX group) with 8 weeks of muscular endurance training, while six continued their regular aerobic activity (CON group). No significant group differences were observed for all pretraining variables. Following eight weeks of training no significant differences in body mass, GET, and VO2max were observed for either group. However, the EX group showed a significant improvement for both absolute and relative VO2 at OBLA compared to the CON group. LC and LE 1-RM assessments for the EX group showed a significant improvement compared to CON group. Muscular endurance training did not improve GET and VO2max, but significantly increased VO2 at OBLA, LP, and LC. These findings suggest that this training protocol maybe useful in the development of submaximal aerobic performance and leg strength for endurance athletes.

  11. Consistently High Sports/Exercise Activity Is Associated with Better Sleep Quality, Continuity and Depth in Midlife Women: The SWAN Sleep Study

    Science.gov (United States)

    Kline, Christopher E.; Irish, Leah A.; Krafty, Robert T.; Sternfeld, Barbara; Kravitz, Howard M.; Buysse, Daniel J.; Bromberger, Joyce T.; Dugan, Sheila A.; Hall, Martica H.

    2013-01-01

    Study Objectives: To examine relationships between different physical activity (PA) domains and sleep, and the influence of consistent PA on sleep, in midlife women. Design: Cross-sectional. Setting: Community-based. Participants: 339 women in the Study of Women's Health Across the Nation Sleep Study (52.1 ± 2.1 y). Interventions: None. Measurements and Results: Sleep was examined using questionnaires, diaries and in-home polysomnography (PSG). PA was assessed in three domains (Active Living, Household/Caregiving, Sports/Exercise) using the Kaiser Physical Activity Survey (KPAS) up to 4 times over 6 years preceding the sleep assessments. The association between recent PA and sleep was evaluated using KPAS scores immediately preceding the sleep assessments. The association between the historical PA pattern and sleep was examined by categorizing PA in each KPAS domain according to its pattern over the 6 years preceding sleep assessments (consistently low, inconsistent/consistently moderate, or consistently high). Greater recent Sports/Exercise activity was associated with better sleep quality (diary “restedness” [P sleep continuity (diary sleep efficiency [SE; P = 0.02]) and depth (higher NREM delta electroencephalographic [EEG] power [P = 0.04], lower NREM beta EEG power [P activity was also associated with better Pittsburgh Sleep Quality Index scores (P = 0.02) and higher PSG-assessed SE (P sleep and Active Living or Household/Caregiving activity (either recent or historical pattern) were noted. Conclusion: Consistently high levels of recreational physical activity, but not lifestyle- or household-related activity, are associated with better sleep in midlife women. Increasing recreational physical activity early in midlife may protect against sleep disturbance in this population. Citation: Kline CE; Irish LA; Krafty RT; Sternfeld B; Kravitz HM; Buysse DJ; Bromberger JT; Dugan SA; Hall MH. Consistently high sports/exercise activity is associated with better

  12. Cardiovascular responses during a submaximal exercise test in patients with Parkinson's disease.

    NARCIS (Netherlands)

    Speelman, A.D.; Groothuis, J.T.; Nimwegen, M. van; Scheer, E.S. van der; Borm, G.F.; Bloem, B.R.; Hopman, M.T.E.; Munneke, M.

    2012-01-01

    BACKGROUND: Patients with Parkinson's disease (PD) are physically less active than controls, and autonomic dysfunction may contribute to this sedentary lifestyle. Specifically, an altered cardiovascular response to physical effort may restrict physical activities. OBJECTIVE: To assess the

  13. Sex and Exercise Intensity Do Not Influence Oxygen Uptake Kinetics in Submaximal Swimming

    Science.gov (United States)

    Reis, Joana F.; Millet, Gregoire P.; Bruno, Paula M.; Vleck, Veronica; Alves, Francisco B.

    2017-01-01

    The aim of this study was to compare the oxygen uptake (V˙O2) kinetics in front crawl between male and female swimmers at moderate and heavy intensity. We hypothesized that the time constant for the primary phase V˙O2 kinetics was faster in men than in women, for both intensities. Nineteen well trained swimmers (8 females mean ± SD; age 17.9 ± 3.5 years; mass 55.2 ± 3.6 kg; height 1.66 ± 0.05 m and 11 male 21.9 ± 2.8 years; 78.2 ± 11.1 kg; 1.81 ± 0.08 m) performed a discontinuous maximal incremental test and two 600-m square wave transitions for both moderate and heavy intensities to determine the V˙O2 kinetics parameters using mono- and bi-exponential models, respectively. All the tests involved breath-by-breath analysis of front crawl swimming using a swimming snorkel. The maximal oxygen uptake (V˙O2max) was higher in men than in women [4,492 ± 585 ml·min−1 and 57.7 ± 4.4 ml·kg−1·min−1 vs. 2,752.4 ± 187.9 ml·min−1 (p ≤ 0.001) and 50.0 ± 5.7 ml·kg−1·min−1(p = 0.007), respectively]. Similarly, the absolute amplitude of the primary component was higher in men for both intensities (moderate: 1,736 ± 164 vs. 1,121 ± 149 ml·min−1; heavy: 2,948 ± 227 vs. 1,927 ± 243 ml·min−1, p ≤ 0.001, for males and females, respectively). However, the time constant of the primary component (τp) was not influenced by sex (p = 0.527) or swimming intensity (p = 0.804) (moderate: 15.1 ± 5.6 vs. 14.4 ± 5.1 s; heavy: 13.5 ± 3.3 vs. 16.0 ± 4.5 s, for females and males, respectively). The slow component in the heavy domain was not significantly different between female and male swimmers (3.2 ± 2.4 vs. 3.8 ± 1.0 ml·kg−1·min−1, p = 0.476). Overall, only the absolute amplitude of the primary component was higher in men, while the other V˙O2 kinetics parameters were similar between female and male swimmers at both moderate and heavy intensities. The mechanisms underlying these similarities remain unclear. PMID:28239356

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

    NARCIS (Netherlands)

    Sartor, F.; Vernillo, G.; de Morree, H.M.; Bonomi, A.G.; La Torre, A.; Kubis, H.P.; Veicsteinas, A.

    2013-01-01

    Assessment of the functional capacity of the cardiovascular system is essential in sports medicine. For athletes, the maximal oxygen uptake (V˙O2max) provides valuable information about their aerobic power. In the clinical setting, the V˙O2max provides important diagnostic and prognostic information

  15. Within- and Between-Day Repeatability and Variability in Children's Physiological Responses during Submaximal Treadmill Exercise

    Science.gov (United States)

    Amorim, Paulo R. S.; Byrne, Nuala Mary; Hills, Andrew P.

    2009-01-01

    The purpose of this study was to verify within- and between-day repeatability and variability in children's oxygen uptake (VO[subscript 2]), gross economy (GE; VO[subscript 2] divided by speed) and heart rate (HR) during treadmill walking based on self-selected speed (SS). Fourteen children (10.1 plus or minus 1.4 years) undertook three testing…

  16. Description of a standardized rehabilitation program based on sub-maximal eccentric following a platelet-rich plasma infiltration for jumper’s knee

    Science.gov (United States)

    Kaux, Jean-François; Forthomme, Bénédicte; Namurois, Marie-Hélène; Bauvir, Philippe; Defawe, Nathalie; Delvaux, François; Lehance, Cédric; Crielaard, Jean-Michel; Croisier, Jean-Louis

    2014-01-01

    Summary Introduction. Different series emphasized the necessity of rehabilitation program after infiltration of platelet-rich plasma (PRP) in case of tendinopathy. However, most of them describe only briefly the reeducation protocol and these programs vary. Our aim was to extensively describe a specific standardized rehabilitation program. Methods. After a review of literature of post-PRP infiltration protocols, we had developed a standardized rehabilitation protocol. This protocol was evaluated by 30 subjects with chronic jumper’s knee who. A standardised progressive sub-maximal eccentric program supervised by a physical therapist for 6 weeks was started 1 week post-infiltration. The patient benefited also from electromyostimulation, isometric strengthening and stretching of the quadriceps, cycloergometer and cryotherapy. After the supervised program, the patient had to make an auto-reeducation added to the reathletisation protocol for 6 more weeks which was followed by maintenance exercises up to 1 year. The assessments were made using a VAS, IKDC and VISA-P scores. Results. The VAS, IKDC and VISA-P scores decreased very significantly with time. The compliance to auto-reeducation was good. Conclusions. We proposed a simple and efficient protocol based on sub-maximal eccentric reeducation to add to PRP infiltrations in case of patellar tendinopathy. PMID:24932453

  17. Exercise responses during functional electrical stimulation cycling in individuals with spinal cord injury.

    Science.gov (United States)

    Hasnan, Nazirah; Ektas, Nalan; Tanhoffer, Aldre Izabel P; Tanhoffer, Ricardo; Fornusek, Che; Middleton, James W; Husain, Ruby; Davis, Glen M

    2013-06-01

    This study compared acute exercise responses during arm cranking, functional electrical stimulation (FES)-assisted leg cycling, and combined arm and leg ("hybrid") cycling in individuals with spinal cord injury during maximal and submaximal exercise. Nine male subjects with long-standing neurological lesions from C7 to T12 were recruited. All subjects performed arm crank ergometry (ACE), FES leg cycle exercise (FES-LCE), combined ACE + FES-LCE, and cycling on a hybrid FES tricycle (HYBRID). They were assessed for their peak exercise responses in all four modalities. Subsequently, their submaximal heart rates (HR), cardiac outputs (Q), stroke volumes (SV), and arteriovenous oxygen extractions (Ca-Cv)O2 were measured at 40%, 60%, and 80% of mode-specific V˙O2peak. Arm exercise alone and arm + leg exercise resulted in significantly higher V˙O2peak and HRpeak compared with FES-LCE (P spinal cord injury population.

  18. Intensity-dependent EMG response for the biceps brachii during sustained maximal and submaximal isometric contractions.

    Science.gov (United States)

    Carr, Joshua C; Beck, Travis W; Ye, Xin; Wages, Nathan P

    2016-09-01

    There have been recent attempts to characterize the mechanisms associated with fatigue-induced task failure. We compared the time to failure and the corresponding changes in the surface electromyogram (EMG) during sustained maximal and submaximal isometric force tasks. EMG activity was measured from the biceps brachii of 18 male participants as they sustained either a maximal or submaximal (60 % MVC) isometric contraction of the dominant elbow flexors until force could not be maintained above 55 % MVC. Intensity-dependent patterns of change were observed for EMG amplitude and mean power frequency (MNF) between the two force tasks. Interestingly, the only significant predictor of failure time was the rate of change in EMG MNF during the submaximal task (r (2) = 0.304). In addition, EMG amplitude at submaximal failure was significantly lower (p EMG response emphasize the basis of neuromuscular fatigue and task dependency. Additionally, our data suggest that the EMG MNF should be used when monitoring the progression of local muscle fatigue.

  19. THE EFFECT OF SUBMAXIMAL INHALATION ON MEASURES DERIVED FROM FORCED EXPIRATORY SPIROMETRY

    Science.gov (United States)

    THE EFFECT OF SUBMAXIMAL INHALATION ON MEASURES DERIVED FROM FORCED EXPIRATORY SPIROMETRY. William F. McDonnell Human Studies Division, NHEERL, U.S. Environmental Protection Agency, RTP, NC 27711. Short-term exposure to ozone results in a neurally-mediated decrease in the ab...

  20. Calibration of EMG to force for knee muscles is applicable with submaximal voluntary contractions

    NARCIS (Netherlands)

    Doorenbosch, C.A.M.; Joosten, A.; Harlaar, J.

    2005-01-01

    Purpose: In this study, the influence of using submaximal isokinetic contractions about the knee compared to maximal voluntary contractions as input to obtain the calibration of an EMG-force model for knee muscles is investigated. Methods: Isokinetic knee flexion and extension contractions were

  1. Variability of Respiration and Metabolism: Responses to Submaximal Cycling and Running.

    Science.gov (United States)

    Armstrong, Lawrence E.; Costill, David L.

    1985-01-01

    This investigation examined day-to-day variations in metabolic measurements during submaximal running and cycling. Significant differences were found in the oxygen uptake (VO2) of runners and cyclists and the minute ventilation (VE) of cyclists while running, but blood lactic acid (HLA) did not differ day to day. (Author/MT)

  2. Exercise thermoregulation in men after 1 and 24-hours of 6 degrees head-down tilt

    Science.gov (United States)

    Ertl, A. C.; Dearborn, A. S.; Weidhofer, A. R.; Bernauer, E. M.; Greenleaf, J. E.

    2000-01-01

    BACKGROUND: Exercise thermoregulation is dependent on heat loss by increased skin blood flow (convective and conductive heat loss) and through enhanced sweating (evaporative heat loss). Reduction of plasma volume (PV), increased plasma osmolality, physical deconditioning, and duration of exposure to simulated and actual microgravity reduces the ability to thermoregulate during exercise. HYPOTHESIS: We hypothesized that 24 h of head down tilt (HDT24) would alter thermoregulatory responses to a submaximal exercise test and result in a higher exercise rectal temperature (Tre) when compared with exercise Tre after 1 h of head down tilt (HDT1). METHODS: Seven men (31+/-SD 6 yr, peak oxygen uptake (VpO2peak) of 44+/-6 ml x kg(-1) x min(-1)) were studied during 70 min of supine cycling at 58+/-SE 1.5% VO2peak at 22.0 degrees C Tdb and 47% rh. RESULTS: Relative to pre-tilt sitting chair rest data, HDT1 resulted in a 6.1+/-0.9% increase and HDT24 in a 4.3+/-2.3% decrease in PV (delta = 10.4% between experiments, p<0.05) while plasma osmolality remained unchanged (NS). Pre-exercise Tre was elevated after HDT24 (36.71 degrees C +/-0.06 HDT1 vs. 36.93 degrees C+/-0.11 HDT24, p<0.05). The 70 min of exercise did not alter this relationship (p<0.05) with respective end exercise increases in Tre to 38.01 degrees C and 38.26 degrees C (degrees = 1.30 degrees C (HDT1) and 1.33 degrees C (HDT24)). While there were no pre-exercise differences in mean skin temperature (Tsk), a significant (p<0.05) time x treatment interaction occurred during exercise: after min 30 in HDT24 the Tsk leveled off at 31.1 degrees C, while it continued to increase reaching 31.5 degrees C at min 70 in HDT1. A similar response (NS) occurred in skin blood velocity. Neither local sweating rates nor changes in body weight during exercise of -1.63+/-0.24 kg (HDT1) or - 1.33+/-0.09 kg (HDT24) were different (NS) between experiments. CONCLUSION: While HDT24 resulted in elevated pre-exercise Tre, reduced PV

  3. Consistently high sports/exercise activity is associated with better sleep quality, continuity and depth in midlife women: the SWAN sleep study.

    Science.gov (United States)

    Kline, Christopher E; Irish, Leah A; Krafty, Robert T; Sternfeld, Barbara; Kravitz, Howard M; Buysse, Daniel J; Bromberger, Joyce T; Dugan, Sheila A; Hall, Martica H

    2013-09-01

    To examine relationships between different physical activity (PA) domains and sleep, and the influence of consistent PA on sleep, in midlife women. Cross-sectional. Community-based. 339 women in the Study of Women's Health Across the Nation Sleep Study (52.1 ± 2.1 y). None. Sleep was examined using questionnaires, diaries and in-home polysomnography (PSG). PA was assessed in three domains (Active Living, Household/Caregiving, Sports/Exercise) using the Kaiser Physical Activity Survey (KPAS) up to 4 times over 6 years preceding the sleep assessments. The association between recent PA and sleep was evaluated using KPAS scores immediately preceding the sleep assessments. The association between the historical PA pattern and sleep was examined by categorizing PA in each KPAS domain according to its pattern over the 6 years preceding sleep assessments (consistently low, inconsistent/consistently moderate, or consistently high). Greater recent Sports/Exercise activity was associated with better sleep quality (diary "restedness" [P sleep continuity (diary sleep efficiency [SE; P = 0.02]) and depth (higher NREM delta electroencephalographic [EEG] power [P = 0.04], lower NREM beta EEG power [P Exercise activity was also associated with better Pittsburgh Sleep Quality Index scores (P = 0.02) and higher PSG-assessed SE (P sleep and Active Living or Household/Caregiving activity (either recent or historical pattern) were noted. Consistently high levels of recreational physical activity, but not lifestyle- or household-related activity, are associated with better sleep in midlife women. Increasing recreational physical activity early in midlife may protect against sleep disturbance in this population.

  4. Dual-task functional exercises as an effective way to improve dynamic balance in persons with intellectual disability – continuation of the project

    Directory of Open Access Journals (Sweden)

    Edyta Mikołajczyk

    2017-06-01

    Full Text Available Introduction: Balance disorders are common in people with intellectual disability (ID. Aim of the research: The continuation of the project is aimed at finding out whether extension of the unstable surface dual-task functional exercises programme by another 12 weeks affects the level of dynamic balance in adolescents with ID and what those changes are like after the 8-week summer holidays. Material and methods: A total of 17 adolescents with ID aged 14–16 years (E performed functional exercises for another 12 weeks on unstable surfaces, and a group of 17 individuals with ID were the controls. Dynamic balance was assessed three times: after the first stage of the programme (test 2, after another 12 weeks (test 3, after the 8-week holiday (test 4. ALFA AC An International East stabilometric platform was used for measurements. Results : No statistical differences were discovered in group E, in dynamic balance assessment between test 2 and 3; however, the mean scores in group E, in test 3, were slightly better than in test 2, and notably better than in group C. No significant differences between test 3 and 4 were found in group E either. Conclusions : Extension of the intervention program helped to maintain improved dynamic balance. Discontinuation of the program for the period of 8 weeks resulted in decreased level of balance; however, it was still higher than at the beginning of the project. Dual-task functional exercises based on activities of daily living (ADLs and stimulation of righting reactions may enhance dynamic balance in individuals with ID, but it should be constantly stimulated.

  5. Effect of High-Intensity Interval Versus Continuous Exercise Training on Functional Capacity and Quality of Life in Patients With Coronary Artery Disease: A RANDOMIZED CLINICAL TRIAL.

    Science.gov (United States)

    Jaureguizar, Koldobika Villelabeitia; Vicente-Campos, Davinia; Bautista, Lorena Ruiz; de la Peña, Cesar Hernández; Gómez, María José Arriaza; Rueda, María José Calero; Fernández Mahillo, Ignacio

    2016-01-01

    There is strong evidence that exercise training has beneficial health effects in patients with cardiovascular disease. Most studies have focused on moderate continuous training (MCT); however, a body of evidence has begun to emerge demonstrating that high-intensity interval training (HIIT) has significantly better results in terms of morbidity and mortality. The aim of this study was to compare the effects of MCT versus HIIT on functional capacity and quality of life and to assess safety. Seventy-two patients with ischemic heart disease were assigned to either HIIT or MCT for 8 weeks. We analyzed cardiopulmonary exercise test data, quality of life, and adverse events. High-intensity interval training resulted in a significantly greater increase in (Equation is included in full-text article.)O2peak (4.5 ± 4.7 mL·kg·min) compared with MCT (2.5 ± 3.6 mL·kg·min) (P training protocols improved quality of life. No adverse events were reported in either of the groups. On the basis of the results of this study, HIIT should be considered for use in cardiac rehabilitation as it resulted in a greater increase in functional capacity compared with MCT. We also observed greater improvement in quality of life without any increase in cardiovascular risk.

  6. Safety and feasibility of regadenoson use for suboptimal heart rate response during symptom-limited standard Bruce exercise stress test.

    Science.gov (United States)

    Partington, Sara L; Lanka, Viswanatha; Hainer, Jon; Blankstein, Ron; Skali, Hicham; Forman, Daniel E; Di Carli, Marcelo F; Dorbala, Sharmila

    2012-10-01

    Regadenoson during exercise stress test (ETT) can provide maximal hyperemia for myocardial perfusion imaging (MPI), along with exercise information. Our aim was to study the feasibility and safety of regadenoson injection at peak ETT for submaximal heart rate (HR) response. Consecutive patients who underwent SPECT MPI with standard Bruce ETT or supine-regadenoson (Supine-Reg) were analyzed. ETT patients were grouped as ETT-Max [maximal HR > 0.85 * (220 - age), N = 1,522], ETT-Submax (submaximal HR no regadenoson, N = 504), ETT-Reg (submaximal HR and regadenoson, N = 211). The HR during ETT was submaximal in 715 (32%) patients. Of these, 211 patients (30%) underwent ETT-Reg (mean exercise duration: 5.5 ± 2.5 minutes). ETT-Reg patients had a higher frequency of hypertension, diabetes, smoking and beta-blocker use, similar rest systolic blood pressure (SBP), but lower rest and peak HR and peak SBP compared to ETT-Max patients. There were no serious complications with regadenoson. Side effects (49% vs 6%, P < .0001) were fewer and aminophylline use was lower with ETT-Reg compared to Supine-Reg (0.5% vs 8.1%, P = .001). Submaximal HR response to ETT is common. ETT-Reg is safe, feasible, and well-tolerated. ETT-Reg facilitates a diagnostic MPI with reporting of functional capacity, exercise ECG/hemodynamic changes and MPI at maximal hyperemia.

  7. Concurrent exercise incorporating high-intensity interval or continuous training modulates mTORC1 signaling and microRNA expression in human skeletal muscle.

    Science.gov (United States)

    Fyfe, Jackson J; Bishop, David J; Zacharewicz, Evelyn; Russell, Aaron P; Stepto, Nigel K

    2016-06-01

    We compared the effects of concurrent exercise, incorporating either high-intensity interval training (HIT) or moderate-intensity continuous training (MICT), on mechanistic target of rapamycin complex 1 (mTORC1) signaling and microRNA expression in skeletal muscle, relative to resistance exercise (RE) alone. Eight males (mean ± SD: age, 27 ± 4 yr; V̇o2 peak , 45.7 ± 9 ml·kg(-1)·min(-1)) performed three experimental trials in a randomized order: 1) RE (8 × 5 leg press repetitions at 80% 1-repetition maximum) performed alone and RE preceded by either 2) HIT cycling [10 × 2 min at 120% lactate threshold (LT); HIT + RE] or 3) work-matched MICT cycling (30 min at 80% LT; MICT + RE). Vastus lateralis muscle biopsies were obtained immediately before RE, either without (REST) or with (POST) preceding endurance exercise and +1 h (RE + 1 h) and +3 h (RE + 3 h) after RE. Prior HIT and MICT similarly reduced muscle glycogen content and increased ACC(Ser79) and p70S6K(Thr389) phosphorylation before subsequent RE (i.e., at POST). Compared with MICT, HIT induced greater mTOR(Ser2448) and rps6(Ser235/236) phosphorylation at POST. RE-induced increases in p70S6K and rps6 phosphorylation were not influenced by prior HIT or MICT; however, mTOR phosphorylation was reduced at RE + 1 h for MICT + RE vs. both HIT + RE and RE. Expression of miR-133a, miR-378, and miR-486 was reduced at RE + 1 h for HIT + RE vs. both MICT + RE and RE. Postexercise mTORC1 signaling following RE is therefore not compromised by prior HIT or MICT, and concurrent exercise incorporating HIT, but not MICT, reduces postexercise expression of miRNAs implicated in skeletal muscle adaptation to RE. Copyright © 2016 the American Physiological Society.

  8. Heavy strength training improves running and cycling performance following prolonged submaximal work in well-trained female athletes.

    Science.gov (United States)

    Vikmoen, Olav; Rønnestad, Bent R; Ellefsen, Stian; Raastad, Truls

    2017-03-01

    The purpose of this study was to investigate the effects of adding heavy strength training to female duathletes' normal endurance training on both cycling and running performance. Nineteen well-trained female duathletes ( V O 2max cycling: 54 ± 3 ml∙kg -1 ∙min -1 , VO 2max running: 53 ± 3 ml∙kg -1 ∙min -1 ) were randomly assigned to either normal endurance training ( E , n  = 8) or normal endurance training combined with strength training ( E+S , n  = 11). The strength training consisted of four lower body exercises [3 × 4-10 repetition maximum (RM)] twice a week for 11 weeks. Running and cycling performance were assessed using 5-min all-out tests, performed immediately after prolonged periods of submaximal work (3 h cycling or 1.5 h running). E+S increased 1RM in half squat (45 ± 22%) and lean mass in the legs (3.1 ± 4.0%) more than E Performance during the 5-min all-out test increased in both cycling (7.0 ± 4.5%) and running (4.7 ± 6.0%) in E+S, whereas no changes occurred in E The changes in running performance were different between groups. E+S reduced oxygen consumption and heart rate during the final 2 h of prolonged cycling, whereas no changes occurred in E No changes occurred during the prolonged running in any group. Adding strength training to normal endurance training in well-trained female duathletes improved both running and cycling performance when tested immediately after prolonged submaximal work. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  9. Time to adapt exercise training regimens in pulmonary rehabilitation – a review of the literature

    Directory of Open Access Journals (Sweden)

    Lee AL

    2014-11-01

    Full Text Available Annemarie L Lee,1–4 Anne E Holland1–3 1Physiotherapy, Alfred Health, Melbourne, VIC, Australia; 2Institute for Breathing and Sleep, Austin Health, Melbourne, VIC, Australia; 3Physiotherapy, La Trobe University, Melbourne, VIC, Australia; 4Westpark Healthcare Centre, ON, Canada Abstract: Exercise intolerance, exertional dyspnea, reduced health-related quality of life, and acute exacerbations are features characteristic of chronic obstructive pulmonary disease (COPD. Patients with a primary diagnosis of COPD often report comorbidities and other secondary manifestations, which diversifies the clinical presentation. Pulmonary rehabilitation that includes whole body exercise training is a critical part of management, and core programs involve endurance and resistance training for the upper and lower limbs. Improvement in maximal and submaximal exercise capacity, dyspnea, fatigue, health-related quality of life, and psychological symptoms are outcomes associated with exercise training in pulmonary rehabilitation, irrespective of the clinical state in which it is commenced. There may be benefits for the health care system as well as the individual patient, with fewer exacerbations and subsequent hospitalization reported with exercise training. The varying clinical profile of COPD may direct the need for modification to traditional training strategies for some patients. Interval training, one-legged cycling (partitioning and non-linear periodized training appear to be equally or more effective than continuous training. Inspiratory muscle training may have a role as an adjunct to whole body training in selected patients. The benefits of balance training are also emerging. Strategies to ensure that health enhancing behaviors are adopted and maintained are essential. These may include training for an extended duration, alternative environments to undertake the initial program, maintenance programs following initial exercise training, program repetition

  10. Cardiovascular control during exercise in type 2 diabetes mellitus.

    Science.gov (United States)

    Green, Simon; Egaña, Mikel; Baldi, J Chris; Lamberts, Regis; Regensteiner, Judith G

    2015-01-01

    Controlled studies of male and female subjects with type 2 diabetes mellitus (DM) of short duration (~3-5 years) show that DM reduces peak VO2 (L·min(-1) and mL·kg(-1)·min(-1)) by an average of 12-15% and induces a greater slowing of the dynamic response of pulmonary VO2 during submaximal exercise. These effects occur in individuals less than 60 years of age but are reduced or absent in older males and are consistently associated with significant increases in the exercise pressor response despite normal resting blood pressure. This exaggerated pressor response, evidence of exertional hypertension in DM, is manifest during moderate submaximal exercise and coincides with a more constrained vasodilation in contracting muscles. Maximum vasodilation during contractions involving single muscle groups is reduced by DM, and the dynamic response of vasodilation during submaximal contractions is slowed. Such vascular constraint most likely contributes to exertional hypertension, impairs dynamic and peak VO2 responses, and reduces exercise tolerance. There is a need to establish the effect of DM on dynamic aspects of vascular control in skeletal muscle during whole-body exercise and to clarify contributions of altered cardiovascular control and increased arterial stiffness to exertional hypertension.

  11. High-intensity interval training vs. moderate-intensity continuous exercise training in heart failure with preserved ejection fraction: a pilot study.

    Science.gov (United States)

    Angadi, Siddhartha S; Mookadam, Farouk; Lee, Chong D; Tucker, Wesley J; Haykowsky, Mark J; Gaesser, Glenn A

    2015-09-15

    Heart failure with preserved ejection fraction (HFpEF) is a major cause of morbidity and mortality. Exercise training is an established adjuvant therapy in heart failure; however, the effects of high-intensity interval training (HIIT) in HFpEF are unknown. We compared the effects of HIIT vs. moderate-intensity aerobic continuous training (MI-ACT) on peak oxygen uptake (V̇o₂peak), left ventricular diastolic dysfunction, and endothelial function in patients with HFpEF. Nineteen patients with HFpEF (age 70 ± 8.3 yr) were randomized to either HIIT (4 × 4 min at 85-90% peak heart rate, with 3 min active recovery) or MI-ACT (30 min at 70% peak heart rate). Fifteen patients completed exercise training (HIIT: n = 9; MI-ACT: n = 6). Patients trained 3 days/wk for 4 wk. Before and after training patients underwent a treadmill test for V̇o₂peak determination, 2D-echocardiography for assessment of left ventricular diastolic dysfunction, and brachial artery flow-mediated dilation (FMD) for assessment of endothelial function. HIIT improved V̇o₂peak (pre = 19.2 ± 5.2 ml·kg(-1)·min(-1); post = 21.0 ± 5.2 ml·kg(-1)·min(-1); P = 0.04) and left ventricular diastolic dysfunction grade (pre = 2.1 ± 0.3; post = 1.3 ± 0.7; P = 0.02), but FMD was unchanged (pre = 6.9 ± 3.7%; post = 7.0 ± 4.2%). No changes were observed following MI-ACT. A trend for reduced left atrial volume index was observed following HIIT compared with MI-ACT (-3.3 ± 6.6 vs. +5.8 ± 10.7 ml/m(2); P = 0.06). In HFpEF patients 4 wk of HIIT significantly improved V̇o₂peak and left ventricular diastolic dysfunction. HIIT may provide a more robust stimulus than MI-ACT for early exercise training adaptations in HFpEF. Copyright © 2015 the American Physiological Society.

  12. Non-invasive measurement of adrenal response after standardized exercise tests in prepubertal children

    NARCIS (Netherlands)

    Heijsman, Sigrid M.; Koers, Nicoline F.; Bocca, Gianni; van der Veen, Betty S.; Appelhof, Maaike; Kamps, Arvid W. A.

