scholarly journals Postexercise cooling interventions and the effects on exercise-induced heat stress in a temperate environment

2012 ◽  
Vol 37 (5) ◽  
pp. 965-975 ◽  
Author(s):  
Christophe Hausswirth ◽  
Rob Duffield ◽  
Hervé Pournot ◽  
François Bieuzen ◽  
Julien Louis ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Passive Control ◽  
Minute Ventilation ◽  
Water Immersion ◽  
Thermal Strain ◽  
Exercise Bout ◽  
Endurance Cycling ◽  
Temperate Environment ◽  
Cooling Jacket ◽  
Exercise Induced

The aim of this study was to examine the effects of cool water immersion (20 °C; CWI) while wearing a cooling jacket (Cryovest;V) and a passive control (PAS) as recovery methods on physiological and thermoregulatory responses between 2 exercise bouts in temperate conditions. Nine well-trained male cyclists performed 2 successive bouts of 45 min of endurance cycling exercise in a temperate environment (20 °C) separated by 25 min of the respective recovery interventions. Capillary blood samples were obtained to measure lactate (La–), sodium (Na+), bicarbonate (HCO3–) concentrations and pH, whilst body mass loss (BML), core temperature (Tcore), skin temperature (Tskin), heart rate (HR), oxygen uptake , and minute ventilation were measured before (Pre), immediately after the first exercise bout (Ex1), the recovery (R), and after the second exercise bout (Ex2). V and CWI both resulted in a reduction of Tskin at R (–2.1 ± 0.01 °C and –11.6 ± 0.01 °C, respectively, p < 0.01). Despite no difference in final values post-Ex2 (p > 0.05), V attenuated the rise in HR, minute ventilation, and oxygen uptake from Ex1 to Ex2, while Tcore and Tskin were significantly lower following the second session (p < 0.05). Further, CWI was also beneficial in lowering Tcore, Tskin, and BML, while a rise in Na+ was observed following Ex2 (p < 0.05). Overall results indicate that cooling interventions (V and CWI) following exercise in a temperate environment provide a reduction in thermal strain during ensuing exercise bouts.

scholarly journals A systematic upregulation of nuclear and mitochondrial genes is not present in the initial postexercise recovery period in human skeletal muscle

2017 ◽  
Vol 42 (6) ◽  
pp. 571-578 ◽  
Author(s):  
Trisha D. Scribbans ◽  
Brittany A. Edgett ◽  
Jacob T. Bonafiglia ◽  
Brittany L. Baechler ◽  
Joe Quadrilatero ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Messenger Rna ◽  
Acute Exercise ◽  
Recovery Period ◽  
Exercise Bout ◽  
Peak Oxygen Uptake ◽  
Peroxisome Proliferator ◽  
Glycogen Depletion ◽  
Peroxisome Proliferator Activated Receptor ◽  
Exercise Induced

The purpose of the current investigation was to determine if an exercise-mediated upregulation of nuclear and mitochondrial-encoded genes targeted by the transcriptional co-activator peroxisome-proliferator-activated receptor gamma co-activator-1 alpha (PGC-1α) occurs in a systematic manner following different exercise intensities in humans. Ten recreationally active males (age: 23 ± 3 years; peak oxygen uptake: 41.8 ± 6.6 mL·kg−1·min−1) completed 2 acute bouts of work-matched interval exercise at ∼73% (low; LO) and ∼100% (high; HI) of work rate at peak oxygen uptake in a randomized crossover design. Muscle biopsies were taken before, immediately after, and 3 h into recovery following each exercise bout. A main effect of time (p < 0.05) was observed for glycogen depletion. PGC-1α messenger RNA (mRNA) increased following both conditions and was significantly (p < 0.05) higher following HI compared with LO (PGC-1α, LO: +442% vs. HI: +845%). PDK4 mRNA increased following LO whereas PPARα, NRF1, and CS increased following HI. However, a systematic upregulation of nuclear and mitochondrial-encoded genes was not present as TFAM, COXIV, COXI, COXII, ND1, and ND4 mRNA were unchanged. However, changes in COXI, COXII, ND1 and ND4 mRNA were positively correlated following LO and COXI, ND1, and ND4 were positively correlated following HI, which suggests mitochondrial-encoded gene expression was coordinated. PGC-1α and ND4 mRNA, as well as PGC-1α mRNA and the change in muscle glycogen, were positively correlated in response to LO. The lack of observed systematic upregulation of nuclear- and mitochondrial-encoded genes suggests that exercise-induced upregulation of PGC-1α targets are differentially regulated during the initial hours following acute exercise in humans.

