The Truth About BCAA

THE TRUTH ABOUT BCAA
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BCAAs stand for “branched chain amino acids”, and represent three out of our 20 amino acids (leucine, isoleucine, and valine). These, especially leucine, are marketed to be ”the best” amino acids for muscle gain because they boost muscle protein synthesis (1).
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Therefore, it might seem intuitive that its better to supplement with BCAAs than “regular” protein. BUT, there are 4 things you should keep in mind.

1. A combination of MANY amino acids is better at stimulating muscle protein synthesis compared to BCAA alone (2,3)
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2. Foods in your regular diet also contain BCAAs, and if you already eat enough protein (1.6 g/kg/bw), BCAAs won’t help you make more gains (4).
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3. Adding BCAAs to suboptimal protein increases muscle protein synthesis LESS compared to simply eating more protein or adding only leucine. (5)
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4. Of BCAAs, leucine is most important to jumpstart muscle protein synthesis. Isoleucine and valine use the same transporter as leucine for gut uptake. Therefore, it is speculated that they COMPETE with leucine, resulting in a smaller blood leucine peak. Thus, taking “leucine ONLY” supplements would likely be better. Alternatively whey or another compelete protein. Either way, BCAAs are the worst option.