    Objective: To determine the feasibility of non-invasive evaluation of adrenal response in healthy prepubertal children by standardized exercise tests. Methods: On separate occasions, healthy prepubertal children performed a submaximal cycling test, a maximal cycling test, and a 20-m shuttle-run

  13. Racing Skiers and Swimmers’ Heart Electric Field during Ventricular Depolarization at Recovery Period after Moderate and Submaximal Physical Load

    Directory of Open Access Journals (Sweden)

    Svetlana V. Strelnikova

    2013-01-01

    Full Text Available The article presents the results of cardioelectrotopographic investigation of racing skiers and swimmers’ heart electric activity during ventricular depolarization at recovery period after moderate and submaximal physical load. Changes in ventricular depolarization time and ventricular depolarization phases ratio due to longer duration of the first and second cardioelectric potential inversions on the chest surface in racing skiers and less duration of the depolarization initial phase in swimmers were detected after moderate and submaximal load

  14. A Submaximal Running Test With Postexercise Cardiac Autonomic and Neuromuscular Function in Monitoring Endurance Training Adaptation.

    Science.gov (United States)

    Vesterinen, Ville; Nummela, Ari; Laine, Tanja; Hynynen, Esa; Mikkola, Jussi; Häkkinen, Keijo

    2017-01-01

    Vesterinen, V, Nummela, A, Laine, T, Hynynen, E, Mikkola, J, and Häkkinen, K. A submaximal running test with postexercise cardiac autonomic and neuromuscular function in monitoring endurance training adaptation. J Strength Cond Res 31(1): 233-243, 2017-The aim of this study was to investigate whether a submaximal running test (SRT) with postexercise heart rate recovery (HRR), heart rate variability (HRV), and countermovement jump (CMJ) measurements could be used to monitor endurance training adaptation. Thirty-five endurance-trained men and women completed an 18-week endurance training. Maximal endurance performance and maximal oxygen uptake were measured every 8 weeks. In addition, SRTs with postexercise HRR, HRV, and CMJ measurements were carried out every 4 weeks. Submaximal running test consisted of two 6-minute stages at 70 and 80% of maximum heart rate (HRmax) and a 3-minute stage at 90% HRmax, followed by a 2-minute recovery stage for measuring postexercise HRR, HRV, and CMJ test. The highest responders according to the change of maximal endurance performance showed a significant improvement in running speeds during stages 2 and 3 in SRT, whereas no changes were observed in the lowest responders. The strongest correlation was found between the change of maximal endurance performance and running speed during stage 3, whereas no significant relationships were found between the change of maximal endurance performance and the changes of postexercise HRR, HRV, and CMJ. Running speed at 90% HRmax intensity was the most sensitive variable to monitor adaptation to endurance training. The present submaximal test showed potential to monitor endurance training adaptation. Furthermore, it may serve as a practical tool for athletes and coaches to evaluate weekly the effectiveness of training program without interfering in the normal training habits.

  15. Does continuous endurance exercise in water elicit a higher release of ANP and BNP and a higher plasma concentration of FFAs in pre-obese and obese men than high intensity intermittent endurance exercise? ? Study protocol for a randomized controlled trial

    OpenAIRE

    Karner-Rezek, K; Knechtle, B.; Fenzl, M; Gredig, J; Rosemann, T

    2013-01-01

    Background Atrial natriuretic peptides (ANP) and Brain natriuretic peptides (BNP) stimulate fat cell plasma membrane receptors. They are potent lipolytic agents on isolated fat cells from subcutaneous adipose tissue. The physiological effects of continuous endurance exercise on ANP release and plasma free fatty acids (FFA) concentrations have been well described. The enhancement of fat metabolism using high intensity intermittent exercise protocols has been assessed in more recent investigati...

  16. The Role of Autonomic Function in Exercise-induced Endogenous Analgesia: A Case-control Study in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Healthy People.

    Science.gov (United States)

    Oosterwijck, Jessica Van; Marusic, Uros; De Wandele, Inge; Paul, Lorna; Meeus, Mira; Moorkens, Greta; Lambrecht, Luc; Danneels, Lieven; Nijs, Jo

    2017-03-01

    Patients with myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS) are unable to activate brain-orchestrated endogenous analgesia (or descending inhibition) in response to exercise. This physiological impairment is currently regarded as one factor explaining post-exertional malaise in these patients. Autonomic dysfunction is also a feature of ME/CFS. This study aims to examine the role of the autonomic nervous system in exercise-induced analgesia in healthy people and those with ME/CFS, by studying the recovery of autonomic parameters following aerobic exercise and the relation to changes in self-reported pain intensity. A controlled experimental study. The study was conducted at the Human Physiology lab of a University. Twenty women with ME/CFS- and 20 healthy, sedentary controls performed a submaximal bicycle exercise test known as the Aerobic Power Index with continuous cardiorespiratory monitoring. Before and after the exercise, measures of autonomic function (i.e., heart rate variability, blood pressure, and respiration rate) were performed continuously for 10 minutes and self-reported pain levels were registered. The relation between autonomous parameters and self-reported pain parameters was examined using correlation analysis. Some relationships of moderate strength between autonomic and pain measures were found. The change (post-exercise minus pre-exercise score) in pain severity was correlated (r = .580, P = .007) with the change in diastolic blood pressure in the healthy group. In the ME/CFS group, positive correlations between the changes in pain severity and low frequency (r = .552, P = .014), and between the changes in bodily pain and diastolic blood pressure (r = .472, P = .036), were seen. In addition, in ME/CHFS the change in headache severity was inversely correlated (r = -.480, P = .038) with the change in high frequency heart rate variability. Based on the cross-sectional design of the study, no firm conclusions can be drawn on the

  17. L-tryptophan supplementation can decrease fatigue perception during an aerobic exercise with supramaximal intercalated anaerobic bouts in young healthy men.

    Science.gov (United States)

    Javierre, C; Segura, R; Ventura, J L; Suárez, A; Rosés, J M

    2010-05-01

    Physical exercise is often terminated not due to muscle fatigue but because of inadequate neural drive in the serotonergic system. Modifications in activity levels of the serotonergic system, induced by variations in the availability of L-tryptophan (a serotonin precursor) may alter neural drive. We examined the effect of L-tryptophan supplementation on physical performance by combining aerobic work with brief periods of supramaximal intensity that closely mimics the activity typical of team sports. Twenty healthy young sportsmen (mean age 21.2 +/- 0.7 years) performed a submaximal exercise on a cycle ergometer, with a workload corresponding to 50% of their respective VO(2) max for 10 min, followed by a maximal intensity exercise for 30 s. This sequence was repeated three times and, after the fourth series, each participant continued to exercise at the highest speed that he could sustain for 20 min. This protocol was performed twice: once with and finally without supplementation of L-tryptophan, in random order and double-blind. Peak power output, average anaerobic power output, and power output during the last 20 min of the trial were higher on the trials performed with L-tryptophan supplementation than on those performed with placebo. The distance covered during the last 20 min of the trial was 11,959 +/- 1,753 m on placebo and 12,526 +/- 1,617 m on L-tryptophan (p exercises, modification of the serotonergic system may improve the physical performance.

  18. Effects of aerobic endurance, muscle strength, and motor control exercise on physical fitness and musculoskeletal injury rate in preprofessional dancers: an uncontrolled trial.

    Science.gov (United States)

    Mistiaen, Wilhelm; Roussel, Nathalie A; Vissers, Dirk; Daenen, Liesbeth; Truijen, Steven; Nijs, Jo

    2012-06-01

    The purpose of this study was to evaluate musculoskeletal injury rate and physical fitness before and 6 months after an endurance, strength, and motor control exercise program in preprofessional dancers. This uncontrolled trial was completed at a college offering a professional bachelor degree in dance. Forty preprofessional dancers underwent a test battery before and after a 6-month lasting exercise program in addition to their regular dance lessons. Physical fitness was evaluated by means of a submaximal exercise test with continuous physiological monitoring and by a field test for explosive strength. Anthropometric measurements were taken to analyze the influence of fitness training on body composition. Musculoskeletal injury incidence and quality of life were recorded during the 6-month lasting intervention. An intention-to-treat analysis ("last observation carried forward" method) was used with a Student t test for normally distributed variables. The Wilcoxon signed rank and Mann-Whitney U tests were used as nonparametric tests. Physical fitness improved after the 6 months of additional training program (Pdancing. The combination of regular dance lessons with an additional exercise program resulted in improved physical fitness in preprofessional dancers, without affecting the aesthetical appearance. A relatively high injury rate was observed during the intervention period. These results suggest that a randomized, controlled trial should be performed to examine the effectiveness of additional exercise in dancers on physical fitness and musculoskeletal injury rate. Copyright © 2012 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

  19. Comparison of High-Intensity Interval Training and Moderate-to-Vigorous Continuous Training for Cardiometabolic Health and Exercise Enjoyment in Obese Young Women: A Randomized Controlled Trial.

    Directory of Open Access Journals (Sweden)

    Zhaowei Kong

    Full Text Available The aim of this study was to compare the effects of 5-week high-intensity interval training (HIIT and moderate-to-vigorous intensity continuous training (MVCT on cardiometabolic health outcomes and enjoyment of exercise in obese young women.A randomized controlled experiment was conducted that involved thirty-one obese females (age range of 18-30 randomly assigned to either HIIT or MVCT five-week training programs. Participants in HIIT condition performed 20 min of repeated 8 s cycling interspersed with 12 s rest intervals, and those in MVCT condition cycled continuously for 40 min at 60-80% of peak oxygen consumption ([Formula: see text]O2peak, both for four days in a week. Outcomes such as [Formula: see text]O2peak, body composition estimated by bioimpedance analysis, blood lipids, and serum sexual hormones were measured at pre-and post-training. The scores of Physical Activity Enjoyment Scale (PAES were collected during the intervention.After training, [Formula: see text]O2peak increased significantly for both training programs (9.1% in HIIT and 10.3% in MVCT (p = 0.010, η2 = 0.41. Although MVCT group had a significant reduction in total body weight (TBW, -1.8%, p = 0.034, fat mass (FM, - 4.7%, p = 0.002 and percentage body fat (PBF, -2.9%, p = 0.016, there were no significant between-group differences in the change of the pre- and post-measures of these variables. The HIIT group had a higher score on PAES than the MVCT group during the intervention. For both conditions, exercise training led to a decline in resting testosterone and estradiol levels, but had no significant effect on blood lipids.Both HIIT and MVCT are effective in improving cardiorespiratory fitness and in reducing sexual hormones in obese young women; however, HIIT is a more enjoyable and time-efficient strategy. The mild-HIIT protocol seems to be useful for at least maintaining the body weight among sedentary individuals.

  20. Comparison of High-Intensity Interval Training and Moderate-to-Vigorous Continuous Training for Cardiometabolic Health and Exercise Enjoyment in Obese Young Women: A Randomized Controlled Trial

    Science.gov (United States)

    Sun, Shengyan; Song, Lili; Shi, Qingde

    2016-01-01

    Objective The aim of this study was to compare the effects of 5-week high-intensity interval training (HIIT) and moderate-to-vigorous intensity continuous training (MVCT) on cardiometabolic health outcomes and enjoyment of exercise in obese young women. Methods A randomized controlled experiment was conducted that involved thirty-one obese females (age range of 18–30) randomly assigned to either HIIT or MVCT five-week training programs. Participants in HIIT condition performed 20 min of repeated 8 s cycling interspersed with 12 s rest intervals, and those in MVCT condition cycled continuously for 40 min at 60–80% of peak oxygen consumption (V˙O2peak), both for four days in a week. Outcomes such as V˙O2peak, body composition estimated by bioimpedance analysis, blood lipids, and serum sexual hormones were measured at pre-and post-training. The scores of Physical Activity Enjoyment Scale (PAES) were collected during the intervention. Results After training, V˙O2peak increased significantly for both training programs (9.1% in HIIT and 10.3% in MVCT) (p = 0.010, η2 = 0.41). Although MVCT group had a significant reduction in total body weight (TBW, −1.8%, p = 0.034), fat mass (FM, - 4.7%, p = 0.002) and percentage body fat (PBF, −2.9%, p = 0.016), there were no significant between-group differences in the change of the pre- and post-measures of these variables. The HIIT group had a higher score on PAES than the MVCT group during the intervention. For both conditions, exercise training led to a decline in resting testosterone and estradiol levels, but had no significant effect on blood lipids. Conclusion Both HIIT and MVCT are effective in improving cardiorespiratory fitness and in reducing sexual hormones in obese young women; however, HIIT is a more enjoyable and time-efficient strategy. The mild-HIIT protocol seems to be useful for at least maintaining the body weight among sedentary individuals. PMID:27368057

  1. Characterization of Symmetry Properties of First Integrals for Submaximal Linearizable Third-Order ODEs

    Directory of Open Access Journals (Sweden)

    K. S. Mahomed

    2013-01-01

    Full Text Available The relationship between first integrals of submaximal linearizable third-order ordinary differential equations (ODEs and their symmetries is investigated. We obtain the classifying relations between the symmetries and the first integral for submaximal cases of linear third-order ODEs. It is known that the maximum Lie algebra of the first integral is achieved for the simplest equation and is four-dimensional. We show that for the other two classes they are not unique. We also obtain counting theorems of the symmetry properties of the first integrals for these classes of linear third-order ODEs. For the 5 symmetry class of linear third-order ODEs, the first integrals can have 0, 1, 2, and 3 symmetries, and for the 4 symmetry class of linear third-order ODEs, they are 0, 1, and 2 symmetries, respectively. In the case of submaximal linear higher-order ODEs, we show that their full Lie algebras can be generated by the subalgebras of certain basic integrals.

  2. THE HEART LEFT VENTRICLE DIASTOLIC FUNCTION DURING EXERCISES OF DIFFERENT POWER IN ATHLETES.

    Science.gov (United States)

    Nekhanevych, О; Zhylyuk, V; Logvinenko, V; Kramareva, Y

    2017-01-01

    The aim of the research was to investigate diastolic left ventricle function in athletes performing exercises requiring varying power using echocardiography. We surveyed 68 athletes aged from 12 to 27 years who were involved in swimming and volleyball. Echocardiography was used to assess cardiohaemodynamic changes in athletes using a bicycle ergometer to exercise at varying intensities. Exercising at submaximal and average power produces a proportional increase in indices of diastolic function of the heart: maximum speed of early diastolic mitral inflow streams (E) to 81,9±20,0 сm/s and maximum speed of early diastolic and mitral annulus velocity (е') to 16,6±5,7 сm/s. It led to constant ratio E/e' 6,73±2,83 units. The early symptoms of physical strain on the cardiovascular system were signs of myocardial relaxation violation during diastole. Symptoms appeared during the maximum power load and led to a large increase in E compared to e', which was manifested in the Е/е' increase to 7,33±3,69 units (р<0,05). Continued physical activity lowered the global systolic function of the left ventricle. Additional early indicator of physical strain is length of early diastolic inflow deceleration time, which at above-threshold load was reduced more than 50 ms.

  3. Time to adapt exercise training regimens in pulmonary rehabilitation--a review of the literature.

    Science.gov (United States)

    Lee, Annemarie L; Holland, Anne E

    2014-01-01

    Exercise intolerance, exertional dyspnea, reduced health-related quality of life, and acute exacerbations are features characteristic of chronic obstructive pulmonary disease (COPD). Patients with a primary diagnosis of COPD often report comorbidities and other secondary manifestations, which diversifies the clinical presentation. Pulmonary rehabilitation that includes whole body exercise training is a critical part of management, and core programs involve endurance and resistance training for the upper and lower limbs. Improvement in maximal and submaximal exercise capacity, dyspnea, fatigue, health-related quality of life, and psychological symptoms are outcomes associated with exercise training in pulmonary rehabilitation, irrespective of the clinical state in which it is commenced. There may be benefits for the health care system as well as the individual patient, with fewer exacerbations and subsequent hospitalization reported with exercise training. The varying clinical profile of COPD may direct the need for modification to traditional training strategies for some patients. Interval training, one-legged cycling (partitioning) and non-linear periodized training appear to be equally or more effective than continuous training. Inspiratory muscle training may have a role as an adjunct to whole body training in selected patients. The benefits of balance training are also emerging. Strategies to ensure that health enhancing behaviors are adopted and maintained are essential. These may include training for an extended duration, alternative environments to undertake the initial program, maintenance programs following initial exercise training, program repetition, and incorporation of approaches to address behavioral change. This may be complemented by methods designed to maximize uptake and completion of a pulmonary rehabilitation program.

  4. Effects of Cooling During Exercise on Thermoregulatory Responses of Men With Paraplegia.

    Science.gov (United States)

    Bongers, Coen C W G; Eijsvogels, Thijs M H; van Nes, Ilse J W; Hopman, Maria T E; Thijssen, Dick H J

    2016-05-01

    People with spinal cord injury (SCI) have an altered afferent input to the thermoregulatory center, resulting in a reduced efferent response (vasomotor control and sweating capacity) below the level of the lesion. Consequently, core body temperature rises more rapidly during exercise in individuals with SCI compared with people who are able-bodied. Cooling strategies may reduce the thermophysiological strain in SCI. The aim of this study was to examine the effects of a cooling vest on the core body temperature response of people with a thoracic SCI during submaximal exercise. Ten men (mean age=44 years, SD=11) with a thoracic lesion (T4-T5 or below) participated in this randomized crossover study. Participants performed two 45-minute exercise bouts at 50% maximal workload (ambient temperature 25°C), with participants randomized to a group wearing a cooling vest or a group wearing no vest (separate days). Core body temperature and skin temperature were continuously measured, and thermal sensation was assessed every 3 minutes. Exercise resulted in an increased core body temperature, skin temperature, and thermal sensation, whereas cooling did not affect core body temperature. The cooling vest effectively decreased skin temperature, increased the core-to-trunk skin temperature gradient, and tended to lower thermal sensation compared with the control condition. The lack of differences in core body temperature among conditions may be a result of the relative moderate ambient temperature in which the exercise was performed. Despite effectively lowering skin temperature and increasing the core-to-trunk skin temperature gradient, there was no impact of the cooling vest on the exercise-induced increase in core body temperature in men with low thoracic SCI. © 2016 American Physical Therapy Association.

  5. Evidence of cardiac functional reserve upon exhaustion during incremental exercise to determine VO2max.

    Science.gov (United States)

    Elliott, Adrian D; Skowno, Justin; Prabhu, Mahesh; Noakes, Timothy David; Ansley, Les

    2015-01-01

    There remains considerable debate regarding the limiting factor(s) for maximal oxygen uptake (VO2max). Previous studies have shown that the central circulation may be the primary limiting factor for VO2max and that cardiac work increases beyond VO2max. We sought to evaluate whether the work of the heart limits VO2max during upright incremental cycle exercise to exhaustion. Eight trained men completed two incremental exercise trials, each terminating with exercise at two different rates of work eliciting VO2max (MAX and SUPRAMAX). During each exercise trial we continuously recorded cardiac output using pulse-contour analysis calibrated with a lithium dilution method. Intra-arterial pressure was recorded from the radial artery while pulmonary gas exchange was measured continuously for an assessment of oxygen uptake. The workload during SUPRAMAX (mean±SD: 346.5±43.2 W) was 10% greater than that achieved during MAX (315±39.3 W). There was no significant difference between MAX and SUPRAMAX for Q (28.7 vs 29.4 L/min) or VO2 (4.3 vs 4.3 L/min). Mean arterial pressure was significantly higher during SUPRAMAX, corresponding to a higher cardiac power output (8.1 vs 8.5 W; p<0.06). Despite similar VO2 and Q, the greater cardiac work during SUPRAMAX supports the view that the heart is working submaximally at exhaustion during an incremental exercise test (MAX). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  6. Exercise capacity in lean versus obese women.

    Science.gov (United States)

    Hulens, M; Vansant, G; Lysens, R; Claessens, A L; Muls, E

    2001-10-01

    The aim of this study was to assess the nature and magnitude of the differences in submaximal and maximal exercise capacity parameters between lean and obese women. A total of 225 healthy obese women 18-65 years (BMI> or=30 kg/m(2)) and 81 non-athletic lean women (BMI< or=26 kg/m(2)) were selected. Anthropometric measurements (weight and height), body composition assessment (bioelectrical impedance method) and a maximal exercise capacity test on a bicycle ergometer were performed. Oxygen uptake (VO(2)), carbon dioxide production (VCO(2)), expired ventilation (VE), respiratory quotient (RQ), breathing efficiency (VE/VO(2)), mechanical efficiency (ME) and anaerobic threshold (AT) were calculated. At a submaximal intensity load of 70 W, VO(2) (l/min) was larger in the obese women and was already 78% of their peak VO(2), whereas in the non-obese it was only 69% (P=0.0001). VE (l/min) was larger, VE/VO(2) did not differ and ME was lower in obese compared to the lean women. AT occurred at the same percentage of peak VO(2) in both lean and obese women. At peak effort, achieved load, terminal VO(2) (l min(-1) kg(-1)), VE, heart rate, RQ respiratory exchange ratio and perceived exertion were lower in obese subjects compared to the non-obese. Obese subjects mentioned significantly more musculoskeletal pain as a reason to end the test, whereas in lean subjects it was leg fatigue. Lean women recovered better as after 2 min they were already at 35% of the peak VO(2), whereas in the obese women it was 47% (P=0.0001). Our results confirm that exercise capacity is decreased in obesity, both at submaximal and peak intensity, and during recovery. Moreover, at peak effort musculoskeletal pain was an important reason to end the test and not true leg fatigue. These findings are important when designing exercise programs for obese subjects.

  7. Effect of strength training with blood flow restriction on muscle power and submaximal strength in eumenorrheic women.

    Science.gov (United States)

    Gil, Ana L S; Neto, Gabriel R; Sousa, Maria S C; Dias, Ingrid; Vianna, Jeferson; Nunes, Rodolfo A M; Novaes, Jefferson S

    2017-03-01

    Blood flow restriction (BFR) training stimulates muscle size and strength by increasing muscle activation, accumulation of metabolites and muscle swelling. This method has been used in different populations, but no studies have evaluated the effects of training on muscle power and submaximal strength (SS) in accounted for the menstrual cycle. The aim of this study was to analyse the effect of strength training (ST) with BFR on the muscle power and SS of upper and lower limbs in eumenorrheic women. Forty untrained women (18-40 years) were divided randomly and proportionally into four groups: (i) high-intensity ST at 80% of 1RM (HI), (ii) low-intensity ST at 20% of 1RM combined with partial blood flow restriction (LI + BFR), (iii) low-intensity ST at 20% of 1RM (LI) and d) control group (CG). Each training group performed eight training sessions. Tests with a medicine ball (MB), horizontal jump (HJ), vertical jump (VJ), biceps curls (BC) and knee extension (KE) were performed during the 1st day follicular phase (FP), 14th day (ovulatory phase) and 26-28th days (luteal phase) of the menstrual cycle. There was no significant difference among groups in terms of the MB, HJ, VJ or BC results at any time point (P>0·05). SS in the KE exercise was significantly greater in the LI + BFR group compared to the CG group (P = 0·014) during the LP. Therefore, ST with BFR does not appear to improve the power of upper and lower limbs and may be an alternative to improve the SS of lower limbs of eumenorrheic women. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  8. Separate and combined effects of exercise training and weight loss on exercise efficiency and substrate oxidation.

    Science.gov (United States)

    Amati, Francesca; Dubé, John J; Shay, Chris; Goodpaster, Bret H

    2008-09-01

    Perturbations in body weight have been shown to affect energy expenditure and efficiency during physical activity. The separate effects of weight loss and exercise training on exercise efficiency or the proportion of energy derived from fat oxidation during physical activity, however, are not known. The purpose of this study was to determine the separate and combined effects of exercise training and weight loss on metabolic efficiency, economy (EC), and fat oxidation during steady-state moderate submaximal exercise. Sixty-four sedentary older (67 +/- 0.5 yr) overweight to obese (30.7 +/- 0.4 kg/m(2)) volunteers completed 4 mo of either diet-induced weight loss (WL; n = 11), exercise training (EX; n = 36), or the combination of both interventions (WLEX; n = 17). Energy expenditure, gross efficiency (GE), EC, and proportion of energy expended from fat (EF) were determined during a 1-h submaximal (50% of peak aerobic capacity) cycle ergometry exercise before the intervention and at the same absolute work rate after the intervention. We found that EX increased GE by 4.7 +/- 2.2%. EC was similarly increased by 4.2 +/- 2.1% by EX. The addition of concomitant WL to EX (WLEX) resulted in greater increases in GE (9.0 +/- 3.3%) compared with WL alone but not compared with EX alone. These effects remained after adjusting for changes in lean body mass. The proportion of energy derived from fat during the bout of moderate exercise increased with EX and WLEX but not with WL. From these findings, we conclude that exercise training, either alone or in combination with weight loss, increases both exercise efficiency and the utilization of fat during moderate physical activity in previously sedentary, obese older adults. Weight loss alone, however, significantly improves neither efficiency nor utilization of fat during exercise.

  9. Preventing exercise-induced hypoglycemia in type 1 diabetes using real-time continuous glucose monitoring and a new carbohydrate intake algorithm: an observational field study.

    Science.gov (United States)

    Riddell, Michael C; Milliken, Jill

    2011-08-01

    Real-time (RT) continuous glucose monitoring (CGM) offers the possibility to better manage glucose levels during exercise in active individuals with type 1 diabetes mellitus (T1DM). However, studies have yet to determine the appropriate actions to take when glucose levels are trending toward hypoglycemia. The purpose of this observational field study was to test the effectiveness of RT-GCM and a new carbohydrate intake algorithm designed for maintaining euglycemia during sports. During a 2-week sports camp, 25 adolescents (8-17 years old) with T1DM were fitted with a RT-CGM device and instructed to ingest fast-acting carbohydrates (8-20 g, depending on the concentration of glucose at the time of RT-CGM alert and rates of change in glycemia) when glucose levels were trending toward hypoglycemia. Rates of change in glucose were measured before and after algorithm use, and the incidence of hypoglycemia was documented. With RT-CGM and algorithm use, euglycemia was largely maintained with modest amounts of carbohydrate intake, even when glucose levels were initially dropping at an elevated rate (>0.55 mmol/L per 5 min). Mild biochemical hypoglycemia (3.0-3.9 mmol/L) occurred just twice out of 22 uses of the algorithm (9%) when trend arrows alerted the subjects that glucose levels were dropping. When glucose levels were already below target (carbohydrate being ingested. Average glucose levels during sports in the 60 min following algorithm use were 5.8 ± 1.2 mmol/L, 5.3 ± 1.0 mmol/L, and 6.2 ± 0.8 mmol/L in the 20-, 16-, and 8-g carbohydrate intake protocols when glucose levels were initially on target but dropping toward hypoglycemia. When coupled with RT-CGM, a new carbohydrate intake algorithm prevents hypoglycemia and maintains euglycemia during exercise, particularly if patients ingest carbohydrate when trend arrows alert them of a drop in glycemia.

  10. Music during exercise: does tempo influence psychophysical responses?

    OpenAIRE

    Elliott, David

    2007-01-01

    This study examined whether music of different tempi would influence the psychophysical responses of exercise participants performing a sub-maximal cycle task. Specifically, the investigation assessed the effect of musical tempo upon aerobic work rate and whether dissociation, and/or, arousal could be implicated in any physical responses. Eighteen student participants (10 females, 8 males) were required to partake in four experimental conditions: no music, ‘slow’ music, ‘moderately fast’ musi...

  11. Four weeks of speed endurance training reduces energy expenditure during exercise and maintains muscle oxidative capacity despite a reduction in training volume

    DEFF Research Database (Denmark)

    Iaia, F. Marcello; Hellsten, Ylva; Nielsen, Jens Jung

    2009-01-01

    We studied the effect of an alteration from regular endurance to speed endurance training on muscle oxidative capacity, capillarization, as well as energy expenditure during submaximal exercise and its relationship to mitochondrial uncoupling protein 3 (UCP3) in humans. Seventeen endurance-trained...... runners were assigned to either a speed endurance training (SET; n = 9) or a control (Con; n = 8) group. For a 4-wk intervention (IT) period, SET replaced the ordinary training ( approximately 45 km/wk) with frequent high-intensity sessions each consisting of 8-12 30-s sprint runs separated by 3 min...... of rest (5.7 +/- 0.1 km/wk) with additional 9.9 +/- 0.3 km/wk at low running speed, whereas Con continued the endurance training. After the IT period, oxygen uptake was 6.6, 7.6, 5.7, and 6.4% lower (P

  12. Exercise in Pregnancy

    OpenAIRE

    Hinman, Sally K.; Smith, Kristy B.; Quillen, David M.; Smith, M. Seth

    2015-01-01

    Context: Health professionals who care for pregnant women should discuss potential health benefits and harms of exercise. Although most pregnant women do not meet minimal exercise recommendations, there are a growing number of physically active women who wish to continue training throughout pregnancy. Evidence Acquisition: A search of the Web of Science database of articles and reviews available in English through 2014. The search terms exercise pregnancy, strenuous exercise pregnancy, and vi...

  13. Optoelectronic plethysmography compared to spirometry during maximal exercise.

    Science.gov (United States)

    Layton, Aimee M; Moran, Sienna L; Garber, Carol Ewing; Armstrong, Hilary F; Basner, Robert C; Thomashow, Byron M; Bartels, Matthew N

    2013-01-15

    The purpose of this study was to compare simultaneous measurements of tidal volume (Vt) by optoelectronic plethysmography (OEP) and spirometry during a maximal cycling exercise test to quantify possible differences between methods. Vt measured simultaneously by OEP and spirometry was collected during a maximal exercise test in thirty healthy participants. The two methods were compared by linear regression and Bland-Altman analysis at submaximal and maximal exercise. The average difference between the two methods and the mean percentage discrepancy were calculated. Submaximal exercise (SM) and maximal exercise (M) Vt measured by OEP and spirometry had very good correlation, SM R=0.963 (pspirometry. OEP could measure exercise Vt as much as 0.188 L above and -0.017 L below that of spirometry. The discrepancy between measurements was -2.0 ± 7.2% at SM and -2.4 ± 3.9% at M. In conclusion, Vt measurements at during exercise by OEP and spirometry are closely correlated and the difference between measurements was insignificant. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Assessment of right ventricular function during exercise with quantitative Doppler tissue imaging in children late after repair of tetralogy of Fallot.

