BCAAs

What are BCAAs?

Amino acids—the building blocks of life—are molecules that combine to build proteins. There are 20 amino acids and nine of those 20 are essential proteins, which means the body can’t make them and they must come from outside sources.

Of the nine essential amino acids, three are BCAAs: leucine, isoleucine, and valine. All essential amino acids play a vital role in making proteins and building muscle. However, BCAAs have a unique molecular structure that might make them a bit more beneficial to your body’s musculature.

Most amino acid catabolism—breakdown—occurs in the liver. But not BCAAs. Catabolism of these amino acids primarily happens in the skeletal muscles. Unlike other essential amino acids, BCAAs also act as a source of energy for your muscles during a workout.

Why are BCAAs so popular among the athletic community? Experts explains that BCAAs are so popular in the athletic community because they may increase muscle growth, decrease muscle soreness, reduce exercise fatigue, and prevent muscle breakdown.

What Does the Research Say?

Athletes and recreational exercises have been using BCAA supplements for decades. The supplement industry has made millions selling BCAAs, claiming they improve athletic performance, build muscle, and aid in recovery. However, the Office of Dietary Supplements (ODS) says there’s very little evidence to back up these claims.So, what does the research say?

May Increase Muscle Growth

Though it’s well-established that protein is essential for building muscle when exercising, it’s not clear if separating out the BCAAs from the other essential amino acids offers more benefits. A 2017 clinical study published in Frontiers in Physiology found that ingesting BCAAs after resistance training increased muscle growth.However, this study was small, including only 11 healthy young male volunteers, and results from other studies on BCAAs and muscle growth are mixed.

May Decrease Muscle Soreness

Muscle soreness is a common side effect after an intense workout. However, this soreness is usually a sign that your muscles are responding to your workout. While there’s some evidence that BCAA supplements may help decrease muscle soreness following a workout, the research is limited. In addition, the effects appear negligible if you consume at least 1.2 grams of protein per kilogram of your body weight.

May Reduce Exercise Fatigue

Your muscles use BCAAs as a source of energy. If you engage in physical activities that require endurance, then muscle fatigue may be your biggest enemy.

A 2020 study published in the Journal of Human Kinetics found that supplementing with BCAAs before exercise increased endurance by decreasing serotonin levels in the blood. Serotonin is a chemical believed to play a role in central fatigue, which is the mental fatigue that occurs during long aerobic workouts. Though promising, this was a small study and didn’t include other markers for measuring central fatigue.

May Prevent Muscle Breakdown

Your body continuously breaks down and rebuilds your muscles. In order to maintain muscle mass, or build muscle, you need a steady supply of essential amino acids. While there’s some evidence that infusing BCAAs directly into the bloodstream may prevent muscle breakdown, the same cannot be said about oral supplements. The claim that oral BCAA supplements can prevent muscle breakdown is baseless. According to Jones, “Additional studies are needed to assess the true value of BCAA supplementation on muscle performance and fatigue.”