You’ve probably heard that protein helps build muscle. But when you eat it matters almost as much as how much you eat — and most people are unknowingly leaving gains on the table by getting the timing wrong.

Here’s what the science actually says, and how to apply it practically.

When you strength train or do intense cardio, you create small tears in your muscle fibers. This sounds alarming, but it’s the whole point — your body repairs those tears and builds the fibers back slightly thicker and stronger. This process is called muscle protein synthesis (MPS).

For MPS to happen efficiently, your body needs amino acids available in the bloodstream. Those amino acids come from dietary protein. Without enough of them at the right time, recovery is slower and adaptation is blunted.

You’ve probably heard about the “anabolic window” — the idea that you must eat protein within 30 minutes of finishing a workout or the benefits disappear. The reality is more forgiving than that.

Research suggests the window is closer to 2 hours post-exercise, not 30 minutes. That said, eating protein sooner rather than later is still a good habit, especially if you trained in a fasted state or your last meal was more than 3–4 hours ago.

A practical target: aim to consume 20–40g of protein within 1–2 hours of finishing your workout.

Your body can’t store excess protein the way it stores fat or glycogen. When you eat more protein than your body can use at once for MPS, the excess is either used for energy or excreted.

Research consistently shows that muscle protein synthesis is maximally stimulated by roughly 20–40g of high-quality protein per meal — with diminishing returns beyond that threshold for most people. The exception is larger individuals or those doing very high training volumes, who may benefit from the higher end of that range.

This means that eating 150g of protein in one sitting is far less effective for MPS than distributing that same amount across 3–5 meals throughout the day.

Most people focus on post-workout nutrition, but what you eat before training matters too. Consuming protein 1–2 hours before exercise elevates amino acid availability during the workout itself, which can reduce muscle breakdown mid-session.

A meal with 20–30g of protein 1–2 hours before training — like Greek yogurt with fruit, eggs and toast, or a chicken wrap — sets you up well without weighing you down.

Muscle repair continues overnight, and research on casein protein — a slow-digesting protein found in dairy — suggests that consuming 30–40g before sleep can support overnight MPS. Cottage cheese, Greek yogurt, or a casein-based shake are practical options if recovery is a priority and you’re eating in a caloric surplus or maintenance.

You don’t need to obsess over every gram. A framework that covers the research:

Distribute protein evenly across 3–5 meals rather than loading it all at dinner

Eat protein before training — a meal 1–2 hours prior works well

Eat protein after training — within 2 hours, 20–40g from a quality source

Consider a protein-rich snack before bed if recovery and muscle building are goals

Total daily protein intake is the biggest lever — most adults benefit from 1.2–1.8g per kilogram of body weight per day, but consistently active adults may need closer to 1.6–2.2g/kg per day. Once you’re hitting that target, timing is the next variable worth optimizing. Spread it out, front-load around your workouts, and let your body do the rest overnight.