    Science.gov (United States)

    Harada, Kenji; Toyono, Manatomo; Yamamoto, Fumio

    2004-08-01

    Doppler tissue imaging (DTI) has been developed to assess ventricular wall-motion velocity quantitatively for patients with various types of heart disease. This technique has a possibility of assessing right ventricular (RV) function reserve during exercise. To investigate RV function during exercise using DTI, 21 patients (9.3 +/- 3.3 years) who had undergone operation for tetralogy of Fallot at 1 to 3 years of age and 19 age-matched healthy children were studied. Echocardiography combined with DTI was performed at rest and during supine bicycle submaximal exercise. DTI of tricuspid annulus movement during systole (Sa) was obtained from a 4-chamber view. RV pressure was estimated by maximal tricuspid regurgitation (TR) velocity. The peak value of the first derivation of RV pressure (peak dP/dt) was measured from the continuous wave Doppler-derived TR profile. Adequate spectral Doppler recordings of TR were obtained in all participants. However, 9 healthy children and 2 patients with tetralogy of Fallot were excluded from the study because of an inability to determine the entire spectral TR velocity envelope during exercise. Therefore, data were analyzed in 29 participants. At rest, the mean RV pressure for patients was higher than that in control subjects (27 +/- 4 vs 18 +/- 3 mm Hg, P exercise. However, the magnitude of increases in Sa and peak dP/dt was significantly less for patients than in control subjects (37 +/- 16 vs 66 +/- 19% and 42 +/- 10 vs 80 +/- 13%, P exercise. This technique has a potential as a useful indicator of the effect of exercise on RV systolic function. An insufficient increase in Sa suggests impaired response to exercise of RV in patients with tetralogy of Fallot.

  15. Exercise thermoregulation after 14 days of bed rest

    Science.gov (United States)

    Greenleaf, J. E.; Reese, R. D.

    1980-01-01

    The effects of bed rest and exercise training during bed rest on body temperature and thermoregulatory responses at rest and during exercise are investigated. Seven male subjects underwent three two-week periods of bed rest during which isometric, isotonic, or no exercises were performed, separated by two ambulatory control periods and preceded by a two-week control period, during which they exercised regularly. Rectal and mean skin temperatures and sweating responses were determined during 70-min submaximal supine exercise during the bed rest and recovery periods. Measurements reveal a reduction in basal oral temperature during the control-recovery periods, with a relatively constant level during bed rest periods, and a significant increase in the rectal temperature elavation brought on by exercise following all three bed-rest regimes. It is concluded that the excessive increase in rectal temperature could be influenced by changes in skin heat conductance or the inhibition of sweating.

  16. Effects of music during exercise in different training status.

    Science.gov (United States)

    Baldari, C; Macone, D; Bonavolontà, V; Guidetti, L

    2010-09-01

    This study examined the interaction of exercise and music to establish the impact of these factors on state-anxiety and time to exhaustion comparing trained and active participants. Twenty-six university students (13 trained, 13 active) completed the State-anxiety Inventory questionnaire before and after a submaximal treadmill running until volitional exhaustion in both music and no-music condition. ANOVA showed that both trained and active groups significantly reduced their State-Anxiety scores after exercise tasks (Pmusic. Finding also revealed that active group reported a higher significant reduction of their state anxiety score after exercise in music condition compared to no-music task (Pmusic (Pmusic during exercise may improve this effect in active but not in trained participants. Further, listening to music during exercise may prolong the participants' exercise experience but different training status seems to qualify differently this response.

  17. Heart rate response and parasympathetic modulation during recovery from exercise in boys and men.

    Science.gov (United States)

    Guilkey, Justin P; Overstreet, Matthew; Fernhall, Bo; Mahon, Anthony D

    2014-08-01

    The purpose of this study was to examine the influence of postexercise parasympathetic modulation, measured by heart rate variability (HRV), on heart rate recovery (HRR) in boys (n = 13, 10.1 ± 0.8 years) and men (n = 13, 23.9 ± 1.5 years) following maximal and submaximal exercise. Subjects completed 10 min of supine rest, followed by graded exercise on a cycle ergometer to maximal effort. On a separate day, subjects exercised at an intensity equivalent to ventilatory threshold. Immediately following both exercise bouts, 1-min HRR was assessed in the supine position. HRV was analyzed under controlled breathing during the final 5 min of rest and recovery in the time and frequency domains and transformed to natural log (ln) values. Boys had a greater 1-min HRR than men following maximal (58 ± 8 vs. 47 ± 11 beats·min(-1)) and submaximal (59 ± 8 vs. 47 ± 15 beats·min(-1)) exercise (p 0.05). In conclusion, it appears that greater parasympathetic modulation accounts for greater HRR following maximal exercise in boys versus men. Although submaximal HRR was greater in boys, parasympathetic responses were similar between groups.

  18. The effect of lifelong exercise dose on cardiovascular function during exercise

    Science.gov (United States)

    Carrick-Ranson, Graeme; Hastings, Jeffrey L.; Bhella, Paul S.; Fujimoto, Naoki; Shibata, Shigeki; Palmer, M. Dean; Boyd, Kara; Livingston, Sheryl; Dijk, Erika

    2014-01-01

    An increased “dose” of endurance exercise training is associated with a greater maximal oxygen uptake (V̇o2max), a larger left ventricular (LV) mass, and improved heart rate and blood pressure control. However, the effect of lifelong exercise dose on metabolic and hemodynamic response during exercise has not been previously examined. We performed a cross-sectional study on 101 (69 men) seniors (60 yr and older) focusing on lifelong exercise frequency as an index of exercise dose. These included 27 who had performed ≤2 exercise sessions/wk (sedentary), 25 who performed 2–3 sessions/wk (casual), 24 who performed 4–5 sessions/wk (committed) and 25 who performed ≥6 sessions/wk plus regular competitions (Masters athletes) over at least the last 25 yr. Oxygen uptake and hemodynamics [cardiac output, stroke volume (SV)] were collected at rest, two levels of steady-state submaximal exercise, and maximal exercise. Doppler ultrasound measures of LV diastolic filling were assessed at rest and during LV loading (saline infusion) to simulate increased LV filling. Body composition, total blood volume, and heart rate recovery after maximal exercise were also examined. V̇o2max increased in a dose-dependent manner (P exercise, cardiac output and SV were largest in committed exercisers and Masters athletes (P exercise, effective arterial elastance, an index of ventricular-arterial coupling, was lower in committed exercisers and Masters athletes (P exercise frequency. These data suggest that performing four or more weekly endurance exercise sessions over a lifetime results in significant gains in V̇o2max, SV, and heart rate regulation during exercise; however, improved SV regulation during exercise is not coupled with favorable effects on LV filling, even when the heart is fully loaded. PMID:24458750

  19. Reduced modulation of pain in older adults following isometric and aerobic exercise

    Science.gov (United States)

    Naugle, Kelly M.; Naugle, Keith E.; Riley, Joseph L.

    2016-01-01

    Laboratory based studies show that acute aerobic and isometric exercise reduces sensitivity to painful stimuli in young healthy individuals, indicative of a hypoalgesic response. However, little is known regarding the effect of aging on exercise-induced hypoalgesia (EIH). The purpose of this study was to examine age differences in EIH following submaximal isometric exercise, and moderate and vigorous aerobic exercise. Healthy older and younger adults completed one training session and four testing sessions consisting of either a submaximal isometric handgrip exercise, vigorous or moderate intensity stationary cycling, or quiet rest (control). The following measures were taken pre and post exercise/quiet rest: 1) pressure pain thresholds (PPTs), 2) suprathreshold pressure pain ratings, 3) pain ratings during 30-s of prolonged noxious heat stimulation, and 3) temporal summation of heat pain. The results revealed age differences in EIH following isometric and aerobic exercise, with younger adults experiencing greater EIH compared to older adults. The age differences in EIH varied across pain induction techniques and exercise type. These results provide evidence for abnormal pain modulation following acute exercise in older adults. PERSPECTIVE This article enhances our understanding of the influence of a single bout of exercise on pain sensitivity and perception in healthy older compared to younger adults. This knowledge could potentially help clinicians optimize exercise as a method of pain management. PMID:26993959

  20. Reduced Modulation of Pain in Older Adults After Isometric and Aerobic Exercise.

    Science.gov (United States)

    Naugle, Kelly M; Naugle, Keith E; Riley, Joseph L

    2016-06-01

    Laboratory-based studies show that acute aerobic and isometric exercise reduces sensitivity to painful stimuli in young healthy individuals, indicative of a hypoalgesic response. However, little is known regarding the effect of aging on exercise-induced hypoalgesia (EIH). The purpose of this study was to examine age differences in EIH after submaximal isometric exercise and moderate and vigorous aerobic exercise. Healthy older and younger adults completed 1 training session and 4 testing sessions consisting of a submaximal isometric handgrip exercise, vigorous or moderate intensity stationary cycling, or quiet rest (control). The following measures were taken before and after exercise/quiet rest: 1) pressure pain thresholds, 2) suprathreshold pressure pain ratings, 3) pain ratings during 30 seconds of prolonged noxious heat stimulation, and 4) temporal summation of heat pain. The results revealed age differences in EIH after isometric and aerobic exercise, with younger adults experiencing greater EIH compared with older adults. The age differences in EIH varied across pain induction techniques and exercise type. These results provide evidence for abnormal pain modulation after acute exercise in older adults. This article enhances our understanding of the influence of a single bout of exercise on pain sensitivity and perception in healthy older compared with younger adults. This knowledge could help clinicians optimize exercise as a method of pain management. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

  1. Effects of Pedal Speed and Crank Length on Pedaling Mechanics during Submaximal Cycling

    Science.gov (United States)

    BARRATT, PAUL RICHARD; MARTIN, JAMES C.; ELMER, STEVE J.; KORFF, THOMAS

    2016-01-01

    ABSTRACT During submaximal cycling, the neuromuscular system has the freedom to select different intermuscular coordination strategies. From both a basic science and an applied perspective, it is important to understand how the central nervous system adjusts pedaling mechanics in response to changes in pedaling conditions. Purpose To determine the effect of changes in pedal speed (a marker of muscle shortening velocity) and crank length (a marker of muscle length) on pedaling mechanics during submaximal cycling. Methods Fifteen trained cyclists performed submaximal isokinetic cycling trials (90 rpm, 240 W) using pedal speeds of 1.41 to 1.61 m·s−1 and crank lengths of 150 to 190 mm. Joint powers were calculated using inverse dynamics. Results Increases in pedal speed and crank length caused large increases knee and hip angular excursions and velocities (P 0.05). Joint moments and joint powers were less affected by changes in the independent variables, but some interesting effects and trends were observed. Most noteworthy, knee extension moments and powers tended to decrease, whereas hip extension power tended to increase with an increase in crank length. Conclusions The distribution of joint moments and powers is largely maintained across a range of pedaling conditions. The crank length induced differences in knee extension moments, and powers may represent a trade-off between the central nervous system’s attempts to simultaneously minimize muscle metabolic and mechanical stresses. These results increase our understanding of the neural and mechanical mechanisms underlying multi-joint task performance, and they have practical relevance to coaches, athletes, and clinicians. PMID:26559455

  2. Effects of pentoxifylline on hemorheologic alterations induced by incremental treadmill exercise in thoroughbreds.

    Science.gov (United States)

    Weiss, D J; Geor, R J; Burger, K

    1996-09-01

    To determine whether pentoxifylline treatment altered hematologic, rheologic, electrolyte, or blood gas test results of Thoroughbreds during submaximal treadmill exercise. 5 healthy Thoroughbreds that had raced within the past year and had no history of exercise-induced pulmonary hemorrhage. Mixed venous blood samples were obtained before exercise, at treadmill speeds of 9 and 13 m/s, and 20 minutes after exercise; hematologic, rheologic, electrolyte, and blood gas test results were determined. Pentoxifylline treatment resulted in a 45% reduction in RBC filtration pressures for horses at rest. The improved RBC filterability persisted during treadmill exercise. Horses treated with pentoxifylline had a greater decrease in Po2 values and a lesser increase in plasma lactate concentration during treadmill exercise. Administration of pentoxifylline improved RBC deformability of horses at rest and during treadmill exercise. Improved RBC deformability resulting from pentoxifylline treatment may reduce exercise-associated shear stress in pulmonary capillaries, thereby attenuating exercise-induced pulmonary hemorrhage.

  3. Effects of wheel and hand-rim size on submaximal propulsion in wheelchair athletes.

    Science.gov (United States)

    Mason, Barry S; Van Der Woude, Lucas H V; Tolfrey, Keith; Lenton, John P; Goosey-Tolfrey, Victoria L

    2012-01-01

    This study aimed to investigate the effects of fixed gear ratio wheel sizes on the physiological and biomechanical responses to submaximal wheelchair propulsion. Highly trained wheelchair basketball players (N = 13) propelled an adjustable sports wheelchair in three different wheel sizes (24, 25, and 26 inches) on a motor-driven treadmill. Each wheel was equipped with force-sensing hand-rims (SMARTWheel), which collected kinetic and temporal data. Oxygen uptake (V˙O2) and HR responses were measured with high-speed video footage collected to determine three-dimensional upper body joint kinematics. Mean power output and work per cycle decreased progressively with increasing wheel size (P wheelchair propulsion.

  4. Telemetry pill versus rectal and esophageal temperature during extreme rates of exercise-induced core temperature change

    NARCIS (Netherlands)

    Teunissen, L.P.J.; Haan, A. de; Koning, J.J. de; Daanen, H.A.M.

    2012-01-01

    Core temperature measurement with an ingestible telemetry pill has been scarcely investigated during extreme rates of temperature change, induced by short high-intensity exercise in the heat. Therefore, nine participants performed a protocol of rest, (sub)maximal cycling and recovery at 30 °C. The

  5. Effects of exercise in polluted air on the aerobic power, serum lactate level and cell blood count of active individuals

    Directory of Open Access Journals (Sweden)

    Mehdi Kargarfard

    2011-01-01

    Conclusions: Exercise in high-polluted air resulted in a significant reduction in the performance at submaximal levels of physical exertion. Therefore, the acute exposure to polluted air may cause a significant reduction in the performance of active individuals. The clinical importance of these findings should be assessed in longitudinal studies.

  6. Balance in single-limb stance in healthy subjects – reliability of testing procedure and the effect of short-duration sub-maximal cycling

    Directory of Open Access Journals (Sweden)

    Roberts David

    2003-06-01

    Full Text Available Abstract Background To assess balance in single-limb stance, center of pressure movements can be registered by stabilometry with force platforms. This can be used for evaluation of injuries to the lower extremities. It is important to ensure that the assessment tools we use in the clinical setting and in research have minimal measurement error. Previous studies have shown that the ability to maintain standing balance is decreased by fatiguing exercise. There is, however, a need for further studies regarding possible effects of general exercise on balance in single-limb stance. The aims of this study were: 1 to assess the test-retest reliability of balance variables measured in single-limb stance on a force platform, and 2 to study the effect of exercise on balance in single-limb stance, in healthy subjects. Methods Forty-two individuals were examined for test-retest reliability, and 24 individuals were tested before (pre-exercise and after (post-exercise short-duration, sub-maximal cycling. Amplitude and average speed of center of pressure movements were registered in the frontal and sagittal planes. Mean difference between test and retest with 95% confidence interval, the intraclass correlation coefficient, and the Bland and Altman graphs with limits of agreement, were used as statistical methods for assessing test-retest reliability. The paired t-test was used for comparisons between pre- and post-exercise measurements. Results No difference was found between test and retest. The intraclass correlation coefficients ranged from 0.79 to 0.95 in all stabilometric variables except one. The limits of agreement revealed that small changes in an individual's performance cannot be detected. Higher values were found after cycling in three of the eight stabilometric variables. Conclusions The absence of systematic variation and the high ICC values, indicate that the test is reliable for distinguishing among groups of subjects. However, relatively large

  7. Low-protein vegetarian diet does not have a short-term effect on blood acid–base status but raises oxygen consumption during submaximal cycling

    Directory of Open Access Journals (Sweden)

    Hietavala Enni-Maria

    2012-11-01

    Full Text Available Abstract Background Acid–base balance refers to the equilibrium between acids and bases in the human body. Nutrition may affect acid–base balance and further physical performance. With the help of PRAL (potential renal acid load, a low-protein vegetarian diet (LPVD was designed to enhance the production of bases in body. The aim of this study was to investigate if LPVD has an effect on blood acid–base status and performance during submaximal and maximal aerobic cycling. Methods Nine healthy, recreationally active men (age 23.5 ± 3.4 yr participated in the study and were randomly divided into two groups in a cross-over study design. Group 1 followed LPVD for 4 days and group 2 ate normally (ND before performing a cycle ergometer test. The test included three 10-min stages at 40, 60 and 80% of VO2max. The fourth stage was performed at 100% of VO2max until exhaustion. After 10–16 days, the groups started a second 4-day diet, and at the end performed the similar ergometer test. Venous blood samples were collected at the beginning and at the end of both diet periods and after every stage cycled. Results Diet caused no significant difference in venous blood pH, strong ion difference (SID, total concentration of weak acids (Atot, partial pressure of CO2 (pCO2 or HCO3- at rest or during cycling between LPVD and ND. In the LPVD group, at rest SID significantly increased over the diet period (38.6 ± 1.8 vs. 39.8 ± 0.9, p=0.009. Diet had no significant effect on exercise time to exhaustion, but VO2 was significantly higher at 40, 60 and 80% of VO2max after LPVD compared to ND (2.03 ± 0.25 vs. 1.82 ± 0.21 l/min, p=0.035; 2.86 ± 0.36 vs. 2.52 ± 0.33 l/min, p Conclusion There was no difference in venous blood acid–base status between a 4-day LPVD and ND. VO2 was increased during submaximal cycling after LPVD suggesting that the exercise economy was poorer. This had no further effect on maximal aerobic performance. More studies are needed to

  8. Exercise performance over the menstrual cycle in temperate and hot, humid conditions.

    Science.gov (United States)

    Janse DE Jonge, Xanne A K; Thompson, Martin W; Chuter, Vivienne H; Silk, Leslie N; Thom, Jeanette M

    2012-11-01

    This study investigated the effects of the menstrual cycle on prolonged exercise performance both in temperate (20°C, 45% relative humidity) and hot, humid (32°C, 60% relative humidity) conditions. For each environmental condition, 12 recreationally active females were tested during the early follicular (day 3-6) and midluteal (day 19-25) phases, verified by measurement of estradiol and progesterone. For all four tests, thermoregulatory, cardiorespiratory, and perceptual responses were measured during 60 min of exercise at 60% of maximal oxygen consumption followed by an incremental test to exhaustion. No differences in exercise performance between menstrual cycle phases were found during temperate conditions (n = 8) despite a higher resting and submaximal exercise core temperature (Tc) in the luteal phase. In hot, humid conditions (n = 8), however, prolonged exercise performance, as exercise time to fatigue, was significantly reduced during the luteal phase. This finding was not only accompanied by higher resting and submaximal exercise Tc but also a higher rate of increase in Tc during the luteal phase. Furthermore, submaximal exercise HR, minute ventilation, and RPE measures were higher during the luteal phase in hot, humid conditions. No significant differences were found over the menstrual cycle in heat loss responses (partitional calorimetry, sweat rate, upper arm sweat composition) and Tc at exhaustion. In temperate conditions, no changes in prolonged exercise performance were found over the menstrual cycle, whereas in hot, humid conditions, performance was decreased during the luteal phase. The combination of both exercise and heat stress with the elevated luteal phase Tc at the onset of exercise resulted in physiological and perceptual changes and a greater thermosensitivity, which may explain the decrease in performance.

  9. Hormone responses to a continuous bout of rock climbing in men.

    Science.gov (United States)

    Sherk, Vanessa D; Sherk, Kyle A; Kim, SoJung; Young, Kaelin C; Bemben, Debra A

    2011-04-01

    Rock climbing is rapidly increasing in popularity as a recreational activity and as a competitive sport. Few studies have tested acute physiological responses to climbing, and no studies to date have tested hormone responses to a climbing-based workout. This study aimed to measure testosterone (T), growth hormone (GH), and cortisol (C) responses to continuous vertical climbing in young male rock climbers. Ten male rock climbers, aged between 21 and 30 years, climbed laps on a submaximal 55' climbing route for 30 min, or until exhaustion, whichever came first. Heart rate (HR) was recorded after every lap. Blood samples were collected by venipuncture before (Pre), immediately post (IP), and 15 min after the climbing exercise (P15) to assess blood lactate and plasma GH, T, and C. Subjects climbed 24.9 ± 1.9 min and 507.5 ± 82.5 feet. Peak HR was 182.1 ± 2.3 bpm, and lactate (Pre: 2.9 ± 0.6 mmol/dL, IP: 11.1 ± 1.0 mmol/dL) significantly (P climbing was an effective exercise stimulus for elevating plasma testosterone and growth hormone levels in young males.

  10. Dietary nitrate supplementation and exercise performance.

    Science.gov (United States)

    Jones, Andrew M

    2014-05-01

    Dietary nitrate is growing in popularity as a sports nutrition supplement. This article reviews the evidence base for the potential of inorganic nitrate to enhance sports and exercise performance. Inorganic nitrate is present in numerous foodstuffs and is abundant in green leafy vegetables and beetroot. Following ingestion, nitrate is converted in the body to nitrite and stored and circulated in the blood. In conditions of low oxygen availability, nitrite can be converted into nitric oxide, which is known to play a number of important roles in vascular and metabolic control. Dietary nitrate supplementation increases plasma nitrite concentration and reduces resting blood pressure. Intriguingly, nitrate supplementation also reduces the oxygen cost of submaximal exercise and can, in some circumstances, enhance exercise tolerance and performance. The mechanisms that may be responsible for these effects are reviewed and practical guidelines for safe and efficacious dietary nitrate supplementation are provided.

  11. Achilles tendinopathy alters stretch shortening cycle behaviour during a sub-maximal hopping task.

    Science.gov (United States)

    Debenham, James R; Travers, Mervyn J; Gibson, William; Campbell, Amity; Allison, Garry T

    2016-01-01

    To describe stretch shortening cycle behaviour of the ankle and lower limb in patients with Achilles tendinopathy (AT) and establish differences with healthy volunteers. Between-subjects case-controlled. Fifteen patients with AT (mean age 41.2±12.7 years) and 11 healthy volunteers (CON) (mean age 23.2±6.7 years) performed sub-maximal single-limb hopping on a custom built sledge-jump system. Using 3D motion analysis and surface EMG, temporal kinematic (lower limb stiffness, ankle angle at 80ms pre-contact, ankle angle at contact, peak ankle angle, ankle stretch amplitude) and EMG measures (onset, offset and peak times relative to contact) were captured. Data between AT and CON were compared statistically using a linear mixed model. Patients with AT exhibited significantly increased lower limb stiffness when compared to healthy volunteers (pbehaviour during sub-maximal hopping when compared with healthy volunteers. Patients with AT hop with greater lower limb stiffness, in a greater degree of ankle dorsiflexion and have a greater stretch amplitude. Likewise, delayed muscle activity is evident. These findings have implications in terms of informing the understanding of the pathoaetiology and management of AT. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  12. [Sub-maximal aerobic capacity and quality of life of patients with rheumatoid arthritis].

    Science.gov (United States)

    Lataoui, S; Belghali, S; Zeglaoui, H; Bouajina, E; Ben Saad, H

    2017-01-01

    Studies about sub-maximal aerobic capacity of patients with rheumatoid arthritis are scarce. To assess the sub-maximal aerobic capacity of these patients through the 6-min walk test, estimated age of the "muscular and cardiorespiratory" chain. Thirty-seven consecutive patients (aged 20 to 60 years) with newly diagnosed rheumatoid arthritis will be included. Non-inclusion criteria will be: use of drugs (e.g.; methotrexate, beta-blockers), orthopaedic or rheumatologic conditions (other than rheumatoid arthritis) that may alter walking ability and recent infections. Exclusion criteria will be: 6-min walking test contra-indications and imperfect performance of the required lung function and walking maneuvers. Signs of walking intolerance will be: test interruption, distance ≤lower limit of normal, dyspnea score ≥5/10 (visual analogue scale) at the end of the test, haemoglobin oxygen saturation (SpO2) drop ≥5%, cardiac frequency at the end of the test ≤60% of maximum predicted. An estimated "muscular and cardiorespiratory chain" age higher than the chronological one will be considered as a sign of accelerated ageing. A high percentage of patients suffering from rheumatoid arthritis would show evidences of walking limitation and accelerated "muscular and cardiorespiratory chain" ageing. There would be a significant correlation between the walking test and clinical, biological, radiological and pulmonary function data and the patients' quality-of-life status. Copyright © 2016 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  13. Reliability of laser Doppler, near-infrared spectroscopy and Doppler ultrasound for peripheral blood flow measurements during and after exercise in the heat.

    Science.gov (United States)

    Choo, Hui C; Nosaka, Kazunori; Peiffer, Jeremiah J; Ihsan, Mohammed; Yeo, Chow C; Abbiss, Chris R

    2017-09-01

    This study examined the test-retest reliability of near-infrared spectroscopy (NIRS), laser Doppler flowmetry (LDF) and Doppler ultrasound to assess exercise-induced haemodynamics. Nine men completed two identical trials consisting of 25-min submaximal cycling at first ventilatory threshold followed by repeated 30-s bouts of high-intensity (90% of peak power) cycling in 32.8 ± 0.4°C and 32 ± 5% relative humidity (RH). NIRS (tissue oxygenation index [TOI] and total haemoglobin [tHb]) and LDF (perfusion units [PU]) signals were monitored continuously during exercise, and leg blood flow was assessed by Doppler ultrasound at baseline and after exercise. Cutaneous vascular conductance (CVC; PU/mean arterial pressure (MAP)) was expressed as the percentage change from baseline (%CVCBL). Coefficients of variation (CVs) as indicators of absolute reliability were 18.7-28.4%, 20.2-33.1%, 42.5-59.8%, 7.8-12.4% and 22.2-30.3% for PU, CVC, %CVCBL, TOI and tHb, respectively. CVs for these variables improved as exercise continued beyond 10 min. CVs for baseline and post-exercise leg blood flow were 17.8% and 10.5%, respectively. CVs for PU, tHb (r2 = 0.062) and TOI (r2 = 0.002) were not correlated (P > 0.05). Most variables demonstrated CVs lower than the expected changes (35%) induced by training or heat stress; however, minimum of 10 min exercise is recommended for more reliable measurements.

  14. Exercise thermoregulation with bed rest, confinement, and immersion deconditioning.

    Science.gov (United States)

    Greenleaf, J E

    1997-03-15

    Altered thermoregulation following exposure to prolonged (12-14 days) of bed rest and 6 hr of head-down thermoneutral water immersion in humans, and cage confinement (8 weeks) in male, mongrel dogs resulted in occasional increased core temperature (Tcore) at rest, but consistent "excessive" increase in Tcore during submaximal exercise. This excessive increase in Tcore in nonexercising and exercising subjects was independent of the mode (isometric or isotonic) of exercise training during bed rest, and was associated with the consistent hypovolemia in men but not in women taking estrogen supplementation (1.25 mg premarin/ day) which restored plasma volume during bed rest to ambulatory control levels. Post-bed rest exercise sweating (evaporative heat loss) was unchanged or higher than control levels; however, calculated tissue heat conductance was significantly lower in men, and forearm venoconstriction was greater (venous volume was reduced) in women during exercise after bed rest. Because sweating appeared proportional to the increased level of Tcore, these findings suggest that one major factor for the excessive hyperthermia is decreased core to periphery heat conduction. Exercising dogs respond like humans with excessive increase in both rectal (Tre) and exercising muscle temperatures (Tmu) after confinement and, after eight weeks of exercise training on a treadmill following confinement, they had an attenuated rate of increase of Tre even below ambulatory control levels. Intravenous infusion of glucose also attenuated not only the rise in Tre during exercise in normal dogs, but also the excessive rise in Tre and exercising Tmu after confinement. Oral glucose also appeared to reduce the rate of increase in excessive Tre in men after immersion deconditioning. There was a greater rate of rise in Tcore in two cosmonauts during supine submaximal exercise (65% VO2 max) on the fifth recovery day after the 115-day Mir 18 mission. Thus, the excessive rise in core

  15. Exercise thermoregulation with bed rest, confinement, and immersion deconditioning

    Science.gov (United States)

    Greenleaf, J. E.

    1997-01-01

    Altered thermoregulation following exposure to prolonged (12-14 days) of bed rest and 6 hr of head-down thermoneutral water immersion in humans, and cage confinement (8 weeks) in male, mongrel dogs resulted in occasional increased core temperature (Tcore) at rest, but consistent "excessive" increase in Tcore during submaximal exercise. This excessive increase in Tcore in nonexercising and exercising subjects was independent of the mode (isometric or isotonic) of exercise training during bed rest, and was associated with the consistent hypovolemia in men but not in women taking estrogen supplementation (1.25 mg premarin/ day) which restored plasma volume during bed rest to ambulatory control levels. Post-bed rest exercise sweating (evaporative heat loss) was unchanged or higher than control levels; however, calculated tissue heat conductance was significantly lower in men, and forearm venoconstriction was greater (venous volume was reduced) in women during exercise after bed rest. Because sweating appeared proportional to the increased level of Tcore, these findings suggest that one major factor for the excessive hyperthermia is decreased core to periphery heat conduction. Exercising dogs respond like humans with excessive increase in both rectal (Tre) and exercising muscle temperatures (Tmu) after confinement and, after eight weeks of exercise training on a treadmill following confinement, they had an attenuated rate of increase of Tre even below ambulatory control levels. Intravenous infusion of glucose also attenuated not only the rise in Tre during exercise in normal dogs, but also the excessive rise in Tre and exercising Tmu after confinement. Oral glucose also appeared to reduce the rate of increase in excessive Tre in men after immersion deconditioning. There was a greater rate of rise in Tcore in two cosmonauts during supine submaximal exercise (65% VO2 max) on the fifth recovery day after the 115-day Mir 18 mission. Thus, the excessive rise in core

  16. Impact of a Submaximal Warm-Up on Endurance Performance in Highly Trained and Competitive Male Runners

    Science.gov (United States)

    Zourdos, Michael C.; Bazyler, Caleb D.; Jo, Edward; Khamoui, Andy V.; Park, Bong-Sup; Lee, Sang-Rok; Panton, Lynn B.; Kim, Jeong-Su

    2017-01-01

    Purpose: The purpose of this investigation was to examine the effects of a submaximal running warm-up on running performance in male endurance athletes (n = 16, M[subscript age] = 21 ± 2 years, M[subscript VO2max] = 69.3 ± 5.1 mL/kg/min). Method: Endurance performance was determined by a 30-min distance trial after control and submaximal running…

  17. Cold exposure enhances fat utilization but not non-esterified fatty acids, glycerol or catecholamines availability during submaximal walking and running.

