- Conventional wisdom says that in order to maximize your muscle-building efforts in the gym, you need to eat protein within one hour of your last rep.
- But that’s “bro science,” exercise scientist Brad Schoenfeld said Sunday at the Academy of Nutrition and Dietetics’ annual Food and Nutrition Conference and Expo.
- His research suggests that so long as you eat protein within a several-hour window of your workout — whether before or after — your gains will be more or less the same.
- Schoenfeld also challenged other “bro science” assumptions, like that your body can’t handle more than 20 to 30 grams of protein at a time for muscle-building purposes.
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Conventional wisdom, or at least gym-rat wisdom, says that you need to eat protein within an hour of your last rep to maximize the workout’s muscle-building effects.
But the reality is more nuanced, Brad Schoenfeld, an associate professor in exercise science at CUNY Lehman College, said Sunday during a presentation at the Academy of Nutrition and Dietetics’ annual Food and Nutrition Conference and Expo in Philadelphia.
While it’s true that eating protein post-gym helps repair, and thus grow, muscle tissues, Schoenfeld’s found it’s also true that eating protein pre-gym helps repair, and thus grow, muscle tissues.
In other words, it doesn’t matter so much whether or how quickly you eat protein before or after a workout, so long as you’re doing it at all.
“If you actually take in pre-workout meals, everything is off the table,” said Schoenfeld, who’s also the author of “The Science and Development of Muscle Hypertrophy” and owns the URL lookgreatnaked.com.
In the study supporting this conclusion, Schoenfeld and a colleague recruited 21 fit, college men, and assigned half to take a supplement with 25 grams of protein and 1 gram of carbohydrate before working out and the other half to take the same supplement after working out. Their workouts were the same full-body, weight-training routines performed three days a week for 10 weeks.
After measuring the men’s muscle thickness, strength, and overall body composition using top-tier techniques like ultrasound and dual x-ray absorptiometry imaging, the researchers found no significant difference in the gains of the men who protein-packed pre-workout versus those who did so after hitting the gym.
The findings, Schoenfeld said, suggest the best time to eat protein isn’t a narrow one-hour post-workout window, but more like a “barn door” that may open as wide as four to six hours surrounding the workout itself.
“If you’re eating breakfast, lunch, and dinner and having snacks in between, you’re going to hit your window,” he said. “You don’t have to sweat.”
How much protein your body can handle at once is also nuanced
During his presentation, Schoenfeld also challenged other notions he dubbed “bro science,” like the idea that your muscles can’t use any more than 20 to 30 grams of protein at once, so consuming any more than that for muscle-building purposes is worthless.
While there is some support to that theory, Schoenfeld said; again, it’s nuanced. For one, much of the research that’s come to that conclusion is based on studies where participants are eating “fast-acting protein” like pure whey supplements alone.
In real life, people tend to eat slower-acting proteins (like actual meat or eggs) in combination with other macronutrients, like carbohydrates, which slows down the absorption. Those more complex forms slow down absorption and theoretically allow some people’s muscles to use more than a 30-gram-per-meal cap.
Plus, of course, everyone is different, so such a “cap” may be appropriate for some, but isn’t a universal rule.
Rather, “a relatively simple and elegant solution” is to consume 0.4 grams of protein per kilogram of body weight across at least four meals a day if your goal is muscle building, Schoenfeld and a colleague concluded in a paper published in the Journal of the International Society of Sports Nutrition.
That translates to about 27 grams per meal for a 150-pound person, but a whole 45 grams per meal for a 250-pound person.
Still, the researchers, conclude, “further research is nevertheless needed to quantify a specific upper threshold for per-meal protein intake.”