BCAAs might help muscles build protein after exercise by turning on specific signaling pathways, including mTOR and p70 S6 kinase.
Scientific Claim
BCAAs may mediate their anabolic effects through changes in signaling pathways controlling protein synthesis, including mTOR and p70 S6 kinase activation.
Source Excerpt
“These effects are likely to be mediated through changes in signaling pathways controlling protein synthesis. This involves phosphorylation of the mammalian target of rapamycin (mTOR) and sequential activation of 70-kD S6 protein kinase (p70 S6 kinase) and the eukaryotic initiation factor 4E-binding protein 1.”
Evidence from Studies
Supporting Studies
Branched-chain amino acids activate key enzymes in protein synthesis after physical exercise.
The study suggests that BCAA effects are mediated through signaling pathways including mTOR and p70 S6 kinase activation. This is a mechanistic interpretation of how BCAAs might work.
⚠️ Overstated
The study design is unclear (Level 5 evidence), and the claim uses 'may mediate' which is somewhat appropriate, but 'activation' implies causation. The study only shows association between BCAAs and pathway changes.
More accurate phrasing:
“BCAAs are associated with changes in signaling pathways controlling protein synthesis, including mTOR and p70 S6 kinase activation.”