a Institute of Sport Science and Innovations , Lithuanian Sports University , Kaunas , LT , Lithuania.
b Department of Educational Studies , Kaunas University of Technology , Kaunas , LT , Lithuania.
Int J Hyperthermia. 2019;36(1):65-74. doi: 10.1080/02656736.2018.1533650. Epub 2018 Nov 1.
Healthy aging is associated with a progressive decline in motor performance and thermoregulatory efficiency. Functional consequences of severe whole-body hyperthermia on neurophysiological functions in healthy aged men have not been investigated. To determine whether severe whole-body hyperthermia (increase in rectal temperature of about 2.5 °C) induced by lower-body heating in older men (64-80 years, n = 9) would suppress excitability of reflexes, voluntarily and electrically induced ankle plantar flexor contractile properties were compared with those in young men (19-21 years, n = 11). Though no aging effect on hyperthermia-induced reflex amplitudes was observed, a decrease in maximal H-reflex and V-wave latencies was found to be greater in older than in young men. In older men, lower-body heating was accompanied by a significant increase in twitch and tetani test torque in parallel with a greater decrease in muscle contraction time. There was no temperature-depended aging effect on the voluntary activation and maximal voluntary torque production. Despite delayed and weakened thermoregulation and age-related decline in neuromuscular function, motor performance in whole-body severe hyperthermia is apparently preserved in healthy aging.
健康衰老与运动表现和体温调节效率的逐渐下降有关。尚未研究全身性高热（直肠温度升高约 2.5°C）对健康老年男性神经生理功能的严重影响。为了确定通过下半身加热引起的严重全身性高热（老年男性（64-80 岁，n=9）直肠温度升高约 2.5°C）是否会抑制反射的兴奋性，与年轻人（19-21 岁，n=11）相比，比较了自愿和电诱导的踝关节跖屈肌收缩性能。尽管没有观察到年龄对高热诱导的反射幅度的影响，但发现老年人的最大 H 反射和 V 波潜伏期的下降幅度大于年轻人。在老年男性中，下半身加热伴随着抽搐和强直测试扭矩的显著增加，同时肌肉收缩时间的减少更大。在自愿激活和最大自愿扭矩产生方面，没有温度相关的衰老影响。尽管存在延迟和减弱的体温调节以及与年龄相关的神经肌肉功能下降，但在全身严重高热中，运动表现显然在健康衰老中得到了保留。
