Cooling for protection and recovery from exercise- and environment-induced heat stress in medium-fast bowlers

This thesis examined the effects of practical mixed-method cooling interventions for protection and recovery of medium-fast bowling performance in the heat, particularly focusing on the dosage effects required to elicit an ergogenic response. The initial investigation examined the effects of pre-cooling volume on neuromuscular function and performance during self-paced intermittent-sprint exercise in the heat. Ten male, team-sport athletes completed four randomised trials involving an 85 min cricket-specific self-paced intermittent-sprint exercise protocol in 33°C and 33% relative humidity. Pre-cooling interventions were applied for 20 min pre-exercise and included a control (no cooling; CONT), head (H), head+hand (HH), and whole-body methods (WB). Measures of maximal voluntary contraction (MVC) force and voluntary activation (VA) were obtained pre- and post-intervention and mid- and post-exercise. Self-paced intermittent-sprint running performance, core temperature (Tc), skin temperature (Tsk), heart rate (HR), rating of perceived exertion (RPE) and a thermal sensation scale (TSS) were monitored throughout. Further, venous and capillary blood samples were analysed for metabolite, muscle damage and inflammatory markers. The results demonstrated WB pre-cooling increased hard running distances by 12% compared to CONT (P < 0.05), and 6 â“ 7% compared to HH (P= 0.02) and H (P= 0.001), respectively. Similarly, WB pre-cooling blunted HR, Tc, Tsk, RPE and TSS responses during exercise to the greatest extent. Collectively, these data may highlight a link between pre-cooling volume and subsequent exercise performance, as larger surface area coverage augmented subsequent free-paced exercise capacity, in conjunction with greater suppression of physiological load.