Branched-chain amino acid (BCAA) supplements have been shown to help decrease muscle soreness and damage and increase protein synthesis in your body after exercise. These amino acids, which are the basic building blocks of protein, include leucine, isoleucine and valine. All three are essential amino acids that must be obtained from food.
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What Are BCCA Supplements?
BCAA supplements are made up of amino acids, which your body uses to make proteins. There are 20 amino acids overall, but there are three BCCAs:
The BCAAs are essential amino acids, which means your body can't make them — you have to get them from your diet.
BCAA supplements (often found in powdered form) contain these three amino acids and are most commonly taken to enhance exercise performance, boost muscle growth, reduce fatigue during exercise and reduce soreness after working out. Some people also take them to help with weight loss.
The Benefits of BCAA Supplements
1. Reduced Muscle Soreness
If you experience muscle soreness post-workout, BCAA supplements may help with the pain. In an early October 2004 study in the Journal of Nutrition, athletes who took BCAA supplements after their workout experienced less muscle soreness and had a higher rate of protein synthesis compared to those given a placebo.
The BCAAs themselves contribute directly to muscle recovery. In a June 2010 study in the International Journal of Sport Nutrition and Exercise Metabolism, BCAA supplementation reduced delayed-onset muscle soreness.
2. May Reduce Fatigue During Exercise
For endurance athletes in particular, BCAA supplementation has been shown to increase the lactate threshold, or the point at which exercise stops using your oxygen systems as a primary source of fuel. A February 2009 study in the Journal of Nutritional Science and Vitaminology revealed that, following BCAA supplementation, athletes experienced an increase in their endurance exercise capacity.
Most of the research on supplementing with BCAA is around leucine. In a September 2016 study in the Journal of Strength & Conditioning Research, people who ate 3 grams of beta-hydroxy beta methyl butyrate (a form of leucine) daily for 12 weeks reported they could work out for longer before fatiguing. They also noticed increases in muscle mass and decreases in fat mass.
While these results are promising, there is other research that does not find leucine to have a significant effect on body composition or physical performance among healthy young people.
Can They Boost Muscle Growth?
Although BCAA supplements are popular in the active community, there's no conclusive evidence that supports their effectiveness for muscle growth, per May 2018 research in Nutrition & Metabolism. In other words, there's no evidence that taking BCAA supplements specifically benefits you more than getting these amino acids through foods or other protein supplements.
The 3 Types of BCAAs
What are the BCAA supplements you might find in a vitamin store? There are three types of BCAAs: leucine, isoleucine and valine.
Leucine is an essential amino acid, which means you cannot synthesize it and must consume it through your diet, usually from a protein source, per the National Institutes of Health (NIH).
Leucine is the only protein that directly contributes to muscle protein synthesis. Without this amino acid, your ability to recover from both stress and exercise is compromised. Studies suggest that leucine plays a role in building muscle protein and burning fat.
Leucine also contributes to cell growth and the formation of sterols. Sterols are utilized in the process of forming steroidal hormones such as testosterone and estrogen. Animal protein, soy, dairy and fish are good sources of leucine, per the USDA.
Recommended intake: The recommended daily intake (RDI) for leucine is 17.7 mg per pound of body weight, according to the USDA.
Isoleucine (isolated leucine) plays a big part in your body's muscle metabolism, energy and stress production, per the NIH. Isoleucine also stimulates your immune system. As it is an essential amino acid, isoleucine cannot be produced by the body and has to be sourced from food.
You'll find isoleucine in the same foods you find leucine: Animal protein, soy, dairy and fish, per the USDA. .
Recommended intake: The RDI for isoleucine is 9 mg per pound of body weight, per the USDA.
Valine, the third branched-chain essential amino acid, has stimulant activity, according to the NIH. It promotes muscle growth and tissue repair.
You'll find valine in the same foods you find the other two amino acids: Animal protein, soy, dairy and fish, per the USDA.
Recommended intake: The RDI for valine is 12 mg per pound of body weight, per the USDA.
Foods High in BCAAs
While meat is a major source of all three of the BCAAs, there are also non-meat sources, which can benefit vegetarians and vegans. BCAAs are in eggs, tofu, Greek yogurt, soy protein powder and more.
Some of the most abundant sources include:
- Turkey breast
- Ground beef
- Dairy products, such as milk, yogurt and cheese
When it comes to meat, the leaner the better, because leaner meats have a higher protein content than fattier cuts. Similarly, low-fat dairy products are much better for protein intake than their fattier counterparts and are also more beneficial for health on the whole.
While animal products usually contain all 20 of the essential amino acids and plant-based products may not include this entire group, you don't have to eat meat to benefit from amino acids. As long as you eat a variety of plant-based products, your body will receive a sufficient amount of amino acids, including BCAAs.
Risks of BCAA Supplements
If you include enough protein in your diet, you get all of the amino acids your body needs, per the University of Rochester Medicine. Using a single amino acid supplement may lead to negative nitrogen balance. This can lessen how well your metabolism works and can also make your kidneys work harder. In children, taking single amino acid supplements may also cause growth problems.
Because supplements are not drugs, they do not need to be regulated by the Food and Drug Administration. Therefore, supplement companies do not have to list the exact amount of ingredients in their products or back up their claims. This includes all multivitamins, BCAAs, protein powders and other similar products.
When looking for quality supplementation, the FDA recommends you consult with your physician or dietitian to choose the best supplements for your condition.
- The Journal of Nutrition: "Exercise Promotes BCAA Catabolism: Effects of BCAA Supplementation on Skeletal Muscle During Exercise"
- International Journal of Sport Nutrition and Exercise Metabolism: "Exercise Promotes BCAA Catabolism: Effects of BCAA Supplementation on Skeletal Muscle during Exercise"
- Journal of Nutritional Science and Vitaminology: "Branched-chain amino acid supplementation increases the lactate threshold during an incremental exercise test in trained individuals"
- Journal of Strength & Conditioning Research: "The Effect of β-Hydroxy-β-Methylbutyrate on Aerobic Capacity and Body Composition in Trained Athletes"
- Journal of Nutrition, Health, and Aging: "Effects of leucine-rich protein supplements on anthropometric parameter and muscle strength in the elderly: a systematic review and meta-analysis" "
- NIH: "Leucine"
- Nutrition & Metabolism: "Branched-chain amino acids in health and disease: metabolism, alterations in blood plasma, and as supplements"
- USDA: "Top 10 Foods Highest in Leucine"
- NIH: "Isoleucine"
- USDA: "Top 10 Foods Highest in Isoleucine"
- NIH: "Valine"
- USDA: "Valine:
- University of Rochester Medicine: "Valine"