scholarly journals Impact of Exercise-induced Dehydration on Perceived Exertion During Endurance Exercise: A Systematic Review with Meta-analysis

2021 ◽  
Author(s):  
Thomas A Deshayes ◽  
Timothee Pancrate ◽  
Eric DB Goulet
Keyword(s):  
Mass Loss ◽  
Body Mass ◽  
Endurance Exercise ◽  
Perceived Exertion ◽  
Meta Analysis ◽  
Exercise Adherence ◽  
Rating Of Perceived Exertion ◽  
Body Mass Loss ◽  
Exercise Induced ◽  
The Impact

Understanding the impact of stressors on the rating of perceived exertion (RPE) is relevant from a performance and exercise adherence/participation standpoint. Athletes and recreationally active individuals dehydrate during exercise. No attempt has been made to systematically determine the impact of exercise-induced dehydration (EID) on RPE. The present meta-analysis aimed to determine the effect of EID on RPE during endurance exercise and examine the moderating effect of potential confounders using a meta-analytical approach. Data analyses were performed on raw RPE values using random-effects models weighted mean effect summaries and meta-regressions with robust standard errors, and with a practical meaningful effect set at 1 point difference between euhydration (EUH) and EID. Only controlled crossover studies measuring RPE with a Borg scale in healthy adults performing ≥ 30 min of continuous endurance exercise while dehydrating or drinking to maintain EUH were included. Sixteen studies were included, representing 147 individuals. Mean body mass loss with EUH was 0.5 ± 0.4%, compared to 2.3 ± 0.5% with EID (range 1.7 to 3.1%). Within an EID of 0.5 to 3% body mass, a maximum difference in RPE of 0.81 points (95% CI: 0.36-1.27) was observed between conditions. A meta-regression revealed that RPE increases by 0.21 points for each 1% increase in EID (95% CI: 0.12-0.31). Humidity, ambient temperature and aerobic capacity did not alter the relationship between EID and RPE. Therefore, the effect of EID on RPE is unlikely to be practically meaningful until a body mass loss of at least 3%.

Sex differences in the physiological responses to exercise-induced dehydration: Consequences and mechanisms?

2021 ◽  
Author(s):  
Kate Aiko Wickham ◽  
Devin G. McCarthy ◽  
Lawrence L. Spriet ◽  
Stephen S. Cheung
Keyword(s):  
Sex Differences ◽  
Mass Loss ◽  
Body Mass ◽  
Sweat Gland ◽  
Body Water ◽  
Physiological Strain ◽  
Body Mass Loss ◽  
Cardiac Strain ◽  
Exercise Onset ◽  
Exercise Induced

Physiological strain during exercise is increased by mild dehydration (~1-3% body mass loss). This response may be sex-dependent but there are no direct comparative data in this regard. This review aimed to develop a framework for future research by exploring the potential impact of sex on thermoregulatory and cardiac strain associated with exercise-induced dehydration. Sex-based comparisons were achieved by comparing trends from studies that implemented similar experimental protocols but recruited males and females separately. This revealed a higher core temperature (Tc) in response to exercise-induced dehydration in both sexes, however it seemingly occurred at a lower percent body mass loss in females. Although less clear, similar trends existed for cardiac strain. The average female may have a lower body water volume per body mass compared to males, and therefore the same % body mass loss between the sexes may represent a larger portion of total body water in females potentially posing a greater physiological strain. Additionally, the rate which Tc increases at exercise onset might be faster in females and induce a greater thermoregulatory challenge earlier into exercise. The Tc response at exercise onset is associated with lower sweating rates in females, which is commonly attributed to sex-differences in metabolic heat production. However, a reduced sweat gland sensitivity to stimuli, lower fluid output per sweat gland, and sex hormones promoting fluid retention in females may also contribute. In conclusion, the limited evidence suggests sex-based differences exist in thermoregulatory and cardiac strain associated with exercise-induced dehydration, and this warrants future investigations.

scholarly journals Symposium on ‘Performance, exercise and health’ Hydration, fluids and performance

2008 ◽  
Vol 68 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Susan M. Shirreffs
Keyword(s):  
Mass Loss ◽  
Body Mass ◽  
Endurance Exercise ◽  
Exercise Performance ◽  
Team Sports ◽  
Endurance Performance ◽  
The Body ◽  
Dietary Recommendations ◽  
Mental Performance ◽  
Body Mass Loss

