This study describes the thermoregulatory and metabolic responses during a simulated half-marathon (21 km) run performed outdoors in a hot, humid environment. Ten male runners were recruited for the study, The run was carried out individually under solar radiation on a predetermined path in the following environmental conditions (ambient temperature: 27.96 ± 1.70 °C, globe temperature: 28.52 ± 2.51 °C, relative humidity: 76.88 ± 7.49%, wet bulb globe temperature: 25.80 ± 1.18 °C). Core temperature, skin temperature, head temperature, heat storage, heart rate, expired gases, rating of perceived exertion, and speed were measured or calculated before the start, every 3 km, and immediately following the run. Comparisons were made for each dependent variable using one-way repeated measures analysis of variance tests, and a Bonferroni test. Average run time and pace were 101:00 ± 9:52 min and 4:48 ± 00:16 min km-1, respectively. Participants significantly reduced their running speed, oxygen consumption, and heat storage at 9 km (p < 0.05). While core temperature was significantly increased at 6 km (p < 0.05) before plateauing for the remainder of the run. The key finding was that most of the runners reduced their pace when a Tcore of 39 °C was reached which occurred between 6 and 9 km of the run, yet runners were able to increase their speed demonstrating an "end-spurt" near the end of the run.

中文翻译：

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在炎热潮湿的条件下对半程马拉松的体温调节和代谢反应

本研究描述了在室外炎热潮湿的环境中进行的模拟半程马拉松（21 公里）跑步期间的体温调节和代谢反应。该研究招募了 10 名男性跑步者，在以下环境条件下（环境温度：27.96 ± 1.70 °C，地球温度：28.52 ± 2.51 °C，相对湿度：76.88 ± 7.49%，湿球球温度：25.80 ± 1.18 °C）。在开始前、每 3 公里和跑步后立即测量或计算核心温度、皮肤温度、头部温度、蓄热、心率、呼出气体、感知用力等级和速度。使用方差检验的单向重复测量分析和 Bonferroni 检验对每个因变量进行比较。平均跑步时间和配速分别为 101:00 ± 9:52 min 和 4:48 ± 00:16 min km-1。参与者在 9 公里处显着降低了跑步速度、耗氧量和热量储存（p < 0.05）。而核心温度在 6 公里处显着升高（p < 0.05），然后在剩余的运行中趋于平稳。关键的发现是，大多数跑步者在跑步 6 到 9 公里之间达到 39 °C 的 Tcore 时会降低速度，但跑步者能够提高速度，在接近结束时表现出“终点冲刺”的运行。05) 在运行的剩余时间趋于平稳之前。关键的发现是，大多数跑步者在跑步 6 到 9 公里之间达到 39 °C 的 Tcore 时会降低速度，但跑步者能够提高速度，在接近结束时表现出“终点冲刺”的运行。05) 在运行的剩余时间趋于稳定之前。关键的发现是，大多数跑步者在跑步 6 到 9 公里之间达到 39 °C 的 Tcore 时会降低速度，但跑步者能够提高速度，在接近结束时表现出“终点冲刺”的运行。