Centre for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, Uxbridge, UK.
Welkin Human Performance Laboratories, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Denton Road, Eastbourne, UK.
Sports Med. 2017 Sep;47(9):1751-1768. doi: 10.1007/s40279-017-0717-z.
To prepare for extremes of heat, cold or low partial pressures of oxygen (O), humans can undertake a period of acclimation or acclimatization to induce environment-specific adaptations, e.g. heat acclimation (HA), cold acclimation (CA), or altitude training. While these strategies are effective, they are not always feasible due to logistical impracticalities. Cross-adaptation is a term used to describe the phenomenon whereby alternative environmental interventions, e.g. HA or CA, may be a beneficial alternative to altitude interventions, providing physiological stress and inducing adaptations observable at altitude. HA can attenuate physiological strain at rest and during moderate-intensity exercise at altitude via adaptations allied to improved O delivery to metabolically active tissue, likely following increases in plasma volume and reductions in body temperature. CA appears to improve physiological responses to altitude by attenuating the autonomic response to altitude. While no cross-acclimation-derived exercise performance/capacity data have been measured following CA, post-HA improvements in performance underpinned by aerobic metabolism, and therefore dependent on O delivery at altitude, are likely. At a cellular level, heat shock protein responses to altitude are attenuated by prior HA, suggesting that an attenuation of the cellular stress response and therefore a reduced disruption to homeostasis at altitude has occurred. This process is known as cross-tolerance. The effects of CA on markers of cross-tolerance is an area requiring further investigation. Because much of the evidence relating to cross-adaptation to altitude has examined the benefits at moderate to high altitudes, future research examining responses at lower altitudes should be conducted, given that these environments are more frequently visited by athletes and workers. Mechanistic work to identify the specific physiological and cellular pathways responsible for cross-adaptation between heat and altitude, and between cold and altitude, is warranted, as is exploration of benefits across different populations and physical activity profiles.
为了应对极端高温、低温或低氧分压环境，人类可以进行适应或习服训练，以诱导特定环境的适应性，例如热习服（HA）、冷习服（CA）或高原训练。虽然这些策略有效，但由于实际操作上的限制，并不总是可行。交叉适应是一个术语，用于描述替代环境干预（例如 HA 或 CA）可能是高原干预的有益替代方案的现象，它提供生理应激并诱导在高原上可观察到的适应性。HA 通过改善向代谢活跃组织供氧的适应性，减轻静息和中等强度运动时的高原生理应激，从而减轻高原生理应激。CA 似乎通过减轻对高原的自主神经反应来改善对高原的生理反应。虽然没有测量 CA 后交叉适应训练对运动表现/能力的影响，但基于有氧代谢的 HA 后运动表现的改善，可能依赖于高原的氧输送。在细胞水平上，先前的 HA 减轻了对高原的热休克蛋白反应，这表明高原细胞应激反应减弱，因此高原内的内稳态破坏减少。这个过程被称为交叉耐受。CA 对交叉耐受标志物的影响是一个需要进一步研究的领域。由于与高原交叉适应相关的大部分证据都检查了中等到高海拔的益处，因此应该进行未来的研究，检查低海拔的反应，因为这些环境更常被运动员和工人访问。有必要进行机制研究，以确定热和海拔、冷和海拔之间交叉适应的特定生理和细胞途径，以及探索不同人群和身体活动特征的益处。
