Protein Supplementation During or Following a Marathon Run Influences Post-Exercise Recovery

The effects of protein supplementation on the ratings of energy/fatigue, muscle soreness [ascending (A) and descending (D) stairs], and serum creatine kinase levels following a marathon run were examined. Variables were compared between recreational male and female runners ingesting carbohydrate + protein (CP) during the run (CP_During, n = 8) versus those that were consuming carbohydrate (CHO_During,n = 8). In a second study, outcomes were compared between subjects who consumed CP or CHO immediately following exercise [CP_Post (n = 4) versus CHO_Post (n = 4)]. Magnitude-based inferences revealed no meaningful differences between treatments 24 h post-marathon. At 72 h, recovery [Δ(_{72 hr-Pre})] was likely improved with CP_During versus CHO_During, respectively, for Physical Energy (+14 ± 64 vs -74 ± 70 mm), Mental Fatigue (-52 ± 59 vs +1 ± 11 mm), and Soreness_-D (+15 ± 9 vs +21 ± 70 mm). In addition, recovery at 72 h was likely-very likely improved with CP_Post versus CHO_Post for Physical Fatigue, Mental Energy, and Soreness_-A. Thus, protein supplementation did not meaningfully alter recovery during the initial 24 h following a marathon. However, ratings of energy/fatigue and muscle soreness were improved over 72 h when CP was consumed during exercise, or immediately following the marathon.