A Study on Basal Metabolism of Athletes : I. On Seasonal Variation of Basal and Resting Metabolism

Abstract

Seasonal variation of basal metabolism (BN) and resting metabolism (RM) was examined on six subjects who belonged to a rugby football club and five ordinarily students as a control. In order to estimate the extent of contribution of the skeletal muscles of extremities to the total body metabolism under basal or resting condition, the effect of lighting limbs on the total body metabolism was observed simultaneously. Results obtained are as follows: 1) Average value of BM throughout the whole year was 39.3 Cal/m^2/hr in athletes, being higher than that of nonetheless (36.1 Cal/m^2/hr). 2) BM and RM were increased in winter and decreased in summer. The extent of this seasonal variation of athletes in basal condition amounted to about l6.3% of the annual mean value. 3) The metabolic rate of athletes is depressed by ligature of the limbs by only 10.6% under basal condition. Therefore, the contribution of the skeletal muscles to the total heat production is not so great ad estimated before, and oxygen consumption of the skeletal muscles per kg is greater than that of nonetheless in both basal and resting condition. 4) The seasonal change was not only caused by an alteration of metabolism of internal organs quantitatively, but also by an adaptational change of metabolism in the skeletal muscles itself. 5) The metabolism was in the lowest level in the range of 20-25℃ of the environmental temperature in both groups, and below this range it was raised relatively steeply. The rise in the cold season was mainly brought about by an increment of the heat production of the skeletal muscles, and this tendency was significantly demonstrated in both groups, especially in athletes.