The influence of whole-body vs. torso pre-cooling on physiological strain and performance of high-intensity exercise in the heat

2001 ◽  
Vol 128 (4) ◽  
pp. 657-666 ◽  
Author(s):  
G.G. Sleivert ◽  
J.D. Cotter ◽  
W.S. Roberts ◽  
M.A. Febbraio
Keyword(s):  
High Intensity ◽  
High Intensity Exercise ◽  
Whole Body ◽  
Physiological Strain ◽  
And Performance

Influence of endurance training on muscle [PCr] kinetics during high-intensity exercise

2007 ◽  
Vol 293 (1) ◽  
pp. R392-R401 ◽  
Author(s):  
Andrew M. Jones ◽  
Daryl P. Wilkerson ◽  
Nicolas J. Berger ◽  
Jonathan Fulford
Keyword(s):  
Endurance Training ◽  
High Intensity ◽  
Slow Component ◽  
Knee Extension ◽  
High Intensity Exercise ◽  
Whole Body ◽  
Time To Exhaustion ◽  
Exercise Tests ◽  
Before And After ◽  
Knee Extension Exercise

We hypothesized that a period of endurance training would result in a speeding of muscle phosphocreatine concentration ([PCr]) kinetics over the fundamental phase of the response and a reduction in the amplitude of the [PCr] slow component during high-intensity exercise. Six male subjects (age 26 ± 5 yr) completed 5 wk of single-legged knee-extension exercise training with the alternate leg serving as a control. Before and after the intervention period, the subjects completed incremental and high-intensity step exercise tests of 6-min duration with both legs separately inside the bore of a whole-body magnetic resonance spectrometer. The time-to-exhaustion during incremental exercise was not changed in the control leg [preintervention group (PRE): 19.4 ± 2.3 min vs. postintervention group (POST): 19.4 ± 1.9 min] but was significantly increased in the trained leg (PRE: 19.6 ± 1.6 min vs. POST: 22.0 ± 2.2 min; P < 0.05). During step exercise, there were no significant changes in the control leg, but end-exercise pH and [PCr] were higher after vs. before training. The time constant for the [PCr] kinetics over the fundamental exponential region of the response was not significantly altered in either the control leg (PRE: 40 ± 13 s vs. POST: 43 ± 10 s) or the trained leg (PRE: 38 ± 8 s vs. POST: 40 ± 12 s). However, the amplitude of the [PCr] slow component was significantly reduced in the trained leg (PRE: 15 ± 7 vs. POST: 7 ± 7% change in [PCr]; P < 0.05) with there being no change in the control leg (PRE: 13 ± 8 vs. POST: 12 ± 10% change in [PCr]). The attenuation of the [PCr] slow component might be mechanistically linked with enhanced exercise tolerance following endurance training.

scholarly journals Complex I is bypassed during high intensity exercise

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Avlant Nilsson ◽  
Elias Björnson ◽  
Mikael Flockhart ◽  
Filip J. Larsen ◽  
Jens Nielsen
Keyword(s):  
High Intensity ◽  
Complex I ◽  
Atp Synthesis ◽  
Metabolic Model ◽  
High Intensity Exercise ◽  
Whole Body ◽  
Synthesis Rate ◽  
Proteomics Data ◽  
Exercise Tests

Abstract Human muscles are tailored towards ATP synthesis. When exercising at high work rates muscles convert glucose to lactate, which is less nutrient efficient than respiration. There is hence a trade-off between endurance and power. Metabolic models have been developed to study how limited catalytic capacity of enzymes affects ATP synthesis. Here we integrate an enzyme-constrained metabolic model with proteomics data from muscle fibers. We find that ATP synthesis is constrained by several enzymes. A metabolic bypass of mitochondrial complex I is found to increase the ATP synthesis rate per gram of protein compared to full respiration. To test if this metabolic mode occurs in vivo, we conduct a high resolved incremental exercise tests for five subjects. Their gas exchange at different work rates is accurately reproduced by a whole-body metabolic model incorporating complex I bypass. The study therefore shows how proteome allocation influences metabolism during high intensity exercise.

