Myth or fact

You have to eat protein within 30 minutes of a workout

Short answerNo

By GyroscopeUpdated November 14, 20266 sources

No. When researchers pooled 23 studies of protein timing, eating protein right around a workout made no difference to muscle growth once the day’s total protein was counted, and the total was the strongest predictor of growth. Eat a normal meal with protein in the hours before or after you train, whenever it suits you.

Why people believe it

Plenty of people drink a shake before they’ve left the gym, worried they’ll miss it. The idea behind it sounds like science. Lifting breaks muscle down, the muscle is hungry for amino acids right after, and if you miss the 30 to 60 minute “anabolic window”, the chance to grow is gone.

Part of it is true. Muscle does respond more strongly to protein after a workout. The deadline is the part that doesn’t hold up.

What the studies found

In 2013, Brad Schoenfeld, Alan Aragon and James Krieger pooled the trials that compared protein timed around a workout with protein at other times. For muscle size, they had 23 studies and 525 people.

At first glance, timing seemed to help a little. Then they looked more closely. In most of the trials, the two groups didn’t eat the same total protein over the day. Once the researchers accounted for total protein, the timing effect disappeared. The day’s total was the strongest predictor of how much muscle people gained. For strength, timing made no difference at all.

They wrote that the results “refute the commonly held belief that the timing of protein intake in and around a training session is critical”.

The window is a day wide

A 2015 review noted that the muscle stays more responsive to protein for at least 24 hours after a workout, and that the window “does not have as drastic an effect on outcomes as has been believed”.

Think of watering a garden on a hot week. Whether you water at 7:00 or 7:30 doesn’t decide how the plants do. Whether they got enough water over the week does. Protein after a workout works the same way, on a scale of days.

A 2023 trial adds one more reason not to rush. Young men who drank 100 g of protein after training kept building muscle for more than 12 hours. A meal you eat an hour or two later is still well inside the time your muscle is building.

Where timing can help

There are a few cases where timing can help. If you train hard fasted, first thing in the morning, you’ve gone many hours without protein, and a breakfast with protein afterward makes sense. If you train twice a day, you’ll want protein between sessions. And if a shake after the gym is the only way you’d reach your daily range, it’s a fine habit.

In all three, the shake works because it adds to the day, or keeps a long gap from getting longer. The clock on the wall has little to do with it.

What decides muscle growth instead

The lifting comes first. In the 2018 review of 49 lifting trials, extra protein added about 0.3 kg of lean mass over programs of six weeks or more, on top of what the training itself built. Gains leveled off at about 1.6 g per kg a day. Timing didn’t come into it.

The order of what counts is lifting, then the day’s protein, then whether each meal has enough. The exact minute you drink a shake is far down the list.