Short-term exercise-heat acclimation enhances skin vasodilation but not hyperthermic hyperpnea in humans exercising in a hot environment
Short-term exercise-heat acclimation enhances skin vasodilation but not hyperthermic hyperpnea in humans exercising in a hot environment
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DOI：
10.1007/s00421-011-1980-6
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发表时间：
2012-01-01
影响因子：
3
通讯作者：
Nishiyasu, Takeshi
中科院分区：
文献类型：
--
作者：
Fujii, Naoto;Honda, Yasushi;Nishiyasu, Takeshi
我们测试了短期运动热适应（EHA）减弱在热环境中运动的人中高血压诱导的换气过度的假设。21例男性受试者分为对照组（C组，n = 11）和EHA组（n = 10）. C中的受试者在6天的间隔之前和之后进行运动-热测试[在58%Vover dot 0（2峰值）（37摄氏度，50%相对湿度）下循环运动类似于75分钟]，没有训练，而EHA中的受试者在热环境（37摄氏度）中运动训练之前和之后进行测试。训练需要四次20分钟的50%Vover dotO运动（2峰），每天休息10分钟，持续6天。在C组中，比较无训练期前后记录的变量没有发现变化。在EHA中，训练增加了静息血浆容量，同时降低了食管温度（T-es）、静息和运动时的心率以及运动时的动脉血压和摄氧量（Vover dot（O2））。训练降低了增加前臂血管传导性（FVC）的T-es阈值，同时增加了运动期间FVC与T-es和峰值FVC相关的斜率。在运动中也降低了每分钟通气量（Vover dot（E）），但在消除Vover dot（O2）对Vover dot（E）的影响后，这种影响消失。训练并没有改变斜率相关的解释变量T-ES。我们的结论是，短期EHA降低通气很大程度上是通过减少代谢，但它不影响敏感性的高温诱导过度通气在次最大，中等强度的运动在人类。
We tested the hypothesis that short- term exercise- heat acclimation (EHA) attenuates hyperthermiainduced 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 similar to 75 min at 58% Vover dotO(2peak) (37 degrees 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 degrees C). The training entailed four 20- min bouts of exercise at 50% Vover dotO(2peak) 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 (Vover dot(O2)) 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 (Vover dot(E)) during exercise, but this effect disappeared after removing the influence of Vover dot(O2) on Vover dot(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.