Presidential Closing Remarks 12:05 PM - 12:15 PM: Immediately Following President's Lectures ROOM: Ballroom 2/3 and Ballroom 1: D-12 Free Communication/Slide - Body Temperature and Exercise THURSDAY, JUNE 1, 2006 1:00 PM - 2:45 PM ROOM: 301
Skill performance deteriorates as hyperthermia develops during intermittent exercise in the heat. As pre-cooling lowers initial body temperature, it may play a role in improving skill performance during intermittent exercise in hot ambient conditions. However, there has been no little or no examination of this proposal.
PURPOSE: To examine the influence of whole body pre-cooling on skill performance during simulated squash match play in the heat.
METHODS: Six male squash players (22 ± 3 yr, 181 ± 5 cm, 75 ± 4 kg) were either pre-cooled for 60 min in a cool water shower or rested for 60 min before performing a skill test (ST 1), a 55 min simulated squash match in the heat (air temperature 28°C) and a second skill test (ST 2). By replicating shots performed in a match, skill performance was assessed using accuracy of a squash ball hitting pre-determined targets on the court floor. Comparisons between conditions were performed using a paired t statistic and simple, standardised effect size (ES). We also calculated the probability that the true population effect was practically significant (defined as one hit or one error) and interpreted this using a scale of qualitative descriptors and 90% confidence intervals (CI).
RESULTS: Pre-cooling did not affect shot accuracy in ST 1, with no change in either targets hit (5 ± 2 hits vs. 5 ± 2 hits; p = 0.741; ES = 0.1) or errors (9 ± 4 errors vs. 10 ± 3 errors; p = 0.910; ES = 0.0). Pre-cooling was found to diminish the skill decrement seen at the end of intermittent exercise in heat, with increased targets hit (5 ± 3 hits vs. 2±1 hits; p = 0.004; ES = 3.0) and reduced failure (9 ±4 errors vs. 13 ± 4 errors; p = 0.016; ES = 0.9). This indicates that the pre-cooling is ‘almost certainly' (99% probability; 90% CI 2.2 to 5.1) and'very likely'(98% probability; 90% CI-5.7 to-1.6) to be practically beneficial, respectively. Throughout exercise, core temperature was lower (37.7 ± 1.0°C vs. 38.4 ± 0.9°C; p = 0.001; ES = 0.8) and heat storage was greater (373 ± 61 W-nrz vs. 299 ± 43 W-nr2; p = 0.006; ES = 1.7) following pre-cool, which concomitantly attenuated heart rate (161 ± 15 beats-mirr1 vs. 165 ±15 beats-min1: p = 0.008; ES = 0.3) and perceived exertion (14 ±2 vs. 16 ± 2; p = 0.001; ES = 1.0).
CONCLUSION: Whole body pre-cooling is associated with improved skill performance at the end of simulated squash match play in the heat, which may be linked to a reduced thermoregulatory and perceived strain.