Sweat evaporation can be a key thermoregulatory mechanism and it causes a loss of water from all compartments of the body. Hypohydration can also develop with restricted fluid intake or with intake of diuretics. Hypohydration can affect physical and/or mental performance and/or have implications for dietary recommendations. A variety of different types and modes of exercise performance can be influenced by hydration state. Reviews of the published literature are currently most conclusive for endurance exercise. Dehydration equivalent to 2% body mass loss during exercise in a hot environment (31–32°C) impairs endurance performance, but when the exercise is performed in a temperate environment (20–21°C) a 2% body mass loss appears to have a lesser and inconsequential effect. In cold environments a body mass loss >2% may be tolerable for endurance exercise. There is a less conclusive picture as to the effects of hypohydration on other types of physical performance, including strength and power activities, team sports and the skills component of many sports, and for mental performance. A number of physiological mechanisms are responsible for the effects observed. Fluid consumption can be used to attenuate the development of a water deficit or to correct it. The composition and temperature of a drink and the volume and rate of its consumption can all influence the physiological responses to ingestion and can impact on exercise performance.

scholarly journals Peripheral fatigue limits endurance exercise via a sensory feedback-mediated reduction in spinal motoneuronal output

2013 ◽  
Vol 115 (3) ◽  
pp. 355-364 ◽  
Author(s):  
Markus Amann ◽  
Massimo Venturelli ◽  
Stephen J. Ives ◽  
John McDaniel ◽  
Gwenael Layec ◽  
...  
Keyword(s):  
Endurance Exercise ◽  
Exercise Performance ◽  
Perceived Exertion ◽  
Performance Test ◽  
Rating Of Perceived Exertion ◽  
Afferent Feedback ◽  
Peripheral Fatigue ◽  
Time To Exhaustion ◽  
Peripheral Muscle ◽  
Exercise Induced

This study sought to determine whether afferent feedback associated with peripheral muscle fatigue inhibits central motor drive (CMD) and thereby limits endurance exercise performance. On two separate days, eight men performed constant-load, single-leg knee extensor exercise to exhaustion (85% of peak power) with each leg (Leg1 and Leg2). On another day, the performance test was repeated with one leg (Leg1) and consecutively (within 10 s) with the other/contralateral leg (Leg2-post). Exercise-induced quadriceps fatigue was assessed by reductions in potentiated quadriceps twitch-force from pre- to postexercise (ΔQtw,pot) in response to supramaximal magnetic femoral nerve stimulation. The output from spinal motoneurons, estimated from quadriceps electromyography (iEMG), was used to reflect changes in CMD. Rating of perceived exertion (RPE) was recorded during exercise. Time to exhaustion (∼9.3 min) and exercise-induced ΔQtw,pot (∼51%) were similar in Leg1 and Leg2 ( P > 0.5). In the consecutive leg trial, endurance performance of the first leg was similar to that observed during the initial trial (∼9.3 min; P = 0.8); however, time to exhaustion of the consecutively exercising contralateral leg (Leg2-post) was shorter than the initial Leg2 trial (4.7 ± 0.6 vs. 9.2 ± 0.4 min; P < 0.01). Additionally, ΔQtw,pot following Leg2-post was less than Leg2 (33 ± 3 vs 52 ± 3%; P < 0.01). Although the slope of iEMG was similar during Leg2 and Leg2-post, end-exercise iEMG following Leg2-post was 26% lower compared with Leg2 ( P < 0.05). Despite a similar rate of rise, RPE was consistently ∼28% higher throughout Leg2-post vs. Leg2 ( P < 0.05). In conclusion, this study provides evidence that peripheral fatigue and associated afferent feedback limits the development of peripheral fatigue and compromises endurance exercise performance by inhibiting CMD.

