The relationship between body composition and thermal responses to hot and cold water immersion

The current study aimed to examine the influence of body fat percentage on thermal responses to water immersion at the two temperature extremes used in athletic recovery, by comparing the thermal responses of low- and high-fat individuals to immersion in hot water (HWI) or cold water (CWI). Thirty-nine subjects completed a body composition assessment (to determine low-fat and high-fat groups), and 15 minutes of either CWI (n = 20) or HWI (n = 19), followed by 30 minutes of passive rest. Core temperature (Tc), skin temperature (Tsk), and thermal sensation (TSS) were recorded at various time points during immersion and throughout the rest period. There were no significant differences between the low- and high-fat groups during CWI; however, the low-fat group had a significantly lower Tc compared to the high-fat group at 10, 20, and 30 minutes post-CWI (p less than 0.05). During HWI, the low-fat group had a significantly higher Tc at 5 minutes (p less than 0.05). In the low-fat group, TSS was significantly lower at 15 minutes of CWI (p = 0.03) and significantly higher at 15 minutes of HWI (p = 0.03), relative to the high-fat group. There were no significant differences between groups for Tsk measurements. Percentage body fat affects physiological and perceptual responses to immersion in both hot and cold water. Current hydrotherapy practices may need to be individualized to ensure optimal recovery