Sweating economy by graded control in well-trained athletes

Abstract:  Local sweat rates (M _sw) at the chest and thigh and the frequency of sweat expulsions (F _sw) were determined in human subjects with (athletes) or without (non-athletes) long-term physical training during moderate bicycle exercise (80 W for 30 min) at ambient thermoneutrality (23°C) and 60% relative humidity. There was a tendency for M _sw to be lower in athletes. The rise of M _sw with increasing F _sw was significantly less steep and F _sw was also controlled at a significantly lower rate in athletes than in non-athletes. The start of exercise was followed by a temporary decrease in mean skin temperature (T-_s) which was less distinct in athletes. The rise in T-_s at the end of exercise was significant in athletes (0.80 ± 0.26°C) but not in non-athletes (0.26 ± 0.33°C). The results indicate that long-term physical training leads to improved circulatory heat transfer to the skin and to a more graded nervous control of sweat expulsion and, further, tends to reduce the rate of sweating.