PROTEIN ADDED TO CARBOHYDRATE IMPROVES RECOVERY
Rossiter, A., Jakeman, P., O'Sullivan, A. J., & Dunne, C. (2007). Post-exercise feeding of carbohydrate-protein beverages on subsequent endurance performance. ACSM Annual Meeting New Orleans, Presentation Number, 2064.
This study compared cycling performance (time to fatigue) following ingestion of a beverage containing carbohydrate and protein, carbohydrate-only, or placebo over a four-hour period of rest-recovery from prolonged cycling. Endurance trained athletes (M = 5; F = 1) participated in three trial days, each trial separated by at least seven days. Trial days comprised 120 minutes of steady-state cycling, a four-hour period of rest recovery, followed by a steady-state cycle to volitional fatigue. All cycle trials were performed at ~70% VO2max. During recovery Ss consumed one of three two-liter beverages, one liter immediately after the 120 minutes of cycling and 500 mL at one and two hours of recovery. Ss ingested either flavored water (the control condition), a solution containing 1 gm CHO/kg/hour (CHO), or a solution containing 1 gm CHO/kg/hour and 0.33 gm protein/kg/hour (CHO+PRO).
After the 120 minutes of steady-state cycling there was no difference in energy expenditure or carbohydrate oxidation. Compared to the control/placebo condition, mean time to fatigue in the after the volitional trial to fatigue was 40% longer for the carbohydrate condition and 68% longer for carbohydrate-protein condition. Compared to placebo, the average rate of carbohydrate oxidation was greater for carbohydrate and the carbohydrate-protein conditions.
Implication. Ingestion of a carbohydrate-protein beverage during four hours of recovery from prolonged exercise resulted in a significantly higher rate of carbohydrate oxidation and post-recovery endurance performance. These data support previous reports of an ergogenic effect attributed to the rapid restoration of muscle glycogen when protein is added to a carbohydrate beverage.
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