Kissling Lorenz S, Akerman Ashley P, Cotter James D
The School of Physical Education, Sport and Exercise Sciences, University of Otago, Dunedin, New Zealand.
Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada.
Temperature (Austin). 2019 Sep 3;7(2):129-148. doi: 10.1080/23328940.2019.1653736.
Tokyo 2020 will likely be the most heat stressful Olympics to date, so preparation to mitigate the effects of humid heat will be essential for performance in several of the 33 sports. One key consideration is heat acclimation (HA); the repeated exposure to heat to elicit physiological and psychophysical adaptations that improve tolerance and exercise performance in the heat. Heat can be imposed in various ways, including exercise in the heat, hot water immersion, or passive exposure to hot air (., sauna). The physical requirements of each sport will determine the impact that the heat has on performance, and the adaptations required from HA to mitigate these effects. This review focuses on one key adaptation, plasma volume expansion (PVE), and how the mode of HA may affect the kinetics of adaptation. PVE constitutes a primary HA-mediated adaptation and contributes to functional adaptations (e.g., lower heart rate and increased heat loss capacity), which may be particularly important in athletes of "sub-elite" cardiorespiratory fitness (., team sports), alongside athletes of prolonged endurance events. This review: i) highlights the ability of exercise in the heat, hot-water immersion, and passive hot air to expand PV, providing the first quantitative assessment of the efficacy of different heating modes; ii) discusses how this may apply to athletes at Tokyo 2020; and iii) provides recommendations regarding the protocol of HA and the prospect for achieving PVE (and the related outcomes).
2020年东京奥运会可能会成为迄今为止对高温压力最为敏感的奥运会，因此，对于33个比赛项目中的多个项目而言，做好准备以减轻湿热影响对于运动员的表现至关重要。一个关键的考虑因素是热适应（HA）；即反复暴露于高温环境中，以引发生理和心理物理适应，从而提高在高温环境下的耐受性和运动表现。施加热量的方式有多种，包括在高温环境中运动、热水浸泡或被动暴露于热空气（如桑拿）中。每个运动项目的身体要求将决定高温对表现的影响，以及热适应为减轻这些影响所需的适应性变化。本综述重点关注一种关键的适应性变化，即血浆容量扩充（PVE），以及热适应模式如何影响适应的动力学。PVE是热适应介导的主要适应性变化，有助于功能性适应（如降低心率和增加散热能力），这对于“次精英”心肺功能的运动员（如团队运动项目）以及长时间耐力项目的运动员可能尤为重要。本综述：i）强调在高温环境中运动、热水浸泡和被动热空气扩充血浆容量的能力，首次对不同加热模式的效果进行定量评估；ii）讨论这如何适用于2020年东京奥运会的运动员；iii）提供有关热适应方案和实现血浆容量扩充（及相关结果）前景的建议。
