“You must eat protein within 30 minutes after training.”
You must eat protein within 30 minutes after training.
Daily total and per-meal distribution beat post-workout timing.
A meta-analysis of 23 trials found an apparent timing benefit that disappeared once total daily protein was controlled for. The 'window' effect was really a total-intake effect.
Where the myth comes from
Early studies gave one group a protein shake right after training and the other group nothing extra. The shake group did better — but they also ate substantially more protein per day, which is the variable that actually changed.
What the research actually shows
Schoenfeld and Aragon's meta-regression across 23 studies found that when total daily protein was equated between groups, timing no longer predicted gains in strength or . Their conclusion: total intake is the dominant variable, and the so-called anabolic window is far wider than 30 minutes.
How long the window really is
A resistance-training session leaves muscle sensitised to protein for roughly 24 hours, and elevated has been measured for up to 48 hours in less-trained lifters. A pre-training meal is also still digesting and delivering amino acids well into the post-session period.
What to do instead
Hit 1.6–2.2 g per kg of bodyweight per day, spread across three to five meals of roughly 0.3–0.4 g/kg each. If you trained fasted or it's been many hours since your last meal, eating soon afterwards is sensible — but as convenience, not as a deadline.
Meet your daily protein target across evenly spaced meals. Missing a 30-minute shake costs you nothing.