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Author Fujii, Naoto ♦ Honda, Yasushi ♦ Ogawa, Takeshi ♦ Tsuji, Bun ♦ Kondo, Narihiko ♦ Koga, Shunsaku ♦ Nishiyasu, Takeshi
Source SpringerLink
Content type Text
Publisher Springer-Verlag
File Format PDF
Copyright Year ©2011
Language English
Subject Domain (in DDC) Technology ♦ Medicine & health
Subject Keyword Adaptation to heat ♦ Body temperature ♦ Respiration ♦ Thermoregulation ♦ Occupational Medicine/Industrial Medicine ♦ Human Physiology ♦ Sports Medicine
Abstract We tested the hypothesis that short-term exercise-heat acclimation (EHA) attenuates hyperthermia-induced hyperventilation in humans exercising in a hot environment. Twenty-one male subjects were divided into the two groups: control (C, n = 11) and EHA (n = 10). Subjects in C performed exercise-heat tests [cycle exercise for ~75 min at 58% $ \dot{V}_{{{\text{O}}_{{ 2 {\text{peak}}}} }} $ (37°C, 50% relative humidity)] before and after a 6-day interval with no training, while subjects in EHA performed the tests before and after exercise training in a hot environment (37°C). The training entailed four 20-min bouts of exercise at 50% $ \dot{V}_{{{\text{O}}_{{ 2 {\text{peak}}}} }} $ separated by 10 min of rest daily for 6 days. In C, comparison of the variables recorded before and after the no-training period revealed no changes. In EHA, the training increased resting plasma volume, while it reduced esophageal temperature (T es), heart rate at rest and during exercise, and arterial blood pressure and oxygen uptake ( $ \dot{V}_{{{\text{O}}_{2} }} $ ) during exercise. The training lowered the T es threshold for increasing forearm vascular conductance (FVC), while it increased the slope relating FVC to T es and the peak FVC during exercise. It also lowered minute ventilation ( $ \dot{V}_{\text{E}} $ ) during exercise, but this effect disappeared after removing the influence of $ \dot{V}_{{{\text{O}}_{2} }} $ on $ \dot{V}_{\text{E}} $ . The training did not change the slope relating ventilatory variables to T es. We conclude that short-term EHA lowers ventilation largely by reducing metabolism, but it does not affect the sensitivity of hyperthermia-induced hyperventilation during submaximal, moderate-intensity exercise in humans.
ISSN 14396319
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2011-05-06
Publisher Place Berlin/Heidelberg
e-ISSN 14396327
Journal European Journal of Applied Physiology
Volume Number 112
Issue Number 1
Page Count 13
Starting Page 295
Ending Page 307

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Source: SpringerLink