Effect of initial core temperature on hyperthermic hyperventilation during prolonged submaximal exercise in the heat

2012 ◽  
Vol 302 (1) ◽  
pp. R94-R102 ◽  
Author(s):  
Bun Tsuji ◽  
Yasushi Honda ◽  
Naoto Fujii ◽  
Narihiko Kondo ◽  
Takeshi Nishiyasu
Keyword(s):  
Relative Humidity ◽  
Oxygen Uptake ◽  
Core Temperature ◽  
Minute Ventilation ◽  
Water Immersion ◽  
Peak Oxygen Uptake ◽  
Submaximal Exercise ◽  
Temperature Threshold ◽  
Esophageal Temperature ◽  
Male Subjects

We investigated whether a core temperature threshold for hyperthermic hyperventilation is seen during prolonged submaximal exercise in the heat when core temperature before the exercise is reduced and whether the evoked hyperventilatory response is affected by altering the initial core temperature. Ten male subjects performed three exercise trials at 50% of peak oxygen uptake in the heat (37°C and 50% relative humidity) after altering their initial esophageal temperature (Tes). Initial Tes was manipulated by immersion for 25 min in water at 18°C (Precooling), 35°C (Control), or 40°C (Preheating). Tes after the water immersion was significantly higher in the Preheating trial (37.5 ± 0.3°C) and lower in the Precooling trial (36.1 ± 0.3°C) than in the Control trial (36.9 ± 0.3°C). In the Precooling trial, minute ventilation (V̇e) showed little change until Tes reached 37.1 ± 0.4°C. Above this core temperature threshold, V̇e increased linearly in proportion to increasing Tes. In the Control trial, V̇e increased as Tes increased from 37.0°C to 38.6°C after the onset of exercise. In the Preheating trial, V̇e increased from the initially elevated levels of Tes (from 37.6 to 38.6°C) and V̇e. The sensitivity of V̇e to increasing Tes above the threshold for hyperventilation (the slope of the Tes-V̇e relation) did not significantly vary across trials (Precooling trial = 10.6 ± 5.9, Control trial = 8.7 ± 5.1, and Preheating trial = 9.2 ± 6.9 L·min−1·°C−1). These results suggest that during prolonged submaximal exercise at a constant workload in humans, there is a clear core temperature threshold for hyperthermic hyperventilation and that the evoked hyperventilatory response is unaffected by altering initial core temperature.

scholarly journals Special Training of Inspiratory Muscles in Fitness Activities and Exercise Capacity in Young Women

2017 ◽  
Vol 18 (3) ◽  
Author(s):  
Viktor Mishchenko ◽  
Stanislaw Sawczyn ◽  
Agnieszka Cybulska ◽  
Marcin Pasek
Keyword(s):  
Oxygen Uptake ◽  
Exercise Capacity ◽  
Young Women ◽  
Vital Capacity ◽  
Perceived Exertion ◽  
Minute Ventilation ◽  
Work Capacity ◽  
Control Group ◽  
Inspiratory Muscles ◽  
Fitness Training

AbstractPurpose. The aim of the study was to determine if an 8-week-long endurance fitness training with elastic belts would increase the strength-endurance of the inspiratory muscles and lung function characteristics, and to assess whether these changes were consistent with an increase in aerobic power and exercise capacity in healthy young women. Methods. Twenty-two females aged 20-25 years were randomly allocated into 2 groups. The experimental group preformed 8-week-long exercises on stationary bikes with an elastic belt on the lower part of the chest. The control group underwent the same workout, without elastic belts. Vital capacity, forced vital capacity, maximal voluntary ventilation, maximal inspiratory and expiratory pressure, sustained maximal inspiratory pressure, physical activity status, and perceived exertion scores were measured. In the incremental exercise test, work capacity and maximal oxygen uptake were assessed. Tidal volume, minute ventilation (VE), oxygen uptake (VO

scholarly journals Hormone therapy attenuates exercise-induced skeletal muscle damage in postmenopausal women

