FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, 42100, Trikala, Greece.
Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, 125 University Private, Room 367, Montpetit Hall, Ottawa, ON, K1N 6N5, Canada.
Eur J Appl Physiol. 2020 Feb;120(2):453-465. doi: 10.1007/s00421-019-04290-8. Epub 2020 Jan 1.
This study aimed to detect potential differences in heart-rate variability (HRV) during a moderate-intensity intermittent exercise in the heat among physically active young (25.8 ± 1.9 years), middle-aged (43.5 ± 2.8 years), and older (62.9 ± 3.7 years) men.
Thirty-three participants (11/group) performed four successive bouts of 15-min cycling at a moderate fixed rate of metabolic heat production of ~ 400 W; each separated by a 15-min recovery with 1 h of final recovery in a hot and dry environment (35 °C, 20% relative humidity). Twelve HRV indices were computed that have been commonly described in the literature, and characterized various domains of the variability and complexity of heart rate.
Cardiac autonomic regulation during intermittent exercise in the heat, as well as during pre-exercise rest and recovery was significantly affected by age, as changes were observed among the three different aged groups in five indices (p ≤ 0.05). Similarly, time influenced cardiac autonomic regulation as three indices showed changes across time (p ≤ 0.05) during intermittent exercise, whilst five indices displayed significant changes (p ≤ 0.05) during rest and recovery in the heat.
This study supports that moderate-intensity intermittent exercise in the heat is associated with significant cardiac autonomic dysregulation in older men, as compared to young and middle-aged men, yet it highlights the importance of developing preventative health strategies for heat-related illness in aged individuals.
本研究旨在检测活跃的年轻（25.8±1.9 岁）、中年（43.5±2.8 岁）和老年（62.9±3.7 岁）男性在热环境中进行中等强度间歇运动时心率变异性（HRV）的潜在差异。
33 名参与者（每组 11 人）以约 400 W 的代谢产热率进行 4 次连续 15 分钟的自行车骑行，每次骑行之间间隔 15 分钟恢复期，最后 1 小时在炎热干燥的环境（35°C，20%相对湿度）中恢复。计算了 12 个 HRV 指数，这些指数在文献中已有广泛描述，可用于描述心率变异性和复杂性的各个领域。
热环境中间歇运动期间以及运动前休息和恢复期的心脏自主神经调节受到年龄的显著影响，三个不同年龄组的 5 个指数（p≤0.05）均发生变化。同样，时间也影响心脏自主神经调节，因为有 3 个指数在间歇运动期间随时间变化（p≤0.05），而在热环境中休息和恢复期有 5 个指数显示出显著变化（p≤0.05）。
本研究支持与年轻和中年男性相比，热环境中中等强度间歇运动与老年男性的心脏自主神经调节显著失调有关，但也强调了为老年个体制定预防与热相关疾病的健康策略的重要性。
