Perception of Thermal Comfort During Exercise

Abstract

Exercise is a significant contributor to health and wellbeing, and many activities rely on a dedicated indoor facility to take place. Substantial resource is used to condition indoor sport facilities despite there being limited understanding of what constitutes thermal comfort during exercise. Conventional metrics to evaluate thermal comfort are derived from sedentary or near-sedentary individuals, prompting investigation into the fundamental notions of comfort during exercise. Whilst insightful, prior research on this topic has predominantly occurred in laboratory settings that lack experiential realism. Thermal surveys to explore occupant sensation, comfort, preference, acceptability, tolerance and environmental perception were undertaken in a naturally ventilated multipurpose indoor sports hall in the United Kingdom over a 24-month period. Environmental conditions were monitored at four locations in the hall, with the sample encompassing low (< 3 MET), medium (3–5 MET) and high (> 5 MET) activity intensities. The study highlights the complexity of monitoring large open indoor spaces, particularly direct measurement of radiant effects at the centre of the space. Using nonparametric methods, data were analysed to evaluate thermal judgements and their implications for space conditioning. Comfort was observed across a broad range of environmental air temperatures (13°C–24°C), with discomfort increasing as thermal sensation became more intense. Exercising individuals exhibited a drift in thermal neutrality, with a preference for a warmer personal thermal sensation corresponding to +0.7 scale points on the thermal sensation scale. This did not apply to environmental air temperature, where preference was for thermally neutral conditions (i.e., neither cool nor warm). This suggests that the commonly used 7-point thermal sensation scale is not an appropriate proxy for satisfaction with environmental conditions for exercising individuals. Metabolic rate was significant in the perception of thermal sensation during exercise (r_s = 0.337, p < 0.001), with environmental conditions observed to have less impact. Environmental air temperature was, however, a critical factor for the acceptance (r_s = −0.269, p = 0.002) and tolerance (r_s = 0.283, p = 0.001) of overall thermal state, declining where environmental conditions exceeded 24°C and highlighting the significance of appropriate sport facility conditioning strategies.