Romano, B. C., Todd, M. K., & Saunders, M. J. (2004). Effect of a 4:1 ratio carbohydrate/protein beverage on endurance performance, muscle damage, and recovery. Medicine and Science in Sports and Exercise, 36(5), Supplement abstract 851.

Male cyclists (N = 11) were studied to compare the effects of an antioxidant-fortified, 4:1 carbohydrate/protein beverage (CHO/P) to an isocaloric carbohydrate-only (CHO) beverage on time to fatigue, recovery, and muscle damage. Ss performed two sets of two exercise bouts to exhaustion on a cycle ergometer. In each set, the first exercise bout was performed at 70% of VO2max and the second (22-24 hours later) was performed at 80% of VO2max. Either CHO or CHO/P (8 ml/kg) was consumed every 15 minutes during exercise and a single 10 ml/kg dose was given immediately after exercise. The second set of exhaustive exercise was performed four to seven days later with the opposite beverage. Markers of muscle damage and ratings of soreness were measured prior to the first and second rides and 24- and 48-hours later.

No differences were found in time to fatigue or plasma LDH values. Ratings of soreness 24-hours after the initial exercise bout were increased in the CHO trials only. CK (creatine kinase to indicate muscle damage) levels were increased on Day Two in the CHO trials only, and attenuated in the CHO/P group by 45% on Day Two. Glucose, lactate, diet, VO2 and HR were similar between treatments.

Implication. A 4:1 carbohydrate/protein recovery beverage decreased muscle damage, as evidenced by CK values, and subjective ratings of soreness when compared to a carbohydrate replacement beverage. There was no ergogenic effect on time to fatigue demonstrated.

Return to Table of Contents for this issue.