Brace yourselves, winter is coming: a pilot study of the effects of brief, infrequent cold water immersion upon body composition in young adult males

Background: The existence of functioning brown adipose tissue (BAT) in adult humans has brought into question the possibility of utilising the BAT mechanism as an obesity tackling strategy. This pilot study examined the effects of a short-term (6wk) cold water immersion (CWI) programme on the body composition of (n=10) healthy male adults. It was hypothesized that the thermal stresses would produce reductions in fat mass (FM) and body fat percentage (BFp) as a result of thermogenic activation of the BAT mechanism. Methods: Using a single arm prospective trial design, participants were subjected to singular acute (18min) cold water exposures (15±1°C) weekly for the duration of the intervention (6wk). Results: Non-significant decreases were observed in FM (-1.55±2.24kg; p = 0.057) and BFp (-1.62±2.46%; p = 0.067), and significant increases in fat free mass (FFM; 1.46±1.68kg; p = 0.023). Conclusions: The results indicate that the intervention could be adopted as a plausible method to exert positive changes to body composition. These findings should stimulate follow up studies to examine the interventions efficacy in a larger more representative sample and examine its feasibility of implementation as a genuine obesity tackling strategy