Strategies to Reduce Heat Strain During Tennis Match-Play in Hot, Humid Conditions

Tennis match play often occurs in hot humid conditions increasing the risk of heat illness incidence, primarily due to increased body temperature and cardiovascular strain. Physiological and perceptual strain causes behavioural thermoregulation and can impair performance. Therefore, strategies which alleviate this heat strain could be beneficial from either a safety or performance perspective, or both. Little research has been conducted on the efficacy of heat alleviation strategies during tennis match play in hot conditions so it is unknown which strategies might be most beneficial. Consequently, the aim of this thesis was to assess the efficacy of acute heat alleviation strategies during simulated tennis match play in hot humid conditions and to better understand current practice and perceptions of heat alleviation strategies. The purpose of study 1 was to design and evaluate the test-retest reliability and validity of a tennis-specific treadmill protocol in temperate and hot, humid environmental conditions to allow confident interpretation of subsequent studies. Tennis players behaviourally increase the between�point rest length during tennis match play in hot humid conditions, therefore the aim of study 2 was to assess the thermal physiological and perceptual responses of this phenomenon. Increasing between-point rest from 20 to 30 seconds attenuated the rise in core temperature but had no effect on thermal perception. The aim of study 3 was to quantify the physiological and perceptual responses to internal, external, and combined internal and external cooling during simulated tennis match play in hot humid conditions. Internal cooling attenuated the rise in core temperature and lowers skin temperature and thermal sensation; external cooling only lowered skin temperature; combined cooling attenuated the rise in core temperature to the same extent but skin temperature and thermal perception to a greater extent than each strategy alone. The purpose of study 4 was to understand heat alleviation strategy current practice and perceptions of tennis players and support staff. Heat alleviation is perceived to be a useful tool for players competing in hot humid conditions and highlighted the importance of practicality. The findings from these studies improved the understanding of the physiological and perceptual responses to these strategies providing evidence that a longer between-point rest and internal cooling can slow the rate of rise in core temperature, and external cooling decreases the perception of the thermal sensation. All these strategies have the potential to enhance performance in hot humid conditions either physiologically or perceptually, in turn affecting autonomic and behavioural thermoregulation. The findings also have implications for future heat policy making and the application of heat alleviation in a hot humid environment.