    Science.gov (United States)

    Gagnon, Dominique D; Rintamäki, Hannu; Gagnon, Sheila S; Cheung, Stephen S; Herzig, Karl-Heinz; Porvari, Katja; Kyröläinen, Heikki

    2013-01-01

    Cold exposure modulates the use of carbohydrates (CHOs) and fat during exercise. This phenomenon has mostly been observed in controlled cycling studies, but not during walking and running when core temperature and oxygen consumption are controlled, as both may alter energy metabolism. This study aimed at examining energy substrate availability and utilization during walking and running in the cold when core temperature and oxygen consumption are maintained. Ten lightly clothed male subjects walked or ran for 60-min, at 50% and 70% of maximal oxygen consumption, respectively, in a climatic chamber set at 0°C or 22°C. Thermal, cardiovascular, and oxidative responses were measured every 15-min during exercise. Blood samples for serum non-esterified fatty acids (NEFAs), glycerol, glucose, beta-hydroxybutyrate (BHB), plasma catecholamines, and serum lipids were collected immediately prior, and at 30- and 60-min of exercise. Skin temperature strongly decreased while core temperature did not change during cold trials. Heart rate (HR) was also lower in cold trials. A rise in fat utilization in the cold was seen through lower respiratory quotient (RQ) (-0.03 ± 0.02), greater fat oxidation (+0.14 ± 0.13 g · min(-1)) and contribution of fat to total energy expenditure (+1.62 ± 1.99 kcal · min(-1)). No differences from cold exposure were observed in blood parameters. During submaximal walking and running, a greater reliance on derived fat sources occurs in the cold, despite the absence of concurrent alterations in NEFAs, glycerol, or catecholamine concentrations. This disparity may suggest a greater reliance on intra-muscular energy sources such as triglycerides during both walking and running.

  18. Cold exposure enhances fat utilization but not non-esterified fatty acids, glycerol or catecholamines availability during submaximal walking and running

    Directory of Open Access Journals (Sweden)

    Dominique Daniel Gagnon

    2013-05-01

    Full Text Available Cold exposure modulates the use of carbohydrates and fat during exercise. This phenomenon has mostly been observed in controlled cycling studies, but not during walking and running when core temperature and oxygen consumption are controlled, as both may alter energy metabolism. This study aimed at examining energy substrate availability and utilization during walking and running in the cold when core temperature and oxygen consumption are maintained. Ten lightly clothed male subjects walked or ran for 60-min, at 50% and 70% of maximal oxygen consumption, respectively, in a climatic chamber set at 0°C or 22°C. Thermal, cardiovascular, and oxidative responses were measured every 15-min during exercise. Blood samples for serum non-esterified fatty acids, glycerol, glucose, beta-hydroxybutyrate, plasma catecholamines, and serum lipids were collected immediately prior, and at 30- and 60-min of exercise. Skin temperature strongly decreased while core temperature did not change during cold trials. Heart rate was also lower in cold trials. A rise in fat utilization in the cold was seen through lower respiratory quotient (-0.03 ± 0.02, greater fat oxidation (+0.14 ± 0.13 g•min-1 and contribution of fat to total energy expenditure (+1.62 ± 1.99 kcal•min-1. No differences from cold exposure were observed in blood parameters. During submaximal walking and running, a greater reliance on derived fat sources occurs in the cold, despite the absence of concurrent alterations in non-esterified fatty acids, glycerol, or catecholamine concentrations. This disparity may suggest a greater reliance on intra-muscular energy sources such as triglycerides during both walking and running.

  19. Non-exercise estimation of VO2max 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 (VO2max) as well as submaximal exercise testing. The International Physical Activity Questionnaire (IPAQ) is the most widely used and validated self-report measure of physical activity. This study aimed to develop and test a VO2max estimation equation derived from the IPAQ-Short Form (IPAQ-S). College-aged males and females (n = 80) completed the IPAQ-S and performed a maximal exercise test. The estimation equation was created with multivariate regression in a gender-balanced subsample of participants, equally representing five levels of fitness (n = 50) and validated in the remaining participants (n = 30). The resulting equation explained 43% of the variance in measured VO2max (SEE = 5.45 ml·kg-1·min-1). Estimated VO2max for 87% of individuals fell within acceptable limits of error observed with submaximal exercise testing (20% error). The IPAQ-S can be used to successfully estimate VO2max as well as submaximal exercise tests. Development of other population-specific estimation equations is warranted. PMID:21927551

  20. Special Needs to Prescribe Exercise Intensity for Scientific Studies

    Directory of Open Access Journals (Sweden)

    Peter Hofmann

    2011-01-01

    exercise training. A wide range of intensities is used to prescribe exercise, but this approach is limited. Usually percentages of maximal oxygen uptake (VO2 or heart rate (HR are applied to set exercise training intensity but this approach yields substantially variable metabolic and cardiocirculatory responses. Heterogeneous acute responses and training effects are explained by the nonuniform heart rate performance curve during incremental exercise which significantly alters the calculations of %HRmax and %HRR target HR data. Similar limitations hold true for using %VO2max and %VO2R. The solution of these shortcomings is to strictly apply objective submaximal markers such as thresholds or turn points and to tailor exercise training within defined regions.

  1. Exercise thermoregulation in men after 6 hours of immersion

    Science.gov (United States)

    Greenleaf, J. E.; Spaul, W. A.; Kravik, S. E.; Wong, N.; Elder, C. A.

    1985-01-01

    The present investigation is concerned with thermoregulation at rest and during exercise after water-immersion deconditioning, giving particular attention to the effects of fluid shifts and negative water balance on sweat rate and rectal temperature. Six healthy males 20-35 years old were used in the experiments. Rectal and mean skin temperature, skin heat conductance, heart rate, and total body sweat rate were measured during 70 min of supine leg exercise at 50 percent of peak O2 uptake. The data were taken after a 6-h control period in air and after immersion to the neck in water (34.5 C) for 6 h after overnight food and fluid restriction. Attention is given to end exercise heart rates and data during exercise. The obtained results suggest that, compared with control responses, the equilibrium level of core temperature during submaximal exercise is regulated at a higher level after immersion.

  2. Prevention: Exercise

    Medline Plus

    Full Text Available ... Smoking Weight Patient Safety Exercise Strengthening Strengthen Your Core! Stretching/Flexibility Aerobic Exercise Cervical Exercise Strength Training for the Elderly Other Back Pack Safety ...

  3. Impact of menstrual cycle phase on the exercise status of young, sedentary women.

    Science.gov (United States)

    Redman, Leanne M; Scroop, Garry C; Norman, Robert J

    2003-11-01

    The purpose of the present study was to compare exercise status during the follicular (FP) and luteal (LP) phases of the menstrual cycle of a single group of young, sedentary women, where the marked differential in the blood concentrations of 17beta-oestradiol ([E(2)]) and progesterone ([P(4)]) has the potential to alter the metabolic response to exercise. Fourteen females [21.8 (4.0) years, peak oxygen uptake ( VO(2peak)) cycle ergometer exercise while measurements were made of several metabolic and hormonal variables. With the incremental exercise test, time to exhaustion, maximal power output and total work done were not different between the two phases, nor were the absolute values for VO(2peak) or the corresponding values for ventilation ( VE), respiratory frequency ( f(R)) and heart rate (HR). Resting, end-exercise and peak (post-exercise) plasma lactate concentrations and the lactate threshold were not different between the two phases either. However, as the workloads increased during the incremental protocol, plasma lactate concentration, carbon dioxide output ( VCO(2)) and the respiratory exchange ratio (RER) all were lower during LP, while oxygen uptake ( VO(2)) was higher. With steady-state submaximal exercise, at workloads corresponding to 25% and 75% of menstrual cycle phase-specific VO(2peak), VO(2) and the oxygen pulse ( VO(2)/HR) were higher and RER and plasma lactate concentration lower during LP. Regardless of phase, [E(2)] increased with both incremental and steady-state submaximal exercise, while [P(4)] was unchanged. It is concluded that while exercise capacity, as defined by VO(2peak) and the lactate threshold, is unaffected by cycle phase in young, sedentary women, the metabolic responses in the LP during both incremental and steady-state submaximal exercise suggest a greater dependence on fat as an energy source.

  4. Effects of prior exercise on the action of insulin-like growth factor I in skeletal muscle

    Science.gov (United States)

    Henriksen, E. J.; Louters, L. L.; Stump, C. S.; Tipton, C. M.

    1992-01-01

    Prior exercise increases insulin sensitivity for glucose and system A neutral amino acid transport activities in skeletal muscle. Insulin-like growth factor I (IGF-I) also activates these transport processes in resting muscle. It is not known, however, whether prior exercise increases IGF-I action in muscle. Therefore we determined the effect of a single exhausting bout of swim exercise on IGF-I-stimulated glucose transport activity [assessed by 2-deoxy-D-glucose (2-DG) uptake] and system A activity [assessed by alpha-(methylamino)isobutyric acid (MeAIB) uptake] in the isolated rat epitrochlearis muscle. When measured 3.5 h after exercise, the responses to a submaximal concentration (0.2 nM), but not a maximal concentration (13.3 nM), of insulin for activation of 2-DG uptake and MeAIB uptake were enhanced. In contrast, prior exercise increased markedly both the submaximal (5 nM) and maximal (20 nM) responses to IGF-I for activation of 2-DG uptake, whereas only the submaximal response to IGF-I (3 nM) for MeAIB uptake was enhanced after exercise. We conclude that 1) prior exercise significantly enhances the response to a submaximal concentration of IGF-I for activation of the glucose transport and system A neutral amino acid transport systems in skeletal muscle and 2) the enhanced maximal response for IGF-I action after exercise is restricted to the signaling pathway for activation of the glucose transport system.

  5. Should menopausal characteristics be considered during cardiorespiratory exercise prescription in postmenopausal women?

    Science.gov (United States)

    Aragão, F R; Moreira, M H; Gabriel, R E; Abrantes, C G

    2015-04-01

    Menopausal characteristics (i.e. the nature of menopause, hormone therapy, and time elapsed since menopause) are known to affect women's health-related quality of life. The purpose of this study was to determine whether menopausal characteristics affect the cardiorespiratory exercise response and which characteristics should be considered for exercise prescription. Fifty-eight postmenopausal women (60.21 ± 4.49 years of age; 66.26 ± 8.99 kg body weight; 157.09 ± 4.92 cm in height; 29.70 ± 4.79 ml·kg(-1)·min(-1) maximal oxygen uptake) participated in this study. A graded 25-W/min(2) cycle ergometer exercise protocol was applied to assess aerobic power and ventilatory thresholds. Participants' heart rates and gas-exchange variables were measured continuously using a COSMED K4b(2) portable gas analyzer system. The first and the second ventilatory thresholds were determined by the time-course curves of ventilation and oxygen and carbon dioxide ventilatory equivalents. Using age as a covariate, an analysis of covariance was performed to assess the effect of menopause characteristics upon the data. Regardless of the nature of menopause, use of hormone therapy, time elapsed since menopause, and the interaction between these characteristics, the participants presented no differences in maximal oxygen uptake values, neither on submaximal variables often used in evaluations of exercise prescription, such as percent of maximal oxygen uptake, maximal heart rate, and heart rate reserve, nor in respiratory exchange ratio and gas exchange energy expenditure at aerobic and anaerobic ventilatory thresholds. These data suggest that a personalized cardiorespiratory target zone for this population should be set according to the published literature, and that consideration of the individual menopausal characteristics seems to be unnecessary.

  6. Central and peripheral blood flow during exercise with a continuous-flow left ventricular assist device: constant versus increasing pump speed: a pilot study

    DEFF Research Database (Denmark)

    Brassard, Patrice; Jensen, Annette S; Nordsborg, Nikolai

    2011-01-01

    with work rate would increase organ blood flow. Methods and Results- Invasively determined CO and leg blood flow and Doppler-determined cerebral perfusion were measured during 2 incremental cycle exercise tests on the same day in 8 patients provided with a HeartMate II LVAD. In random order, patients...

  7. Estimating the number needed to treat from continuous outcomes in randomised controlled trials: methodological challenges and worked example using data from the UK Back Pain Exercise and Manipulation (BEAM trial

    Directory of Open Access Journals (Sweden)

    Froud Robert

    2009-06-01

    Full Text Available Abstract Background Reporting numbers needed to treat (NNT improves interpretability of trial results. It is unusual that continuous outcomes are converted to numbers of individual responders to treatment (i.e., those who reach a particular threshold of change; and deteriorations prevented are only rarely considered. We consider how numbers needed to treat can be derived from continuous outcomes; illustrated with a worked example showing the methods and challenges. Methods We used data from the UK BEAM trial (n = 1, 334 of physical treatments for back pain; originally reported as showing, at best, small to moderate benefits. Participants were randomised to receive 'best care' in general practice, the comparator treatment, or one of three manual and/or exercise treatments: 'best care' plus manipulation, exercise, or manipulation followed by exercise. We used established consensus thresholds for improvement in Roland-Morris disability questionnaire scores at three and twelve months to derive NNTs for improvements and for benefits (improvements gained+deteriorations prevented. Results At three months, NNT estimates ranged from 5.1 (95% CI 3.4 to 10.7 to 9.0 (5.0 to 45.5 for exercise, 5.0 (3.4 to 9.8 to 5.4 (3.8 to 9.9 for manipulation, and 3.3 (2.5 to 4.9 to 4.8 (3.5 to 7.8 for manipulation followed by exercise. Corresponding between-group mean differences in the Roland-Morris disability questionnaire were 1.6 (0.8 to 2.3, 1.4 (0.6 to 2.1, and 1.9 (1.2 to 2.6 points. Conclusion In contrast to small mean differences originally reported, NNTs were small and could be attractive to clinicians, patients, and purchasers. NNTs can aid the interpretation of results of trials using continuous outcomes. Where possible, these should be reported alongside mean differences. Challenges remain in calculating NNTs for some continuous outcomes. Trial Registration UK BEAM trial registration: ISRCTN32683578.

  8. Cycling on rollers: Kreitler fan resistance at submaximal levels of effort.

    Science.gov (United States)

    Reiser, R F; Hart, C R

    2008-03-01

    The goal of this investigation was to characterize the commercially available fan unit for the KreitlerAlloy rollers at submaximal levels of effort (cyclist rode six times at each of three fan inlet settings (closed, half, and full open) and five fan speeds (900, 1800, 2700, 3600, and 4500 rpm). Fan power requirements were isolated by subtracting roller resistance from separate trials. Power requirements relative to fan inlet and fan speed possessed a significant interaction with the main effects for each also significant (all p or = 0.997). Fan resistance was virtually non existent at 900 rpm. Fan resistance then significantly increased with increasing fan speed and inlet opening. At 4500 rpm power requirements of the fan reached 269 +/- 6, 352 +/- 7, and 406 +/- 9 W with the inlet closed, half, and fully open, respectively (p training and testing environments.

  9. The effect of short-duration sub-maximal cycling on balance in single-limb stance in patients with anterior cruciate ligament injury: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Roberts David

    2004-11-01

    Full Text Available Abstract Background It has previously been shown that an anterior cruciate ligament (ACL injury may lead to impaired postural control, and that the ability to maintain postural control is decreased by fatigue in healthy subjects. To our knowledge, no studies have reported the effect of fatigue on postural control in subjects with ACL injury. This study was aimed at examining the effect of fatigue on balance in single-limb stance in subjects with ACL injury, and to compare the effects, and the ability to maintain balance, with that of a control group of uninjured subjects. Methods Thirty-six patients with unilateral, non-operated, non-acute ACL injury, and 24 uninjured subjects were examined with stabilometry before (pre-exercise and immediately after (post-exercise short-duration, sub-maximal cycling. In addition, the post-exercise measurements were compared, to evaluate the instantaneous ability to maintain balance and any possible recovery. The amplitude and average speed of center of pressure movements were registered in the frontal and sagittal planes. The paired t-test was used for the intra-group comparisons, and the independent t-test for the inter-group comparisons, with Bonferroni correction for multiple comparisons. Results No differences were found in the effects of exercise between the patients and the controls. Analysis of the post-exercise measurements revealed greater effects or a tendency towards greater effects on the injured leg than in the control group. The average speed was lower among the patients than in the control group. Conclusions The results of the present study showed no differences in the effects of exercise between the patients and the controls. However, the patients seemed to react differently regarding ability to maintain balance in single-limb stance directly after exercise than the control group. The lower average speed among the patients may be an expression of different neuromuscular adaptive strategies than

  10. Muscle vibration sustains motor unit firing rate during submaximal isometric fatigue in humans.

    Science.gov (United States)

    Griffin, L; Garland, S J; Ivanova, T; Gossen, E R

    2001-09-15

    1. In keeping with the 'muscular wisdom hypothesis', many studies have documented that the firing rate of the majority of motor units decreased during fatiguing isometric contractions. The present study investigated whether the application of periodic muscle vibration, which strongly activates muscle spindles, would alter the modulation of motor unit firing rate during submaximal fatiguing isometric contractions. 2. Thirty-three motor units from the lateral head of the triceps brachii muscle were recorded from 10 subjects during a sustained isometric 20 % maximal voluntary contraction (MVC) of the elbow extensors. Vibration was interposed on the contraction for 2 s every 10 s. Twenty-two motor units were recorded from the beginning of the fatigue task. The discharge rate of the majority of motor units remained constant (12/22) or increased (4/22) with fatigue. Six motor units demonstrated a reduction in discharge rate that later returned toward initial values; these motor units had higher initial discharge rates than the other 16 motor units. 3. In a second series of experiments, four subjects held a sustained isometric 20 % MVC for 2 min and then vibration was applied as above for the remainder of the contraction. In this case, motor units initially demonstrated a decrease in firing rate that increased after the vibration was applied. Thus muscle spindle disfacilitation of the motoneurone pool may be associated with the decline of motor unit discharge rate observed during the first 2 min of the contraction. 4. In a third set of experiments, seven subjects performed the main experiment on one occasion and repeated the fatigue task without vibration on a second occasion. Neither the endurance time of the fatiguing contraction nor the MVC torque following fatigue was affected by the application of vibration. This finding calls into question the applicability of the muscular wisdom hypothesis to submaximal contractions.

  11. 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.

  12. The effects of continuous and intermittent aerobic exercise on lipid profile and fasting blood sugar in women with a body mass index more than 25 kg/m2: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Alizadeh Z

    2011-07-01

    Full Text Available "n 800x600 Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} Background: Obesity is a major health problem all around the world. On the other hand, few people, especially women, are physically active to the levels recommended by Healthy People 2010 web site managed by the U.S. Department of Health and Human Services. The objective of this study was to compare the potential effects of intermittent and continuous exercise programs combined with concurrent calorie restriction diets on lipid profile and fasting blood sugar in overweight and obese females."n"nMethods : Forty-five women with a sedentary life style and a BMI greater than 25 kg/m2, were randomly assigned to one of the three groups (15 subjects in each group: a 40 minutes of medium-intensity intermittent exercise (64-76% of maximal heart rate, 3 bouts per day for 5 days a week, b a single bout of a 40-minute continuous exercise per day for 5 days a week, C the non-exercising control group. A self-monitored calorie restricted diet was recommended to all participants by a dietitian. The lipid profile, fasting blood sugar and blood pressure of all participants were assessed at baseline and 12 weeks after the intervention period."n"nResults : After the intervention, there were no significant differences among the groups in terms of lipid profile [cholesterol (P=0.94, triglyceride (P=0.62] fasting blood sugar (P=0.054, systolic blood pressure (P=0.84 or diastolic blood pressure (P=0.30."n"nConclusion: There seems to be no significant differences between short term continuous and intermittent aerobic

  13. Disproportional changes in hematocrit, plasma volume, and proteins during exercise and bed rest.

    Science.gov (United States)

    Van Beaumont, W.; Greenleaf, J. E.; Juhos, L.

    1972-01-01

    The interrelationships between the changes in plasma volume, hematocrit, and plasma proteins during muscular exercise and bed rest were investigated. Proportionally, the changes in hematocrit are always smaller than the changes in plasma volume. For this reason changes in the concentration of blood constituents can only be quantitated on the basis of plasma volume changes. During short periods of intensive exercise, there was a small loss of plasma proteins. With prolonged submaximal exercise there was a net gain in plasma protein, which contributes to stabilization of the vascular volume. Prolonged bed rest induced hypoproteinemia; this loss of plasma protein probably plays an important role in recumbency hypovolemia.

  14. Exhaled nitric oxide predicts exercise-induced bronchoconstriction in asthmatic school children

    DEFF Research Database (Denmark)

    Buchvald, Frederik; Hermansen, Mette N; Nielsen, Kim G

    2005-01-01

    to a standardized submaximal exercise test on the treadmill were measured in 111 school children with asthma. EIB could be excluded with a probability of 90% in asthmatic children with FeNO levels ... reducing the need for exercise testing. OBJECTIVE: The aim of this study was to estimate the value of FeNO as a predictor of EIB in asthmatic children. METHODS: Stable outpatient asthmatic school children performed standard exercise challenge tests and measurement of FeNO. RESULTS: FeNO and response...

  15. A Low-Glycemic Diet Lifestyle Intervention Improves Fat Utilization during Exercise in Older Obese Humans

    DEFF Research Database (Denmark)

    Solomon, Thomas; Haus, Jacob M; Cook, Marc A

    2013-01-01

    Objective: To determine the influence of dietary glycemic index on exercise training-induced adaptations in substrate oxidation in obesity. Design and Methods: Twenty older, obese individuals undertook 3 months of fully supervised aerobic exercise and were randomized to low- (LoGIX) or high......-glycemic (HiGIX) diets. Changes in indirect calorimetry (VO2 ; VCO2 ) were assessed at rest, during a hyperinsulinemic-euglycemic clamp, and during submaximal exercise (walking: 65% VO2 max, 200 kcal energy expenditure). Intramyocellular lipid (IMCL) was measured by (1) H-magnetic resonance spectroscopy...

  16. Eccentric exercise decreases maximal insulin action in humans

    DEFF Research Database (Denmark)

    Asp, Svend; Daugaard, J R; Kristiansen, S

    1996-01-01

    ) necessary to maintain euglycaemia during maximal insulin stimulation was lower during PEC compared with CC (15.7%, 81.3 +/- 3.2 vs. 96.4 +/- 8.8 mumol kg-1 min-1, P 2 days after unaccustomed eccentric exercise, muscle and whole-body insulin action is impaired at maximal...... subjects participated in two euglycaemic clamps, performed in random order. One clamp was preceded 2 days earlier by one-legged eccentric exercise (post-eccentric exercise clamp (PEC)) and one was without the prior exercise (control clamp (CC)). 2. During PEC the maximal insulin-stimulated glucose uptake...... over the eccentric thigh was marginally lower when compared with the control thigh, (11.9%, 64.6 +/- 10.3 vs. 73.3 +/- 10.2 mumol kg-1 min-1, P = 0.08), whereas no inter-thigh difference was observed at a submaximal insulin concentration. The glycogen concentration was lower in the eccentric thigh...

  17. High-intensity interval training versus moderate-intensity continuous training on exercise capacity and quality of life in patients with coronary artery disease: A systematic review and meta-analysis.

    Science.gov (United States)

    Gomes-Neto, Mansueto; Durães, André R; Reis, Helena F Correia Dos; Neves, Victor R; Martinez, Bruno P; Carvalho, Vitor O

    2017-11-01

    Background Exercise is an effective strategy for reducing total and cardiovascular mortality in patients with coronary artery disease. However, it is not clear which modality is best. We performed a meta-analysis to investigate the effects of high-intensity interval versus moderate-intensity continuous training of coronary artery disease patients. Methods We searched MEDLINE, PEDro, LILACS, SciELO and the Cochrane Library (from the earliest date available to November 2016) for controlled trials that evaluated the effects of high-intensity interval versus moderate-intensity continuous training for coronary artery disease patients. Weighted mean differences and 95% confidence intervals were calculated, and heterogeneity was assessed using the I2 test. Results Twelve studies met the study criteria, including 609 patients. High-intensity interval training resulted in improvement in peak oxygen uptake weighted mean difference (1.3 ml/kg/min, 95% confidence interval: 0.6-1.9, n = 594) compared with moderate-intensity continuous training. No significant difference in physical, emotional, and social domain of quality of life was found for participants for participants in the high-intensity interval training group compared with the moderate-intensity continuous training group. Sub-analysis of three studies with isocaloric exercise training showed no significant difference in peak oxygen uptake weighted mean difference (0.4 ml/kg/min, 95% confidence interval: -0.1-0.9, n = 137) for participants in the high-intensity interval training group compared with moderate-intensity continuous training group. Conclusions High-intensity interval training may improve peak oxygen uptake and should be considered as a component of care of coronary artery disease patients. However, this superiority disappeared when isocaloric protocol is compared.

  18. A Preliminary Exploration of the Effects of a 6-week Interactive Video Dance Exercise Program in an Adult Population.

    Science.gov (United States)

    Mejia-Downs, Anne; Fruth, Stacie J; Clifford, Anne; Hine, Stephanie; Huckstep, Jeremy; Merkel, Heidi; Wilkinson, Hilary; Yoder, Jason

    2011-12-01

    The purpose of this study was to determine the effects of a 6-week interactive video dance game (IVDG) program on adult participants' cardiorespiratory status and body mass index (BMI). Twenty-seven healthy adult participants attended IVDG sessions over a 6-week period. Participants completed pre- and post-testing consisting of a submaximal VO(2) treadmill test, assessment of resting heart rate (RHR) and blood pressure (BP), BMI, and general health questionnaires. Data were analyzed using descriptives, paired t-tests to assess pre-to post-testing differences, and one-way ANOVAs to analyze variables among select groups of participants. Questionnaire data was manually coded and assessed. Twenty participants attended at least 75% of available sessions and were used in data analysis. Mean BMI decreased significantly (from 26.96 kg/m(2) to 26.21 kg/m(2); 2.87%) and cardiorespiratory fitness measured by peak VO(2) increased significantly (from 20.63 ml/kg/min to 21.69 ml/kg/min; 5.14%). Most participants reported that the IVDG program was a good workout, and that they were encouraged to continue or start an exercise routine. Forty percent reported improvements in sleep, and nearly half stated they had or were considering purchasing a home version of a video dance game. Interactive video dance game is an effective and enjoyable exercise program for adults who wish to decrease their BMI and improve components of cardiorespiratory fitness.

  19. Regadenoson in Europe: first-year experience of regadenoson stress combined with submaximal exercise in patients undergoing myocardial perfusion scintigraphy

    OpenAIRE

    Brinkert, M.; Reyes, E.; Walker, S.; Latus, K.; Maenhout, A.; Mizumoto, R.; Nkomo, C.; Standbridge, K.; Wechalekar, K.; Underwood, S. R.

    2013-01-01

    Purpose Regadenoson was approved for clinical use in Europe in 2011. Since then, it has become the default form of stress at our institution. We have assessed the side-effect profile and tolerability of regadenoson in patients undergoing clinically indicated myocardial perfusion scintigraphy between July 2011 and July 2012. Methods Clinical, stress and imaging data were recorded prospectively. Symptoms during stress were recorded and defined as mild, moderate or severe. An adverse event was d...

  20. Differential glucose uptake in quadriceps and other leg muscles during one-legged dynamic submaximal knee-extension exercise

    DEFF Research Database (Denmark)

    Kalliokoski, Kari K; Boushel, Robert; Langberg, Henning

    2011-01-01

    to mean GU in QF (=100%), GU was on average 73% in VL, 84% in rectus femoris, 115% in vastus medialis, and 142% in VI. Variable activation of hamstring muscles and muscles of the lower leg was also observed. These results show that GU of different muscles of quadriceps muscle group as well as between...

  1. A Three Month Home Exercise Programme Augmented with Nordic Poles for Patients with Intermittent Claudication Enhances Quality of Life and Continues to Improve Walking Distance and Compliance After One Year.

