6 Benefits of BCAAs (Branched-Chain Amino Acids), and the Potential Side Effects

Building muscle is a simple, yet not easy, process. You fuel up, you train hard, and you recover well. You follow a program with progressive overload; you hit your macros, nutrition, and hydration goals. Put all these pieces together, and you can create muscle protein synthesis. Branched-Chain Amino Acids or, BCAAs, may play a key role in stimulating that process.

BCAAs exist in protein-rich foods but can also be consumed through some of the best BCAA supplements on the market. Including BCAAs in your diet and training program may help you with everything from hypertrophy to reduced muscle soreness. Here, you’ll learn about the biggest BCAA benefits and understand how these amino acids may help you build muscle, improve your recovery, and maintain your muscle as you age.

What Are Branched-Chain Amino Acids?

Branched-chain amino acids or, BCAAs, are a group of amino acids typically in the form of leucine, valine, and isoleucine. (1) Amino acids are the building blocks of protein and are required by your body to maintain and improve muscle performance. Of the 20 amino acids that make up muscle protein, 11 are what are considered essential amino acids — your body cannot produce them, meaning they need to be consumed either through supplementation or your regular protein-rich diet.

BCAAs are EAAs, in theory, but are categorized differently given their molecular structure. All 11 EAAs — BCAAs, included — play a role in muscle protein synthesis, a process that causes a change in skeletal muscle mass after resistance training. (2)(3)

https://youtu.be/3mepgoHLmPU

While BCAA (and EAA) supplements remain popular amongst gymgoers, you can also achieve proper stores from your diet alone. Common BCAA-rich food sources include meat options like chicken, turkey, beef, and fish, along with dairy products, eggs, plant-based protein sources, and more.

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Potential Benefits of BCAAs

The benefits of taking BCAAS are all wrapped up in muscle protein synthesis. This muscle-building occurs as you train to reach muscle hypertrophy. Read on to see how these amino acids help stimulate this process and what you can expect from getting enough BCAAs in your diet.

May Improve Athletic Performance

There is some evidence that BCAAs may improve athletic performance. A review of the effects of BCAA supplements on athletes showed that BCAAs are oxidized in the muscle, which may stimulate anabolic signals. It follows that they might, in turn, improve performance in the gym. (4)

Now, when it comes to supplementing with BCAAs for the sake of increased power and performance, these perks are mostly centered around post-workout consumption. Don’t think that downing a quick mix before your gym session is going to give you otherworldly strength — it’s about stimulating muscle growth after you’ve put the work in. Speaking of…

May Increase Muscle Growth

BCAA supplements promise that taking BCAAs will help to build muscle due to their stimulation of muscle protein synthesis. Studies report that BCAAs have been repeatedly shown to help increase muscle mass. (5) BCAAs — combined with resistance training and proper nutrition — have been shown to aid in muscular hypertrophy in humans. (6) 

So do you need BCAAs to build muscle? It certainly seems helpful. However, they don’t work in a vacuum. Studies also show that without the rest of the essential amino acids, BCAAs alone may not increase muscle growth. (6) While BCAA supplements may help you get your gains, this research suggests that getting all of your amino acids is essential for complete success. So, don’t rely on BCAA supplements alone — mix in proper whole food dishes or the best protein powders to set yourself up for maximum success.

May Decrease Soreness

Taking BCAAs for muscle soreness may be fairly effective. Feeding your muscles the protein they need to rebuild after high-intensity training may alleviate muscle soreness. Data suggests that BCAAs may decrease delayed onset muscle soreness (DOMS) caused by exercise-induced muscle damage, or EMID. (7)

What about timing? One study was done on 15 cisgender males. Three groups were given placebos before and after exercise — placebos before and BCAAs after exercise; and BCAAs before and placebos after exercise. The research demonstrated that BCAA supplementation before exercise was more beneficial in alleviating DOMS after EMID. (8) Essentially, supplementing with the right amount of BCAAs pre-workout can help defend against sore muscle tissue, while post-workout supplementation can help with muscle growth.

