The Effects of BCAA-Enriched Essential Amino Acid Mixtures and Exercise on the Muscles: A Randomized, Single-Blind, Placebo-Controlled Trial

Background: Protein intake provides the essential amino acids (EAA) necessary for promoting muscle protein synthesis. Branched-chain amino acids (BCAA) belonging to the EAA in particular are known to have more potent effects. We developed BCAA-enriched essential amino acids (BEAA®) to improve muscle health and performance. Therefore, we aimed at comparing the effects of BEAA® and whey protein intake in combination with exercise on muscle mass and strength in humans. Methods: A randomized, single-blind, placebo-controlled, parallel-group study was conducted to evaluate the impact of BEAA® and exercise on the muscles in healthy participants. Seventy-five healthy male participants were enrolled and randomly divided into three groups; the BCAA-enriched essential amino acids (BEAA), whey protein (WHEY), and placebo (PLA) groups. The participants consumed either the food containing BEAA® 3 g, whey protein 20 g, or dextrin 3 g for 12 weeks. The participants exercised five times weekly, and the exercise load was gradually increased. The primary (muscle mass) and secondary (muscle strength) outcomes were evaluated. Results: Whole-body muscle mass and lower-limb muscle mass showed statistical significance in the BEAA group compared to the PLA group (P Conclusions: Overall, BEAA® was shown to increase muscle mass in healthy adult males when combined with exercise.