    Science.gov (United States)

    Oakley, C; Spafford, C; Beard, J D

    2017-05-01

    The objective of this study was to collect 1 year follow-up information on walking distance, speed, compliance, and cost in patients with intermittent claudication who took part in a previously reported 12 week randomised clinical trial of a home exercise programme augmented with Nordic pole walking versus controls who walked normally. A second objective was to look at quality of life and ankle brachial pressure indices (ABPIs) after a 12 week augmented home exercise programme. Thirty-two of the 38 patients who completed the original trial were followed-up after 6 and 12 months. Frequency, duration, speed, and distance of walking were recorded using diaries and pedometers. A new observational cohort of 29 patients was recruited to the same augmented home exercise programme. ABPIs, walking improvement, and quality of life questionnaire were recorded at baseline and 12 weeks (end of the programme). Both groups in the follow-up study continued to improve their walking distance and speed over the following year. Compliance was excellent: 98% of the augmented group were still walking with poles at both 6 and 12 months, while 74% of the control group were still walking at the same point. The augmented group increased their mean walking distance to 17.5 km by 12 months, with a mean speed of 4.2 km/hour. The control group only increased their mean walking distance from 4.2 km to 5.6 km, and speed to 3.3 km/hour. Repeated ANOVA showed the results to be highly significant (p = .002). The 21/29 patients who completed the observational study showed a statistically significant increase in resting ABPIs from baseline (mean ± SD 0.75 ± 0.12) to week 12 (mean ± SD 0.85 ± 0.12) (t = (20) -8.89, p = .000 [two-tailed]). All their walking improvement and quality of life parameters improved significantly (p = .002 or less in the six categories) over the same period and their mean health scores improved by 79%. Following a 12 week augmented home exercise

  2. Basic science behind the cardiovascular benefits of exercise.

    Science.gov (United States)

    Wilson, Mathew G; Ellison, Georgina M; Cable, N Tim

    2016-01-01

    Cardiorespiratory fitness is a strong predictor of cardiovascular (CV) disease and all-cause mortality, with increases in cardiorespiratory fitness associated with corresponding decreases in CV disease risk. The effects of exercise upon the myocardium and vascular system are dependent upon the frequency, intensity and duration of the exercise itself. Following a prolonged period (≥6 months) of regular intensive exercise in previously untrained individuals, resting and submaximal exercising heart rates are typically 5-20 beats lower, with an increase in stroke volume of ∼20% and enhanced myocardial contractility. Structurally, all four heart chambers increase in volume with mild increases in wall thickness, resulting in greater cardiac mass due to increased myocardial cell size. With this in mind, the present paper aims to review the basic science behind the CV benefits of exercise. Attention will be paid to understanding (1) the relationship between exercise and cardiac remodelling; (2) the cardiac cellular and molecular adaptations in response to exercise, including the examination of molecular mechanisms of physiological cardiac growth and applying these mechanisms to identify new therapeutic targets to prevent or reverse pathological remodelling and heart failure; and (3) vascular adaptations in response to exercise. Finally, this review will briefly examine how to optimise the CV benefits of exercise by considering how much and how intense exercise should be. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  3. Walking tests during the exercise training: Specific use for the cardiac rehabilitation

    OpenAIRE

    Casillas, J.-M.; Hannequin, A.; Besson, D.; Benaïm, S.; Krawcow, C.; Laurent, Y.; Gremeaux, V.

    2013-01-01

    International audience; Walk tests, principally the six-minute walk test (6mWT), constitute a safe, useful submaximal tool for exercise tolerance testing in cardiac rehabilitation (CR). The 6mWT result reflects functional status, walking autonomy and efficacy of CR on walking endurance, which is more pronounced in patients with low functional capacity (heart failure - cardiac surgery). The 6mWT result is a strong predictor of mortality. However, clinically significant changes and reliability ...

  4. Effects of reducing exposure to air pollution on submaximal cardiopulmonary test in patients with heart failure: Analysis of the randomized, double-blind and controlled FILTER-HF trial.

    Science.gov (United States)

    Vieira, Jefferson L; Guimaraes, Guilherme V; de Andre, Paulo A; Saldiva, Paulo H Nascimento; Bocchi, Edimar A

    2016-07-15

    Air pollution exposure could mitigate the health benefits of exercise in patients with heart failure (HF). We tested the effects of a respiratory filter on HF patients exposed to air pollution during exercise. Ancillary analysis of the FILTER-HF trial, focused on the exercise outcomes. In a randomized, double-blind, 3-way crossover design, 26 HF patients and 15 control volunteers were exposed to clean air, unfiltered dilute diesel engine exhaust (DE), or filtered DE for 6min during a submaximal cardiopulmonary testing in a controlled-exposure facility. Prospectively collected data included six-minute walking test [6mwt], VO2, VE/VCO2 Slope, O2Pulse, pulmonary ventilation [VE], tidal volume, VD/Vt, oxyhemoglobin saturation and CO2-rebreathing. Compared to clean air, DE adversely affected VO2 (11.0±3.9 vs. 8.4±2.8ml/kg/min; peffects of pollution on VO2 and O2Pulse. Given the worldwide prevalence of exposure to traffic-related air pollution, these findings are relevant for public health especially in this highly susceptible population. The filter intervention holds great promise that needs to be tested in future studies. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. A New Submaximal Rowing Test to Predict 2,000-m Rowing Ergometer Performance.

    Science.gov (United States)

    Otter, Ruby T A; Brink, Michel S; Lamberts, Robert P; Lemmink, Koen A P M

    2015-09-01

    The purpose of this study was to assess predictive value of a new submaximal rowing test (SmRT) on 2,000-m ergometer rowing time-trial performance in competitive rowers. In addition, the reliability of the SmRT was investigated. Twenty-four competitive male rowers participated in this study. After determining individual HRmax, all rowers performed an SmRT followed by a 2,000-m rowing ergometer time trial. In addition, the SmRT was performed 4 times (2 days in between) to determine the reliability. The SmRT consists of two 6-minute stages of rowing at 70 and 80% HRmax, followed by a 3-minute stage at 90% HRmax. Power was captured during the 3 stages, and 60 seconds of heart rate recovery (HRR60s) was measured directly after the third stage. Results showed that predictive value of power during the SmRT on 2,000-m rowing time also increased with stages. CVTEE% is 2.4, 1.9, and 1.3%. Pearson correlations (95% confidence interval [95% CI]) were -0.73 (-0.88 to -0.45), -0.80 (-0.94 to -0.67), and -0.93 (-0.97 to -0.84). 2,000-m rowing time and HRR60s showed no relationship. Reliability of power during the SmRT improved with the increasing intensity of the stages. The coefficient of variation (CVTEM%) was 9.2, 5.6, and 0.4%. Intraclass correlation coefficients (ICC) and 95% CI were 0.91 (0.78-0.97), 0.92 (0.81-0.97), and 0.99 (0.97-1.00). The CVTEM% and ICC of HRR60s were 8.1% and 0.93 (0.82-0.98). In conclusion, the data of this study shows that the SmRT is a reliable test that it is able to accurately predict 2,000-m rowing time on an ergometer. The SmRT is a practical and valuable submaximal test for rowers, which can potentially assist with monitoring, fine-tuning and optimizing training prescription in rowers.

  6. DHEA, DHEA-S and cortisol responses to acute exercise in older adults in relation to exercise training status and sex.

    Science.gov (United States)

    Heaney, Jennifer L J; Carroll, Douglas; Phillips, Anna C

    2013-04-01

    The aim of the present study was to investigate resting measures of dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEA-S) and cortisol, and the response and recovery of these hormones to acute exercise, in male and female older adults of different exercise training status. Participants were 49 community-dwelling older adults (23 females) aged between 60 and 77 years who were either sedentary (n=14), moderately active (n=14) or endurance trained (n=21). Participants undertook an acute bout of exercise in the form of an incremental submaximal treadmill test. The exercise lasted on average 23 min 49 s (SD=2 min 8 s) and participants reached 76.5% (SD=5.44) of the predicted maximal heart rate. Blood samples were collected prior to exercise, immediately, and 1 h post-exercise. DHEA levels significantly increased immediately post-exercise; however, DHEA-S levels only significantly increased in females. Cortisol significantly decreased immediately post-exercise and 1 h post-exercise compared to pre-exercise. There were no significant differences in resting hormone levels or hormonal responses to exercise between training status groups. The findings suggest that exercise can stimulate DHEA production in older adults and that hormonal responses to exercise differ between male and female older adults.

  7. Continuous exercise training and curcumin attenuate changes in brain-derived neurotrophic factor and oxidative stress induced by lead acetate in the hippocampus of male rats.

    Science.gov (United States)

    Hosseinzadeh, Somayeh; Roshan, Valiollah Dabidi; Mahjoub, Soleiman

    2013-02-01

    For many years it has been known that lead is life-threatening, not only as an air pollutant but also because of it has been associated with several conditions including neurodegenerative disease. Curcumin (the principal curcuminoid found in turmeric) has demonstrated potent antioxidant properties. We investigated neuroprotective effects of endurance exercise and/or curcumin on lead acetate-induced neurotoxicity in the rat hippocampus. Forty male Wistar rats were randomly divided into five groups: 1) lead acetate, 2) curcumin, 3) training, 4) training + curcumin, and 5) control. The rats in the training groups performed treadmill running five times a week for 8 weeks (15-22 m/min, 25-64 min). All groups except control received lead acetate (20 mg/kg), whereas the control group received curcumin solution (ethyl oleate). In addition, the curcumin and training + curcumin groups received curcumin solution (30 mg/kg) intraperioneally. Lead acetate resulted in a significantly increase in the malondialdehyde (MDA) in plasma (72%), but not significant in hippocampus (59%). In addition, it led to significantly decreased brain-derived neurotrophic factor in hippocampus (17%) and total antioxidant capacity (27%), as compared to control group. Treadmill running, curcumin supplementation or both resulted in a significant decrease in hippocampus MDA (17, 20, 31%, respectively) and plasma MDA (60, 22, 71%) and also, significantly increased brain-derived neurotrophic factor (76, 45, 94%) and total antioxidant capacity (47.13, 47.11, 61%) levels, as compared to lead acetate group. These results provide a rationale for an inhibitory role of curcumin and regular exercise in the attenuation of lead-induced neurotoxicity.

  8. Prevention: Exercise

    Medline Plus

    Full Text Available ... A SPECIALIST Prevention Strengthening Exercise Committee Exercise Committee Core Strengthening Many popular forms of exercise focus on ... acute pain, you should stop doing it. Transverse Core Strengthening This strengthens the muscles that cross from ...

  9. Prevention: Exercise

    Medline Plus

    Full Text Available ... Smoking Weight Patient Safety Exercise Strengthening Strengthen Your Core! Stretching/Flexibility Aerobic Exercise Cervical Exercise Strength Training for the Elderly Other Back Pack Safety Pregnancy ...

  10. Exercise Physiologists

    Science.gov (United States)

    ... SITE MAP | EN ESPAÑOL Occupational Outlook Handbook > Healthcare > Exercise Physiologists PRINTER-FRIENDLY EN ESPAÑOL Summary What They ... of workers and occupations. What They Do -> What Exercise Physiologists Do About this section Exercise physiologists analyze ...

  11. How to Regulate the Acute Physiological Response to “Aerobic” High-Intensity Interval Exercise

    Science.gov (United States)

    Tschakert, Gerhard; Kroepfl, Julia; Mueller, Alexander; Moser, Othmar; Groeschl, Werner; Hofmann, Peter

    2015-01-01

    The acute physiological processes during “aerobic” high-intensity interval exercise (HIIE) and their regulation are inadequately studied. The main goal of this study was to investigate the acute metabolic and cardiorespiratory response to long and short HIIE compared to continuous exercise (CE) as well as its regulation and predictability. Six healthy well-trained sport students (5 males, 1 female; age: 25.7 ± 3.1 years; height: 1.80 ± 0.04 m; weight: 76.7 ± 6.4 kg; VO2max: 4.33 ± 0.7 l·min-1) performed a maximal incremental exercise test (IET) and subsequently three different exercise sessions matched for mean load (Pmean) and exercise duration (28 min): 1) long HIIE with submaximal peak workloads (Ppeak = power output at 95 % of maximum heart rate), peak workload durations (tpeak) of 4 min, and recovery durations (trec) of 3 min, 2) short HIIE with Ppeak according to the maximum power output (Pmax) from IET, tpeak of 20 s, and individually calculated trec (26.7 ± 13.4 s), and 3) CE with a target workload (Ptarget) equating to Pmean of HIIE. In short HIIE, mean lactate (Lamean) (5.22 ± 1.41 mmol·l-1), peak La (7.14 ± 2.48 mmol·l-1), and peak heart rate (HRpeak) (181.00 ± 6.66 b·min-1) were significantly lower compared to long HIIE (Lamean: 9.83 ± 2.78 mmol·l-1; Lapeak: 12.37 ± 4.17 mmol·l-1, HRpeak: 187.67 ± 5.72 b·min-1). No significant differences in any parameters were found between short HIIE and CE despite considerably higher peak workloads in short HIIE. The acute metabolic and peak cardiorespiratory demand during “aerobic” short HIIE was significantly lower compared to long HIIE and regulable via Pmean. Consequently, short HIIE allows a consciously aimed triggering of specific and desired or required acute physiological responses. Key points High-intensity interval exercise (HIIE) with short peak workload durations (tpeak) induce a lower acute metabolic and peak cardiorespiratory response compared to intervals with long tpeak

  12. 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

    to 3.7 +/- 0.2 in the first minutes of the recovery (P exercise did not change the uptake ratio significantly. Yet, in a second experiment, when submaximal exercise required a maximal effort due to partial neuromuscular blockade, the ratio decreased and remained low (4.9 +/- 0.2......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......) in the early recovery (n = 10; P 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...

  13. Vascular Dynamics and Peripheral Oxygen Uptake in Obese Individuals during Progressive Physical Exercise.

    Science.gov (United States)

    Brunani, Amelia; Lanzi, Stefano; Codecasa, Franco; Cornacchia, Mauro; Maestrini, Sabrina; Soranna, Davide; Zambon, Antonella; Cattaldo, Stefania; Fanari, Paolo; Malatesta, Davide; Salvadori, Alberto

    2017-01-01

    Obese men show higher O2 consumption than lean men during physical exercise, with a trend toward higher peripheral O2 extraction; this is probably due to their larger muscle mass. The aim of this study was to examine this phenomenon by measuring 2 vasoactive substances, endothelin-1 (ET-1) and nitric oxide (NO), during a progressive submaximal exercise. Seventeen obese (body mass index [BMI] 38.6) and 15 lean (BMI 22.5) men performed a maximal progressive cycle ergometer exercise to determine peak power output (PPO) and peak O2 consumption (V∙O2peak); thereafter, they performed a submaximal cycle ergometer incremental test (every 6 min) at the same percentage of V∙O2peak until they reached 57.5% PPO. Blood samples were collected at rest and at the end of every step to measure ET-1 and NO concentrations. At rest, the ET-1 and NO concentrations in obese men and lean controls were the same. However, during exercise, the ET-1 concentration at each step was significantly lower (p < 0.05) in the obese group. There was no significant difference in NO concentration between the 2 groups, although the increase at the beginning of the exercise session was faster in obese individuals. During submaximal exercise, end-tidal O2 pressure (PETO2) was lower in the obese group, with a significant difference in the PETO2/fat-free mass ratio at each step. ET-1 and NO levels during physical exercise are different in obese versus lean men. This may support the notion that increased O2 consumption in obesity is due to different behaviors of the cardiorespiratory and circulatory systems. © 2017 S. Karger AG, Basel.

  14. "Tailored" submaximal step test for VO2max prediction in healthy older adults.

    Science.gov (United States)

    Pogliaghi, Silvia; Bellotti, Cecilia; Paterson, Donald H

    2014-04-01

    The authors developed and validated a "tailored" version of the Astrand-Rhyming step test (tA-R) and a new equation for VO2max prediction in older adults (OA). Sixty subjects (age 68 ± 4 yr, 30 male, 30 female) performed their tA-R step test (5-min, 30-cm step, tailored stepping rate) and an incremental cycling test to exhaustion. VO2max was (a) predicted using the standard A-R equation (predicted VO2max), (b) predicted based on the authors' new multiple linear equation (equation VO2max), and (c) directly measured by incremental cycling test (direct VO2max). Agreement among values of VO2max was evaluated by Bland-Altman analysis. The predicted VO2max was not significantly different from the direct VO2max, yet with relatively large imprecision. The equation VO2max allowed more precise as well as accurate predictions of VO2max compared with standard A-R prediction. The "tailored" version of the Astrand-Rhyming step test and the new prediction equation appear suitable for a rapid (5-min), safe (submaximal), accurate, and precise VO2max prediction in healthy OA.

  15. Predictability of maximum voluntary isometric knee extension force from submaximal contractions in older adults.

    Science.gov (United States)

    Stackhouse, Scott K; Stevens, Jennifer E; Johnson, Christopher D; Snyder-Mackler, Lynn; Binder-Macleod, Stuart A

    2003-01-01

    The purposes of this study were to develop and test a model describing the relationship between the central activation ratio (CAR; a measure of voluntary muscle activation) and percent maximum voluntary contraction (%MVC) force for old adults and to provide a method for more accurate determination of voluntary muscle activation failure. Twenty-one adults (ages 64-81) performed isometric testing of the quadriceps at 25%, 50%, 75%, and 100% MVC. During each contraction, a 100-HZ, 120-ms train of electrical pulses was delivered to the quadriceps muscle to quantify voluntary muscle activation. Similar to a young, healthy population (ages 20-35), a curvilinear relationship existed between the CAR and %MVC force for older adults. Predictions of subjects' MVCs using the linear model of CAR-%MVC force relationship generally demonstrated poor agreement with actual MVCs. Predictions of MVC from submaximal contractions (25%, 50%, and 75%) using a previously identified curvilinear young adult CAR-%MVC relationship were good [ICC (2,1): 0.81, 0.96, and 0.82, respectively]. Similar agreement was obtained from the curvilinear older adult CAR-%MVC relationship. These data suggest that the CAR-%MVC relationship is similar in young and older adult subjects and that curvilinear models of this relationship can predict MVC forces in older adults more accurately. Reexamination of the relationship between the CAR and %MVC force may allow a more accurate determination of how failure of voluntary muscle activation contributes to weakness in old adults.

  16. Relationship between the Pedaling Biomechanics and Strain of Bicycle Frame during Submaximal Tests

    Directory of Open Access Journals (Sweden)

    Aneliya V. Manolova

    2015-06-01

    Full Text Available The aim of this study was to analyse the effect of forces applied to pedals and cranks on the strain imposed to an instrumented bicycle motocross (BMX frame. Using results from a finite element analysis to determine the localisation of highest stress, eight strain gauges were located on the down tube, the seat tube and the right chain stay. Before the pedaling tests, static loads were applied to the frame during bench tests. Two pedaling conditions have been analysed. In the first, the rider was in static standing position on the pedals and applied maximal muscular isometric force to the right pedal. The second pedaling condition corresponds to three pedaling sprint tests at submaximal intensities at 150, 300 and 550 W on a cycle-trainer. The results showed that smaller strain was observed in the pedaling condition than in the rider static standing position condition. The highest strains were located in the seat tube and the right chain stay near the bottom bracket area. The maximum stress observed through all conditions was 41 MPa on the right chain stay. This stress was 11 times lower than the yield stress of the frame material (460 MPa. This protocol could help to adapt the frame design to the riders as a function of their force and mechanical power output. These results could also help design BMX frames for specific populations (females and rider morphology.

  17. Prevention: Exercise

    Medline Plus

    Full Text Available ... strengthening programs. Simple exercises can be done at home as well. Some specific core strengthening exercises are described below. ... © 2017 North American Spine Society | ...

  18. Clinical physiology of exercise in pregnancy: a literature review.

    Science.gov (United States)

    Wolfe, Larry A; Weissgerber, Tracey L

    2003-06-01

    To review the existing literature on the physiology of exercise in pregnancy as a basis for clinical practice guidelines for prenatal exercise prescription. MEDLINE search for English language abstracts and articles published between 1966 and 2003 related to physiological adaptations to pregnancy, effects of pregnancy on responses to acute exercise and aerobic conditioning, effects of acute maternal exercise on indexes of fetal well-being, impact of physical conditioning on birth weight and other pregnancy outcomes, and use of exercise to prevent or treat gestational diabetes mellitus and preeclampsia. Maximal aerobic power (VO(2)max, L/min) is well-preserved in pregnant women who remain physically active, but anaerobic working capacity may be reduced in late gestation. The increase in resting heart rate, reduction in maximal heart rate, and resulting smaller heart rate reserve render heart rate a less precise way of estimating exercise intensity. As rating of perceived exertion (RPE) is not altered by pregnancy, the use of revised pulse rate target zones along with Borg's RPE scale is recommended to prescribe exercise intensity during pregnancy. Responses to prolonged submaximal exercise (>30 min) in late gestation include a moderate reduction in maternal blood glucose concentration, which may transiently reduce fetal glucose availability. The normal response to sustained submaximal exercise is an increase in fetal heart rate (FHR) baseline. Transient reductions in FHR reactivity, fetal breathing movements, and FHR variability may also occur in association with more strenuous exercise. Controlled prospective studies have demonstrated that moderate prenatal exercise during the second and third trimesters is useful to improve aerobic fitness and maternal-fetal physiological reserve without affecting fetal growth. The Physical Activity Readiness Medical Examination for Pregnancy is recommended for use by physicians and midwives to provide medical clearance for

  19. Psychosocial Influences on Exercise-Induced Hypoalgesia.

    Science.gov (United States)

    Brellenthin, Angelique G; Crombie, Kevin M; Cook, Dane B; Sehgal, Nalini; Koltyn, Kelli F

    2017-03-01

    The purpose of this study was to examine psychosocial influences on exercise-induced hypoalgesia (EIH). Randomized controlled trial. Clinical research unit in a hospital. Fifty-eight healthy men and women (mean age = 21 ± 3 years) participated in this study. Participants were first asked to complete a series of baseline demographic and psychological questionnaires including the Pain Catastrophizing Scale, the Fear of Pain Questionnaire, and the Family Environment Scale. Following this, they were familiarized with both temporal summation of heat pain and pressure pain testing protocols. During their next session, participants completed the Profile of Mood States, rated the intensity of heat pulses, and indicated their pressure pain thresholds and ratings before and after three minutes of submaximal, isometric exercise. Situational catastrophizing was assessed at the end of the experimental session. Results indicated that experimental pain sensitivity was significantly reduced after exercise ( P   0.05). Positive family environments predicted attenuated pain sensitivity and greater EIH, whereas negative and chronic pain-present family environments predicted worse pain and EIH outcomes. Situational catastrophizing and negative mood state also predicted worse pain and EIH outcomes and were additionally associated with increased ratings of perceived exertion and muscle pain during exercise. This study provides preliminary evidence that psychosocial variables, such as the family environment and mood states, can affect both pain sensitivity and the ability to modulate pain through exercise-induced hypoalgesia.

  20. Physiologic considerations for exercise performance in women.

    Science.gov (United States)

    Charkoudian, Nisha; Joyner, Michael J

    2004-06-01

    Women exhibit several anatomic and physiologic characteristics that distinguish their responses to exercise from those of men. Women are smaller than men, have less muscle mass, and more fat mass for a given body size. Blood volume, stroke volume, and cardiac output are all lower in women than in men. These and other factors contribute to lower maximal aerobic power (even for similar training status) in women. The reproductive hormones, estrogen and progesterone, can influence ventilation, substrate metabolism, and thermoregulation during exercise. Women have a greater tendency for EIAH, which can limit VO2max as well as submaximal exercise performance at higher intensities. Women tend to use a greater percentage of fats during exercise, but also rely on CHOs. Thermoregulatory control is altered significantly over the course of the menstrual cycle by fluctuations in circulating levels of progesterone and estrogen. It is important for women to include regular exercise in their daily routines, particularly because regular physical activity has been implicated in the prevention of osteoporosis, breast cancer, heart disease, and depression.

  1. Aquatic exercise training for fibromyalgia.

    Science.gov (United States)

    Bidonde, Julia; Busch, Angela J; Webber, Sandra C; Schachter, Candice L; Danyliw, Adrienne; Overend, Tom J; Richards, Rachel S; Rader, Tamara

    2014-10-28

    Exercise training is commonly recommended for individuals with fibromyalgia. This review examined the effects of supervised group aquatic training programs (led by an instructor). We defined aquatic training as exercising in a pool while standing at waist, chest, or shoulder depth. This review is part of the update of the 'Exercise for treating fibromyalgia syndrome' review first published in 2002, and previously updated in 2007. The objective of this systematic review was to evaluate the benefits and harms of aquatic exercise training in adults with fibromyalgia. We searched The Cochrane Library 2013, Issue 2 (Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, Health Technology Assessment Database, NHS Economic Evaluation Database), MEDLINE, EMBASE, CINAHL, PEDro, Dissertation Abstracts, WHO international Clinical Trials Registry Platform, and AMED, as well as other sources (i.e., reference lists from key journals, identified articles, meta-analyses, and reviews of all types of treatment for fibromyalgia) from inception to October 2013. Using Cochrane methods, we screened citations, abstracts, and full-text articles. Subsequently, we identified aquatic exercise training studies. Selection criteria were: a) full-text publication of a randomized controlled trial (RCT) in adults diagnosed with fibromyalgia based on published criteria, and b) between-group data for an aquatic intervention and a control or other intervention. We excluded studies if exercise in water was less than 50% of the full intervention. We independently assessed risk of bias and extracted data (24 outcomes), of which we designated seven as major outcomes: multidimensional function, self reported physical function, pain, stiffness, muscle strength, submaximal cardiorespiratory function, withdrawal rates and adverse effects. We resolved discordance through discussion. We evaluated interventions using mean differences

  2. Effects of parental smoking on exercise systolic blood pressure in adolescents.

    Science.gov (United States)

    Hacke, Claudia; Weisser, Burkhard

    2015-05-11

    In adults, exercise blood pressure seems to be more closely related to cardiovascular risk than resting blood pressure; however, few data are available on the effects of familial risk factors, including smoking habits, on exercise blood pressure in adolescents. Blood pressure at rest and during exercise, parental smoking, and other familial risk factors were investigated in 532 adolescents aged 12 to 17 years (14.6±1.5 years) in the Kiel EX.PRESS. (EXercise PRESSure) Study. Exercise blood pressure was determined at 1.5 W/kg body weight using a standardized submaximal cycle ergometer test. Mean resting blood pressure was 113.1±12.8/57.2±7.1 mm Hg, and exercise blood pressure was 149.9±19.8/54.2±8.6 mm Hg. Parental smoking increased exercise systolic blood pressure (+4.0 mm Hg, 3.1 to 4.9; P=0.03) but not resting blood pressure of the subjects (adjusted for age, sex, height, body mass index percentile, fitness). Parental overweight and familial hypertension were related to both higher resting and exercise systolic blood pressure values, whereas associations with an inactive lifestyle and a low educational level of the parents were found only with adolescents' blood pressure during exercise. The cumulative effect of familial risk factors on exercise systolic blood pressure was more pronounced than on blood pressure at rest. Parental smoking might be a novel risk factor for higher blood pressure, especially during exercise. In addition, systolic blood pressure during a submaximal exercise test was more closely associated with familial risk factors than was resting blood pressure, even in adolescents. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  3. Blunted lipolysis and fatty acid oxidation during moderate exercise in HIV-infected subjects taking HAART

    Science.gov (United States)

    Cade, W. Todd; Reeds, Dominic N.; Mittendorfer, Bettina; Patterson, Bruce W.; Powderly, William G.; Klein, Samuel; Yarasheski, Kevin E.

    2014-01-01

    The protease inhibitor (PI) ritonavir (RTV) has been associated with elevated resting lipolytic rate, hyperlipidemia, and insulin resistance/glucose intolerance. The purpose of this study was to examine relationships between lipolysis and fatty acid (FA) oxidation during rest, moderate exercise and recovery, and measures of insulin sensitivity/glucose tolerance and fat redistribution in HIV-positive subjects taking RTV (n = 12), HAART but no PI (n = 10), and HIV-seronegative controls (n = 10). Stable isotope tracers [1-13C]palmitate and [1,1,2,3,3- 2H5]glycerol were continuously infused with blood and breath collection during 1-h rest, 70-min submaximal exercise (50%V̇ O2 peak), and 1-h recovery. Body composition was evaluated using DEXA, MRI, and MRS, and 2-h oral glucose tolerance tests with insulin monitoring were used to evaluate glucose tolerance and insulin resistance. Lipolytic and FA oxidation rates were similar during rest and recovery in all groups; however, they were lower during moderate exercise in both HIV-infected groups [glycerol Ra: HIV + RTV 5.1 ± 1.2 vs. HIV + no PI 5.9 ± 2.8 vs. Control 7.4 ± 2.2 µmol·kg fat-free mass (FFM)−1 · min−1; palmitate oxidation: HIV + RTV 1.6 ± 0.8 vs. HIV + no PI 1.6 ± 0.8 vs. Control 2.5 ± 1.7 µmol·kg FFM·min, P < 0.01]. Fasting and orally-challenged glucose and insulin values were similar among groups. Lipolytic and FA oxidation rates were blunted during moderate exercise in HIV-positive subjects taking HAART. Lower FA oxidation during exercise was primarily due to impaired plasma FA oxidation, with a minor contribution from lower nonplasma FA oxidation. Regional differences in adipose tissue lipolysis during rest and moderate exercise may be important in HIV and warrant further study. PMID:17106066

  4. Assessment Of Physiological Cardio respiratory Parameters During Sub maximal Exercise On Acute Exposure To Normobaric Hypoxia In Healthy Young Males

    Directory of Open Access Journals (Sweden)

    Bipin K Shrestha

    2016-06-01

    Full Text Available To estimate changes in SBP, DBP, HR, RR and Lactate Level at Near Sea Level (NSL and at Simulated altitude (3000meters at rest and during sub-maximal exercise.Mean Resting values at NSL vs. Hypoxic Chamber were: SBP (1276vs1325mmHg, DBP (703vs786mmHg, HR (725vs806bpm, RR (254vs293/min and LL (2.10.35vs2.50.42mmol/l. Similarly, mean values at the end of exercise were: SBP (1529vs16913mmHg, DBP (836vs926mmHg, HR (13412vs1557bpm, RR (356vs516/min and LL (7.110.89vs8.011.03mmol/l.  A significant difference exists in mean resting values of SBP, DBP, HR and RR at NSL and on acute exposure to Normobaric Hypoxia. Sub-maximal exercise in hypoxic conditions appears to depend more on anaerobic metabolism and results in greater sympathetic activity. Keywords: Cardiorespiratory parameters, Normobaric hypoxia, Sub-maximal exercise, Near Sea Level

  5. A novel device based on smart textile to control heart's activity during exercise.

    Science.gov (United States)

    Romagnoli, Marco; Alis, Rafael; Guillen, Javier; Basterra, Javier; Villacastin, J P; Guillen, Sergio

    2014-06-01

    In recent years, several systems have been developed to control cardiac function during exercise, and some are also capable of recording RR data to provide heart rate variability (HRV) analyses. In this study we compare time between heart beats and HRV parameters obtained with a smart textile system (GOW; Weartech sl., Spain) and an electrocardiogram machine commonly used in hospitals during continuous cycling tests. Twelve cardiology patients performed a 30-min cycling test at stable submaximal intensity. RR interval data were recorded during the test by both systems. 3-min RR segments were taken to compare the time intervals between beats and HRV variables using Bland-Altman analyses and intraclass correlation coefficients. Limits of agreement (LoAs) on RR intervals were stable at around 3 ms (widest LoAs -5.754 to 6.094 ms, tightest LoAs -2.557 to 3.105 ms, medium LoAs -3.638 ± 0.812 to 3.145 ± 0.539 ms). HRV parameters related to short-term change presented wide LoAs (RMSSD -0.17 to 18.41 %, HF -17.64 to 33.21 %, SD1 -0.50 to 17.54 %) as an effect of the error measurement of the GOW system. The GOW system is a valid tool for controlling HR during physical activity, although its use as a clinical tool for HRV cannot be supported.

