Are BCAAs Crucial for Muscle Growth?

The supplement world is booming. There are hundreds of supplements out there claiming to do everything from burn fat all the way to increase muscle mass. Branched chain amino acids (BCAAs) are one of the most widely used supplements in the fitness industry. So before you go spending lots of money on BCAAs, let’s look at the research to see if it’s even worth the effort.

Amino acids are the building blocks of protein. There are nine essential amino acids, meaning that they are crucial to our survival, and without them we would die. Out of these nine essential amino acids, three of them make up BCAAs: leucine, isoleucine, and valine. And together these 3 amino acids account for about 33% of muscle tissue.

When you exercise, you are actually breaking down your muscle tissue. After exercise your muscles then work to repair themselves, and this is how we get stronger. The theory behind BCAA supplementation is that if we break down our muscles during exercise, why not supplement to help them recover and rebuild quicker?

A 2009 study looked at the effects of BCAA consumption on lean mass, muscle strength and fat loss during a resistance training program (2). The subjects were randomly assigned to receive either 14 grams of BCAAs, 28 grams of whey protein, or 28 grams of carbohydrates from a sports drink. The study last 8 weeks and had each participant follow a four-day muscle split workout. The study found that BCAA supplementation resulted in “a greater decrease in percent body fat, an increase in lean mass, and 10-RM strength gains on the bench press and squat vs. ingestion of a whey supplement or a sports drink” (2).

The also came across another study that analyzed the effects of BCAA consumption during endurance exercise (1). The subjects were split into two groups: the BCAA group and the placebo group. Each participant then had to complete an endurance test on the bike. The researchers analyzed multiple different markers of fatigue. The study concluded that “the intake of the BCAA help[ed] contribute to enhancing exercise performance by exerting its influence on fatigue substances, muscle damage substances, and energy metabolism substances”(2). This means that BCAA supplementation can be beneficial during endurance exercise by helping to prevent fatigue and muscle damage.

So overall it looks like BCAAs are actually one of the few beneficial supplements on the market these days. When choosing a BCAA supplement to buy, look for one that is free of stimulants and isn’t loaded with sugar. I personally really like the Scivation Xtend BCAAs (in pink lemonade) and About Time AminoHydrate (in orange cream). So lthere you have it. BCAAs are a great tool for anybody involved in resistance training or doing heavy endurance training.



1) Kim, D.-H., Kim, S.-H., Jeong, W.-S., & Lee, H.-Y. (2013). Effect of BCAA intake during endurance exercises on fatigue substances, muscle damage substances, and energy metabolism substances. Journal of Exercise Nutrition and Biochemistry, 17(4), 169–180. doi:10.5717/jenb.2013.17.4.169

2) Stoppani, J., Scheett, T., Pena, J., Rudolph, C., & Charlebois, D. (2009). Consuming a supplement containing branched-chain amino acids during a resistance-training program increases lean mass, muscle strength and fat loss. Journal of the International Society of Sports Nutrition, 6(Suppl 1), P1. doi:10.1186/1550-2783-6-s1-p1


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