Environmental Extremes Laboratory, University of Brighton, Eastbourne, BN20 7SN, United Kingdom.
Environmental Extremes Laboratory, University of Brighton, Eastbourne, BN20 7SN, United Kingdom.
Public Health. 2018 Aug;161:163-170. doi: 10.1016/j.puhe.2018.04.012. Epub 2018 Jun 18.
The elderly population is at an increasingly significant health risk to heat-related illnesses and mortality when compared with younger people in the same conditions. This is due to an increased frequency and severity of heatwaves, attributed to climate change, and reduced ability of elderly individuals to dissipate excess heat. Consequently, most excess deaths and emergency visits during heatwaves occur in people aged more than 65 years. The aim of this investigation was to assess the physiological and perceptual responses of elderly people during exercise sessions equating to activities of daily living in UK summer climatic conditions.
Mixed-method, randomised research design.
Twenty-eight participants (17 males, 10 females and 1 transgender female) were randomly assigned into three experimental groups; 15°C, 25°C or 35°C, with 50% relative humidity. Participants completed one preliminary and three experimental trials within their assigned environment. The data from the preliminary incremental recumbent cycling test was used to calculate participant's individual exercise intensities equating to 2, 4 and 6 metabolic equivalents (METs) for the subsequent trials. During experimental trials, participants completed 30-min seated rest and 30-min cycling.
No change was observed in thermal comfort ([TC] just uncomfortable in both trials), and only modest changes in ratings of perceived exertion (14 ± 2 vs 15 ± 2) at 6 METs in 25°C compared with those in 35°C were observed. In contrast, thermal strain markers did significantly increase (P < 0.05) across the same conditions, including change in rectal temperature (ΔT) during exercise (0.27 ± 0.17°C vs 0.64 ± 0.18°C) and peak skin temperature ([T] 32.94 ± 1.15°C vs 36.11 ± 0.44°C).
When completing exercise that equates to activities of daily living, elderly people could have a decreased perceptual awareness of the environment even though physiological markers of thermal strain are elevated. Consequently, the elderly could be less likely to implement behavioural thermoregulation interventions (i.e. seek shade and/or remove excess layers) due to a decreased awareness of an increasingly thermally challenging environment.
与同条件下的年轻人相比，老年人因热浪的发生频率和严重程度增加，以及老年人散发过多热量的能力下降，而面临着越来越大的与热相关疾病和死亡的健康风险。因此，热浪期间大多数超额死亡和紧急就诊发生在 65 岁以上的人群中。本研究旨在评估老年人在英国夏季气候条件下进行日常生活活动等效的运动过程中的生理和感知反应。
混合方法、随机研究设计。
将 28 名参与者（17 名男性、10 名女性和 1 名跨性别女性）随机分配到三个实验组中：15°C、25°C 或 35°C，相对湿度为 50%。参与者在其指定的环境中完成一次初步和三次实验试验。初步递增卧位自行车测试的数据用于计算参与者在随后的试验中相当于 2、4 和 6 代谢当量（MET）的个人运动强度。在实验试验中，参与者完成 30 分钟的坐姿休息和 30 分钟的骑行。
在 25°C 下，热舒适度（两次试验均为仅稍有不适）没有变化，与 35°C 相比，6MET 时的感知用力评级仅略有变化（14±2 对 15±2）。相比之下，在相同条件下，热应激标志物显著增加（P<0.05），包括运动期间直肠温度的变化（ΔT）（0.27±0.17°C 对 0.64±0.18°C）和峰值皮肤温度（[T]32.94±1.15°C 对 36.11±0.44°C）。
当进行相当于日常生活活动的运动时，老年人即使生理热应激标志物升高，对环境的感知也可能降低。因此，由于对日益热挑战环境的感知降低，老年人可能不太可能采取行为性体温调节干预措施（即寻找阴凉处和/或去除多余的衣物）。
