Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA.
Sports Performance Laboratory, Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX 79409, USA.
Int J Environ Res Public Health. 2022 May 25;19(11):6412. doi: 10.3390/ijerph19116412.
The purpose of this study was to examine the changes in metabolic heat production (Hprod), evaporative heat loss (Hevap), and dry heat loss (Hdry), following heat acclimatization (HAz) and heat acclimation (HA). Twenty-two male endurance athletes (mean ± standard deviation; age, 37 ± 12 y; body mass, 73.4 ± 8.7 kg; height, 178.7 ± 6.8 cm; and VO2max, 57.1 ± 7.2 mL·kg−1·min−1) completed three trials (baseline; post-HAz; and post-HA), which consisted of 60 min steady state exercise at 59 ± 2% velocityVO2max in the heat (ambient temperature [Tamb], 35.2 ± 0.6 °C; relative humidity [%rh] 47.5 ± 0.4%). During the trial, VO2 and RER were collected to calculate Hprod, Hevap, and Hdry. Following the baseline trial, participants completed self-directed outdoor summer training followed by a post-HAz trial. Then, five days of HA were completed over eight days in the heat (Tamb, 38.7 ± 1.1 °C; %rh, 51.2 ± 2.3%). During the HA sessions, participants exercised to maintain hyperthermia (38.50 °C and 39.75 °C) for 60 min. Then, a post-HA trial was performed. There were no differences in Hprod between the baseline (459 ± 59 W·m−2), post-HAz (460 ± 61 W·m−2), and post-HA (464 ± 55 W·m−2, p = 0.866). However, Hevap was significantly increased post-HA (385 ± 84 W·m−2) compared to post-HAz (342 ± 86 W·m−2, p = 0.043) and the baseline (332 ± 77 W·m−2, p = 0.037). Additionally, Hdry was significantly lower at post-HAz (125 ± 8 W·m−2, p = 0.013) and post-HA (121 ± 10 W·m−2, p < 0.001) compared to the baseline (128 ± 7 W·m−2). Hdry at post-HA was also lower than post-HAz (p = 0.049). Hprod did not change following HAz and HA. While Hdry was decreased following HA, the decrease in Hdry was smaller than the increases in Hevap. Adaptations in body heat exchange can occur by HA following HAz.
这项研究的目的是观察热适应（HAz）和热适应（HA）后代谢产热（Hprod）、蒸发散热（Hevap）和干燥散热（Hdry）的变化。22 名男性耐力运动员（平均值±标准差；年龄 37±12 岁；体重 73.4±8.7kg；身高 178.7±6.8cm；最大摄氧量 57.1±7.2ml·kg-1·min-1）完成了三次试验（基础；HAz 后；HA 后），每次试验均包括 60 分钟在热环境（环境温度[Tamb]为 35.2±0.6°C；相对湿度[%rh]为 47.5±0.4%）中以 59±2%最大摄氧量速度进行的稳态运动。在试验过程中，收集 VO2 和 RER 以计算 Hprod、Hevap 和 Hdry。在基础试验后，参与者进行了自我指导的户外夏季训练，然后进行了 HAz 后试验。然后，在热环境中进行了为期 8 天的 5 天 HA（Tamb，38.7±1.1°C；%rh，51.2±2.3%）。在 HA 期间，参与者运动以保持 38.50°C 和 39.75°C 的体温（38.50°C 和 39.75°C），持续 60 分钟。然后进行了 HA 后试验。与 HAz 后（460±61 W·m-2）和基础（464±55 W·m-2，p=0.866）相比，基础（459±59 W·m-2）、HAz 后（460±61 W·m-2）和 HAz 后（464±55 W·m-2，p=0.866）没有差异。然而，与 HAz 后（342±86 W·m-2，p=0.043）和基础（332±77 W·m-2，p=0.037）相比，Hevap 明显增加。此外，与基础（128±7 W·m-2）相比，HAz 后（125±8 W·m-2，p=0.013）和 HA 后（121±10 W·m-2，p<0.001）的 Hdry 明显较低。HA 后（p=0.049）的 Hdry 也低于 HAz 后。HAz 和 HA 后 Hprod 没有变化。尽管 HA 后 Hdry 降低，但 Hdry 的降低幅度小于 Hevap 的增加幅度。HAz 后可以通过 HA 来改变身体的热交换。