May Improve Recovery

Muscle recovery is about more than just decreasing soreness. Recovering from training in the hours and days after your session is when your muscles can grow bigger and stronger. Research shows that taking BCAAs can improve post-exercise recovery and may improve muscle function. (9) This can be especially helpful to athletes who need to reduce muscle damage and maintain muscle function in sports with short rest times. (9)

May Reduce Fatigue

When you’re training hard, you want to maximize your time and energy before your muscles start to fatigue. Fatigue can be caused after the amino acid tryptophan converts to serotonin. (10) Some claims suggest that BCAAs can stop the process of tryptophan converting to serotonin. One study on athletes ingesting BCAA before exercising showed reduced serotonin levels, which delays central nervous system fatigue. (11)

This is one of the many potential benefits of BCAAs for bodybuilding. In strength sports that require you to train extensively at a high intensity, reducing muscle fatigue may be a critical part of your training strategy. BCAA supplements seem to be helpful here.

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May Prevent Muscle Loss

As humans age, they may experience sarcopenia or the loss of skeletal muscle mass and strength. Resistance exercise and nutrition have been shown to be helpful ways to maintain muscle and fight this process. (12)

Research on people aged 60 to 70 shows that lower blood levels of leucine — the key BCAA — were associated with lower skeletal muscle mass, grip strength, and athletic performance. (12) It suggests that including BCAAs in the diets of older adults, combined with training and complete nutrition, may help prevent naturally occurring muscle loss caused by aging.

BCAA Myths

Whether looking at protein supplements, pre-workouts, creatine, or other supplements available today, you’ll come across a wide range of nutrition myths. BCAAs are no different. Let’s debunk some of the most common myths associated with this helpful muscle-building support system.

Myth: BCAAs alone will help me build muscle. 

While BCAAs help stimulate muscle protein synthesis, research has shown that you’ll benefit most if you get all of your essential amino acids. (6) In addition to specific amino acids, it’s also recommended that you meet your daily protein goals for hypertrophy. Check out BarBend’s protein intake calculator to find your personal needs.

Myth: BCAAs will make me lose weight.

BCAAs, on their own, will not cause weight loss. However, if your goal is losing body fat, including amino acids and adequate protein in your diet may be beneficial. Protein helps to keep you full longer, so it might help it become more emotionally sustainable to eat at a calorie deficit. Of course, though, fat loss is best achieved when you combine a well-rounded nutritional plan with an organized training regimen, so don’t rely on supplements or training alone when trying to change your body composition.

Myth: BCAAs will give me energy for training.

While BCAAs can be taken alongside the best pre-workout supplements for muscle-building benefits, they are not a direct energy source for your workouts. They might help reduce your fatigue development — which can certainly have advantages in terms of energy. That said, unlike caffeine, for example, BCAAs are not explicitly related to energy levels.

Potential Side Effects of BCAAs

With potential benefits come potential unwanted side effects. Here are a few possible downsides of BCAAs.

May Cause Nausea and Headache

Several side effects have been reported with taking BCAA supplements. Each individual may react differently, but some can experience nausea and headaches with BCAAs. As with any food or food-based supplement, take note of how your body tends to respond after ingestion.

BCAA Supplements May Include Additives

BCAA supplements — like all dietary supplements — do not need to be FDA-approved for marketing and sale. Since they are unregulated, some supplements may include inactive ingredients and additives that you may not want. It’s always advisable to read the ingredients and research what you’re putting into your body, including prioritizing supplements that are third-party tested without proprietary blends.

Not Ideal for Some Individuals

There are a handful of groups that should be hesitant to add BCAA supplements to their regimen. Research suggests that there may be an association between BCAAs in early pregnancy with gestational diabetes. (13) So if you’re pregnant, BCAAs will likely be up there with the list of foods, drinks, and supplements you take a break from.

Additionally, athletes with diabetes may want to be mindful of their BCAA intake. Studies suggest that BCAAs can increase insulin resistance, which can be detrimental to your blood sugar control. (14) BCAAs can also compete with other amino acids in the brain that help with producing neurotransmitters — vital molecules that communicate messages to the brain to manage learning, behavior, and emotions. (14) If you have specific mental health needs regarding your neurotransmitters, it may be best to speak with your medical provider prior to starting a BCAA supplement routine.

