Of these three, leucine is the muscle-building powerhouse. To unlock the full effects of leucine, the latest research suggests consuming 2 to 3 grams a sitting, at least 3 times during the day. You’ll find that sweet spot of 2 to 3 grams leucine in 1 scoop of whey protein (of which about 25 percent is from BCAAs), 1 cup of cottage cheese, or 3 ounces of chicken breast. (We love this organic whey protein from the Men’s Health store.) In fact, any animal protein has the leucine, isoleucine, and valine you need–in doses that are actually doable.
So Do BCAAs Help You Build Muscle?
“Bottom line: If you’re taking in adequate protein, then BCAAs are a complete waste of money,” says protein researcher, Stuart Phillips, Ph.D., of McMaster University.
Men’s Health nutrition advisor, Mike Roussell, Ph.D. agrees. “It is important to realize that BCAAs are found naturally in the proteins that you are already eating, like whey or casein protein shakes, eggs, beef, fish, and chicken,” he says. “This means that for the average guy looking to get fit, there’s no need to add a BCAA supplement to your post-workout protein shake. It’s overkill and it won’t get you any better results.”
Related Video: Do BCAA's Work?:
It’s not that taking more will hurt you, it’s just that those added aminos may not help you build any more muscle. In fact, one study in the journal Amino Acids (yes, there’s actually a research journal named that) found that the additional supplementation of leucine, one of the BCAAs, taken before and during anaerobic running, did not improve exercise performance.
On the flip, one study published in the Journal of the International Society of Sports Nutrition found that individuals were able to maintain lean body mass when supplementing with BCAAs during a calorie-restricted diet.
So, these study participants weren’t eating the recommended 2 to 3 grams of BCAAs per sitting in their low-calorie diet, but when they took BCAA supplements, it helped them retain muscle. And that’s hard to do when you’re trying to drastically slim down.
The final verdict? It’s not that BCAA supplements have no merit. You should take them if you’re not getting enough in your daily diet. But when you eat 2 to 3 grams of leucine from food sources at least 3 times a day, you don’t need them.
Chris Mohr Ph.D, R.D., is the owner of Mohr Results. He has Bachelor and Master of Science degrees in nutrition from The Pennsylvania State University and University of Massachusetts, respectively. He earned his Ph.D. in exercise physiology from the University of Pittsburgh and was formerly the consulting sports nutritionist for the Cincinnati Bengals and University of Massachusetts Athletic Program.