Effects of High-Intensity Exercise Repetition Number During Warm-up on Physiological Responses, Perceptions, Readiness, and Performance

2021 ◽  
pp. 1-10
Author(s):  
Naoto Fujii ◽  
Kouta Fujisawa ◽  
Kohei Dobashi ◽  
Yinhang Cao ◽  
Ryoko Matsutake ◽  
...  
Keyword(s):  
High Intensity ◽  
Physiological Responses ◽  
High Intensity Exercise ◽  
Warm Up ◽  
And Performance ◽  
Repetition Number

Effects of Lactate Consumption on Blood Bicarbonate Levels and Performance During High-Intensity Exercise

2011 ◽  
Vol 21 (4) ◽  
pp. 311-317 ◽  
Author(s):  
David M. Morris ◽  
Rebecca S. Shafer ◽  
Kimberly R. Fairbrother ◽  
Mark W. Woodall
Keyword(s):  
Body Mass ◽  
High Intensity ◽  
Performance Test ◽  
Cycle Ergometer ◽  
High Intensity Exercise ◽  
Time To Exhaustion ◽  
Total Work ◽  
Male And Female ◽  
Lactate Consumption ◽  
And Performance

The authors sought to determine the effects of oral lactate consumption on blood bicarbonate (HCO3−) levels, pH levels, and performance during high-intensity exercise on a cycle ergometer. Subjects (N = 11) were trained male and female cyclists. Time to exhaustion (TTE) and total work were measured during high-intensity exercise bouts 80 min after the consumption of 120 mg/kg body mass of lactate (L), an equal volume of placebo (PL), or no treatment (NT). Blood HCO3− increased significantly after ingestion of lactate (p < .05) but was not affected in PL or NT (p > .05). No changes in pH were observed as a result of treatment. TTE and total work during the performance test increased significantly by 17% in L compared with PL and NT (p = .02). No significant differences in TTE and total work were seen between the PL and NT protocols (p = .85). The authors conclude that consuming 120 mg/kg body mass of lactate increases HCO3− levels and increases exercise performance during high-intensity cycling ergometry to exhaustion.

Short-Duration, High-Intensity Exercise and Performance of a Sports-Specific Skill: A Preliminary Study

2007 ◽  
Vol 105 (2) ◽  
pp. 523-530 ◽  
Author(s):  
Terry McMorris ◽  
Tom Rayment
Keyword(s):  
Short Duration ◽  
High Intensity ◽  
High Intensity Exercise ◽  
Perceptual Judgment ◽  
Negative Effect ◽  
Specific Skill ◽  
Preliminary Study ◽  
And Performance ◽  
Variable Errors ◽  
Number Of Passes

The purpose of this study was to examine the effect of one bout and three intermittent bouts of short-duration, high-intensity running on the performance of a sports-specific psychomotor skill. Participants ( N = 13) were male soccer players ( M age 20.5 yr., SD = 2.0) who had been playing semi-professionally for M = 2.1 years, SD = 1.11 and trained twice a week. They undertook a soccer-passing test in three conditions: following rest, following a 100-m sprint and following 3 × 100-m sprints, with 30-sec. rest intervals between sprints. Passing accuracy showed a significant linear deterioration, while number of passes showed a significant quadratic effect. Low to moderate linear regression correlations were found between posttest heart rate and absolute and variable errors on the test. It was concluded that short-duration, high-intensity exercise has a negative effect on accuracy in a sports-specific task that requires both perceptual judgment and motor control.

Effects of high-intensity exercise training on body composition, abdominal fat loss, and cardiorespiratory fitness in middle-aged Korean females

2012 ◽  
Vol 37 (6) ◽  
pp. 1019-1027 ◽  
Author(s):  
Man-Gyoon Lee ◽  
Kyung-Shin Park ◽  
Do-Ung Kim ◽  
Soon-Mi Choi ◽  
Hyoung-Jun Kim
Keyword(s):  
Oxygen Consumption ◽  
Exercise Training ◽  
High Intensity ◽  
Maximal Oxygen Consumption ◽  
Training Group ◽  
Abdominal Fat ◽  
High Intensity Exercise ◽  
Whole Body ◽  
Fat Loss ◽  
Intensity Training

The primary purpose of this study was to investigate the effects of high-intensity exercise training under relatively equal energy expenditure on whole body fat and abdominal fat loss, and cardiorespiratory fitness. Twenty-two untrained middle-aged Korean females were randomized into one of the following groups: control, low-intensity training group (LI), and high-intensity training group (HI). Subjects completed 14 weeks of training at 50% maximal oxygen consumption (LI) or 70% maximal oxygen consumption (HI) with the volume of exercise equated relative to kilograms of body weight. Weekly exercise volumes were 13.5 METs⋅h/week for the first 4 weeks, 18 METs⋅h/week for next 5 weeks, and 22.5 METs⋅h/week for the final 5 weeks. Data were analyzed using 2-way repeated measures ANOVA with post hoc test, using Bonferroni’s correction. HI showed significant reductions in fat mass (p < 0.05), total abdominal fat (p < 0.01), and subcutaneous abdominal fat (p < 0.01). LI reduced total abdominal fat (p < 0.05), but there were no other significant changes found in the control or LI groups. Maximal oxygen consumption was enhanced in both HI and LI with no significant group difference. High-density lipoprotein cholesterol increased significantly in HI (p < 0.05). IL-6, C-reactive protein, TNF-α, and other blood lipids were unaltered following training. Results indicate that high-intensity exercise training is more beneficial in whole body and abdominal fat loss; however, cardiorespiratory enhancement shows a dose–response relationship with weekly exercise volume. It is suggested that 14 weeks of aerobic exercise training at either high- or low-intensity is not sufficient enough to induce changes in levels of inflammatory proteins.

scholarly journals Effects of mild whole body hypothermia on self-paced exercise performance

2018 ◽  
Vol 125 (2) ◽  
pp. 479-485
Author(s):  
Steven A. H. Ferguson ◽  
Neil D. Eves ◽  
Brian D. Roy ◽  
Gary J. Hodges ◽  
Stephen S. Cheung
Keyword(s):  
Rectal Temperature ◽  
Exercise Performance ◽  
Power Output ◽  
High Intensity ◽  
Mild Hypothermia ◽  
Oxygenation Index ◽  
Time Trial ◽  
Oxygen Availability ◽  
High Intensity Exercise ◽  
Whole Body

This study examined self-paced, high-intensity exercise during mild hypothermia and whether hyperoxia might offset any potential impairment. Twelve trained males each completed 15-km time trials in three environmental conditions: Neutral (23°C, [Formula: see text] 0.21), Cold (0°C, [Formula: see text] 0.21), and Cold+Hyper (0°C, [Formula: see text] 0.40). Cold and Cold+Hyper trials occurred after a 0.5°C drop in rectal temperature. Rectal temperature was higher ( P ≤ 0.016) throughout Neutral compared with Cold and Cold+Hyper; Cold had a higher ( P ≤ 0.035) rectal temperature than Cold+Hyper from 2.5 to 7.5 km, and hyperoxia did not alter thermal sensation or comfort. Oxyhemoglobin saturation decreased from ~98% to ~94% with Neutral and Cold, but was maintained at ~99% in Cold+Hyper ( P < 0.01). Cerebral tissue oxygenation index (TOI) was higher in Neutral than in Cold throughout the time trial (TT) ( P ≤ 0.001), whereas Cold+Hyper were unchanged ( P ≥ 0.567) from Neutral by 2.5 km. Muscle TOI was maintained in Cold+Hyper compared with Neutral and was higher ( P ≤ 0.046) than Cold throughout the entire TT. Power output during Cold (246 ± 41 W) was lower than Neutral (260 ± 38 W) at all 2.5-km intervals ( P ≤ 0.012) except at 12.5 km. Power output during Cold+Hyper (256 ± 42 W) was unchanged ( P ≥ 0.161) from Neutral throughout the TT, and was higher than Cold from 7.5 km onward. Average cadence was higher in Neutral (93 ± 8 rpm) than in either Cold or Cold+Hyper (Cold: 89 ± 7 and Cold+Hyper: 90 ± 8 rpm, P = 0.031). In conclusion, mild hypothermia reduced self-paced exercise performance; hyperoxia during mild hypothermia restored performance to thermoneutral levels, likely due to maintenance of oxygen availability rather than any thermogenic benefit. NEW & NOTEWORTHY We examined self-paced, high-intensity exercise with 0.5°C rectal temperature decreases in a 0°C ambient environment, along with whether hyperoxia could offset any potential impairment. During a 15-km time trial, power output was lower with hypothermia than with thermoneutral. However, with hypothermia, hyperoxia of [Formula: see text] = 0.40 restored power output despite there being no thermophysiological improvement. Hypothermia impairs exercise performance, whereas hyperoxia likely restored performance due to maintenance of oxygen availability rather than any thermogenic benefit.

scholarly journals Does whole-body cryotherapy improve vertical jump recovery following a high-intensity exercise bout?

2015 ◽  
pp. 49 ◽  
Author(s):  
Amilton Vieira ◽  
MARTIM BOTTARO ◽  
Joao Ferreira-Junior ◽  
Carlos Vieira ◽  
Vitor Cleto ◽  
...  
Keyword(s):  
High Intensity ◽  
Vertical Jump ◽  
Exercise Bout ◽  
High Intensity Exercise ◽  
Whole Body ◽  
Whole Body Cryotherapy
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