BCAA (branched-chain amino acids)
BCAA (branched-chain amino acids), an amino acid. Mixture of the three branched-chain essential amino acids — leucine, isoleucine, valine — typically in a 2:1:1…
Mixture of the three branched-chain essential amino acids — leucine, isoleucine, valine — typically in a 2:1:1 ratio. Leucine is the canonical mTORC1 activator (sensed by Sestrin2 → GATOR → Rag GTPases → lysosomal mTORC1) → muscle protein synthesis stimulation; the broader BCAA pool also competes with tryptophan for LAT1 transport across BBB (theoretical effect on central serotonin during exercise, "central fatigue" hypothesis — equivocal evidence). Overall protein-anabolic effect of isolated BCAAs is now thought to be modest compared with complete-protein sources, since muscle protein synthesis is also rate-limited by other essential amino acids.
Sources: PMID:40284200