Carbohydrate-Protein Beverage Improves Recovery From Muscle Damage Induced By Downhill Running

Abstract

Downhill running has been shown to induce muscle fiber damage, delayed-onset muscle soreness, and various functional deficits. Consumption of carbohydrate-protein beverages during or immediately following strenuous exercise have been shown to reduce muscle damage, however its effects on performance recovery following downhill running have yet to be elucidated. PURPOSE: This study examined the effects of CHO+PRO vs. CHO on multiple aspects of muscle recovery following one bout of unaccustomed novel eccentric exercise (downhill running). METHODS: 20 physically active but untrained participants were randomly assigned to either CHO or CHO+PRO (n=10/group). Subjects consumed either 1.2 g·kg-1 CHO (CHO) or 1.2 g·kg-1 CHO + 0.3 g·kg-1 protein (CHO+PRO) daily for 7 days prior to eccentric exercise, and for 2 days following exercise. For eccentric exercise, subjects performed a 30-min downhill run (DHR) at 75% of their maximal heart rate on a -18% gradient. Creatine kinase activity (CK), lower extremity muscle soreness (SOR), and maximal isometric and isokinetic torque, were all assessed prior to 24 hr post, and 48 hr post DHR. Athletic performance was also assessed including 20-m sprint time, gross motor skills, vertical jump, and multistage fitness test prior to DHR and 48 hr post DHR. RESULTS: CK was increased at 24 hr and 48 hr post DHR (P<0.05) but there was no differences between the two treatments. SOR ratings from all three different lower body exercises were significantly elevated over time compared to pre exercise (PRE) and magnitude of hamstring soreness was attenuated at both 24 hr and 48 hr post exercise in the CHO+PRO group (P<0.01). CHO+PRO significantly reduced the deterioration in maximal isokinetic hamstring torque compared to CHO at 24 and 48 hr post DHR (P<0.05) but there were no treatment differences in maximal isometric torque. CHO+PRO treatment also resulted in better 20-m sprint performance 48 hr post DHR. CONCLUSION: The results of this study reveal that short term consumption of CHO+PRO beverage before and after one bout of eccentric exercise can enhance multiple aspects of muscle recovery which may have important implications for athletes and military personnel.