Effect of Leucine Supplementation on Indices of Muscle Damage and Recovery Following Eccentric-Based Resistance Exercise

In vitro, the amino acid leucine has been able to reduce proteolysis and be a potent stimulus for protein synthesis. The purpose of this study was to determine the effect of leucine supplementation on indices of muscle damage and muscular function following eccentric-based resistance exercise. METHODS: Twenty-seven untrained individuals were randomly divided into 3 groups; leucine (L), placebo (P) and control (C). The L and P groups performed 100 depth jumps from 60 cm and 6 sets of 10 repetitions of eccentric-only leg presses. Either leucine (250 mg/kg bm) or placebo was ingested at 3 time points during exercise and each recovery day following exercise. Serum muscle damage markers and muscle function assessment were used to monitor recovery. RESULTS: No significant differences existed between experimental groups for the serum markers of damage. The L group was able to maintain peak force outputs during the muscle function tests CONCLUSIONS: Leucine supplementation may facilitate the recovery process. Leucine may need further examination, as it was unable to shown a between group difference compared to P but did minimize the change in muscle damage markers compared to PRE. Leucine supplementation minimized the decrement in muscle function and maintained force output when compared to a placebo.