BCAAs and Strength Training
In the first post of this series (Introduction to BCAAs), we looked at what BCAAs are, how they work, and some of their potential benefits. One of the areas where BCAAs have the most promise is improving strength. BCAAs can provide the muscle with energy, increase protein synthesis, and decrease muscle breakdown. Put together, these benefits should increase strength training performance. Let’s look at what the research says.
Research on BCAAs and Strength Training
Study 1: The effects of 8 weeks of heavy resistance training and branched-chain amino acid supplementation on body composition and muscle performance1
The first study looked at the effects of BCAA supplementation on resistance training performance. Nineteen participants were split into a supplement and placebo group. The supplement group took nine grams of BCAAs per day, half before, half after. They performed three sets at 8-10 repetitions of an exercise four times per week for eight weeks.
The results showed a similar strength increase in both the supplement and placebo groups. The researchers concluded that when combined with heavy resistance training, BCAA supplementation had no positive effect on muscular strength or endurance.
Study 2: Branched-chain amino acid supplementation and resistance training maintains lean body mass during a caloric restricted diet2
This study looked at the effects of a calorie restricted diet on multiple measurements including strength. Seventeen participants were randomly assigned to either a BCAA or carbohydrate group. During the eight week study, participants were either given a pre and post workout BCAA supplement or a pre and post workout carbohydrate supplement. Each group got 14 grams of their respective supplement before and after working out for a total of 28 grams.
Researchers measured strength using a one repetition maximum bench press and squat. Subjects then completed as many repetitions as possible at 80% of their maximum bench press and squat to measure endurance. Both groups saw strength increases in both the upper and lower body.
The BCAA group saw an increase of 33 pounds on their squat while the carbohydrate group only saw an increase of 10.6 pounds. The BCAA group saw an increase of 15.6 pounds on the bench press while the carbohydrate group saw a decrease of 8 pounds. Researchers concluded that BCAA supplementation had the potential to preserve muscle strength while on a calorie restricted diet.
Study 3: Consuming a supplement containing branched-chain amino acids during a resistance-training program increases lean mass, muscle strength and fat loss3
This study looked at the effects of BCAA supplementation on strength during an eight week resistance training program. Thirty six participants were split into three groups. One group received 14 grams of BCAAs, the second group received 28 grams of whey protein, and the third group received 28 grams of carbohydrates in the form of a sports drink. Strength was measured using a ten repetition max on the bench press before and after the eight week training program started.
The results showed an increase of 13 pounds on the 10-RM bench press for the BCAA group, 6.6 pound increase for the whey group, and a 4.4 pound increase in the carbohydrate group. The BCAA group saw a 24 pound increase on the 10-RM squat. They whey group saw an 11 pound increase while the carbohydrate saw a 6.6 pound increase. The researchers concluded that a BCAA supplement combined with a resistance training program yields strength gains on both the bench press and squat. This study was funded by Scivation, a company that sells BCAA supplements.
The Bottom Line – Do BCAAs increase strength?
The results of the three studies are mixed. The first study showed no difference in strength between the BCAA and placebo group. The second study showed positive effects of BCAA supplementation during a calorie deficit. Unfortunately, comparing BCAAs to a post workout carbohydrate supplement is an unfair comparison. The results probably don’t have much real world application because most people use a post workout protein supplement in combination with carbohydrates. The real test is whether BCAAs, when added to a protein supplement, increase strength.
The third study compared BCAAs to whey protein. This study showed an increase in strength when BCAAs were used. The strength increase was also pretty significant. This study, however, was funded by a company with an extensive line of BCAA supplements. A bit of skepticism is warranted as a company has no interest to fund research that would conclude their product is ineffective.
There is some evidence showing BCAAs use may increase strength. There is also evidence showing the opposite is true. Unfortunately, at this time, the research is not in agreement on BCAA’s role in increasing strength.
- Spillane, M., & Emerson, C. (2013). The effects of 8 weeks of heavy resistance training and branched-chain amino acid supplementation on body composition and muscle performance. Journal of the International Society of Sports Nutrition, 10(Suppl 1). doi:10.1186/1550-2783-10-s1-p25
- Dudgeon, W. D., & Kelley, E. P. (2016). In a single-blind, matched group design: Branched-chain amino acid supplementation and resistance training maintains lean body mass during a caloric restricted diet. Journal of the International Society of Sports Nutrition, 13(1). doi:10.1186/s12970-015-0112-9
- Stoppani, J., & Scheett, T. (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). doi:10.1186/1550-2783-6-s1-p1