Protein Synthesis
Protein synthesis is the cellular process of building new proteins from amino acids. In muscle tissue, this process is called muscle protein synthesis (MPS), and it is what your body does to repair training damage and grow new contractile tissue.
Why It Matters
Every protein in your body, from antibodies to enzymes to muscle fibers, gets built through protein synthesis. Lifting weights breaks down muscle proteins; synthesis builds them back, often slightly stronger. Net protein balance over weeks and months determines whether you gain, hold, or lose muscle.
Leucine, a branched-chain amino acid, is the primary trigger that switches synthesis on. A meal containing roughly 0.4 grams of high-quality protein per kilogram of body weight typically delivers enough leucine to maximize the response.
How to Spot It on a Label
You will see protein synthesis referenced in marketing copy on most premium whey tubs. Look for verified leucine threshold or supports muscle protein synthesis claims, then check the back panel to confirm the product actually delivers 2.5g+ of leucine per serving.
Examples from real products
Related Terms
Keep learning with these closely-linked entries: