Center for Research and Education in Special Environments (CRESE), Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York U.S.
Army Research Institute of Environmental Medicine (USARIEM), Natick, Massachusetts U.S.
Undersea Hyperb Med. 2022 Second Quarter;49(2):197-206.
Diving in warm water increases thermal risk during exercise compared to thermoneutral waters. The purpose of this study was to evaluate exercise endurance in warm- and hot-water conditions in divers habituated to wet or dry heat.
Nineteen male divers completed this study at the Navy Experimental Diving Unit. Subjects were assigned DRY or WET heat habituation groups. The DRY group (n=9) cycled at 125-150W for one hour in a non-immersed condition (34.4˚C, 50%RH), while the WET group (n=10) cycled at 50W for one hour while immersed in 34.4˚C water. Exercise time to exhaustion was tested on an underwater cycle ergometer in 35.8˚C (WARM) and 37.2˚C (HOT) water at 50W. Core temperature (Tc) was continuously recorded and for all dives.
Time to exhaustion was reduced in HOT compared to WARM water (p ≺0.01) in both DRY (92.7 ± 41.6 minutes in 35.8°C vs. 43.4 ± 17.5 minutes in 37.2°C) and WET (95.9 ± 39.2 minutes in 35.8°C vs. 53.4 ± 27.5 minutes in 37.2°C) groups, but did not differ between groups (p=0.62). Rate of Tc rise was greater with higher water temperature (p ≺0.01), but was not different between groups (p=0.68). Maximum Tc (p=0.94 and p=0.95) and Tc change from baseline (p=0.38 and p=0.34) was not different between water temperatures or habituation group, respectively.
Endurance decreased with increased water temperature but was not different between WET and DRY. Divers became exhausted at a similar core temperature during WARM- and HOT-water exercise. Mechanisms and applications of heat acclimation for warm-water diving should be further explored.
与中性水温相比，温水潜水会增加运动时的热风险。本研究的目的是评估习惯湿热和干热的潜水员在温水和热水条件下的运动耐力。
19 名男性潜水员在海军实验潜水部队完成了这项研究。受试者被分配到 DRY 或 WET 热适应组。DRY 组（n=9）在非浸泡条件下以 125-150W 骑行一小时（34.4°C，50%RH），而 WET 组（n=10）在 34.4°C 水中浸泡一小时，以 50W 骑行。在 50W 下，在 35.8°C（温水）和 37.2°C（热水）的水下自行车测功计上测试运动至力竭的时间。核心温度（Tc）连续记录，所有潜水均如此。
与 WARM 水相比，HOT 水中的力竭时间明显缩短（p≺0.01），在 DRY（35.8°C 时 92.7±41.6 分钟，37.2°C 时 43.4±17.5 分钟）和 WET（35.8°C 时 95.9±39.2 分钟，37.2°C 时 53.4±27.5 分钟）组中均如此，但组间差异无统计学意义（p=0.62）。随着水温升高，Tc 上升率更大（p≺0.01），但组间差异无统计学意义（p=0.68）。最大 Tc（p=0.94 和 p=0.95）和 Tc 与基线的差值（p=0.38 和 p=0.34）在不同水温或适应组之间无差异。
随着水温升高，耐力下降，但 WET 和 DRY 之间无差异。在 WARM-和 HOT-水中运动时，潜水员的核心温度相似。需要进一步探讨湿热条件下的热适应机制及其在温水潜水方面的应用。
