Protein Guide
Protein for muscle growth: how much, when, and why
Muscle isn't built in the gym — it's built afterward, from amino acids, and only if enough of them are available.
The mechanism: muscle protein synthesis
Resistance training damages muscle fibers at a microscopic level and triggers muscle protein synthesis (MPS) — the process your body uses to repair and build new muscle tissue. Both exercise and protein intake independently stimulate MPS, and the two together are more powerful than either alone. After a resistance training session, MPS can stay elevated for up to 48 hours as your body remodels the trained muscle.[1] Without enough dietary protein available during that window, the repair process is incomplete.
How much, and how often
- Daily total: 1.6–2.2 g/kg body weight for most people actively training for muscle growth
- Per-meal target: roughly 0.4 g/kg, spread across 3–4 meals — this appears to maximize MPS response better than getting most of your protein in one large meal
- Consistency matters more than precision — hitting your daily total most days beats hitting an exact number occasionally
Does the "anabolic window" matter?
The idea that you must eat protein within 30–60 minutes of training to avoid "missing the window" is largely overstated. Total daily protein intake and consistent spacing across the day matter far more than precise post-workout timing for most people. See our full breakdown of protein timing research.
Keep reading: Does protein timing matter? · How much protein per day · Macros for building muscle