CARBOHYDRATE-PROTEIN COMPLEX INCREASES THE RATE OF MUSCLE GLYCOGEN-STORAGE AFTER EXERCISE

Carbohydrate, protein, and carbohydrate-protein supplements were compared to determine their effects on muscle glycogen storage during recovery from prolonged exhaustive exercise. Nine male subjects cycled for 2 h on three separate occasions to deplete their muscle glycogen stores. Immediately and 2 h after each exercise bout, they ingested 112.0 g carbohydrate (CHO), 40.7 g protein (PRO), or 112.0 g carbohydrate and 40.7 g protein (CHO-PRO). Blood samples were drawn before exercise, immediately after exercise, and throughout recovery. Muscle biopsies were taken from the vastus lateralis immediately and 4 h after exercise. During recovery the plasma glucose response of the CHO treatment was significantly greater than that of the CHO-PRO treatment, but the plasma insulin response of the CHO-PRO treatment was significantly greater than that of the CHO treatment. Both the CHO and CHO-PRO treatments produced plasma glucose and insulin responses that were greater than those produced by the PRO treatment (P < 0.05). The rate of muscle glycogen storage during the CHO-PRO treatment [35.5 +/- 3.3 (SE) mu-mol.g protein-1.h-1] was significantly faster than during the CHO treatment (25.6 +/- 2.3-mu-mol.g protein-1.h-1), which was significantly faster than during the PRO treatment (7.6 +/- 1.4-mu-mol.g protein-1.h-1). The results suggest that postexercise muscle glycogen storage can be enhanced with a carbohydrate-protein supplement as a result of the interaction of carbohydrate and protein on insulin secretion.