Branched-chain amino acids (BCAAs) have repeatedly been proven to aid recovery and muscle protein synthesis, and leucine in particular appears to play a big role in these functions. One study from the University of Birmington in England found that when healthy men consumed a BCAA formula containing 3.5g of leucine before and after resistance training, they reported significantly less muscle soreness 48 and 72 hours afterward than the control group. In another study, published in The American Journal of Clinical Nutrition, researchers tested whether the amount of leucine in a BCAA supplement affected its impact on muscle protein synthesis after exercise. Sure enough, the group that was given a leucine-enriched dose experienced 33% greater muscle protein synthesis than the group who consumed the standard mix of essential amino acids. It looks like leucine may even be able to slow down the loss of muscle that occurs naturally with age, according to a study published in the Journal of Nutrition, which concluded that long-term BCAA supplementation containing excess leucine can overpower muscles’ increasing resistance to protein synthesis over time. When it comes to recovery, you simply can’t beat BCAAs, especially leucine-enriched formulas, which appear to deliver the best results.
REFERENCES: S.R. Jackman, et al., Med Sci Sports Exerc. 2010 May; 42(5):962-70.; S.M. Pasiakos, et al., Am J Clin Nutr. 2011 Sept; 94(3):809-18. E-pub 2011 Jul 20.; S. Fujita, et al., J Nutr. 2006 Jan; 136(1 Suppl):277S-80SCheck out the latest in Science Behind the Supps