BCAAs help build muscle by making muscles create more protein and break down less protein when people are at rest.
Scientific Claim
BCAAs have anabolic effects on protein metabolism by increasing protein synthesis and decreasing protein degradation in resting human muscle.
Source Excerpt
“BCAAs (leucine, isoleucine, and valine), particularly leucine, have anabolic effects on protein metabolism by increasing the rate of protein synthesis and decreasing the rate of protein degradation in resting human muscle.”
Evidence from Studies
Supporting Studies
Branched-chain amino acids activate key enzymes in protein synthesis after physical exercise.
The study explicitly states that BCAAs have anabolic effects on protein metabolism in resting human muscle by increasing synthesis and decreasing degradation. This is a descriptive finding about BCAA effects in non-exercising conditions.
⚠️ Overstated
The study design is unclear (Level 5 evidence), and the claim uses 'have anabolic effects' which implies causation. The study only shows association between BCAAs and these effects.
More accurate phrasing:
“BCAAs are associated with increased protein synthesis and decreased protein degradation in resting human muscle, suggesting potential anabolic effects on protein metabolism.”