抄録
To study the effects of kendo uniform and protectors in a hot environment on dehydration during exercise, we compared two conditions ; 30 min exercise with and without kendo uniform and protectors. Five male college kendo fencers performed modelately severe kendo practice at dry bulb temperatures of 30.2 ± 1.0°C and wet bulb temperatures of 24.9 ± 2.1°C. Other five fencers performed bicycle exercise designed to the same intensity as kendo practice at dry bulb temperatures of 36 .5 ± 0.5°C and wet bulb temperatures of 27.0 ± 1.7°C. After both exercises, body weight was significantly decreased, and hematocrit, serum total protein concentration, and heart rate were significantly increased. In kendo practice, however, the decrease in body weight and the increases in hematocrit and serum total protein concentration were significantly higher than those in bicycle exercise. There is no significant difference in the change in heart rate between kendo and bicycle exercises. We conclude that exercise with kendo uniform and protectors in hot environment results in marked dehydration and plasma volume loss, by the increase in sweat, which may be caused by insulation of heat dissipation and/or added heat production by the weight of protectors, and that the improvement of kendo uniform and protectors may prevent marked dehydration and plasma volume loss, and, consequently, heat stroke.
