The physiological effects of pre-event and midevent cooling during intermittent running in the heat in elite female soccer players.

Abstract

The purpose of this study was to examine the effects of both pre-exercise and combined pre-exercise and midexercise cooling strategies during simulated match play in elite female soccer players in the heat. Eight elite female soccer players performed two 45 min periods of intermittent running separated by 15 min seated rest on 3 separate occasions (30.6 +/- 0.2 degrees C, 63.4 +/- 2.5% relative humidity). Participants undertook a no-cooling (CON) or ice-vest cooling for 20 min pre-exercise (PRE) or both pre-exercise and during the 15 min rest period (PRE+MID). Rectal temperature (Tre), skin temperatures, and heart rate were monitored continuously. Mean skin temperature (TMS) and heat storage were calculated. Significant interactions (trial x time) were observed for the change in Tre from rest, TMS, and heat storage (p < 0.05). The change in Tre from rest was greater during CON when compared with PRE and PRE+MID from 35 min until the end of exercise (p < 0.05). When compared with CON (p < 0.05), TMS was lower after precooling (PRE and PRE+MID) and during the 15 min rest period and the first 5 min of the second exercise bout for PRE+MID. Heat storage was also lower after precooling (PRE and PRE+MID) (p < 0.05) and from 60 min until the end of exercise for PRE+MID (p < 0.05) and until 85 min and again at 95 min during PRE (p < 0.05). The results of this study suggest that both cooling strategies were effective in reducing thermal strain during intermittent exercise in the heat. However, PRE+MID cooling was more effective than PRE cooling in offsetting heat storage.