BCAAs: Are They Worth Trying?

If your fitness goals are to build muscle and improve performance, then you may have branched-chain amino acid (BCAA) supplements on your radar. BCAAs are popular in the sports world because of their purported benefits.

While there’s some evidence that BCAA supplementation may reduce muscle soreness and shorten recovery time, most athletes may not need to take this supplement to gain benefits, especially if you are consuming a lot of protein (at least 1.2 grams of protein per kilogram of your bodyweight). Instead, they should focus on rest, hydration, and nutrition to enhance recovery and meet their fitness goals. 

However, if you're interested in delving into the science behind the supplement, we lay it all out for you.

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? Jerlyn Jones, MS, MPA, RDN, LD, CLT, owner of The Lifestyle Dietitian® LLC and spokesperson for the Academy of Nutrition and Dietetics (AND), 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.”

Are BCAAs Harmful?

According to the ODS, you can safely take up to 20 grams of BCAA supplements a day. However, BCAA supplements are harmful to certain groups of people.

For example, people with maple syrup urine disease (MSUD), a rare metabolic disorder, shouldn’t take BCAA supplements.

People with MSUD are deficient in the enzymes needed to break down BCAAs and must follow a low-protein diet that restricts the intake of BCAA-rich foods. When you lack the enzymes needed to break down BCAAs, toxic levels of these amino acids build up in the blood, causing brain damage and death within weeks or months.

BCAAs may also increase blood glucose levels during and after surgery, according to Jones. She also recommends caution with BCAA supplements if you have cancer or alcohol use disorder, or if you’re pregnant or nursing. 

Best Ways to Boost BCAAs

You need all of the essential amino acids to make muscle—not just the BCAAs. So, do you really need to take a supplement? Probably not. Here are some easy ways to boost your BCAA intake naturally.

Choose Foods Rich in BCAAs

People who eat balanced meals get enough of these essential amino acids, says Jones, without the need for supplementation. 

She says, “Ditch the BCAA supplements and add these whole foods to your daily meals.”

Hit Your Daily Protein Goals

The International Society of Sports Nutrition (ISSN) says that in order to build muscle and maintain mass, you need a positive muscle protein balance. They recommend you get 0.6 to 0.9 grams of protein per pound of bodyweight to create this positive muscle protein balance.

So, if you weigh 200 pounds, you need 120 to 180 grams of protein a day. For perspective, a 6-ounce serving of chicken breast has 54 grams of protein, one egg has 6 grams, and 1/2 cup of tofu has 10 grams.  

When strength-training, ISSN says you may need at least 1.3 grams per pound of body weight per day. That’s 260 grams of protein a day for a 200-pound person. 

Adding protein to your diet is easy. Make your oatmeal with milk, add beans and nuts to your grilled chicken salad, and snack on hard-boiled eggs and low-fat yogurt.

Importance of Recovery

Whether you’re the star athlete on the team or part of your neighborhood running club, rest and recovery is an important part of your exercise routine. Recovery helps you “physically and psychologically,” according to Jones.

It gives your muscles the time it needs to repair and strengthen in between workouts, adapt to the stress, and replenish energy stores.

So you may not need to take BCAAs to recover from your workouts. What you do need is proper nutrition, rehydration, and adequate sleep.

A Word From Verywell

At Verywell Fit, we aim to provide the facts behind the fads, especially when it comes to products and health habits that are popular but may not be entirely rooted in science. When it comes to supplements, including items like BCAAs, be a cautious consumer.

While there are some purported health benefits of BCAA supplements, the science is limited. Instead of reaching for a product that may not provide everything the label claims, we suggest looking to adequate fiber and hydration, balanced nutrition, good sleep hygiene, daily movement, and other positive lifestyle factors to ensure you feel your best.

If you do choose to supplement your diet with BCAAs, speak with a healthcare professional and registered dietitian nutritionist to decide which product and dosage is best for you.