Nose Hiroshi, Kamijo Yoshi-Ichiro, Masuki Shizue
Department of Sports Medical Sciences, Shinshu University Graduate School of Medicine, Institute for Biomedical Sciences, Shinshu University, Matsumoto, Japan.
Department of Sports Medical Sciences, Shinshu University Graduate School of Medicine, Institute for Biomedical Sciences, Shinshu University, Matsumoto, Japan.
Handb Clin Neurol. 2018;156:417-429. doi: 10.1016/B978-0-444-63912-7.00025-4.
Humans are unique in their ability to control body temperature with a large amount of skin blood flow and sweat rate while exercising in an upright position. However, cutaneous vasodilation in the body reduces total peripheral resistance and blood pooling in cutaneous veins decreases venous return to the heart and cardiac filling pressure. In addition, hypovolemia by sweating accelerates the reduction in cardiac filling pressure. These may threaten the maintenance of blood pressure if they are not compensated for. To prevent this, cutaneous vasodilation and sweat rate are suppressed by baroreflexes or hyperosmolality with dehydration. These mechanisms suppress heat dissipation, accelerate the increase in body temperature, and sometimes cause heat stroke. As a countermeasure to prevent this, we have recommended glucose electrolyte solutions but recently found that aerobic training with carbohydrate + whey protein supplementation markedly improves heat dissipation mechanisms by plasma volume expansion. In this article, we will discuss the importance of improving body fluid homeostasis for thermoregulation under heat stress in humans and the strategy to attain this.
人类在直立运动时，能够通过大量的皮肤血流量和出汗率来控制体温，这一点独一无二。然而，身体皮肤血管舒张会降低总外周阻力，皮肤静脉中的血液淤积会减少心脏的静脉回流和心脏充盈压。此外，出汗导致的血容量减少会加速心脏充盈压的降低。如果这些情况得不到代偿，可能会威胁血压的维持。为防止这种情况发生，压力反射或脱水引起的高渗状态会抑制皮肤血管舒张和出汗率。这些机制会抑制散热，加速体温升高，有时还会导致中暑。作为预防措施，我们曾推荐使用葡萄糖电解质溶液，但最近发现，补充碳水化合物+乳清蛋白的有氧训练可通过扩充血浆量显著改善散热机制。在本文中，我们将讨论改善人体热应激下体温调节的体液稳态的重要性以及实现这一目标的策略。