  6. Heart rate recovery and heart rate variability are unchanged in patients with coronary artery disease following 12 weeks of high-intensity interval and moderate-intensity endurance exercise training.

    Science.gov (United States)

    Currie, Katharine D; Rosen, Lee M; Millar, Philip J; McKelvie, Robert S; MacDonald, Maureen J

    2013-06-01

    Decreased heart rate variability and attenuated heart rate recovery following exercise are associated with an increased risk of mortality in cardiac patients. This study investigated the effects of 12 weeks of moderate-intensity endurance exercise (END) and a novel low-volume high-intensity interval exercise protocol (HIT) on measures of heart rate recovery and heart rate variability in patients with coronary artery disease (CAD). Fourteen males with CAD participated in 12 weeks of END or HIT training, each consisting of 2 supervised exercise sessions per week. END consisted of 30-50 min of continuous cycling at 60% peak power output (PPO). HIT involved ten 1-min intervals at 88% PPO separated by 1-min intervals at 10% PPO. Heart rate recovery at 1 min and 2 min was measured before and after training (pre- and post-training, respectively) using a submaximal exercise bout. Resting time and spectral and nonlinear domain measures of heart rate variability were calculated. Following 12 weeks of END and HIT, there was no change in heart rate recovery at 1 min (END, 40 ± 12 beats·min(-1) vs. 37 ± 19 beats·min(-1); HIT, 31 ± 8 beats·min(-1) vs. 35 ± 8 beats·min(-1); p ≥ 0.05 for pre- vs. post-training) or 2 min (END, 44 ± 18 beats·min(-1) vs. 43 ± 19 beats·min(-1); HIT, 42 ± 10 beats·min(-1) vs. 50 ± 6 beats·min(-1); p ≥ 0.05 for pre- vs. post-training). All heart rate variability indices were unchanged following END and HIT training. In conclusion, neither END nor HIT exercise programs elicited training-induced improvements in cardiac autonomic function in patients with CAD. The absence of improvements with training may be attributed to the optimal medical management and normative pretraining state of our sample.

  7. Exercise Prescription.

    Science.gov (United States)

    Ribisl, Paul M.

    If exercise programs are to become effective in producing the desired results, then the correct exercise prescription must be applied. Four variables should be controlled in the prescription of exercise: (a) type of activity, (b) intensity, (c) duration, and (d) frequency. The long-term prescription of exercise involves the use of a (a) starter…

  8. Inductive plethysmography potential as a surrogate for ventilatory measurements during rest and moderate physical exercise

    Directory of Open Access Journals (Sweden)

    Ramona Cabiddu

    2016-01-01

    Full Text Available Background: Portable respiratory inductive plethysmography (RIP systems have been validated for ventilatory assessment during resting conditions and during incremental treadmill exercise. However, in clinical settings and during field-based exercise, intensity is usually constant and submaximal. A demonstration of the ability of RIP to detect respiratory measurements accurately during constant intensity conditions would promote and validate the routine use of portable RIP devices as an alternative to ergospirometry (ES, the current gold standard technique for ventilatory measures. Objective: To investigate the agreement between respiratory variables recorded by a portable RIP device and by ES during rest and constant intensity exercise. Method: Tidal volume (VT, respiratory rate (RR and minute ventilation (VE were concurrently acquired by portable RIP and ES in seven healthy male volunteers during standing rest position and constant intensity treadmill exercise. Results: Significant agreement was found between RIP and ES acquisitions during the standing rest position and constant intensity treadmill exercise for RR and during the standing rest position for VE. Conclusion: Our results suggest that portable RIP devices might represent a suitable alternative to ES during rest and during constant submaximal exercise.

  9. Effects of antiorthostatic bedrest on the cardiorespiratory responses to exercise

    Science.gov (United States)

    Convertino, V. A.; Bisson, R.; Bates, R.; Goldwater, D.; Sandler, H.

    1981-01-01

    The cardiorespiratory changes in exercise performance induced by horizontal and antiorthostatic bed rest are compared in order to determine the physiological changes occurring in the antiorthostatic position and their degree of similarity to those observed in weightlessness. Systolic and diastolic pressures, heart rates, maximum oxygen uptake, ventilation volume during and following 5 min of submaximal exercise in the supine position and body weight and composition were determined in subjects before and following 7 days of bed rest in the horizontal or 6-deg head-down positions. Bed rest is found to result in a general decrease in exercise tolerance as indicated by cardiorespiratory parameters in both groups, with the 6-deg head-down treatment causing greater cardiovascular deconditioning. When compared with space flight data, the antiorthostatic position is shown to simulate the effects of weightlessness more effectively than horizontal bed rest

  10. Affect-regulated exercise intensity: does training at an intensity that feels 'good' improve physical health?

    Science.gov (United States)

    Parfitt, Gaynor; Alrumh, Amnah; Rowlands, Alex V

    2012-11-01

    Affect-regulated exercise to feel 'good' can be used to control exercise intensity amongst both active and sedentary individuals and should support exercise adherence. It is not known, however, whether affect-regulated exercise training can lead to physical health gains. The aim of this study was to examine if affect-regulated exercise to feel 'good' leads to improved fitness over the course of an 8-week training programme. A repeated measures design (pretest-posttest) with independent groups (training and control). 20 sedentary females completed a submaximal graded exercise test and were then allocated to either a training group or control group. The training group completed two supervised sessions and one unsupervised session per week for 8 weeks. Exercise intensity was affect-regulated to feel 'good'. Following the 8 weeks of training, both groups completed a second submaximal graded exercise test. Repeated measures analyses of variance indicated a significant increase in the time to reach ventilatory threshold in the training group (318 ± 23.7s) compared to control (248 ± 16.9s). Overall compliance to training was high (>92%). Participants in the training group exercised at intensities that would be classified as being in the lower range of the recommended guidelines (≈ 50% V˙O(2) max) for cardiovascular health. Affect-regulated exercise to feel 'good' can be used in a training programme to regulate exercise intensity. This approach led to a 19% increase in time to reach ventilatory threshold, which is indicative of improved fitness. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  11. Cortical and spinal mechanisms of task failure of sustained submaximal fatiguing contractions.

    Directory of Open Access Journals (Sweden)

    Petra S Williams

    Full Text Available In this and the subsequent companion paper, results are presented that collectively seek to delineate the contribution that supraspinal circuits have in determining the time to task failure (TTF of sustained submaximal contractions. The purpose of this study was to compare adjustments in supraspinal and spinal excitability taken concurrently throughout the performance of two different fatigue tasks with identical mechanical demands but different TTF (i.e., force-matching and position-matching tasks. On separate visits, ten healthy volunteers performed the force-matching or position-matching task at 15% of maximum strength with the elbow flexors to task failure. Single-pulse transcranial magnetic stimulation (TMS, paired-pulse TMS, paired cortico-cervicomedullary stimulation, and brachial plexus electrical stimulation were delivered in a 6-stimuli sequence at baseline and every 2-3 minutes throughout fatigue-task performance. Contrary to expectations, the force-matching task TTF was 42% shorter (17.5 ± 7.9 min than the position-matching task (26.9 ± 15.11 min; p0.05. Therefore, failure occurred after a similar mean decline in motorneuron excitability developed (p0.10 and an index of upstream excitation of the motor cortex remained constant (p>0.40. Together, these results suggest that as fatigue develops prior to task failure, the increase in corticospinal excitability observed in relationship to the decrease in spinal excitability results from a combination of decreasing intracortical inhibition with constant levels of intracortical facilitation and upstream excitability that together eventually fail to provide the input to the motor cortex necessary for descending drive to overcome the spinal cord resistance, thereby contributing to task failure.

  12. Cortical and Spinal Mechanisms of Task Failure of Sustained Submaximal Fatiguing Contractions

    Science.gov (United States)

    Williams, Petra S.; Hoffman, Richard L.; Clark, Brian C.

    2014-01-01

    In this and the subsequent companion paper, results are presented that collectively seek to delineate the contribution that supraspinal circuits have in determining the time to task failure (TTF) of sustained submaximal contractions. The purpose of this study was to compare adjustments in supraspinal and spinal excitability taken concurrently throughout the performance of two different fatigue tasks with identical mechanical demands but different TTF (i.e., force-matching and position-matching tasks). On separate visits, ten healthy volunteers performed the force-matching or position-matching task at 15% of maximum strength with the elbow flexors to task failure. Single-pulse transcranial magnetic stimulation (TMS), paired-pulse TMS, paired cortico-cervicomedullary stimulation, and brachial plexus electrical stimulation were delivered in a 6-stimuli sequence at baseline and every 2–3 minutes throughout fatigue-task performance. Contrary to expectations, the force-matching task TTF was 42% shorter (17.5±7.9 min) than the position-matching task (26.9±15.11 min; pmuscle fatigue (p = 0.59). There were no task-specific differences for the total amount or rate of change in the neurophysiologic outcome variables over time (p>0.05). Therefore, failure occurred after a similar mean decline in motorneuron excitability developed (p0.10) and an index of upstream excitation of the motor cortex remained constant (p>0.40). Together, these results suggest that as fatigue develops prior to task failure, the increase in corticospinal excitability observed in relationship to the decrease in spinal excitability results from a combination of decreasing intracortical inhibition with constant levels of intracortical facilitation and upstream excitability that together eventually fail to provide the input to the motor cortex necessary for descending drive to overcome the spinal cord resistance, thereby contributing to task failure. PMID:24667484

  13. Inspiratory muscle training improves exercise capacity with thoracic load carriage.

    Science.gov (United States)

    Shei, Ren-Jay; Chapman, Robert F; Gruber, Allison H; Mickleborough, Timothy D

    2018-02-01

    Thoracic load carriage (LC) exercise impairs exercise performance compared to unloaded exercise, partially due to impaired respiratory mechanics. We investigated the effects of LC on exercise and diaphragmatic fatigue in a constant-load exercise task; and whether inspiratory muscle training (IMT) improved exercise capacity and diaphragmatic fatigue with LC. Twelve recreationally active males completed three separate running trials to exhaustion (T lim ) at a fixed speed eliciting 70% of their V˙O 2max . The first two trials were completed either unloaded (UL) or while carrying a 10 kg backpack (LC). Subjects then completed 6 weeks of either true IMT or placebo-IMT. Posttraining, subjects completed an additional LC trial identical to the pretraining LC trial. Exercise metabolic and ventilatory measures were recorded. Diaphragm fatigue was assessed as the difference between preexercise and postexercise twitch diaphragmatic pressure (P di, tw ), assessed by bilateral stimulation of the phrenic nerve with esophageal balloon-tipped catheters measuring intrathoracic pressures. T lim was significantly shorter (P  0.05). Minute ventilation and breathing mechanics were unchanged post-IMT (P > 0.05). Six weeks of flow-resistive IMT improved exercise capacity, but did not mitigate diaphragmatic fatigue following submaximal, constant-load running to volitional exhaustion with LC. © 2018 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  14. Exercise Testing Reveals Everyday Physical Challenges of Bariatric Surgery Candidates.

    Science.gov (United States)

    Creel, David B; Schuh, Leslie M; Newton, Robert L; Stote, Joseph J; Cacucci, Brenda M

    2017-10-12

    Few studies have quantified cardiorespiratory fitness among individuals seeking bariatric surgery. Treadmill testing allows researchers to determine exercise capacity through metabolic equivalents. These findings can assist clinicians in understanding patients' capabilities to carry out various activities of daily living. The purpose of this study was to determine exercise tolerance and the variables associated with fitness, among individuals seeking bariatric surgery. Bariatric surgery candidates completed submaximal treadmill testing and provided ratings of perceived exertion. Each participant also completed questionnaires related to history of exercise, mood, and perceived barriers/benefits of exercise. Over half of participants reported that exercise was "hard to very hard" before reaching 70% of heart rate reserve, and one-third of participants reported that exercise was "moderately hard" at less than 3 metabolic equivalents (light activity). Body mass index and age accounted for the majority of the variance in exercise tolerance, but athletic history, employment status, and perceived health benefits also contributed. Perceived benefit scores were higher than barrier scores. Categories commonly used to describe moderate-intensity exercise (3-6 metabolic equivalents) do not coincide with perceptions of intensity among many bariatric surgery candidates, especially those with a body mass index of 50 or more.

  15. Health benefits of exercise in an aging society.

    Science.gov (United States)

    Larson, E B; Bruce, R A

    1987-02-01

    The effects of regular aerobic exercise are important to an aging society increasingly preoccupied with exercise. Traditionally, most attention has been directed to the relationship between a physically active life-style and cardiovascular mortality. In an aging society, however, active life expectancy and maintenance of independence may be as important as effects of regular exercise on longevity. Regular exercise results in increased maximum aerobic capacity due to peripheral changes in muscle (increased capacity for aerobic metabolism and improved substrate and oxygen extraction with a widened arteriovenous oxygen difference) and also due to cardiovascular changes with increased stroke volume and cardiac output in normal persons. "Therapeutic benefits" of conditioning probably occur at submaximal work loads common to everyday activity, when cardiac work and myocardial oxygen consumption are less for any given work load, muscles are more efficient, and relative oxygen requirements are less. Aging is associated with a linear decline in maximum aerobic capacity. The rate of decline is twofold greater when comparing sedentary with physically active middle-aged men. Thus, regular exercise could conceivably lower functional aerobic age by slowing this functional decline. Exercise, particularly excessive exercise, is also associated with serious hazards, including sudden death, nonfatal myocardial infarction, excessive fatigue, hyperthermia, and significant musculoskeletal problems. Accounts of the health effects of exercise should consider a wide range of risks and benefits, especially those related to improving function, minimizing disability, and prolonging independent living.

  16. Effect of acute aerobic exercise and histamine receptor blockade on arterial stiffness in African Americans and Caucasians.

    Science.gov (United States)

    Yan, Huimin; Ranadive, Sushant M; Lane-Cordova, Abbi D; Kappus, Rebecca M; Behun, Michael A; Cook, Marc D; Woods, Jeffrey A; Wilund, Kenneth R; Baynard, Tracy; Halliwill, John R; Fernhall, Bo

    2017-02-01

    African Americans (AA) exhibit exaggerated central blood pressure (BP) and arterial stiffness measured by pulse wave velocity (PWV) in response to an acute bout of maximal exercise compared with Caucasians (CA). However, whether potential racial differences exist in central BP, elastic, or muscular arterial distensibility after submaximal aerobic exercise remains unknown. Histamine receptor activation mediates sustained postexercise hyperemia in CA but the effect on arterial stiffness is unknown. This study sought to determine the effects of an acute bout of aerobic exercise on central BP and arterial stiffness and the role of histamine receptors, in AA and CA. Forty-nine (22 AA, 27 CA) young and healthy subjects completed the study. Subjects were randomly assigned to take either histamine receptor antagonist or control placebo. Central blood BP and arterial stiffness measurements were obtained at baseline, and at 30, 60, and 90 min after 45 min of moderate treadmill exercise. AA exhibited greater central diastolic BP, elevated brachial PWV, and local carotid arterial stiffness after an acute bout of submaximal exercise compared with CA, which may contribute to their higher risk of cardiovascular disease. Unexpectedly, histamine receptor blockade did not affect central BP or PWV in AA or CA after exercise, but it may play a role in mediating local carotid arterial stiffness. Furthermore, histamine may mediate postexercise carotid arterial dilation in CA but not in AA. These observations provide evidence that young and healthy AA exhibit an exaggerated hemodynamic response to exercise and attenuated vasodilator response compared with CA.NEW & NOTEWORTHY African Americans are at greater risk for developing cardiovascular disease than Caucasians. We are the first to show that young and healthy African Americans exhibit greater central blood pressure, elevated brachial stiffness, and local carotid arterial stiffness following an acute bout of submaximal exercise

  17. Time-to-Fatigue and Intramuscular pH Measured via NIRS During Handgrip Exercise in Trained and Sedentary Individuals

    Science.gov (United States)

    Everett, M. E.; Lee, S. M. C.; Stroud, L.; Scott, P.; Hagan, R. D.; Soller, B. R.

    2009-01-01

    In exercising muscles force production and muscular endurance are impaired by a decrease in intramuscular pH. The effects of aerobic training (AT) on preventing acidosis and prolonging exercise time in muscles not specifically targeted by the training are unknown. Purpose: To compare interstitial pH, measured non-invasively with near infrared spectroscopy (NIRS), in the flexor digitorum profundus (FDP) during rhythmic handgrip exercise in sedentary subjects and those who participate in AT activities that target the lower body. Methods: Maximal isometric force (MIF) was measured on three separate days in AT (n=5) and sedentary (n=8) subjects using a handgrip dynamometer (HGD). Isometric muscular endurance (IME) was measured during five trials, each separated by at least 48 hrs. For each IME trial subjects rhythmically squeezed (4 sec at 40% of MVC) and relaxed (2 sec) to fatigue or failure to reach the target force in three consecutive contractions or four non-consecutive contractions. Interstitial pH was derived from spectra collected using a NIRS sensor adhered to the skin over the FDP. The first four IME trials served to familiarize subjects with the protocol; the fifth trial was used for analysis. NIRS-derived pH was averaged in 30 sec increments. Between group differences in MIF and exercise time were tested using paired t-tests. A repeated measures ANOVA was used to analyze effects of AT and exercise time on pH. Results: MIF was not different between groups (mean SD; aerobic=415.6 95.4 N vs. sedentary =505.1 107.4 N). Time to fatigue was greater in the AT than in the sedentary group (mean SD: 611 173 sec vs. 377 162 sec, pexercise (pH=6.9), but did not decrease further throughout the remainder of exercise. Conclusion: Although between group differences in pH were not detected, differences during the onset of exercise may exist with a more frequent sampling. AT individuals appear to better tolerate decreased interstitial pH and are able to continue submaximal

  18. DIURNAL VARIATION OF HAEMOSTATIC RESPONSE TO EXERCISE IN YOUNG SEDENTARY MALES

    OpenAIRE

    Marefat Siahkouhian; Davar Khodadadi; Lotfali Bolboli

    2013-01-01

    The aim of this study was to evaluate diurnal variations in the haemostatic response to submaximal exercise performed by young, sedentary men. Fifteen healthy young sedentary males aged 25.6 ± 1.34 (mean ± SD) years performed two exercise sessions, morning and evening, at 70% of maximal oxygen consumption ( V . O2max) on a cycle ergometer for 30 min. Platelet count (PC), activated partial thromboplastin time (aPTT), prothrombin time (PT), fibrinogen, tissue plasminogen activator (tPA) and pla...

  19. Effects of training status on PDH regulation in human skeletal muscle during exercise

    DEFF Research Database (Denmark)

    Gudiksen, Anders; Bertholdt, Lærke; Stankiewicz, Tomasz

    2017-01-01

    of this study was to investigate the impact of training state on post-translational regulation of PDHa activity during submaximal and exhaustive exercise. Eight untrained and nine endurance exercise-trained healthy male subjects performed incremental exercise on a cycle ergometer: 40 min at 50% incremental peak...... power output (IPPO), 10 min at 65% (IPPO), followed by 80% (IPPO) until exhaustion. Trained subjects had higher (P muscle PDH......Pyruvate dehydrogenase (PDH) is the gateway enzyme for carbohydrate-derived pyruvate feeding into the TCA cycle. PDH may play a central role in regulating substrate shifts during exercise, but the influence of training state on PDH regulation during exercise is not fully elucidated. The purpose...

  20. Sympathetic influence on cerebral blood flow and metabolism during exercise in humans

    DEFF Research Database (Denmark)

    Seifert, Thomas; Secher, Niels H

    2011-01-01

    This review focuses on the possibility that autonomic activity influences cerebral blood flow (CBF) and metabolism during exercise in humans. Apart from cerebral autoregulation, the arterial carbon dioxide tension, and neuronal activation, it may be that the autonomic nervous system influences CBF......-oxidative carbohydrate uptake during exercise. Adrenaline appears to accelerate cerebral glycolysis through a beta2-adrenergic receptor mechanism since noradrenaline is without such an effect. In addition, the exercise-induced cerebral non-oxidative carbohydrate uptake is blocked by combined beta 1/2-adrenergic blockade......, but not by beta1-adrenergic blockade. Furthermore, endurance training appears to lower the cerebral non-oxidative carbohydrate uptake and preserve cerebral oxygenation during submaximal exercise. This is possibly related to an attenuated catecholamine response. Finally, exercise promotes brain health as evidenced...

  1. Hypoxia and exercise provoke both lactate release and lactate oxidation by the human brain

    DEFF Research Database (Denmark)

    Overgaard, Morten; Rasmussen, Peter; Bohm, Aske M

    2012-01-01

    Lactate is shuttled between organs, as demonstrated in the Cori cycle. Although the brain releases lactate at rest, during physical exercise there is a cerebral uptake of lactate. Here, we evaluated the cerebral lactate uptake and release in hypoxia, during exercise and when the two interventions...... were combined. We measured cerebral lactate turnover via a tracer dilution method ([1-(13)C]lactate), using arterial to right internal jugular venous differences in 9 healthy individuals (5 males and 4 females), at rest and during 30 min of submaximal exercise in normoxia and hypoxia (F(i)o(2) 10......%, arterial oxygen saturation 72±10%, mean±SD). Whole-body lactate turnover increased 3.5-fold and 9-fold at two workloads in normoxia and 18-fold during exercise in hypoxia. Although middle cerebral artery mean flow velocity increased during exercise in hypoxia, calculated cerebral mitochondrial oxygen...

  2. Genetic Influences on Physiological and Subjective Responses to an Aerobic Exercise Session among Sedentary Adults

    Directory of Open Access Journals (Sweden)

    Hollis C. Karoly

    2012-01-01

    Full Text Available Objective. To determine whether genetic variants suggested by the literature to be associated with physiology and fitness phenotypes predicted differential physiological and subjective responses to a bout of aerobic exercise among inactive but otherwise healthy adults. Method. Participants completed a 30-minute submaximal aerobic exercise session. Measures of physiological and subjective responding were taken before, during, and after exercise. 14 single nucleotide polymorphisms (SNPs that have been previously associated with various exercise phenotypes were tested for associations with physiological and subjective response to exercise phenotypes. Results. We found that two SNPs in the FTO gene (rs8044769 and rs3751812 were related to positive affect change during exercise. Two SNPs in the CREB1 gene (rs2253206 and 2360969 were related to change in temperature during exercise and with maximal oxygen capacity (VO2 max. The SLIT2 SNP rs1379659 and the FAM5C SNP rs1935881 were associated with norepinephrine change during exercise. Finally, the OPRM1 SNP rs1799971 was related to changes in norepinephrine, lactate, and rate of perceived exertion (RPE during exercise. Conclusion. Genetic factors influence both physiological and subjective responses to exercise. A better understanding of genetic factors underlying physiological and subjective responses to aerobic exercise has implications for development and potential tailoring of exercise interventions.

  3. Different types of compression clothing do not increase sub-maximal and maximal endurance performance in well-trained athletes.

    Science.gov (United States)

    Sperlich, Billy; Haegele, Matthias; Achtzehn, Silvia; Linville, John; Holmberg, Hans-Christer; Mester, Joachim

    2010-04-01

    Three textiles with increasing compressive surface were compared with non-compressive conventional clothing on physiological and perceptual variables during sub-maximal and maximal running. Fifteen well-trained endurance athletes (mean+/-s: age 27.1+/-4.8 years, VO(2max) 63.7+/-4.9 ml x min(-1) x kg(-1)) performed four sub-maximal (approximately 70% VO(2max)) and maximal tests with and without different compression stockings, tights, and whole-body compression suits. Arterial lactate concentration, oxygen saturation and partial pressure, pH, oxygen uptake, and ratings of muscle soreness were recorded before, during, and after all tests. In addition, we assessed time to exhaustion. Sub-maximal (P=0.22) and maximal oxygen uptake (P=0.26), arterial lactate concentration (P=0.16; 0.20), pH (P=0.23; 0.46), oxygen saturation (P=0.13; 0.26), and oxygen partial pressure (P=0.09; 0.20) did not differ between the types of clothing (effect sizes=0.00-0.45). Ratings of perceived exertion (P=0.10; 0.15), muscle soreness (P=0.09; 0.10) and time to exhaustion (P=0.16) were also unaffected by the different clothing (effect sizes=0.28-0.85). This was the first study to evaluate the effect on endurance performance of different types of compression clothing with increasing amounts of compressive surface. Overall, there were no performance benefits when using the compression garments.

  4. The effect of menstruation on chosen physiological and biochemical reactions caused by the physical effort with the submaximal intensity

    Directory of Open Access Journals (Sweden)

    P Zieliński

    2003-03-01

    Full Text Available The aim of this work was to determine the influence of the menstruation phase on changes of respective indicators of the gas exchange and on biochemical parameters of blood during physical efforts with the sub-maximal intensity. Fifteen female students of the Academy of Physical Education took part in the study. Girls were aged from 19 to 22 years old and did not practice sports. The effort tests were conducted in the follicular and luteal phase of two succeeding menstrual cycles. As far the aerobic capacity determination is concerned, one cyclo-ergometric test with graded effort was conducted and it was performed till the “refusal”. It allowed to mark a threshold (TDMA and a maximal level of physiological and biochemical indicators. Basing on the results of the graded test individual loads were determined for every next effort trial (repeated 4 times in every phase of the two succeeding menstrual cycles. The aim of this trial was to evaluate the reaction of women’s constitution on work with the sub-maximal intensity. The above trial consisted on two 10 min efforts divided with the 2 min pause (the first effort with the intensity of 80% of the TDMA threshold, second with the intensity bigger about 30-40% of difference between TDMA and a maximal load established by the graded test. The research did not reveal statistically significant differentiation as considering effort changes of basic physiological and biochemical indicators, determining reaction of women’s organisms on work with the sub- and over- threshold intensity (TDMA. It showed that menstruation has not significant effect on the level of changes of analysed parameters caused by the physical effort with the sub-maximal intensity.

  5. Effects of intermittent bouts of aerobic exercise on oxygen consumption during and after exercise

    OpenAIRE

    韓, 一栄; 向本, 敬洋; 植田, 央; 清田, 寛; 大野, 誠

    2012-01-01

    The purpose of this study was to compare the oxygen consumption (VO2) and energy expenditure (EE) during and after exercise between a single bout of continuous exercise and intermittent bouts of exercise, which of equivalent exercise intensity and total exercise duration. Nine healthy young men performed the following two exercise trials on separate days: 1) A single bout of 30-min exercise (30Ex), followed by 90-min of rest. 2) Three intermittent bouts of 30-min exercise, separated by a 10-m...

  6. Sports drinks, exercise training, and competition.

    Science.gov (United States)

    von Duvillard, Serge P; Arciero, Paul J; Tietjen-Smith, Tara; Alford, Ken

    2008-01-01

    A plethora of investigations examining fluid intake before, during, and after training and competition have suggested that a lack of adequate fluid intake will impair or decrease physical performance. Depending upon the type of training or competition, individuals training for prolonged endurance events should drink fluids containing carbohydrates and electrolytes during and after training or competition. Inadequate hydration will cause significant decrements in performance, increase thermal stress, reduce plasma volume, accelerate fatigue, and possibly cause injuries associated with fluid and sweat loss. However, overdrinking may cause Na+ depletion and in some cases lead to hyponatremia. Maintaining proper hydration before, during, and after training and competition will help reduce fluid loss, maintain performance, lower submaximal exercise heart rate, maintain plasma volume, and reduce heat stress, heat exhaustion, and possibly heat stroke.

  7. Interval training elicits higher enjoyment versus moderate exercise in persons with spinal cord injury.

    Science.gov (United States)

    Astorino, Todd A; Thum, Jacob S

    2018-01-01

    High intensity interval training (HIIT) is a robust and time-efficient approach to improve multiple health indices including maximal oxygen uptake (VO 2 max). Despite the intense nature of HIIT, data in untrained adults report greater enjoyment of HIIT versus continuous exercise (CEX). However, this has yet to be investigated in persons with spinal cord injury (SCI). To examine differences in enjoyment in response to CEX and HIIT in persons with SCI. Repeated measures, within-subjects design. University laboratory in San Diego, CA. Nine habitually active men and women (age = 33.3 ± 10.5 years) with chronic SCI. Participants performed progressive arm ergometry to volitional exhaustion to determine VO 2 peak. During subsequent sessions, they completed CEX, sprint interval training (SIT), or HIIT in randomized order. Physical activity enjoyment (PACES), affect, rating of perceived exertion (RPE), VO 2 , and blood lactate concentration (BLa) were measured. Despite a higher VO 2 , RPE, and BLa consequent with HIIT and SIT (P HIIT (107.4 ± 13.4) and SIT (103.7 ± 12.5) compared to CEX (81.6 ± 25.4). Fifty-five percent of participants preferred HIIT and 45% preferred SIT, with none identifying CEX as their preferred exercise mode. Compared to CEX, brief sessions of submaximal or supramaximal interval training elicit higher enjoyment despite higher metabolic strain. The long-term efficacy and feasibility of HIIT in this population should be explored considering that it is not viewed as more aversive than CEX.

  8. Diet and exercise effects on aerobic fitness and body composition in seriously mentally ill adults.

    Science.gov (United States)

    Giannopoulou, Ifigenia; Botonis, Petros; Kostara, Christina; Skouroliakou, Maria

    2014-01-01

    Low exercise capacity and high obesity levels are the main characteristics of people with serious mental illness (SMI). We conducted a pilot study on the effects of a 3-month exercise and dietary intervention on the aerobic capacity and body composition of obese adults with SMI taking Olanzapine, a second generation antipsychotic medication known to induce weight increments. Fifty adults with SMI (15 males and 35 females) followed a 3-month weight loss intervention programme based on exercise and diet. Pre- and post-intervention, a submaximal [Formula: see text]O2 exercise test was performed in order to assess [Formula: see text]O2max anthropometric and body composition measurements were also performed. All participants were obese (body mass index (BMI): 33.61 ± 0.91 kg/m(2)). Pre- and post-intervention, a submaximal [Formula: see text]O2 exercise test on the treadmill was performed in order to assess [Formula: see text]O2max anthropometric and body composition measurements were also performed. Significant reductions in body weight, BMI, body fat and waist circumference were found from pre to post (p diet improves the aerobic capacity and body composition of obese adults with SMI, despite the use of Olanzapine.

