The influence of cooling during recovery on intermittent sprint exercise in a temperate environment

This research project investigated whether intermittent cooling of the upper body impacted on anaerobic energy contribution and power output during high intensity intermittent cycling performance. Thermal balance was manipulated by the use of a Liquid Conditioning Garment (LCG) that permitted non-uniform thermal control over different regions of the body. This resulted in three systematically different thermal conditions: Control (CON, no thermal manipulation), Upper body Cooling (UC), and Upper body Cooling Leg Heating (UCLH). The exercise protocol performed on a friction loaded cycle ergometer consisted of four 30 s bouts of cycling at a wattage corresponding to 120% V˙O _{2 peak} interspersed with 4 min of passive thermal manipulations followed by a single 30 s ‘all-out’ Wingate sprint at 9% body weight. A randomised counter-balanced design was utilised. Change in body heat content (ΔS_t) prior to the Wingate sprint was greater in UC and UCLH than CON (P < 0.01) at −50.1 (±36.9 kJ·m −2), −32.2 (±18.5 kJ·m−2), and 38.1 (±26.7 kJ·m−2) respectively. Total heat loss from the thigh (Q_thigh) was greater in both UC and CON than UCLH in the first three of the four recovery periods (P < 0.01). No changes were seen in either peak or mean power output from the Wingate sprint or in oxygen deficit, and therefore anaerobic energy contribution, during the supramaximal work bouts. It was concluded that there was no justification for any cooling during recovery periods in intermittent exercise under the present conditions. Furthermore additional warming of the legs is not needed to counteract any loss of heat from the legs due to upper body cooling, Although not an a priori purpose of the study, light warming of the legs did not facilitate power production under the present conditions.