Thermoregulatory and cardiovascular changes after cold water immersion as pre-cooling in amateur young adult mini-marathon runners

Abstract

Long distance running causes an increase in heat production typically exceeding the heat loss capacity resulting in body core temperature elevation that induces muscle fatigue and decrease of running performance. A strategy to prevent fatigue due to thermoregulation pressure caused by strenuous activity by lowering the increase body core temperature with cold water immersion (CWI) before running is essential. This study aimed to investigate the effect of CWI application as pre-cooling on thermoregulation and cardiovascular changes in amateur young-adult mini-marathon runners. Thirty young adult mini marathon runners aged 22.2 ± 3.1 years old, who had moderate to vigorous physical activity lifestyle were recruited to the study. They were divided into two groups by simple random sampling; non-CWI group (n = 15) performed 5-minutes dynamic stretching and CWI group (n = 15) were applied by 8-10°C cold water immersion for 5 minutes. Paired sample t-test was used to compare changes within groups between baseline and after receiving interventions and independent sample t-test was used to compare measured outcome between both groups. Significant changes were found in heart rate (HR), before and after intervention within both group (non-CWI: 82.5 to 110.1 vs 92.9 to 106.5; CWI: 84.2 to 104.7 vs 84.1 to 105.2, p-value < 0.01); body temperature (BT) (non-CWI: 37.1 to 36.6 vs 37.1 to 36.7; CWI: 37.2 to 36.7 vs 37.1 to 36.5, p-value < 0.05); and rating of perceived exertion (RPE) (non-CWI: 9.2 to 14.0 vs 7.9 to 13.5; CWI: 8.4 to 12.9 vs 7.9 to 12.4, p-value < 0.05). There was no significant difference between both groups in all outcomes (p-value > 0.05). These findings indicate that CWI and dynamic stretching application in controlled temperature produced nearly similar results, though CWI appeared to be slightly superior in terms of providing a positive impact on some physiological factors that might be associated with running performance improvement.