Is Protein Before or After Workout Better for Building Muscle?

Neither is clearly better. In a 10-week trial, trained men who drank 25 g of protein right before lifting gained the same strength and muscle as men who drank it right after. A larger analysis found that total daily protein, not timing, was the strongest predictor of muscle growth. So pick whichever fits your day.

The idea of a narrow "anabolic window", where you must drink a shake within 30 minutes of training, has stuck around for years. The research doesn't support it in that strict form. Here's what the studies found, when timing does matter a little, and how much protein to aim for.

What Did the Study That Tested Before vs After Find?

No difference. Researchers had trained men take an identical protein shake either immediately before or immediately after each workout for 10 weeks. Both groups gained similar strength, muscle and body composition changes. The authors concluded the window for protein is far wider than the old 30-minute rule.

That 2017 randomized trial in PeerJ included 21 men with more than a year of lifting experience. One group took 25 g of protein right before training, the other right after, while doing three full-body sessions a week of three sets of 8 to 12 reps.

The authors wrote that the results refute "a narrow post-exercise anabolic window," and suggested the effective window may be as wide as several hours, depending on when you last ate before training.

Does Protein Timing Matter at All?

Much less than total intake. When researchers pooled 23 studies on protein timing, timed protein looked better at first, but the advantage disappeared once they accounted for how much protein people ate overall. Total protein was the strongest predictor of muscle growth. Timing is a minor detail.

That 2013 meta-analysis in the Journal of the International Society of Sports Nutrition covered 525 people in the muscle growth analysis and 478 in the strength analysis. Its conclusion was that "consuming adequate protein in combination with resistance exercise is the key factor."

Factor	How much it matters for muscle growth
Total daily protein	Strongest predictor in the 2013 meta-analysis
Lifting consistently	Essential; protein and exercise work together
Protein spread across meals	Helpful; 20 to 40 g every 3 to 4 hours
Before vs after workout	No meaningful difference in the trial that tested it

How Much Protein Do You Need a Day?

About 1.4 to 2.0 g per kilogram of body weight for most people who lift. Spread it across three to five meals or snacks of roughly 20 to 40 g each. If you're cutting calories while lifting, you may need more, up to about 2.3 to 3.1 g per kg, to hold on to muscle.

Those figures come from the International Society of Sports Nutrition (ISSN) position stand on protein. It also notes that the muscle-building effect of a workout lasts at least 24 hours, which is another reason the exact timing of one shake matters less than your whole day.

For an 80 kg (176 lb) lifter, 1.6 g per kg works out to about 130 g of protein a day. Our guide on how much protein you can absorb at once covers how to split that up.

When Does Protein Timing Matter More?

When you train after a long time without eating. If you lift first thing in the morning on an empty stomach, or many hours after your last meal, it makes more sense to get protein soon after the session. If you ate a protein-rich meal a couple of hours before, there's less urgency.

The 2017 trial authors made this exact point: the post-workout window depends on when your pre-workout meal was eaten. The ISSN agrees that the best time is "likely a matter of individual tolerance," since benefits come from protein taken either before or after training.

Our guide on what to eat before a morning workout has quick options if you train early, and what to eat after a workout covers the meal afterwards.

How Much Protein Should You Have After a Workout?

About 20 to 40 g, or roughly 0.25 g per kg of body weight. Larger, heavier lifters and people who train the whole body in one session may benefit from the higher end. In one study, 40 g after a full-body workout stimulated more muscle building than 20 g.

That 2016 study in Physiological Reports tested 30 resistance-trained men after whole-body lifting. Muscle protein synthesis was about 20% higher after 40 g of whey than after 20 g, and the result held whether the men had more or less lean mass.

If you like a shake after training, protein shakes for muscle recovery covers what they do for strength and soreness, and adding creatine to one works well. Our guide on mixing creatine with a protein shake explains how.

Is a Protein Shake Better Than Whole Food?

No. Whole food works just as well as long as you hit your daily total. Shakes are simply convenient, especially right before or after a workout when you don't want a full meal. Use whichever helps you get enough protein consistently, and don't feel you need a supplement to build muscle.

The ISSN position stand notes that it's possible for active people to get all their protein from whole foods, and describes supplements as "a practical way" of ensuring enough high-quality protein while keeping calories in check. Eggs, dairy, meat, fish, tofu and legumes all count.

If you choose protein before or after your workout based on appetite and schedule, the research says you won't be leaving gains on the table either way.

Is It Better to Have Protein Before Bed?

It can help if it gets you closer to your daily target. Protein before bed is one more chance to add a serving. But it isn't magic. What counts is getting enough protein across the whole day, evenly spread when you can.

The ISSN recommends spreading protein doses evenly, every three to four hours, across the day. For many people, a late serving is simply the easiest way to fill a gap.

The same logic applies to creatine: timing matters less than taking it daily, as our guide on the best time to take creatine explains.