Branched chain amino acids, valine, leucine and isoleucine are widely popular among ergogenic products. Its greatest marketing appeal stems from claims that branched chain amino acids combined with resistance exercise stimulate muscle protein synthesis. However, evidence supporting the effectiveness of branched chain amino acids alone for muscle hypertrophy in humans is not consistent. Understand whether BCAAs aid in muscle hypertrophy.
BCAA and muscle hypertrophy
Existing evidence suggests that branched chain amino acids (BCAA) stimulate muscle protein synthesis after resistance physical exercise. However, in the absence of other essential amino acids, BCAAs are not able to sustain muscle protein synthesis. Therefore, a growing body of literature emphasizes that BCAA supplementation alone does not increase muscle protein more than the complete intake of high-quality protein containing the entire range of amino acids.
Resistance exercise increases the sensitivity of muscle tissue to amino acids for up to 24 hours post-exercise, regardless of whether the protein is consumed before, during or 1 to 3 hours after training. The main factor is the intake of proteins evenly distributed throughout the day, according to individual recommendations. In addition, induction of an anabolic state by repeated resistance of physical exercise and diet is what increases skeletal muscle remodeling and hypertrophy. For this reason, organizations support recommendations for physical resistance exercises combined with daily intake of 1.6g to 2.2g of high-quality BCAA-rich protein containing 700 to 3,000mg of leucine in amounts throughout the day (every 3 to 4 hours) for maximum muscle protein synthesis, including a dose after exercise and one close to bedtime.
Therefore, bcaa supplementation alone has no evidence to support its effect on increased hypertrophy. Therefore, the adequate intake of daily high-quality proteins distributed throughout the day is fundamental regardless of the supplementation of essential amino acids such as leucine, isoleucine and valine.
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: Branched Chain Amino Acids
– Santos CS, Birth FEL. Isolated branched-chain amino acid intake and muscle protein synthesis in humans: a biochemical review. Einstein (Sao Paulo). 2019;17(3):eRB4898. Published 2019 Sep 5. doi:10.31744/einstein_journal/2019RB4898