2009 ◽  
Vol 107 (3) ◽  
pp. 853-858 ◽  
Author(s):  
Christina M. Dieli-Conwright ◽  
Tanya M. Spektor ◽  
Judd C. Rice ◽  
E. Todd Schroeder
Keyword(s):  
Skeletal Muscle ◽  
Hormone Therapy ◽  
Mrna Expression ◽  
Postmenopausal Women ◽  
Muscle Damage ◽  
Exercise Bout ◽  
Control Group ◽  
Skeletal Muscle Damage ◽  
Tnf Α ◽  
Exercise Induced

Hormone therapy (HT) is a potential treatment to relieve symptoms of menopause and prevent the onset of disease such as osteoporosis in postmenopausal women. We evaluated changes in markers of exercise-induced skeletal muscle damage and inflammation [serum creatine kinase (CK), serum lactate dehydrogenase (LDH), and skeletal muscle mRNA expression of IL-6, IL-8, IL-15, and TNF-α] in postmenopausal women after a high-intensity resistance exercise bout. Fourteen postmenopausal women were divided into two groups: women not using HT (control; n = 6, 59 ± 4 yr, 63 ± 17 kg) and women using traditional HT (HT; n = 8, 59 ± 4 yr, 89 ± 24 kg). Both groups performed 10 sets of 10 maximal eccentric repetitions of single-leg extension on the Cybex dynamometer at 60°/s with 20-s rest periods between sets. Muscle biopsies of the vastus lateralis were obtained from the exercised leg at baseline and 4 h after the exercise bout. Gene expression was determined by RT-PCR for IL-6, IL-8, IL-15, and TNF-α. Blood draws were performed at baseline and 3 days after exercise to measure CK and LDH. Independent t-tests were performed to test group differences (control vs. HT). A probability level of P ≤ 0.05 was used to determine statistical significance. We observed significantly greater changes in mRNA expression of IL-6, IL-8, IL-15, and TNF-α ( P ≤ 0.01) in the control group compared with the HT group after the exercise bout. CK and LDH levels were significantly greater after exercise ( P ≤ 0.01) in the control group. Postmenopausal women not using HT experienced greater muscle damage after maximal eccentric exercise, indicating a possible protective effect of HT against exercise-induced skeletal muscle damage.

scholarly journals Resistance training reduces the acute exercise-induced increase in muscle protein turnover

1999 ◽  
Vol 276 (1) ◽  
pp. E118-E124 ◽  
Author(s):  
S. M. Phillips ◽  
K. D. Tipton ◽  
A. A. Ferrando ◽  
R. R. Wolfe
Keyword(s):  
Resistance Training ◽  
Resistance Exercise ◽  
Acute Exercise ◽  
Muscle Protein ◽  
Exercise Bout ◽  
Muscle Contractions ◽  
Breakdown Rates ◽  
Single Bout ◽  
Fractional Synthesis ◽  
Exercise Induced

We examined the effect of resistance training on the response of mixed muscle protein fractional synthesis (FSR) and breakdown rates (FBR) by use of primed constant infusions of [2H5]phenylalanine and [15N]phenylalanine, respectively, to an isolated bout of pleiometric resistance exercise. Trained subjects, who were performing regular resistance exercise (trained, T; n = 6), were compared with sedentary, untrained controls (untrained, UT; n = 6). The exercise test consisted of 10 sets (8 repetitions per set) of single-leg knee flexion (i.e., pleiometric muscle contraction during lowering) at 120% of the subjects’ predetermined single-leg 1 repetition maximum. Subjects exercised one leg while their contralateral leg acted as a nonexercised (resting) control. Exercise resulted in an increase, above resting, in mixed muscle FSR in both groups (UT: rest, 0.036 ± 0.002; exercise, 0.0802 ± 0.01; T: rest, 0.045 ± 0.004; exercise, 0.067 ± 0.01; all values in %/h; P< 0.01). In addition, exercise resulted in an increase in mixed muscle FBR of 37 ± 5% (rest, 0.076 ± 0.005; exercise, 0.105 ± 0.01; all values in %/h; P < 0.01) in the UT group but did not significantly affect FBR in the T group. The resulting muscle net balance (FSR − FBR) was negative throughout the protocol ( P < 0.05) but was increased in the exercised leg in both groups ( P < 0.05). We conclude that pleiometric muscle contractions induce an increase in mixed muscle protein synthetic rate within 4 h of completion of an exercise bout but that resistance training attenuates this increase. A single bout of pleiometric muscle contractions also increased the FBR of mixed muscle protein in UT but not in T subjects.

scholarly journals Coca chewing for exercise: hormonal and metabolic responses of nonhabitual chewers