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Amino Acid Power

BCAAs are three powerful essential amino acids that you can get from the best protein sources and other foods. Plenty of research indicates they may be beneficial to lifters and strength athletes to help stimulate muscle protein synthesis leading to muscle growth, improved recovery, and more. 

While they may give you a little boost combined with your training, it’s still recommended to get the rest of your amino acids and daily protein in addition to those BCAAs.

BCAA Benefits FAQs

References

1. Wolfe RR. Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? J Int Soc Sports Nutr. 2017 Aug 22;14:30.
2. Witard, O. C., Bannock, L., & Tipton, K. D. (2022). Making Sense of Muscle Protein Synthesis: A Focus on Muscle Growth During Resistance Training, International Journal of Sport Nutrition and Exercise Metabolism, 32(1), 49-61. Retrieved Feb 1, 2023, from https://journals.humankinetics.com/view/journals/ijsnem/32/1/article-p49.xml
3. Atherton PJ, Smith K. Muscle protein synthesis in response to nutrition and exercise. J Physiol. 2012 Mar 1;590(5):1049-57.
4. Martinho DV, Nobari H, Faria A, Field A, Duarte D, Sarmento H. Oral Branched-Chain Amino Acids Supplementation in Athletes: A Systematic Review. Nutrients. 2022 Sep 27;14(19):4002.
5. Fouré A, Bendahan D. Is Branched-Chain Amino Acids Supplementation an Efficient Nutritional Strategy to Alleviate Skeletal Muscle Damage? A Systematic Review. Nutrients. 2017 Sep 21;9(10):1047.
6. Santos CS, Nascimento FEL. Isolated branched-chain amino acid intake and muscle protein synthesis in humans: a biochemical review. Einstein (Sao Paulo). 2019 Sep 5;17(3):eRB4898.
7. Weber MG, Dias SS, de Angelis TR, Fernandes EV, Bernardes AG, Milanez VF, Jussiani EI, de Paula Ramos S. The use of BCAA to decrease delayed-onset muscle soreness after a single bout of exercise: a systematic review and meta-analysis. Amino Acids. 2021 Nov;53(11):1663-1678.
8. Ra SG, Miyazaki T, Kojima R, Komine S, Ishikura K, Kawanaka K, Honda A, Matsuzaki Y, Ohmori H. Effect of BCAA supplement timing on exercise-induced muscle soreness and damage: a pilot placebo-controlled double-blind study. J Sports Med Phys Fitness. 2018 Nov;58(11):1582-1591.
9. Arroyo-Cerezo A, Cerrillo I, Ortega Á, Fernández-Pachón MS. Intake of branched chain amino acids favors post-exercise muscle recovery and may improve muscle function: optimal dosage regimens and consumption conditions. J Sports Med Phys Fitness. 2021 Nov;61(11):1478-1489.
10. Yamashita M. Potential Role of Neuroactive Tryptophan Metabolites in Central Fatigue: Establishment of the Fatigue Circuit. Int J Tryptophan Res. 2020 Jun 29;13:1178646920936279.
11. AbuMoh’d MF, Matalqah L, Al-Abdulla Z. Effects of Oral Branched-Chain Amino Acids (BCAAs) Intake on Muscular and Central Fatigue During an Incremental Exercise. J Hum Kinet. 2020 Mar 31;72:69-78.
12. Rondanelli, M., Nichetti, M., Peroni, G., Faliva, M. A., Naso, M., Gasparri, C., Perna, S., Oberto, L., Di Paolo, E., Riva, A., Petrangolini, G., Guerreschi, G., & Tartara, A. (2021). Where to find leucine in food and how to feed elderly with sarcopenia in order to counteract loss of muscle mass: Practical advice. Frontiers in Nutrition, 7. https://doi.org/10.3389/fnut.2020.622391
13. Li N, Li J, Wang H, Liu J, Li W, Yang K, Huo X, Leng J, Yu Z, Hu G, Fang Z, Yang X. Branched-Chain Amino Acids and Their Interactions With Lipid Metabolites for Increased Risk of Gestational Diabetes. J Clin Endocrinol Metab. 2022 Jun 16;107(7):e3058-e3065.
14. HOLEČEK, M. (2022, January 19). Side effects of amino acid supplements. https://www.biomed.cas.cz/physiolres/pdf/2022/71_29.pdf