Enhancing physiological recovery and subsequent exercise performance in the heat using a phase-change material cooling blanket

Abstract

This study aimed to assess the effect of a phase-change material (PCM) cooling blanket for cooling between exercise bouts on recovery of physiological parameters and subsequent exercise performance in the heat. Eighteen male volunteers were recruited to participate in human trials involving two exhaustive treadmill running bouts (Bout1 for 3 km and Bout2 for 1.5 km) in a climate chamber (temperature = 33 °C; relative humidity = 40%). Participants were randomly subjected to one of two cooling conditions for a 10-min period between exercise bouts: CON: natural cooling; 10-min PCM: with a PCM cooling blanket for 10 min. Several physiological parameters including mean skin temperature (Tskin), oral temperature (Toral), core temperature (Tcore), heart rate (HR), mean arterial pressure (MAP), respiratory rate (RR), peripheral capillary oxygen saturation (SpO2), average running speed and rating of perceived exertion (RPE) scale score were analyzed. The results showed that compared to the CON group, participants in the 10-min PCM group had a significant lower Tskin, Tcore, HR and RR at post-cooling, as well as greater reductions in mean skin temperature (ΔTskin) and core temperature (ΔTcore) from post-Bout1 to post-cooling. Additionally, the 10-min PCM group exhibited significantly lower peak Tcore, peak HR and RPE scale score during Bout2, while the average running speed during Bout2 was significantly higher. The present study suggests that cooling with a PCM cooling blanket can enhance physiological recovery and subsequent exercise performance in the heat.