Autonomic and behavioural thermoregulation in tennis.

Abstract

Objectives: This report describes physiological and behavioural mechanisms behind the control of body temperature and thermal comfort during competitive singles tennis. Methods: Thermoregulatory responses and workload were observed during best of three set tennis matches among 25 players. Ninety four matches were played in ambient temperatures ranging from 14.5 to 38.4°C. The thermal environment was assessed by dry bulb, wet bulb and natural wet bulb temperatures, globe temperature and wind speed. Core body and skin temperatures were recorded each minute throughout the match, whilst body mass and fluid intake were measured before the match, after 30 minutes of play and at the completion of the match to determine sweat rate. Subjective ratings of thermal strain included thermal comfort, sweatiness and perceived exertion. Workload observations involved: match duration, game duration, point duration, and the proportion of match time spent in play (effective playing time). Results: Change in rectal temperature was positively correlated with point duration (P < 0.001) and effective playing time (P < 0.05). Sweat rate demonstrated positive associations with air temperature (P < 0.0001), rectal temperature (P < 0.03) and skin temperature (P < 0.0001). Thermal comfort was reduced with increasing rectal temperature (P < 0.03) and skin temperature (P < 0.0001). Point duration and effective playing time were reduced when conditions were rated increasingly difficult (P < 0.002 and P < 0.0002, respectively). Conclusion: Autonomic (increase in sweat rate) and behavioural (reduction in workload) thermoregulation are responsible for the control of body temperature and thermal comfort during tennis.