Investigation of the effects of the pre-cooling on the physiological responses to soccer-specific intermittent exercise.

Abstract

Whole-body cooling prior to activity has the potential to reduce thermal strain and fatigue during subsequent endurance exercise. Intermittent activity is associated with greater increases in rectal temperature compared with continuous exercise. Thus, the effect of pre-cooling on thermoregulatory responses was examined during an intermittent test under "normal" environmental conditions. Six male university soccer players [mean (SD) age 27 (2) years; height 1.77 (0.3) m; mass 72.2 (1.5) kg; maximal oxygen consumption 58.9 (3.5) ml x kg(-1) x min(-1)] completed a 90-minute soccer-specific intermittent exercise protocol on a non-motorized treadmill. The run was completed with and without pre-cooling under normal laboratory conditions (20 degrees C) and without pre-cooling in a heated laboratory (26 degrees C). The pre-cooling strategy involved exposure to a cold shower (26 degrees C) for 60 min. The pre-cooling manipulation lowered rectal temperature prior to exercise [-0.6 (0.6) degrees C, range -1.5 degrees C; P < 0.05]. The rectal temperature response to exercise was significantly lower following pre-cooling than in the heated condition [pre-cooled 38.1 (0.6) degrees C, heated 38.6 (0.3) degrees C]. The increase in rectal temperature during the second half of the protocol following pre-cooling was significantly greater than the increase observed under normal or heated conditions (P < 0.05). No significant differences were observed between the three conditions for oxygen consumption, heart rate, minute ventilation, rating of perceived exertion and plasma lactate, glucose or free fatty acid concentrations. Based on the current investigation, it can be concluded that there is no evidence for the beneficial effects of pre-cooling on the physiological responses to soccer-specific intermittent exercise under normal environmental conditions.