Muscle glycogen restoration in females and males following moderate intensity cycling exercise in differing ambient temperatures
Carbohydrate, VO2 max, Metabolism
The purpose of this study was to determine differences in muscle glycogen restoration between males and females following 90 min of cycle ergometry at varying ambient temperatures. A total of 8 females (n=4) and males (n=4) performed a 90 min cycle ergometry trial (70% VO2 max) followed by 8, 1-min sprints (125% VO2 max) at 5°C, 25°C, and 35°C ambient temperature. The subjects were placed in a 20°C environment and received a carbohydrate supplement (1 g CHO kg body mass-1 ) at immediate- and 60 min post-exercise. Muscle biopsies were obtained before and at immediate- and 180 min post-exercise for the determination of muscle glycogen. Blood samples were obtained before exercise, every 0.5 hr during exercise, and every 0.5 h for 180 min following exercise for determination of serum glucose, insulin, and free fatty acids. There was a significant difference in muscle glycogen resynthesis between groups following cycling exercise at 5°C, 25°C, and 35°C. Males significantly increased muscle glycogen to near or above baseline levels. There was no significant difference between groups for muscle glycogen immediately post-exercise. The primary finding from this study indicates that males restore significantly more muscle glycogen than females in the 180 min immediately following moderate intensity cycling exercise at 5°C, 25°C, and 35°C.
Carper, Michael J., Scott R. Richmond, Samantha A. Whitman, Luke S. Acree, and Michael P. Godard. Muscle glycogen restoration in females and males following moderate intensity cycling exercise in differing ambient temperatures." J Exerc Physiol Online 16, no. 4 (2013)."