The branched-chain amino acid activates the body’s mTOR pathway1, which controls the anabolic (growth) and catabolic (breakdown) signaling of skeletal muscle. “You can think of the BCAA leucine as a trigger or ‘its go-time’ button for muscle protein synthesis (i.e., the critical cellular process for building muscle),” explains mindbodygreen’s former vice president of scientific affairs, Ashley Jordan Ferira, Ph.D., RDN.

