You have probably heard it in a gym or from a trainer. Get a protein shake into you fast after lifting, or your workout is wasted. The clock usually falls somewhere between 30 and 60 minutes.
The idea rests on a so called anabolic window, a short period when muscle is thought to be especially hungry for protein. But the research has moved on.
The 2017 position stand on protein and exercise from the International Society of Sports Nutrition says the body stays sensitive to protein for up to 24 hours after resistance training.
Total daily protein intake matters far more than squeezing a shake into a short post workout window.
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What the research actually says about the window
A 2013 meta analysis in the Journal of the International Society of Sports Nutrition pooled 23 trials on muscle growth. The authors were looking for a timing effect.
Once they adjusted for total daily protein intake, the effect vanished. Timing around the workout no longer made a measurable difference for strength or muscle size.
The researchers, led by exercise scientist Brad Schoenfeld, concluded that if an anabolic window exists at all, it stretches well beyond one hour before and after training.
Why total daily protein does the heavy lifting
The 2017 ISSN protein stand recommends 1.4 to 2.0 grams of protein per kilogram of body weight per day for people who exercise. For a 70 kilogram adult, that works out to roughly 100 to 140 grams of protein a day.
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The stand also suggests about 20 to 25 grams of protein at each main meal, with no more than three to four hours between them.
The small timing benefit that remains
A follow up stand on nutrient timing, published later in 2017 by the International Society of Sports Nutrition and led by Chad Kerksick, reached the same conclusion.
When daily protein intake is at recommended levels, any effect of workout timing on muscle gains is minimal at best.
Timing is not completely pointless. A reasonable pre workout meal appears to extend the useful window further. And spreading protein evenly across the day supports muscle growth better than piling it into one big meal.
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For an active adult in the 1.4 to 2.0 grams per kilogram range, aim for 20 to 25 grams of protein every three to four hours. A post workout shake can fit that pattern easily. If it does not, you have hours of flexibility either side of training.
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This article is made and published by Jesper Bengtson, who may have used AI in the preparation.