Branched-chain amino acids (BCAAs) are a very common supplement for anyone who hits the gym regularly. While they’re sometimes taken on their own as a tablet or powder mixed with water or a shake, they’re also commonly an ingredient in pre-workout combo supplements.

BCAAs are so popular as a supplement because they offer potential benefits for almost everyone. They can help to build muscle mass, increase performance and strength overtime, and help to reduce body fat without losing muscle.

You’ll find in this article:

How Do BCAAs Work?

Muscle protein is always in a state of turnover — building up and breaking down. When you’re trying to lose weight by cutting calories and eating less, you put your body into a catabolic state, as you’re breaking down stored energy (in the form of fat and muscle), instead of building it up in what is known as an anabolic state. Some supplements are designed to help during those cut phases, while others can help with building.

When you reduce your calorie intake and increase your exercise, you run the risk of breaking down muscle tissue in addition to burning fat. To prevent this, it’s important to consume enough protein to support your muscles’ needs. The building blocks of protein are amino acids — and taking BCAAs gives your body those extra pieces to either build or maintain muscle.

Why Take BCAAs?

So, what exactly are BCAAs and why should you take them? Three of the nine essential amino acids are called branched-chain amino acids (BCAAs), classified this way due to their chemical structure. They’re considered “essential” because our body can’t make them on their own, but must obtain them from our diet.1 The three branched-chain amino acids are leucine, isoleucine and valine.

Exercise challenges our muscles and pushes them to the limit, which can lead to muscle breakdown from burning energy. Muscle synthesis can’t occur without available essential amino acids, so taking BCAAs prior to a workout will increase the available amino acids for muscle building.1

One of the branched-chain amino acids, leucine, plays a key role in muscle protein synthesis as it’s not only a building block, but also helps regulate the signaling pathways that cause protein synthesis.2

What Are The Other Benefits Of BCAAs?

BCAAs also have several other benefits:

  • Provide an energy boost: BCAA supplements can help to reduce feelings of tiredness, which can boost your performance.3 This is one more reason that BCAAs are best to take prior to your workout — and why they’re included in many pre-workout supplements.

Serotonin, a hormone that makes you feel happy and relaxed, is typically boosted during exercise, but it can increase your body’s perception of fatigue.3 BCAAs can slow this process of the desire to relax and help you push harder.  When you feel like you have more energy, you’re more likely to lift more weight, try a few more reps, or increase the duration of your workout which can maximize your results.

  • Reduce muscle soreness: BCAAs have also been proven to reduce muscle soreness, especially delayed onset muscle soreness, or DOMS.4 Researchers think this might be due to the free amino acids available to help repair any damage done to your muscles.4 When you feel less sore following a workout, you feel more recovered and ready to hit the gym again sooner.

Are BCAAs Suitable For Me?

Many people who are working out regularly are either looking to preserve or build muscle – by losing weight or lifting heavy – and BCAAs are made for both. Although those are two specific reasons to use BCAAs, research shows they can also provide the benefits of less fatigue and less soreness – which is helpful for any type of workout.

It can be difficult to maintain or build muscle mass as we age, but we know how important strength training is for our bone health. BCAAs have the potential to empower anyone trying to maintain a strength training routine in their later years. While you can see the benefits at any age, everyone has different goals and they might change over time, but BCAAs can still be helpful.

BCAAs also fit into many specific diet plans like intermittent fasting, low carb, or keto diets. Because they’re just the building blocks of protein, they don’t add many calories but can be an extra boost of energy and recovery to help you power through your workouts while maintaining or building muscle even if weight loss if your goal.

What To Take With BCAAs

If you’re already using a protein shake after a workout, why do you need BCAAs as well? BCAAs provide the unique opportunity to provide key amino acids that fuel your muscles during exercise without having a heavy protein shake in your stomach. Keeping your whey (or another source of protein) shake for after your workout can improve recovery and rebuilding, in addition to the pre-workout BCAA boost.

BCAA Side Effects & Safety Precautions

Although BCAAs are simply natural protein building blocks that occur in other foods and within our body, it’s best to talk with your doctor before beginning any supplement, especially if you have certain health conditions or are pregnant. Be aware of other ingredients in your supplement if you’re taking BCAAs as part of a pre-workout.

How Much BCAA Should You Take?

Most studies recommend a dose of about 5-7g of BCAAs prior to exercise to help provide the benefits listed.3,4 Although that’s the most common use, you can also take them during long workouts or as part of your post-workout shake if it’s your only option.

The dosage used in studies to show the benefits of reduced soreness and improved energy vary but averaged around 100mg/kg body weight.3,4 Check the label on your supplement for the best dose for you based on your size and activity level.

Take Home Message

BCAAs are a powerful source of the crucial building blocks of muscle that can help you increase gains or maintain the muscle mass you have while losing weight. Additionally, they can boost your workout by reducing the perception of fatigue and soreness — getting you prepped for your next training session. Although they’re most commonly used pre-workout, BCAAs can give you a boost any time of day.


  1. Wolfe, R. R. (2017). Branched-chain amino acids and muscle protein synthesis in humans: myth or reality?. Journal of the International Society of Sports Nutrition, 14(1), 30.
  2. Blomstrand E, Eliasson J, Karlsson HKR, Kohnke R. Branched-chain amino acids activate key enzymes in protein synthesis after physical exercise. J Nutr. 2006;136:269S–73S. Blomstrand, E., Eliasson, J., Karlsson, H. K., & Köhnke, R. (2006). Branched-chain amino acids activate key enzymes in protein synthesis after physical exercise. The Journal of nutrition, 136(1), 269S-273S.
  3.  Wiśnik, P., Chmura, J., Ziemba, A. W., Mikulski, T., & Nazar, K. (2011). The effect of branched chain amino acids on psychomotor performance during treadmill exercise of changing intensity simulating a soccer game. Applied physiology, nutrition, and metabolism, 36(6), 856-862.
  4. Shimomura, Y., Inaguma, A., Watanabe, S., Yamamoto, Y., Muramatsu, Y., Bajotto, G., … & Mawatari, K. (2010). Branched-chain amino acid supplementation before squat exercise and delayed-onset muscle soreness. International journal of sport nutrition and exercise metabolism, 20(3), 236-244.


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