1996 ◽  
Vol 81 (5) ◽  
pp. 1901-1907 ◽  
Author(s):  
Roland Favier ◽  
Esperanza Caceres ◽  
Laurent Guillon ◽  
Brigitte Sempore ◽  
Michel Sauvain ◽  
...  
Keyword(s):  
Heart Rate ◽  
Gas Exchange ◽  
Oxygen Uptake ◽  
Metabolic Responses ◽  
Physiological Data ◽  
Respiratory Gas Exchange ◽  
Gum Chewing ◽  
Arterial Blood ◽  
Before And After ◽  
Exercise Induced

Favier, Roland, Esperanza Caceres, Laurent Guillon, Brigitte Sempore, Michel Sauvain, Harry Koubi, and Hilde Spielvogel. Coca chewing for exercise: hormonal and metabolic responses of nonhabitual chewers. J. Appl. Physiol. 81(5): 1901–1907, 1996.—To determine the effects of acute coca use on the hormonal and metabolic responses to exercise, 12 healthy nonhabitual coca users were submitted twice to steady-state exercise (∼75% maximal O2 uptake). On one occasion, they were asked to chew 15 g of coca leaves 1 h before exercise, whereas on the other occasion, exercise was performed after 1 h of chewing a sugar-free chewing gum. Plasma epinephrine, norepinephrine, insulin, glucagon, and metabolites (glucose, lactate, glycerol, and free fatty acids) were determined at rest before and after coca chewing and during the 5th, 15th, 30th, and 60th min of exercise. Simultaneously to these determinations, cardiorespiratory variables (heart rate, mean arterial blood pressure, oxygen uptake, and respiratory gas exchange ratio) were also measured. At rest, coca chewing had no effect on plasma hormonal and metabolic levels except for a significantly reduced insulin concentration. During exercise, the oxygen uptake, heart rate, and respiratory gas exchange ratio were significantly increased in the coca-chewing trial compared with the control (gum-chewing) test. The exercise-induced drop in plasma glucose and insulin was prevented by prior coca chewing. These results contrast with previous data obtained in chronic coca users who display during prolonged submaximal exercise an exaggerated plasma sympathetic response, an enhanced availability and utilization of fat (R. Favier, E. Caceres, H. Koubi, B. Sempore, M. Sauvain, and H. Spielvogel. J. Appl. Physiol. 80: 650–655, 1996). We conclude that, whereas coca chewing might affect glucose homeostasis during exercise, none of the physiological data provided by this study would suggest that acute coca chewing in nonhabitual users could enhance tolerance to exercise.

Effect of carbohydrate ingestion on exercise-induced alterations in metabolic gene expression

2005 ◽  
Vol 99 (4) ◽  
pp. 1359-1363 ◽  
Author(s):  
Laura J. Cluberton ◽  
Sean L. McGee ◽  
Robyn M. Murphy ◽  
Mark Hargreaves
Keyword(s):  
Gene Expression ◽  
Oxygen Uptake ◽  
Pyruvate Dehydrogenase Kinase ◽  
Mrna Levels ◽  
Carbohydrate Ingestion ◽  
Pulmonary Oxygen Uptake ◽  
Metabolic Gene ◽  
Metabolic Gene Expression ◽  
Glucose Ingestion ◽  
Exercise Induced

Skeletal muscle possesses a high degree of plasticity and can adapt to both the physical and metabolic challenges that it faces. An acute bout of exercise is sufficient to induce the expression of a variety of metabolic genes, such as GLUT4, pyruvate dehydrogenase kinase 4 (PDK-4), uncoupling protein-3 (UCP3), and peroxisome proliferator-activated receptor-γ coactivator 1 (PGC-1). Reducing muscle glycogen levels before exercise potentiates the effect of exercise on many genes. Similarly, altered substrate availability induces transcription of many of these genes. The purpose of this study was to determine whether glucose ingestion attenuates the exercise-induced increase in a variety of exercise-responsive genes. Six male subjects (28 ± 7 yr; 83 ± 3 kg; peak pulmonary oxygen uptake = 46 ± 6 ml·kg−1·min−1) performed 60 min of cycling at 74 ± 2% of peak pulmonary oxygen uptake on two separate occasions. On one occasion, subjects ingested a 6% carbohydrate drink. On the other occasion, subjects ingested an equal volume of a sweet placebo. Muscle samples were obtained from vastus lateralis at rest, immediately after exercise, and 3 h after exercise. PDK-4, UCP3, PGC-1, and GLUT4 mRNA levels were measured on these samples using real-time RT-PCR. Glucose ingestion attenuated ( P < 0.05) the exercise-induced increase in PDK-4 and UCP3 mRNA. A similar trend ( P = 0.09) was observed for GLUT4 mRNA. In contrast, PGC-1 mRNA increased following exercise to the same extent in both conditions. These data suggest that glucose availability can modulate the effect of exercise on metabolic gene expression.

