ThermosenseLab, Skin Sensing Research Group, School of Health Sciences, The University of Southampton, Southampton, UK.
Sport and Exercise Sciences Research Unit, SPPEFF Department, University of Palermo, Palermo, Italy.
Exp Physiol. 2024 Feb;109(2):255-270. doi: 10.1113/EP091533. Epub 2023 Nov 16.
Women continue to be under-represented in thermoregulatory research despite their undergoing unique physiological changes across the lifespan. This study investigated the biophysical, thermo-physiological, and perceptual determinants of cool-seeking behaviour during exercise in younger and older women. Eleven younger (25 ± 5 years; 1.7 ± 0.1 m; 63.1 ± 5.2 kg) and 11 older women (53 ± 6 years; 1.7 ± 0.1 m; 65.4 ± 13.9 kg) performed a 40-min incremental cycling test in a thermoneutral environment (22 ± 1.7°C; 36 ± 4% relative humidity). Throughout the test, participants freely adjusted the temperature of a cooling probe applied to their wrists to offset their thermal discomfort. We continuously recorded the probe-wrist interface temperature to quantify participants' cool-seeking behaviour. We also measured changes in participants' rate of metabolic heat production, core and mean skin temperatures, and skin wetness. Finally, we body-mapped participants' skin heat, cold and wetness sensitivity. Our results indicated that: (1) older and younger women exhibited similar onset and magnitude of cool-seeking behaviour, despite older women presented reduced autonomic heat-dissipation responses (i.e., whole-body sweat losses); (2) older women's thermal behaviour was less determined by changes in core temperature (this being a key driver in younger women), and more by changes in multiple thermo-physiological and biophysical parameters (i.e., physical skin wetness, temperature and heat production); (3) older women did not present lower regional skin thermal and wetness sensitivity than younger women. We conclude that predictions of female cool-seeking behaviours based on thermo-physiological variables should consider the effects of ageing. These findings are relevant for the design of wearable cooling systems and sports garments that meet the thermal needs of women across the lifespan.
尽管女性在整个生命周期中经历着独特的生理变化，但她们在体温调节研究中仍然代表性不足。本研究调查了年轻和老年女性在运动过程中寻求凉爽行为的生理、生理和感知决定因素。11 名年轻女性（25 ± 5 岁；1.7 ± 0.1 米；63.1 ± 5.2 千克）和 11 名老年女性（53 ± 6 岁；1.7 ± 0.1 米；65.4 ± 13.9 千克）在热中性环境（22 ± 1.7°C；36 ± 4%相对湿度）中进行了 40 分钟的递增式踏车测试。在整个测试过程中，参与者可以自由调节应用于手腕的冷却探头的温度，以抵消他们的热不适。我们连续记录探头-手腕界面温度，以量化参与者的凉爽寻求行为。我们还测量了参与者代谢产热率、核心和平均皮肤温度以及皮肤湿润度的变化。最后，我们对参与者的皮肤热、冷和湿敏感度进行了全身映射。我们的结果表明：（1）尽管老年女性的自主散热反应（即全身汗液流失）减少，但她们和年轻女性一样表现出相似的凉爽寻求行为的开始和幅度；（2）老年女性的热行为受核心温度变化的影响较小（这是年轻女性的关键驱动因素），而受多个生理和生理参数变化的影响较大（即物理皮肤湿度、温度和产热）；（3）老年女性的局部皮肤热和湿敏感度并不低于年轻女性。我们得出结论，基于生理变量预测女性凉爽寻求行为应考虑到衰老的影响。这些发现对于设计满足女性整个生命周期热需求的可穿戴冷却系统和运动服装具有重要意义。
