The effects of lower body passive heating combined with mixed-method cooling during half-time on second-half intermittent sprint performance in the heat.

Purpose: This study examined the effects of combined cooling and lower body heat maintenance during half-time on second-half intermittent sprint performances.

Methods: In a repeated measures design, nine males completed four intermittent cycling trials (32.1 ± 0.3 °C and 55.3 ± 3.7% relative humidity), with either one of the following half-time recovery interventions; mixed-method cooling (ice vest, ice slushy and hand cooling; COOL), lower body passive heating (HEAT), combined HEAT and COOL (COMB) and control (CON). Peak and mean power output (PPO and MPO), rectal (T), estimated muscle (T) and skin (T) temperatures were monitored throughout exercise.

Results: During half-time, the decrease in T was substantially greater in COOL and COMB compared with CON and HEAT, whereas declines in T within HEAT and COMB were substantially attenuated compared with CON and COOL. The decrease in T was most pronounced in COOL compared with CON, HEAT and COMB. During second-half, COMB and HEAT resulted in a larger decrease in PPO and MPO during the initial stages of the second-half when compared to CON. In addition, COOL resulted in an attenuated decrease in PPO and MPO compared to COMB in the latter stages of second-half.

Conclusion: The maintenance of T following half-time was detrimental to prolonged intermittent sprint performance in the heat, even when used together with cooling.