Footstrike is the major cause of hemolysis during running

2003 ◽  
Vol 94 (1) ◽  
pp. 38-42 ◽  
Author(s):  
R. D. Telford ◽  
G. J. Sly ◽  
A. G. Hahn ◽  
R. B. Cunningham ◽  
C. Bryant ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Random Order ◽  
Peak Oxygen Uptake ◽  
Red Cell ◽  
Free Hemoglobin ◽  
Serum Haptoglobin ◽  
Total Hemoglobin ◽  
Exercise Induced

There is a wide body of literature reporting red cell hemolysis as occurring after various forms of exercise. Whereas the trauma associated with footstrike is thought to be the major cause of hemolysis after running, its significance compared with hemolysis that results from other circulatory stresses on the red blood cell has not been thoroughly addressed. To investigate the significance of footstrike, we measured the degree of hemolysis after 1 h of running. To control for the potential effects of oxidative and circulatory stresses on the red blood cell, the same subjects cycled for 1 h at equivalent oxygen uptake. Our subjects were 10 male triathletes, who each completed two separate 1-h sessions of running and cycling at 75% peak oxygen uptake, which were performed in random order 1 wk apart. Plasma free hemoglobin and serum haptoglobin concentrations were measured as indicators of hemolysis. We also measured methemoglobin as a percentage of total hemoglobin immediately postexercise as an indicator of red cell oxidative stress. Plasma free hemoglobin increased after both running ( P < 0.01) and cycling ( P < 0.01), but the increase was fourfold greater after running ( P < 0.01). This was reflected by a significant fall in haptoglobin 1 h after the running trials, whereas no significant changes occurred after cycling at any sample point. Methemoglobin increased twofold after both running and cycling ( P < 0.01), with no significant differences between modes of exercise. The present data indicate that, whereas general circulatory trauma to the red blood cells associated with 1 h of exercise at 75% maximal oxygen uptake may result in some exercise-induced hemolysis, footstrike is the major contributor to hemolysis during running.

scholarly journals Metabolic, Cardiac, and Hemorheological Responses to Submaximal Exercise under Light and Moderate Hypobaric Hypoxia in Healthy Men

Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 144
Author(s):  
Hun-Young Park ◽  
Jeong-Weon Kim ◽  
Sang-Seok Nam
Keyword(s):  
Oxygen Uptake ◽  
Blood Lactate ◽  
Minute Ventilation ◽  
Random Order ◽  
Cycle Ergometer ◽  
Submaximal Exercise ◽  
Erythrocyte Deformability ◽  
Moderate Hypoxia ◽  
Healthy Men ◽  
Significant Difference

We compared the effects of metabolic, cardiac, and hemorheological responses to submaximal exercise under light hypoxia (LH) and moderate hypoxia (MH) versus normoxia (N). Ten healthy men (aged 21.3 ± 1.0 years) completed 30 min submaximal exercise corresponding to 60% maximal oxygen uptake at normoxia on a cycle ergometer under normoxia (760 mmHg), light hypoxia (596 mmHg, simulated 2000 m altitude), and moderate hypoxia (526 mmHg, simulated 3000 m altitude) after a 30 min exposure in the respective environments on different days, in a random order. Metabolic parameters (oxygen saturation (SPO2), minute ventilation, oxygen uptake, carbon dioxide excretion, respiratory exchange ratio, and blood lactate), cardiac function (heart rate (HR), stroke volume, cardiac output, and ejection fraction), and hemorheological properties (erythrocyte deformability and aggregation) were measured at rest and 5, 10, 15, and 30 min after exercise. SPO2 significantly reduced as hypoxia became more severe (MH > LH > N), and blood lactate was significantly higher in the MH than in the LH and N groups. HR significantly increased in the MH and LH groups compared to the N group. There was no significant difference in hemorheological properties, including erythrocyte deformability and aggregation. Thus, submaximal exercise under light/moderate hypoxia induced greater metabolic and cardiac responses but did not affect hemorheological properties.

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