  9. Effect of Peer Influence on Exercise Behavior and Enjoyment in Recreational Runners.

    Science.gov (United States)

    Carnes, Andrew J; Petersen, Jennifer L; Barkley, Jacob E

    2016-02-01

    Fitness professionals and popular media sources often recommend exercising with a partner to increase exercise motivation, adherence, intensity, and/or duration. Although competition with peers has been shown to enhance maximal athletic performance, experimental research examining the impact of peer influence on submaximal exercise behavior in adults is limited. The purpose of this study was to determine the effects of the presence of familiar and unfamiliar peers, vs. running alone, on recreational runners' voluntary running duration, distance, intensity, liking (i.e., enjoyment), and ratings of perceived exertion (RPEs). Recreational runners (n = 12 males, n = 12 females) completed 3 experimental trials, each under a different social condition, in a randomized order. Each trial consisted of self-paced running for a duration voluntarily determined by the participant. The 3 social conditions were running alone, with a sex- and fitness-matched familiar peer, or with a sex- and fitness-matched unfamiliar peer. A wrist-worn global positioning system was used to record running duration, distance, and average speed. Liking and RPE were assessed at the end of each trial. Mixed model regression analysis showed no significant effects of social condition (p ≥ 0.40) for any of the dependent variables. The presence of a familiar or unfamiliar peer did not alter recreational runners' running behavior, liking, or perceived exertion during submaximal exercise. However, exercising with others may have other benefits (e.g., reduced attrition) not examined herein.

  10. Effects of the menstrual cycle on exercise performance.

    Science.gov (United States)

    Janse de Jonge, Xanne A K

    2003-01-01

    This article reviews the potential effects of the female steroid hormone fluctuations during the menstrual cycle on exercise performance. The measurement of estrogen and progesterone concentration to verify menstrual cycle phase is a major consideration in this review. However, even when hormone concentrations are measured, the combination of differences in timing of testing, the high inter- and intra-individual variability in estrogen and progesterone concentration, the pulsatile nature of their secretion and their interaction, may easily obscure possible effects of the menstrual cycle on exercise performance. When focusing on studies using hormone verification and electrical stimulation to ensure maximal neural activation, the current literature suggests that fluctuations in female reproductive hormones throughout the menstrual cycle do not affect muscle contractile characteristics. Most research also reports no changes over the menstrual cycle for the many determinants of maximal oxygen consumption (VO2max), such as lactate response to exercise, bodyweight, plasma volume, haemoglobin concentration, heart rate and ventilation. Therefore, it is not surprising that the current literature indicates that VO2max is not affected by the menstrual cycle. These findings suggest that regularly menstruating female athletes, competing in strength-specific sports and intense anaerobic/aerobic sports, do not need to adjust for menstrual cycle phase to maximise performance. For prolonged exercise performance, however, the menstrual cycle may have an effect. Even though most research suggests that oxygen consumption, heart rate and rating of perceived exertion responses to sub-maximal steady-state exercise are not affected by the menstrual cycle, several studies report a higher cardiovascular strain during moderate exercise in the mid-luteal phase. Nevertheless, time to exhaustion at sub-maximal exercise intensities shows no change over the menstrual cycle. The significance of

  11. Comparable Effects of High-Intensity Interval Training and Prolonged Continuous Exercise Training on Abdominal Visceral Fat Reduction in Obese Young Women

    Directory of Open Access Journals (Sweden)

    Haifeng Zhang

    2017-01-01

    Full Text Available This study compared the effect of prolonged moderate-intensity continuous training (MICT on reducing abdominal visceral fat in obese young women with that of work-equivalent (300 kJ/training session high-intensity interval training (HIIT. Forty-three participants received either HIIT (n=15, MICT (n=15, or no training (CON, n=13 for 12 weeks. The abdominal visceral fat area (AVFA and abdominal subcutaneous fat area (ASFA of the participants were measured through computed tomography scans preintervention and postintervention. Total fat mass and the fat mass of the android, gynoid, and trunk regions were assessed through dual-energy X-ray absorptiometry. Following HIIT and MICT, comparable reductions in AVFA (−9.1, −9.2 cm2, ASFA (−35, −28.3 cm2, and combined AVFA and ASFA (−44.7, −37.5 cm2, p>0.05 were observed. Similarly, reductions in fat percentage (−2.5%, −2.4%, total fat mass (−2.8, −2.8 kg, and fat mass of the android (−0.3, −0.3 kg, gynoid (−0.5, −0.7 kg, and trunk (−1.6, −1.2 kg, p>0.05 regions did not differ between HIIT and MICT. No variable changed in CON. In conclusion, MICT consisting of prolonged sessions has no quantitative advantage, compared with that resulting from HIIT, in abdominal visceral fat reduction. HIIT appears to be the predominant strategy for controlling obesity because of its time efficiency.

  12. Prediction of VO2max in Children and Adolescents Using Exercise Testing and Physical Activity Questionnaire Data.

    Science.gov (United States)

    Black, Nate E; Vehrs, Pat R; Fellingham, Gilbert W; George, James D; Hager, Ron

    2016-01-01

    The purpose of this study was to evaluate the use of a treadmill walk-jog-run exercise test previously validated in adults and physical activity questionnaire data to estimate maximum oxygen consumption (VO2max) in boys (n = 62) and girls (n = 66) aged 12 to 17 years old. Data were collected from Physical Activity Rating (PA-R) and Perceived Functional Ability (PFA) questionnaires, a walk-jog-run submaximal treadmill exercise test, and a maximal graded exercise test. Regression analysis resulted in the development of 2 models to predict VO2max. Submaximal exercise test data were used to build the following model (R2 = .73; SEE = 4.59 mL + kg(- 1) + min(- 1)): VO2max (mL + kg(- 1) + min(- 1)) = 26.890+(5.877 × Gender; 0 = female; 1 = male) - (0.782 × Body Mass Index [BMI])+(0.438 × PFA Score) +(2.712 × Treadmill Speed; mph) +(0.746 × Age) +(0.449 × PA-R Score). Maximal exercise test data were used to build the following model (R2 = .83; SEE = 3.63 mL + kg(- 1) + min(- 1)): VO2max (mL + kg(- 1) + min(- 1)) = 10.716+(1.334 × Maximal Treadmill Grade) +(5.203 × Treadmill Speed; mph) +(3.494 × Gender; 0 = female; 1 = male) - (0.413 × BMI) +(0.249 × PFA). The results of this study demonstrate, for the first time, that regression equations that use both exercise data and physical activity questionnaire data can accurately predict VO2max in youth. The submaximal and maximal exercise tests that use self-selected treadmill speeds can be used to assess cardiorespiratory fitness of youth with a wide range of fitness levels.

  13. Prevention: Exercise

    Medline Plus

    Full Text Available ... provide well-rounded core strengthening programs. Simple exercises can be done at home as well. Some specific ... benefit from this exercise... Sagittal Core Strengthening You can stretch and strengthen the low back muscles that ...

  14. Simulation Exercises

    Science.gov (United States)

    Tansey, Pat

    1976-01-01

    Describes five simulation exercises: a problem for a student teacher, an industrial relations game, a series of student problems; an international relations crisis, and a sociological exercise on public and private opinions. (LS)

  15. Prevention: Exercise

    Medline Plus

    Full Text Available ... martial arts all provide well-rounded core strengthening programs. Simple exercises can be done at home as ... doctor or physical therapist to prescribe an exercise program that matches your abilities. Neck Press This is ...

  16. Prevention: Exercise

    Science.gov (United States)

    ... be done at home as well. Some specific core strengthening exercises are described below. If any of the following ... balls, you will experience more benefit from this exercise... Sagittal Core Strengthening You can stretch and strengthen the low ...

  17. Prevention: Exercise

    Medline Plus

    Full Text Available ... strengthening programs. Simple exercises can be done at home as well. Some specific core strengthening exercises are ... a Success Story to Share? | Contact Us SPINE CARE PROVIDERS GO HERE © 2017 North American Spine Society | ...

  18. Prevention: Exercise

    Medline Plus

    Full Text Available ... prescribe an exercise program that matches your abilities. Neck Press This is an isometric exercise to strengthen your neck. Press your palm against your forehead, then use ...

  19. Prevention: Exercise

    Medline Plus

    Full Text Available ... Back Pain Basics Book RESOURCES Patient Information Feature Articles Patient Q&A Success Stories ... Committee Exercise Committee Core Strengthening Many popular forms of exercise focus on ...

  20. Prevention: Exercise

    Medline Plus

    Full Text Available ... Strengthen Your Core! Stretching/Flexibility Aerobic Exercise Cervical Exercise Strength Training for the Elderly Other Back Pack Safety Pregnancy and Back Pain Preventing Osteoporosis Back Pain Basics ...

  1. Exercise Headaches

    Science.gov (United States)

    ... headaches may require emergency medical attention. Symptoms Primary exercise headaches These headaches: Are usually described as throbbing ... sides of the head in most cases Secondary exercise headaches These headaches may cause: The same symptoms ...

  2. Exercise-Induced Muscle Damage and Running Economy in Humans

    Directory of Open Access Journals (Sweden)

    Cláudio de Oliveira Assumpção

    2013-01-01

    Full Text Available Running economy (RE, defined as the energy demand for a given velocity of submaximal running, has been identified as a critical factor of overall distance running performance. Plyometric and resistance trainings, performed during a relatively short period of time (~15–30 days, have been successfully used to improve RE in trained athletes. However, these exercise types, particularly when they are unaccustomed activities for the individuals, may cause delayed onset muscle soreness, swelling, and reduced muscle strength. Some studies have demonstrated that exercise-induced muscle damage has a negative impact on endurance running performance. Specifically, the muscular damage induced by an acute bout of downhill running has been shown to reduce RE during subsequent moderate and high-intensity exercise (>65% VO2max. However, strength exercise (i.e., jumps, isoinertial and isokinetic eccentric exercises seems to impair RE only for subsequent high-intensity exercise (~90% VO2max. Finally, a single session of resistance exercise or downhill running (i.e., repeated bout effect attenuates changes in indirect markers of muscle damage and blunts changes in RE.

  3. Exercise-Induced Muscle Damage and Running Economy in Humans

    Science.gov (United States)

    Assumpção, Cláudio de Oliveira; Lima, Leonardo Coelho Rabello; Oliveira, Felipe Bruno Dias; Greco, Camila Coelho; Denadai, Benedito Sérgio

    2013-01-01

    Running economy (RE), defined as the energy demand for a given velocity of submaximal running, has been identified as a critical factor of overall distance running performance. Plyometric and resistance trainings, performed during a relatively short period of time (~15–30 days), have been successfully used to improve RE in trained athletes. However, these exercise types, particularly when they are unaccustomed activities for the individuals, may cause delayed onset muscle soreness, swelling, and reduced muscle strength. Some studies have demonstrated that exercise-induced muscle damage has a negative impact on endurance running performance. Specifically, the muscular damage induced by an acute bout of downhill running has been shown to reduce RE during subsequent moderate and high-intensity exercise (>65% VO2max). However, strength exercise (i.e., jumps, isoinertial and isokinetic eccentric exercises) seems to impair RE only for subsequent high-intensity exercise (~90% VO2max). Finally, a single session of resistance exercise or downhill running (i.e., repeated bout effect) attenuates changes in indirect markers of muscle damage and blunts changes in RE. PMID:23431253

  4. Is an elevated submaximal heart rate associated with psychomotor slowness in young elite soccer players?

    NARCIS (Netherlands)

    E. Nederhof; C. Visscher; S.L. Schmikli; Koen A.P.M. Lemmink; Michel S. Brink

    2013-01-01

    Abstract The aim of the present study was to find early markers for overreaching that are applicable in sport practice. In a group of elite soccer players aged 15–18, the stress–recovery balance and reaction times before and after exercise were assessed. Overreaching was indicated by an elevated

  5. Isokinetic performance capacity of trunk muscles. Part II: Coefficient of variation in isokinetic measurement in maximal effort and in submaximal effort.

    Science.gov (United States)

    Luoto, S; Hupli, M; Alaranta, H; Hurri, H

    1996-12-01

    It has been claimed that with the aid of isokinetic trunk strength measuring devices it is possible to distinguish true muscular weakness from submaximal effort in the test. This proposition is based on the presumption that in the isokinetic trunk strength test identical performances can only be reproduced by maximal effort. The purpose of this study was to investigate whether it is possible to distinguish maximal effort from submaximal with the aid of the coefficient of variation (CV) in an isokinetic trunk muscle strength test. The study group included 35 (21 male and 14 female) subjects of whom 12 were healthy, 10 had a mild low-back pain and 13 had a more severe chronic low-back pain. The subjects performed five consecutive bendings both with maximal (100%) and submaximal (50%) efforts at a speed of 90 degrees/second. In maximal effort only healthy subjects reached an average level of CV close to 10% both in extension and in flexion. In the chronic low-back pain group the average CV was close to 20%. The difference in CV was statistically significant (p < 0.05-0.02) between the healthy and the chronic low-back pain subjects. In the submaximal effort all health groups had a CV of approximately 20% or more and no significant differences were found. The group of slightly variable measurements (CV = 11-20%) was remarkably large in both the maximal and submaximal effort. The results suggest that an effort with a CV of 11-20% cannot be classified as definitely submaximal or maximal. When the CV is less than 10% the effort can be fairly certainly classified as maximal.

  6. Exercise testing and training in people with Huntington's disease.

    Science.gov (United States)

    Dawes, H; Collett, J; Debono, K; Quinn, L; Jones, K; Kelson, M J; Simpson, S A; Playle, R; Backx, K; Wasley, D; Nemeth, A H; Rosser, A; Izardi, H; Busse, M

    2015-02-01

    To explore exercise response in people with Huntington's disease (HD). Experimental observational study with a randomly allocated subgroup before/after interventional study. Community. People with HD (n=30) and a healthy comparator group (n=20). Thirteen people from the HD group were randomly allocated to an exercise training program. Heart rate (HR) and perceived exertion on the Borg-CR10 scale (RPE) during a submaximal cycle ergometer exercise test (three minute unloaded and nine minute 65%-75%HRmaximum phase). Expired air and lactate measures were available for 8 people with HD during the exercise. A 12 week gym and home walking exercise programme (n=13). People with HD achieved a lower work rate at nine minutes (82±42(0-195) v 107±35(50 -185) Watts (phealthy group and did not achieve a steady state HR during unloaded cycling. People with HD also demonstrated higher than expected lactate at three 2.5±2.5(1.1-8)mmo.L-1 and nine 3.8±1.9(1.2-6.6)mmo.L-1 minutes and respiratory exchange ratio at three 0.78±0.03 (0.74-0.81) and nine minutes 0.94±0.11(0.81-1.15). After exercise training there were no changes observed in HR or RPE responses during the exercise test. There was a large variability in the observed metabolic and physiological responses to exercise in people with HD. The observed exercise responses suggest that altered exercise prescription parameters may be required for people with HD and that exercise response and factors' affecting this requires further investigation. © The Author(s) 2014.

  7. Exercise stress testing. An overview of current guidelines.

    Science.gov (United States)

    Lear, S A; Brozic, A; Myers, J N; Ignaszewski, A

    1999-05-01

    Exercise stress testing (ET) is an inexpensive noninvasive tool that provides valuable cardiopulmonary information in healthy and diseased populations. It is most commonly used for diagnosing coronary artery disease (CAD) and developing appropriate exercise prescriptions (EP). With its widespread use and application, it is imperative that safe and appropriate guidelines and procedures are used, as there are a number of risks associated with testing in a population with or suspected of having CAD. The focus should be on the patient's safety: personnel must be properly trained and aware of all emergency procedures, contra-indications for ET and indications for test termination must be strictly adhered to. Three main types of testing are prevalent: submaximal, maximal and maximal utilising gas exchange. The maximal test is most commonly used, and the submaximal is appropriate for hospitalised patients. Gas exchange data is essential when assessing congestive heart failure and timing for heart transplantation. ET is commonly performed using a treadmill or a bicycle ergometer. The treadmill provides a more familiar exercise modality and has been shown to have greater diagnostic sensitivity than the bicycle ergometer; it is, however, more expensive and requires more space in the testing room. The bicycle ergometer is more appropriate for those individuals who are severely obese or have problems with extended periods of walking. Regardless of the modality used, an appropriate exercise protocol should be used. In North America, the Bruce protocol is the most common. However, the Bruce protocol, and others that estimate exercise capacity based on equations, tend to overestimate exercise capacity. They may be too demanding for those with limited exercise capacity, and too long for those with high exercise capacity. For these people, an exercise protocol that reaches maximal capacity in 8 to 12 minutes using smaller increments in workload should be considered. Once completed

  8. Exercise addiction

    DEFF Research Database (Denmark)

    Lichtenstein, Mia Beck; Christiansen, Erik; Elklit, Ask

    2014-01-01

    Exercise addiction is characterized by excessive exercise patterns with potential negative consequences such as overuse injuries. The aim of this study was to compare eating disorder symptoms, quality of life, personality traits and attachments styles in exercisers with and without indications...... of exercise addiction. A case-control study with 121 exercisers was conducted. The exercisers were categorized into an addiction group (n=41) or a control group (n=80) on the basis of their responses to the Exercise Addiction Inventory. The participants completed the Eating Disorder Inventory 2, the Short......-Form 36, the NEO Personality Inventory Revised and the Adult Attachment Scale. The addiction group scored higher on eating disorder symptoms, especially on perfectionism but not as high as eating disorder populations. The characteristic personality traits in the addiction group were high levels...

  9. Influence of shoes increasing dorsiflexion and decreasing metatarsus flexion on lower limb muscular activity during fitness exercises, walking, and running.

    Science.gov (United States)

    Bourgit, David; Millet, Guillaume Y; Fuchslocher, Jörg

    2008-05-01

    The aim of the present study was to compare electromyographic activity during fitness exercises, walking, and running among 3 different dorsiflexion shoes (+2 degrees , +4 degrees , and +10 degrees ) and standard shoes (-4 degrees ). The 3 different dorsiflexion shoes tested in this study have a curvature placed in the middle of the sole. This design was specially projected to decrease the metatarsus flexion. Electromyographic activity of 9 lower limb muscles was measured on 12 healthy female subjects during 5 fitness exercises (unload squat, side and front step, submaximal ballistic plantar flexion, and lunge exercise), and during running (10 km x h(-1)) and walking (4.5 km x h(-1)) on a treadmill. EMG signal was analyzed with the root mean square (RMS) and integrated EMG. All RMS data measured during these exercises were expressed as percentages of maximum voluntary isometric contraction. The results show that dorsiflexion affects muscle recruitment and reorganizes the motor pattern. The general tendency was that the tibialis anterior activity increased with dorsiflexion. However, an optimal dorsiflexion existed for various exercises. It is concluded that shoes with moderate dorsiflexion can activate lower limb muscles differently compared with both standard shoes and shoes with large dorsiflexion during submaximal exercises and locomotion.

  10. Use of post-exercise laryngoscopy to evaluate exercise induced dyspnea.

    LENUS (Irish Health Repository)

    McNally, P

    2010-10-01

    We present the case of a child with asthma who continued to have marked exercise induced dyspnea despite appropriate treatment, and in the face of adequate control of all other asthma symptoms. Spirometry showed a marked truncation of inspiratory flow, and laryngoscopy performed immediately after exercise showed laryngomalacia with dynamic, partial inspiratory obstruction. Exercise induced laryngomalacia (EIL) is a rare cause of exercise induced dyspnea which is diagnosed by post exercise flexible laryngoscopy and may require supraglottoplasty.

  11. Middle cerebral artery blood velocity and plasma catecholamines during exercise

    DEFF Research Database (Denmark)

    Pott, F; Jensen, K; Hansen, H

    1996-01-01

    During dynamic exercise, mean blood velocity (Vmean) in the middle cerebral artery (MCA) demonstrates a graded increase to work rate and reflects regional cerebral blood flow. At a high work rate, however, vasoactive levels of plasma catecholamines could mediate vasoconstriction of the MCA...... and thereby elevate Vmean at a given volume flow. To evaluate transcranial Doppler-determined Vmean at high plasma catecholamine levels, seven elite cyclists performed a maximal performance test on a bicycle ergometer. Results were compared with those elicited during five incremental exercise bouts and during...... rhythmic handgrip when plasma catecholamines are low. During rhythmic handgrip the Vmean was elevated by 21 +/- 3% (mean +/- SE), which was not statistically different from that established during moderate cycling. However, at the highest submaximal and maximal work intensities on the bicycle ergometer...

  12. Mesenteric, coeliac and splanchnic blood flow in humans during exercise

    DEFF Research Database (Denmark)

    Perko, M J; Nielsen, H B; Skak, C

    1998-01-01

    1. Exercise reduces splanchnic blood flow, but the mesenteric contribution to this response is uncertain. 2. In nineteen humans, superior mesenteric and coeliac artery flows were determined by duplex ultrasonography during fasting and postprandial submaximal cycling and compared with the splanchnic...... blood flow as assessed by the Indocyanine Green dye-elimination technique. 3. Cycling increased arterial pressure, heart rate and cardiac output, while it reduced total vascular resistance. These responses were not altered in the postprandial state. During fasting, cycling increased mesenteric, coeliac...... decreased by 51 and 31 % (0.49 +/- 0.07 and 0.96 +/- 0.28 l min-1). Splanchnic blood flow values assessed by duplex ultrasound and by dye-elimination techniques were correlated (r = 0.70; P exercise in humans, splanchnic resistance increases and blood flow is reduced following...

  13. Exercise-induced changes in hematocrit and hematocrit/viscosity ratio in male rugby players.

    Science.gov (United States)

    Varlet-Marie, Emmanuelle; Brun, Jean-Frédéric; Raynaud de Mauverger, Eric; Fédou, Christine

    2016-01-01

    We investigated whether the concept of hematocrit/viscosity (h/η) ratio explains the "paradox of hematocrit in athletes", by calculating a "theoretical optimal hematocrit" (i.e., associated with the higher h/η value predicted with Quemada's equation from plasma viscosity, and erythrocyte rigidity index) before and after exercise. 14 rugby players (19-31 yr; weight 65.8-109.2 kg; height 1.7-1.96 m; BMI 21.7-33.1 kg/m2) underwent a standardized submaximal exercise session on cycloergometer corresponding to 225 kjoules over 30 min. The rheologic response to exercise was measured with the MT90 viscometer and the Myrenne aggregometer. After exercise there was an increase in whole blood viscosity (p values of h/η and hematocrit by models may help to interpret the actual values of these parameters. However, these models need to be more extendedly tested and improved.

  14. Acute relief of exercise-induced bronchoconstriction by inhaled formoterol in children with persistent asthma

    DEFF Research Database (Denmark)

    Hermansen, Mette Northman; Nielsen, Kim Gjerum; Buchvald, Frederik

    2006-01-01

    -controlled, crossover study of the immediate effect of formoterol, 9 microg, vs terbutaline, 0.5 mg, and placebo administered as dry powder at different study days. Exercise challenge test was used as a model of acute bronchoconstriction. PATIENTS: Twenty-four 7- to 15-year-old children with persistent asthma....... INTERVENTIONS: The children performed standardized treadmill exercise tests, breathing dry air, with a submaximal workload. Study medication was administered 5 min after exercise if FEV1 dropped > or = 15% within 5 min after exercise. FEV1 and forced expiratory flows were measured repeatedly until 60 min after......% of the maximum increase for both. Median times to recovery within 5% of baseline FEV1 were 5.0 min and 7.4 min for formoterol and terbutaline, respectively (p = 0.33). CONCLUSION: Single-dose formoterol, 9 microg, via dry powder inhaler provided an acute bronchodilatory effect similar to terbutaline during EIB...

  15. What are the dietary protein requirements of physically active individuals? New evidence on the effects of exercise on protein utilization during post-exercise recovery.

    Science.gov (United States)

    Fielding, Roger A; Parkington, Jascha

    2002-01-01

    Exercise and physical activity increase energy expenditure up to 10-fold. This brief review will focus on the effect of exercise on protein requirements. Evidence has accumulated that amino acids are oxidized as substrates during prolonged submaximal exercise. In addition, studies have determined that both endurance and resistance training exercise increase skeletal muscle protein synthesis and breakdown in the post-exercise recovery period. Studies using nitrogen balance have further confirmed that protein requirements for individuals engaged in regular exercise are increased. The current recommended intakes of protein for strength and endurance athletes are 1.6 to 1.7 g/kg and 1.2 to 1.4 g/kg per day, respectively. Presently, most athletes consume an adequate amount of protein in their diet. The timing and nutritional content of the post-exercise meal, although often overlooked, are known to have synergistic effects on protein accretion after exercise. New evidence suggests that individuals engaging in strenuous activity consume a meal rich in amino acids and carbohydrate soon after the exercise bout or training session.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    Mailey, Emily L; White, Siobhan M; Wójcicki, Thomas R; Szabo, Amanda N; Kramer, Arthur F; McAuley, Edward

    2010-02-08

    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. 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. The multiple R for the regression equation was .72, p testing (r = 0.67). All three CRF indices were significantly and inversely associated with reporting more cardiovascular conditions. 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.

  18. Oxygen uptake kinetics of constant-load work - Upright vs. supine exercise

    Science.gov (United States)

    Convertino, V. A.; Goldwater, D. J.; Sandler, H.

    1984-01-01

    Supine and upright positions were used in a comparitive study of the effects of constant load exercise on oxygen uptake (VO2), O2 deficit, steady-state VO2 and VO2 following recovery from constant load work. Ten male subjects (36-40 yr.) performed one submaximal exercise test in the supine and one test in the upright position consisting of 5 min rest and 5 min cycle ergometer exercise at 700 kg/min followed by ten minutes of recovery. It is found that the significant difference in VO2 kinetics during exercise in the upright compared to supine position resulted from changes in oxygen transport and utilization mechanisms rather than changes in mechanical efficiency. To the extent that data measured in the supine position can be used to estimate physiological responses to zero gravity, it is suggested that limitation of systemic O2 consumption may be the result of slow rates of oxygen uptake during transient periods of muscular work. Significant reductions in the rate of steady-state VO2 attainment at submaximal work intensities may produce an onset of muscle fatigue and exhaustion.

  19. Assessment of muscle endurance of the knee extensor muscles in adolescents with spastic cerebral palsy using a submaximal repetitions-to-fatigue protocol.

    Science.gov (United States)

    Eken, Maaike M; Dallmeijer, Annet J; Doorenbosch, Caroline A; Dekkers, Hurnet; Becher, Jules G; Houdijk, Han

    2014-10-01

    To compare muscle endurance in adolescents with spastic cerebral palsy (CP) with typically developing (TD) peers using a submaximal repetitions-to-fatigue (RTF) protocol. Cross sectional. Human motion laboratory. Adolescents with spastic CP (n=16; Gross Motor Function Classification System levels I or II) and TD adolescents (n=18) within the age range of 12 to 19 years old. Not applicable. Each participant performed 3 RTF tests at different submaximal loads, ranging from 50% to 90% of their maximal voluntary knee extension torque. The relation between the number of repetitions (repetition maximum [RM]) and imposed submaximal relative (percent of maximal voluntary torque [%MVT]) and absolute (Nm/kg) torque was quantified. To compare adolescents with CP with TD adolescents, a mixed linear model was used to construct load endurance curves. Surface electromyography of quadriceps muscles was measured to assess changes in normalized amplitude and median frequency (MF) as physiological indicators of muscle fatigue. Adolescents with CP showed a larger decrease in %MVT per RM than TD adolescents (Pmuscles in all tests for both groups. Electromyographic MF decreased significantly (Pmuscle fatigue were reached. Adolescents with CP show slightly lower muscle endurance compared with TD adolescents on a submaximal RTF protocol, which is in contrast with earlier findings in a maximal voluntary fatigue protocol. Accordingly, adolescents with CP have a reduced capacity to endure activities at similar relative loads compared with TD adolescents. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  20. Prevention: Exercise

    Medline Plus

    Full Text Available ... Steroid Injections Lumbar Zygapophysical (Facet) Joint Injections PREVENTION Lifestyle Choices 10 Tips for a Healthy Back Smoking Weight Patient Safety Exercise Strengthening Strengthen ...

  1. Prevention: Exercise

    Medline Plus

    Full Text Available ... Exercises Electrothermal Modalities Ergonomic Changes Hydrotherapy Manual Therapy Physical Therapy Postural Training Traction Watchful Waiting and Education Injection Treatments for Spinal Pain Epidural Steroid Injections ...

  2. Effect of forced exercise and exercise withdrawal on memory, serum and hippocampal corticosterone levels in rats.

    Science.gov (United States)

    Radahmadi, Maryam; Alaei, Hojjatallah; Sharifi, Mohammad Reza; Hosseini, Nasrin

    2015-10-01

    Evidence suggests that there are positive effects of exercise on learning and memory. Moreover, some studies have demonstrated that forced exercise plays the role of a stressor. This study was aimed at investigating the effects of different timing of exercise and exercise withdrawal on memory, and serum and hippocampal corticosterone (CORT) levels. Wistar rats were randomly divided into five groups: control, sham, exercise-rest (exercise withdrawal), rest-exercise (exercised group), and exercise-exercise (continuous exercise). Rats were forced to run on a treadmill for 1 h/day at a speed 20-21-m/min. Memory function was evaluated by the passive avoidance test in different intervals (1, 7 and 21 days) after foot shock. Findings showed that after the exercise withdrawal, short-term and mid-term memories, had significant enhancement compared to the control group, while the long-term memory did not present this result. In addition, the serum and hippocampal CORT levels were at the basal levels after the rest period in the exercise-rest group. In the rest-exercise group, exercise improved mid- and long-term memories, whereas continuous exercise improved all types short-, mid- and long-term memories, particularly the mid-term memory. Twenty-one and forty-two days of exercise significantly decreased the serum and hippocampal CORT levels. It seems that exercise for at least 21 days with no rest could affect biochemical factors in the brain. Also, regular continuous exercise plays an important role in memory function. Hence, the duration and withdraw of exercise are important factors for the neurobiological aspects of the memory responses.

