Abstract
The present study was carried out to investigate the effect of exercise on the minimal protein requirement in men. Six healthy men were used as the subjects. This work substantially consisted of four periods (Exercise-I, Exercise-II, Non-Exercise-I and Non-Exercise-II) according to the physical condition and protein intake levels (76 mgN/kg/day and 111 mgN/kg/day) of the subjects. Urinary nitrogen excretion, fecal nitrogen output and dermal nitrogen loss were measured for the determination of the minimal protein requirement by using the nitrogen balance method.
The results were as follows;
Urinary nitrogen excretion in Exercise-I and II periods significantly decreased, compared with those in Non-Exercise-1 and II periods. Whereas dermal nitrogen loss in Exercise-I and II periods significantly increased, compared with those in Non-Exercise-1 and II periods. There were no significant differences in nitrogen balance between Exercise-I and Non-Exercise-I and between Exercise-II and NonExercise-II. Nitrogen necessary for maintenance of nitrogen equilibrium in the Non-Exercise period was almost the same as that in the Exercise period.
The above results suggest that the increase of dermal nitrogen loss induced by exercise was cornpensated by a decrease of urinary nitrogen excretion. Exercise had no effect on the minimal protein ranquirement.
