장시간 운동시 음료 섭취에 따른 ACTH, 코티졸, 인슐린 및 글루코스의 변화

The purpose of this study was to determine the effects of water intake and sports beverage intake on plasma ACTH, Cortisol, Insulin, and Glucose concentration during prolonged exercise. Eight university male students participated in this study. The subjects cycled on a bicycle ergometer for 2 hours at 60 % VC₂max. Total amount of fluid was net weight loss minus 1 kg after 2 hour of cycle ergometer exercise in the control. All kinds of beverages were administered immediately prior to exercise and every 15 minute throughtout the exercise. The beverages used in this study comprised water and sports beverage. Beverages were administered in a double blind method. The results were as following. First, plasma ACTH concentration was significantly increased during exercise in the all beverage treatments. Plasma ACTH concentrations at 120 min. of exercise were 56.94 ± 33.57 pg/ml, 34.98 ± 19.16 pg/ml, 27.30 ± 9.5 pg/ml in no fluid, water intake and sports beverage intake respectively, that is, plasma ACTH concentration showed the most increase in no fluid and the least increase in sports beverage. Second, plasma cortisol concentration was increased during exercise in the all beverage treatments, but significantly increased only no fluid(p<.001). That in no fluid was significantly increased at 120 min. of exercise. Therefore plasma cortisol concentration made no differences at 60 min. of exercise but was significantly higher in no fluid than in water intake and sports beverage intake at 120 min. of exercise(p<.01). Third, plasma insulin concentration was significantly decreased during exercise in no fluid(p <.01) and in water intake(p<.05), but was insignificantly decreased in sports beverage. No differences existed among the 3 beverage treatments at both of 60 min. and 120 min. of exercise. Fourth, plasma glucose concentration during exercise was significantly decreased in no fluid(p<.001) and water intake(p<.05). But plasma glucose concentration in sports beverage intake wasn t changed by exercise and was maintained constantly. Therefore, plasma glucose concentration at 120 min. of exercise was significantly higher in sports beverage intake than in no fluid and water intake(p<.01). From the results, this study showed that in no fluid and water intake, the maintenance of blood glucose concentration was helped by increasing plasma ACTH and cortisol concentration and decreasing plasma insulin concentration, and in sports beverage intake, gluconeogenesis of liver was decreased by relieving the increase of plasma ACTH and cortisol concentration and inhibiting the decrease of plasma insulin concentration during prolonged exercise.