Circulating Inflammatory Cytokine Responses to Endurance Exercise in Female Rowers

2018 ◽  
Vol 39 (14) ◽  
pp. 1041-1048 ◽  
Author(s):  
Jaak Jürimäe ◽  
Sille Vaiksaar ◽  
Priit Purge
Keyword(s):  
Growth Factor ◽  
Cardiorespiratory Fitness ◽  
Inflammatory Cytokines ◽  
Endurance Exercise ◽  
Perceived Exertion ◽  
Acute Exercise ◽  
Venous Blood ◽  
Rating Of Perceived Exertion ◽  
Metabolic Demand ◽  
Exercise Induced

AbstractThis investigation examined the effects of acute rowing exercise on a panel of 12 different inflammatory cytokines. Fifteen female rowers (18.3±1.6 yrs; 172.0±5.0 cm; 67.5±8.8 kg; maximal oxygen consumption [VO2max]: 47.2±7.9 ml.min.−1kg−1) completed a 1-h endurance exercise (distance: 12.1±1.1 km; energy expenditure [EE]: 639±69 kcal; heart rate: 151±7 beats.min−1; intensity: 79.6±3.5% of the second ventilatory turn point). Venous blood samples were analysed for interleukin (IL)-2, IL-4, IL-6, IL-8, IL-10, vascular endothelial growth factor (VEGF), interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), IL-1α, IL-1β, monocyte chemoattractant protein-1 (MCP-1) and epidermal growth factor (EGF) concentrations. Rowing exercise resulted increment (P<0.05) in IL-6, IL-8, VEGF and MCP-1. Exercise metabolic demand variables such as rating of perceived exertion (r=0.61), distance covered (r=0.60) and EE (r=0.57) were related (P<0.05) to changes in VEGF concentration. Cardiorespiratory fitness as measured by VO2max was correlated with changes in IL-6 (r=–0.55; P<0.05) level. In conclusion, acute exercise-induced inflammatory reaction was induced by a significant increase in IL-6, IL-8, VEGF and MCP-1 concentrations. Variance in exercise-induced increases in inflammatory cytokines in response to prolonged endurance exercise was characterised by exercise metabolic demand and cardiorespiratory fitness measures in female rowers.

scholarly journals A Pilot Study to Examine the Impact of Beta-Alanine Supplementation on Anaerobic Exercise Performance in Collegiate Rugby Athletes

Sports ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 231 ◽  
Author(s):  
Charles R. Smith ◽  
Patrick S. Harty ◽  
Richard A. Stecker ◽  
Chad M. Kerksick
Keyword(s):  
Body Composition ◽  
Pilot Study ◽  
Body Mass ◽  
Exercise Performance ◽  
Perceived Exertion ◽  
Rating Of Perceived Exertion ◽  
Muscular Endurance ◽  
Beta Alanine ◽  
The Impact ◽  
Rugby Players

Beta-alanine (BA) is a precursor to carnosine which functions as a buffer assisting in the maintenance of intracellular pH during high-intensity efforts. Rugby is a sport characterized by multiple intermittent periods of maximal or near maximal efforts with short periods of rest/active recovery. The purpose of this pilot study was to evaluate the impact of six weeks of beta-alanine supplementation on anaerobic performance measures in collegiate rugby players. Twenty-one male, collegiate rugby players were recruited, while fifteen completed post-testing (Mean ± SD; Age: 21.0 ± 1.8 years, Height: 179 ± 6.3 cm, Body Mass: 91.8 ± 13.3 kg, % Body Fat: 21.3 ± 4.4). Supplementation was randomized in a double-blind, placebo-controlled manner between 6.4 g/d of beta-alanine and 6.4 g/d of maltodextrin placebo. Body composition, upper and lower-body maximal strength and muscular endurance, intermittent sprint performance, and post-exercise lactate, heart rate, and rating of perceived exertion were assessed before and after supplementation. Data were analyzed using a 2 × 2 (group × time) mixed factorial analysis of variance (ANOVA) with repeated measures on time. No significant interaction effects were noted for body mass, fat mass, fat-free mass, and percent bodyfat (p > 0.05). No performance effects resulting from beta-alanine supplementation were detected. Results from this initial pilot investigation suggest that BA exerts little to no impact on body composition parameters, muscular strength, muscular endurance, or intermittent sprinting performance. With the limited research exploring the impact of BA in this sporting context, these initial findings offer little support for BA use, but more research is needed to fully understand the potential impact of BA on various aspects of resistance exercise performance.

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