Body weight loss and fluid intake (sports drink) were measured using 7 older men and women in summer and autumm while they enjoyed a ball game called the Gate Ball, which is played on the ground outdoors. At the same time we investigated the type of clothing actually worn by them. Moreover, we interviewed elderly people on the demand and problems for the functionally comfortable clothing whem they played the game.
　The sweat rate, the fluid intake, and the body weight loss in summer were 6.0 ± 11.0 (mean ± SD), 3.4 ± 2.6, 2.5 ± 2.1 g/kg/h, respectively, which were significantly higher than those in autumn. The fluid intake and body weight loss had much individual variations and the rate of rehydration could not compensate for the body weight loss especially in summer. All the subjects wore the hats and the 4 people out of 7 wore long-sleeved shirts against the radiation heat from the sun in summer. The forty-nine percents of the elderly required the size-fitted garments and 35% of them desired the sports wear which can provide the clothing comfort from the aspects of clothing physiology and hygine. The outer upper wear, shoes, socks, headgear, and gloves were the most complaining clothing during the Gate Ball.
　These results suggest that the necessity of more water supply should be advised for the players. Concerning the change of the body shape of the elderly, the improvement of the clothing design should be considered to get the more healthy and comfortable garments during exercise.

DESCENTE SPORTS SCIENCE Vol.17/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE