Abstract
The purpose of this study is to examine whether protein supplementation during 10-day aerobic training enhances the improvement of thermoregulatory capacity in young men. Fourteen subjects (age, 22 ± 4 (SD) yr; Vo2,peak, 56.5 ± 4.4 (SD) ml/kg/min) were divided into two groups according to the composition of supplements; placebo (C, 0.0g protein/kg, n = 7) and protein (S, 0.18g protein/kg, n = 7). Subjects in both groups exercised on a cycle ergometer at 60% peak oxygen consumption rate (Vo2,peak), 60 min/day, for 10 days, at 30°C of room temperature and 50% of relative humidity. They took protein or placebo within 30 min after exercise of each day. After training, Vo2,peak increased by 5.1 ± 0.8(SE)% in S and 5.3 ± 0.8% in C, but with no significant differences between the groups. The esophageal temperature thresholds for forearm skin vasodilation and sweating were measured by having the subjects exercise with a cycle ergometer at pre-training 60% Vo2,peak for 30-min in the same environment as during aerobic training. Both thresholds significantly decreased in S after training but not in C with significantly greater decreases in S than in C (P < 0.05). These results suggest that protein supplementation during 10-day aerobic training enhances the improvement of thermoregulatory capacity. [Jpn J Physiol 55 Suppl:S224 (2005)]