  3. Assessing a commercially available sports drink on exogenous carbohydrate oxidation, fluid delivery and sustained exercise performance.

    Science.gov (United States)

    Roberts, Justin D; Tarpey, Michael D; Kass, Lindsy S; Tarpey, Richard J; Roberts, Michael G

    2014-03-04

    Whilst exogenous carbohydrate oxidation (CHOEXO) is influenced by mono- and disaccharide combinations, debate exists whether such beverages enhance fluid delivery and exercise performance. Therefore, this study aimed to ascertain CHOEXO, fluid delivery and performance times of a commercially available maltodextrin/ fructose beverage in comparison to an isocaloric maltodextrin beverage and placebo. Fourteen club level cyclists (age: 31.79 ± 10.02 years; height: 1.79 ± 0.06 m; weight: 73.69 ± 9.24 kg; VO2max: 60.38 ± 9.36 mL · kg·-1 min-1) performed three trials involving 2.5 hours continuous exercise at 50% maximum power output (Wmax: 176.71 ± 25.92 W) followed by a 60 km cycling performance test. Throughout each trial, athletes were randomly assigned, in a double-blind manner, either: (1) 1.1 g · min-1 maltodextrin + 0.6 g · min-1 fructose (MD + F), (2) 1.7 g · min-1 of maltodextrin (MD) or (3) flavoured water (P). In addition, the test beverage at 60 minutes contained 5.0 g of deuterium oxide (2H2O) to assess quantification of fluid delivery. Expired air samples were analysed for CHOEXO according to the 13C/12C ratio method using gas chromatography continuous flow isotope ratio mass spectrometry. Peak CHOEXO was significantly greater in the final 30 minutes of submaximal exercise with MD + F and MD compared to P (1.45 ± 0.09 g · min-1, 1.07 ± 0.03 g · min-1and 0.00 ± 0.01 g · min-1 respectively, P Performance times significantly improved with MD + F compared with both MD (by 7 min 22 s ± 1 min 56 s, or 7.2%) and P (by 6 min 35 s ± 2 min 33 s, or 6.5%, P performance times.

  4. Effect of acute and regular exercise on antioxidative enzymes, tissue damage markers and membran lipid peroxidation of erythrocytes in sedentary students

    OpenAIRE

    Aslan, Recep

    2014-01-01

    15 healthy sedentary men, 19-25 years old an did not have any programmed physical activity, were studied. The subjects were asked to run submaximal 15-20 min every day for 5 weeks. Erythrocyte lipid peroxidation, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities and glucose and uric acid levels were determined in blood samples which were taken before and immediately after acute exercise and after the end of 5-week training program. Malonaldialdehyde (MDA), sing...

  5. Torque decrease during submaximal evoked contractions of the quadriceps muscle is linked not only to muscle fatigue.

    Science.gov (United States)

    Matkowski, Boris; Lepers, Romuald; Martin, Alain

    2015-05-01

    The aim of this study was to analyze the neuromuscular mechanisms involved in the torque decrease induced by submaximal electromyostimulation (EMS) of the quadriceps muscle. It was hypothesized that torque decrease after EMS would reflect the fatigability of the activated motor units (MUs), but also a reduction in the number of MUs recruited as a result of changes in axonal excitability threshold. Two experiments were performed on 20 men to analyze 1) the supramaximal twitch superimposed and evoked at rest during EMS (Experiment 1, n = 9) and 2) the twitch response and torque-frequency relation of the MUs activated by EMS (Experiment 2, n = 11). Torque loss was assessed by 15 EMS-evoked contractions (50 Hz; 6 s on/6 s off), elicited at a constant intensity that evoked 20% of the maximal voluntary contraction (MVC) torque. The same stimulation intensity delivered over the muscles was used to induce the torque-frequency relation and the single electrical pulse evoked after each EMS contraction (Experiment 2). In Experiment 1, supramaximal twitch was induced by femoral nerve stimulation. Torque decreased by ~60% during EMS-evoked contractions and by only ~18% during MVCs. This was accompanied by a rightward shift of the torque-frequency relation of MUs activated and an increase of the ratio between the superimposed and posttetanic maximal twitch evoked during EMS contraction. These findings suggest that the torque decrease observed during submaximal EMS-evoked contractions involved muscular mechanisms but also a reduction in the number of MUs recruited due to changes in axonal excitability. Copyright © 2015 the American Physiological Society.

  6. Effects of tiotropium on sympathetic activation during exercise in stable chronic obstructive pulmonary disease patients

    Directory of Open Access Journals (Sweden)

    Kitada S

    2012-05-01

    Full Text Available Kenji Yoshimura, Ryoji Maekura, Toru Hiraga, Seigo Kitada, Keisuke Miki, Mari Miki, Yoshitaka TateishiDepartment of Respiratory Medicine, Toneyama National Hospital, Osaka, JapanBackground: Tiotropium partially relieves exertional dyspnea and reduces the risk of congestive heart failure in chronic obstructive pulmonary disease (COPD patients. However, its effect on the sympathetic activation response to exercise is unknown.Aims: This study aimed to determine whether tiotropium use results in a sustained reduction in sympathetic activation during exercise.Methods: We conducted a 12-week, open-label (treatments: tiotropium 18 µg or oxitropium 0.2 mg × 3 mg, crossover study in 17 COPD patients. Treatment order was randomized across subjects. The subjects underwent a pulmonary function test and two modes of cardiopulmonary exercise (constant work rate and incremental exercise testing using a cycle ergometer, with measurement of arterial catecholamines after each treatment period.Results: Forced expiratory volume in 1 second and forced vital capacity were significantly larger in the tiotropium treatment group. In constant exercise testing, exercise endurance time was longer, with improvement in dyspnea during exercise and reduction in dynamic hyperinflation in the tiotropium treatment group. Similarly, in incremental exercise testing, exercise time, carbon dioxide production, and minute ventilation at peak exercise were significantly higher in the tiotropium treatment group. Plasma norepinephrine concentrations and dyspnea intensity were also lower during submaximal isotime exercise and throughout the incremental workload exercise in the tiotropium treatment group.Conclusion: Tiotropium suppressed the increase of sympathetic activation during exercise at the end of the 6-week treatment, as compared with the effect of oxipropium. This effect might be attributed to improvement in lung function and exercise capacity and reduction in exertional dyspnea

  7. Prevention: Exercise

    Medline Plus

    Full Text Available ... be done at home as well. Some specific core strengthening exercises are described below. If any of the following ... balls, you will experience more benefit from this exercise... Sagittal Core Strengthening You can stretch and strengthen the low ...

  8. Prevention: Exercise

    Medline Plus

    Full Text Available ... slow full movements. Repeat 10-15 times, to fatigue... Abdominal Exercise Lay on your back with both knees bent. ... Return leg and extend other leg. Repeat to fatigue, about 10-15 repetitions at a slow ... training is exercise done against something providing resistance. It can be ...

  9. Prevention: Exercise

    Medline Plus

    Full Text Available ... core strengthening, or building the muscles that provide support for your body. Pilates, yoga and martial arts all provide well-rounded core strengthening programs. Simple exercises can be done at home as well. Some specific core strengthening exercises are ...

  10. Cardiovascular adaptations in weightlessness: The influence of in-flight exercise programs on the cardiovascular adjustments during weightlessness and upon returning to Earth

    Science.gov (United States)

    Bennett, C. H.

    1981-01-01

    The effect of in-flight exercise programs on astronauts' cardiovascular adjustments during spaceflight weightlessness and upon return to Earth was studied. Physiological changes in muscle strength and volume, cardiovascular responses during the application of lower body negative pressure, and metabolic activities during pre-flight and flight tests were made on Skylab crewmembers. The successful completion of the Skylab missions showed that man can perform submaximal and maximal aerobic exercise in the weightless enviroment without detrimental trends in any of the physiologic data. Exercise tolerance during flight was unaffected. It was only after return to Earth that a tolerance decrement was noted. The rapid postflight recovery of orthostatic and exercise tolerance following two of the three Skylab missions appeared to be directly related to total in-flight exercise as well as to the graded, regular program of exercise performed during the postflight debriefing period.

  11. Cardiovascular responses in older adults with total knee arthroplasty at rest and with exercise on a positive pressure treadmill.

    Science.gov (United States)

    Webber, Sandra C; Horvey, Karla J; Yurach Pikaluk, Madison T; Butcher, Scott J

    2014-03-01

    We investigated cardiovascular responses at rest and during submaximal exercise on a lower body positive pressure treadmill in older adults with total knee arthroplasty (TKA). Twenty-four adults (mean age 64.6 ± 7.9 SD) with unilateral TKA participated (median time since surgery 8.0 weeks). Heart rate and blood pressure responses were measured at rest standing on the positive pressure treadmill with 0, 10, 20, and 30 mmHg applied. Heart rate, blood pressure, oxygen consumption, minute ventilation, knee pain and perceived exertion were measured during submaximal exercise tests (0 and 40% body weight support) conducted 1 week apart. At rest there were no differences in blood pressure across different treadmill pressures, but heart rate was significantly lower when 30 mmHg was applied compared to ambient pressure conditions (P exercise test stages with 0% body weight support (maximum speed 2.5 mph, 0% incline) and 6.4 stages with 40% body weight support (maximum speed 3.0 mph, 10% incline). During exercise, heart rate, systolic blood pressure, oxygen consumption, and minute ventilation were lower when 40% body weight support was provided for a given test stage (P exercise test stages (P < 0.05). Provision of body weight support allowed TKA patients to walk at faster speeds and/or to tolerate greater incline with relatively lower levels of heart rate, blood pressure, and oxygen consumption.

  12. Transcutaneous electrical nerve stimulation reduces exercise-induced perceived pain and improves endurance exercise performance.

    Science.gov (United States)

    Astokorki, Ali H Y; Mauger, Alexis R

    2017-03-01

    Muscle pain is a natural consequence of intense and prolonged exercise and has been suggested to be a limiter of performance. Transcutaneous electrical nerve stimulation (TENS) and interferential current (IFC) have been shown to reduce both chronic and acute pain in a variety of conditions. This study sought to ascertain whether TENS and IFC could reduce exercise-induced pain (EIP) and whether this would affect exercise performance. It was hypothesised that TENS and IFC would reduce EIP and result in an improved exercise performance. In two parts, 18 (Part I) and 22 (Part II) healthy male and female participants completed an isometric contraction of the dominant bicep until exhaustion (Part I) and a 16.1 km cycling time trial as quickly as they could (Part II) whilst receiving TENS, IFC, and a SHAM placebo in a repeated measures, randomised cross-over, and placebo-controlled design. Perceived EIP was recorded in both tasks using a validated subjective scale. In Part I, TENS significantly reduced perceived EIP (mean reduction of 12%) during the isometric contraction (P = 0.006) and significantly improved participants' time to exhaustion by a mean of 38% (P = 0.02). In Part II, TENS significantly improved (P = 0.003) participants' time trial completion time (~2% improvement) through an increased mean power output. These findings demonstrate that TENS can attenuate perceived EIP in a healthy population and that doing so significantly improves endurance performance in both submaximal isometric single limb exercise and whole-body dynamic exercise.

  13. DIURNAL VARIATION OF HAEMOSTATIC RESPONSE TO EXERCISE IN YOUNG SEDENTARY MALES

    Directory of Open Access Journals (Sweden)

    Marefat Siahkouhian

    2013-04-01

    Full Text Available The aim of this study was to evaluate diurnal variations in the haemostatic response to submaximal exercise performed by young, sedentary men. Fifteen healthy young sedentary males aged 25.6 ± 1.34 (mean ± SD years performed two exercise sessions, morning and evening, at 70�0of maximal oxygen consumption (VO2max on a cycle ergometer for 30 min. Platelet count (PC, activated partial thromboplastin time (aPTT, prothrombin time (PT, fibrinogen, tissue plasminogen activator (tPA and plasminogen activator inhibitor-1 (PAI-1 activity were measured as dependent variables. Exercise produced significant increases in PC and fibrinogen for both sessions (P≤0.05, which returned to the resting values after recovery only in the evening session. APTT and PT shortened immediately after exercise, which remained after recovery for both sessions (P≤0.01. Exercise presented significant increases in tPA activity (P≤0.001, which returned to the baseline after recovery in both exercises. PAI-1 activity was significantly higher during the morning than evening (P≤0.05, but no longer demonstrated exercise-related changes. It was found that exercise caused activation of both coagulation and fibrinolysis processes, partly related to the time of the day when the exercise was performed.

  14. Diurnal variation of haemostatic response to exercise in young sedentary males.

    Science.gov (United States)

    Siahkouhian, M; Khodadadi, D; Bolboli, L

    2013-06-01

    The aim of this study was to evaluate diurnal variations in the haemostatic response to submaximal exercise performed by young, sedentary men. Fifteen healthy young sedentary males aged 25.6 ± 1.34 (mean ± SD) years performed two exercise sessions, morning and evening, at 70% of maximal oxygen consumption ([Formula: see text]O2max) on a cycle ergometer for 30 min. Platelet count (PC), activated partial thromboplastin time (aPTT), prothrombin time (PT), fibrinogen, tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) activity were measured as dependent variables. Exercise produced significant increases in PC and fibrinogen for both sessions (P ≤ 0.05), which returned to the resting values after recovery only in the evening session. APTT and PT shortened immediately after exercise, which remained after recovery for both sessions (P ≤ 0.01). Exercise presented significant increases in tPA activity (P ≤ 0.001), which returned to the baseline after recovery in both exercises. PAI-1 activity was significantly higher during the morning than evening (P ≤ 0.05), but no longer demonstrated exercise-related changes. It was found that exercise caused activation of both coagulation and fibrinolysis processes, partly related to the time of the day when the exercise was performed.

  15. The effect of 1 year of Alagebrium and moderate-intensity exercise training on left ventricular function during exercise in seniors: a randomized controlled trial.

    Science.gov (United States)

    Carrick-Ranson, Graeme; Fujimoto, Naoki; Shafer, Keri M; Hastings, Jeffrey L; Shibata, Shigeki; Palmer, M Dean; Boyd, Kara; Levine, Benjamin D

    2016-08-01

    Sedentary aging leads to left ventricular (LV) and vascular stiffening due in part to advanced glycation end-products (AGEs) cross-linking of extracellular matrix proteins. Vigorous lifelong exercise ameliorates age-related cardiovascular (CV) stiffening and enhances exercise LV function, although this effect is limited when exercise is initiated later in life. We hypothesized that exercise training might be more effective at improving the impact of age-related CV stiffening during exercise when combined with an AGE cross-link breaker (Alagebrium). Sixty-two seniors (≥60 yr) were randomized into four groups: sedentary + placebo, sedentary + Alagebrium, exercise + placebo, and exercise + Alagebrium for 1 yr. Moderate-intensity aerobic exercise was performed 3-4 sessions/wk; controls underwent similar frequency of yoga/balance training. Twenty-four similarly-aged, lifelong exercisers (4-5 sessions/wk) served as a comparator for the effect of lifelong exercise on exercising LV function. Oxygen uptake (Douglas bags), stroke index (SI; acetylene rebreathing), and effective arterial elastance (Ea) were collected at rest and submaximal and maximal exercise. Maximum O2 uptake (23 ± 5 to 25 ± 6 ml·kg(-1)·min(-1)) increased, while SI (35 ± 11 to 39 ± 12 ml/m(2)) and Ea (4.0 ± 1.1 to 3.7 ± 1.2 mmHg·ml(-1)·m(-2)) were improved across all conditions with exercise, but remained unchanged in controls (exercise × time, P ≤ 0.018). SI or Ea were not affected by Alagebrium (medication × time, P ≥ 0.468) or its combination with exercise (interaction P ≥ 0.252). After 1 yr of exercise plus Alagebrium, exercise SI and Ea remained substantially below that of lifelong exercisers (15-24 and 9-22%, respectively, P ≤ 0.415). In conclusion, Alagebrium plus exercise had no synergistic effect on exercise LV function and failed to achieve levels associated with lifelong exercise, despite a similar exercise frequency.

  16. Equine sweat composition: effects of adrenaline infusion, exercise and training.

    Science.gov (United States)

    McConaghy, F F; Hodgson, D R; Evans, D L; Rose, R J

    1995-11-01

    Significant alterations in plasma electrolyte concentrations have been reported in horses following prolonged exercise, resulting from loss of hypertonic sweat. Sweat was collected from 10 horses undergoing a 10 week training programme; 5 at moderate intensity, to speeds of 10 m/s and 5 at low intensity, to speeds of 5 m/s. Sweat was collected from 2 sites in response to a submaximal exercise test (30 min at 50% VO2max and during an adrenaline infusion (dose mean +/- s.d.; 0.3 +/- 0.05 g/kg over 30 min). Sweat samples were analysed for sodium, chloride, potassium, protein, magnesium, calcium and urea concentrations. Sweat produced in response to exercise and adrenaline infusion was hypertonic and showed no significant differences in composition following training. However, the [NaCl] of sweat rose with increased duration of sweating. Sweat produced in response to adrenaline infusion was more dilute than that produced in response to exercise, which may be related to sympathetic outflow during exercise.

  17. Nitrate Supplementation, Exercise, and Kidney Function: Are There Detrimental Effects?

    Science.gov (United States)

    Carpentier, Alain; Stragier, Séverine; Bréjeon, Camille; Poortmans, Jacques R

    2015-07-01

    Recently, dietary supplementation with inorganic nitrate (NO3) has been proposed to endurance athletes to increase their performance. However, it has been suggested that an excess of NO3 might be harmful. The present study analyzed the effect of NO3 supplementation on kidney function. Thirteen young male subjects performed a 20-min cycling exercise at 85% of the maximal oxygen capacity. Seven days before exercise, the subjects ingested either a placebo (Pl) or 450 mg of potassium nitrate (PN) per day. Venous blood samples and urine collections were collected before and immediately after exercise and after 60 min of recovery. Glomerular filtration rates (GFR) and clearances (Cl) were calculated from serum content and urine output for creatinine (Crn), albumin (Alb), and urea. Under resting conditions, GFR and all clearance measures did not differ between Pl and PN. Immediately after exercise, GFR remained stable in both Pl and PN, whereas Cl-urea decreased significantly (P urea returned to initial values in placebo and nitrate supplementation. Alb output and Cl-Alb remained enhanced under PN conditions. These results mainly indicate that dietary nitrate supplementation over a week does not induce any specific kidney function modifications either at rest or during sustained submaximal exercise as compared with Pl.

  18. Cold exposure increases exercise-induced oxidative stress.

    Science.gov (United States)

    Martarelli, D; Cocchioni, M; Scuri, S; Spataro, A; Pompei, P

    2011-06-01

    We determined the combined effects of cold and exercise on oxidative stress during submaximal exercise. Sixteen amateur male cyclists pedaled at a constant speed corresponding to 85% of maximal HR as determined in normal conditions. Eight athletes pedaled indoors at 23 °C while 8 athletes pedaled outdoors at a temperature of 4-6 °C. We then evaluated the levels of reactive oxygen metabolites and plasma levels of antioxidants after exercise. Performing a physical task in cold conditions increased the free radical production, as demonstrated by the augmented levels of reactive oxygen metabolites and the concomitant decrease of plasma levels of antioxidants in outdoors cyclists as compared to indoors cyclists. The overall ANOVA and the post-hoc comparisons revealed a significant exercise and temperature effect. The mean level of reactive oxygen metabolites in athletes who exercised indoors was significantly lower than that of the outdoor athletes. Moreover, the outdoors group presented plasma levels of antioxidants significantly lower than those of the indoors group. Since several sports are performed outdoors during the winter season, the increased risk of oxidative stress in cold conditions must be considered in these disciplines. Cyclists, football and rugby players, and runners are all affected by the elevation in oxygen radicals induced by cold and should take appropriate precautions, such as specific antioxidant integration.

  19. Influence of Dietary Acid Load on Exercise Performance.

    Science.gov (United States)

    Applegate, Catherine; Mueller, Mackenzie; Zuniga, Krystle E

    2017-06-01

    Diet composition can affect systemic pH and acid-base regulation, which may in turn influence exercise performance. An acidic environment in the muscle impairs performance and contributes to fatigue; therefore, current trends in sports nutrition place importance on maximizing the alkalinity of the body with ergogenic aids and dietary strategies. This review examines the evidence on the effects of dietary manipulations on acid load and exercise performance. Ten studies that investigated the effect of high versus low dietary acid loads on athletic performance generally identified that low dietary acid loads increased plasma pH, but did not consistently improve exercise performance at maximal or submaximal exercise intensities. In addition, the few studies conducted have several limitations including lack of female subjects and use of exercise tests exclusive to cycling or treadmill running. Although the research does not strongly support a performance benefit from low dietary acid loads, a more alkaline dietary pattern may be beneficial for overall health, as dietary induced acidosis has been associated with greater risk of cardiovascular disease and bone disease. The review includes dietary recommendations for athletes to reduce dietary acid load while still meeting sports nutrition recommendations.

  20. Variação da pressão intraocular após teste submáximo de força no treinamento resistido Intraocular pressure variation after submaximal strength test in resistance training

    Directory of Open Access Journals (Sweden)

    Marcelo Conte

    2009-06-01

    Full Text Available OBJETIVO: Verificar a variação da pressão intraocular (PIO decorrente da aplicação do teste de predição para uma repetição máxima (1RM. MÉTODOS: Foram avaliados em estudo observacional 145 calouros (22,04 ± 4,17 anos; de ambos os sexos do curso de Educação Física da Escola Superior de Educação Física de Jundiaí (ESEFJ. Os critérios de exclusão foram: opacidade de meios, alteração de globo ocular ou ausência de globo ocular. Todos os participantes assinaram o Termo de Consentimento Livre e Esclarecido. A avaliação da PIO foi determinada por duas medidas consecutivas com o tonômetro de Perkins: i pré-teste: antes do teste de 1RM e ii pós-teste: logo após a realização do teste. O teste de 1RM consistiu em predizer o valor de uma repetição máxima através de repetições até a fadiga. Foram utilizados os seguintes exercícios resistidos: supino, pulley dorsal, desenvolvimento, rosca direta e leg press 45º. Como procedimento estatístico foi empregado o teste "t" de Student pareado. RESULTADOS: Ocorreu redução da PIO após a realização do teste de predição de 1RM: 13,48 ± 3,32 vs.10,20 ± 3,72 mmHg (pPURPOSE: To verify the intraocular pressure (IOP after sub-maximal strength test. METHODS: 145 Physical Education freshmen (22.04 ± 4.17 years old; female and male from Superior Physical Education School of Jundiaí (ESEFJ were evaluated in an observacional study. The exclusion criteria were: media opacity and eyeball absence or changes. All subjects agreed to take part in this research and signed up the Informed Consent. IOP was measured by Perkins tonometer: i pretest: just before the submaximal strength test performance and ii post-test: immediately after the strength test. The strength test consisted in the one-repetition-maximum-assessment through repetition until fatigue. Resistance training exercises such as bench press, pulley dorsal high, shoulder press, arm curl and leg press 45º were performed

  1. Effects of leg strength and bicycle ergometry exercise on cardiovascular deconditioning after 30-day head-down bed rest

    Science.gov (United States)

    Wu, Bin; Liu, Yusheng; Sun, Hongyi; Zhao, Dongming; Wang, Yue; Wu, Ping; Ni, Chengzhi

    2010-10-01

    The purpose of this study is to determine if the intermittent leg muscular strength exercise and bicycle ergometry exercise could attenuate cardiovascular deconditioning induced by prolonged -6° head-down bed rest (HDBR). Fifteen male subjects were randomly allocated into group A ( n=5, 30 days HDBR without exercise), group B ( n=5, 30 days HDBR with leg muscular strength exercise) and group C ( n=5, 30 days HDBR with bicycle ergometry exercise). The orthostatic tolerance (OT) was determined by +75°/20 min head-up tilt (HUT) test and the submaximal exercise capacity was determined by bicycle ergometry before and after HDBR. The results were as follows: (1) Compared with that before HDBR, OT time decreased dramatically by 57.6% ( pexercise time decreased significantly by 17.7% ( p0.77) in group C. (3) compared with that before HDBR, the changes of heart rate (HR) and blood pressure were slightly improved in group B and C, while deteriorated in group A during orthostatic test and exercise test after HDBR. The results indicate that leg muscular strength exercise and bicycle ergometry exercise could partially attenuate the cardiovascular deconditioning induced by 30 d HDBR, and the latter exercise training could fully provide the protection for the loss of exercise capacity.

  2. Exercise in Pregnancy: Guidelines.

    Science.gov (United States)

    Artal, Raul

    2016-09-01

    In recent years it has been recognized that in all phases of life, including pregnancy, physical activity promotes health benefits and precludes comorbidities, the scientific evidence is indisputable. Several organizations around the world have updated in recent years the guidelines and recommendations for exercise in pregnancy. The December 2015, updated guidelines of the American College of Obstetricians and Gynecologists emphasize that physical activity in pregnancy has minimal risk. Although recommending exercise in pregnancy, the anatomic/physiological changes, absolute and relative contraindications should be considered. Women who exercised regularly before pregnancy, in the absence of contraindications, can continue and engage in moderate to strenuous activities, although information on strenuous activities in pregnancy is still limited. This review summarizes the most recent published and recommended guidelines.

  3. Rotator Cuff Exercises

    Science.gov (United States)

    ... Home Prevention and Wellness Exercise and Fitness Injury Rehabilitation Rotator Cuff Exercises Rotator Cuff Exercises Share Print Rotator Cuff ... Best Rotator Cuff ExercisesNational Institutes of Health: MedlinePlus, ... and WellnessTags: Exercise Prescription, prevention, Shoulder Problems, ...

  4. Exercise and Posture

    Science.gov (United States)

    ... About Spondylitis › Treatment Information › Exercise & Posture Print Page Exercise Exercise is an integral part of any spondylitis ... For First Responders For Chiropractors Research Article Archive Exercise Guidelines Having an exercise program that accomplishes your ...

  5. Humanized animal exercise model for clinical implication.

    Science.gov (United States)

    Seo, Dae Yun; Lee, Sung Ryul; Kim, Nari; Ko, Kyung Soo; Rhee, Byoung Doo; Han, Jin

    2014-09-01

    Exercise and physical activity function as a patho-physiological process that can prevent, manage, and regulate numerous chronic conditions, including metabolic syndrome and age-related sarcopenia. Because of research ethics and technical difficulties in humans, exercise models using animals are requisite for the future development of exercise mimetics to treat such abnormalities. Moreover, the beneficial or adverse outcomes of a new regime or exercise intervention in the treatment of a specific condition should be tested prior to implementation in a clinical setting. In rodents, treadmill running (or swimming) and ladder climbing are widely used as aerobic and anaerobic exercise models, respectively. However, exercise models are not limited to these types. Indeed, there are no golden standard exercise modes or protocols for managing or improving health status since the types (aerobic vs. anaerobic), time (morning vs. evening), and duration (continuous vs. acute bouts) of exercise are the critical determinants for achieving expected beneficial effects. To provide insight into the understanding of exercise and exercise physiology, we have summarized current animal exercise models largely based on aerobic and anaerobic criteria. Additionally, specialized exercise models that have been developed for testing the effect of exercise on specific physiological conditions are presented. Finally, we provide suggestions and/or considerations for developing a new regime for an exercise model.

  6. Comparison of cardiovascular adaptations to long-term arm and leg exercise in wheelchair athletes versus long-distance runners.

    Science.gov (United States)

    Price, D T; Davidoff, R; Balady, G J

    2000-04-15

    The effect of long-term arm exercise on cardiac morphology and function is unknown. To study these effects, highly trained wheelchair athletes were compared with long-distance runners and controls. In addition, the wheelchair athletes were compared with the long-distance runners to determine if long-term leg exercise confers a training effect during the performance of dynamic arm exercise. The study included 31 male subjects (mean age of 33+/-5 years), who comprised 3 groups matched for age and weight: wheelchair athletes (n = 9), long-distance runners (n = 12), and healthy controls (n = 10). All underwent echocardiography at rest and arm ergometry exercise testing with expiratory gas analysis. The peak work rate during arm exercise was highest among the wheelchair athletes, and was significantly higher in both groups of trained athletes compared with the control group (pRunners demonstrated a significantly lower submaximal heart rate response to arm exercise compared with wheelchair and control subjects. Wheelchair athletes had increased left ventricular (LV) volume and mass by echocardiography compared with controls, but not to the same degree as that of runners. Although chamber dimensions and wall thickness did not differ among the groups, the LV volume index tended to be largest in the runners. Doppler indexes of diastolic LV filling were similar between the trained and untrained subjects. These data demonstrate that both long-term arm and leg exercise yield increases in LV volume and mass compared with untrained control subjects, although to a lesser degree in arm-trained athletes. Runners demonstrated a transfer of training effect in the performance of dynamic arm exercise, as demonstrated by their ability to achieve a higher peak work rate than controls, and showed a lower heart rate response to submaximal exercise than the wheelchair athletes and control subjects.

  7. Crew Exercise

    Science.gov (United States)

    Rafalik, Kerrie K.

    2017-01-01

    Johnson Space Center (JSC) provides research, engineering, development, integration, and testing of hardware and software technologies for exercise systems applications in support of human spaceflight. This includes sustaining the current suite of on-orbit exercise devices by reducing maintenance, addressing obsolescence, and increasing reliability through creative engineering solutions. Advanced exercise systems technology development efforts focus on the sustainment of crew's physical condition beyond Low Earth Orbit for extended mission durations with significantly reduced mass, volume, and power consumption when compared to the ISS.

  8. Exercise, an Active Lifestyle, and Obesity. Making the Exercise Prescription Work.

    Science.gov (United States)

    Andersen, Ross E.

    1999-01-01

    An active lifestyle is important in helping overweight people both lose and manage their weight. Exercise has many health benefits beyond weight control. The traditional exercise prescription of regular bouts of continuous vigorous exercise may need modification to increase rates of adoption and compliance, with people needing encouragement to…

  9. Prevention: Exercise

    Medline Plus

    Full Text Available ... Choices 10 Tips for a Healthy Back Smoking Weight Patient Safety Exercise Strengthening Strengthen Your Core! Stretching/ ... something providing resistance. It can be done with weights (hand-held or training machines) or using isometric ...

  10. Prevention: Exercise