White, J., Austrin, K., Breer, B., St. John, N., & Patton, L. (2006). Effect of carbohydrate-protein supplement timing on exercise-induced muscle damage. Medicine and Science in Sports and Exercise, 38(5), Supplement abstract 1997.

The purpose of this study was to examine if the timing of a carbohydrate/protein supplement would have an effect on post-resistance-exercise muscle damage, function, and soreness. Untrained males (N = 27) were given a supplement before or after a bout of resistance exercise. SS were randomly assigned to three groups. The pre-exercise group (N = 9) received a carbohydrate/protein drink immediately before the exercise bout and a placebo drink immediately after. The post-exercise group (N = 9) received a placebo drink immediately before the exercise bout and a carbohydrate/protein drink after. The control group (N = 9) received a placebo drink before and after the bout of exercise. Ss performed 50 eccentric quadriceps contractions on an isokinetic dynamometer. Tests for serum creatine kinase (CK), maximal voluntary contraction (MVC) and muscle soreness scores were recorded before the exercise bout then again at six, 24, 48, 72, and 96 hours post-exercise.

Responses were similar for all groups. Serum CK increased post-exercise (peaking at 72 and 96 hours) when compared to pre-exercise values. Maximal voluntary contraction was significantly reduced at six hours, was maximally reduced at 24 hours before gradually returning to pre-exercise values. Muscle soreness scores significantly increased and peaked at 48 hours post-exercise when compared to pre-exercise values.

Implication. Eccentric resistance exercise caused significant muscle damage, soreness, and loss of strength in all groups. The timing or ingestion of the carbohydrate/protein supplement had no effect on these variables.

Return to Table of Contents for this issue.