Are BCAAs Worth It?

While I was putting the final touches onto the supplement chapter of my new book, The Science of Weight Training, it hit me just how controversial and misunderstood the topic I was revising truly is.

Specifically, I am referring the issue of BCAAs and their effectiveness (or lack thereof) for muscle and strength gains.

To gain some insight into the issue, I decided to post an excerpt from the chapter onto the website to give you guys some clarity on what the actual research shows on the matter.

Let’s get to it.

A popular supplement among bodybuilders (38), branched-chain amino acids (BCAAs) are commonly used to stimulate protein synthesis and minimize protein degradation in an effort to enhance muscle growth. Despite their popularity, evidence for the long-term effectiveness of BCAA supplementation has been controversial. Many studies have shown BCAAs to reduce muscle soreness from training (382–385), though these findings are not universal (386). A published abstract by Stoppani and colleagues (387) reported that BCAA supplementation improved muscle and strength gains to a significantly greater extent than both whey protein and carbohydrates over an 8 week training period. Supporting these findings, Dudgeon and colleagues (388) demonstrated that BCAA supplementation retained muscle mass and increased strength to a greater extent than carbohydrates during an 8 week, calorie-restricted training program. It should be noted, however, that the results from this study have been criticized because of discrepancies found in the reported data (389).

Contrasting these findings, Spillane and colleagues (390) showed that BCAAs had no positive effect on muscle or strength gains over an 8 week training period. Furthermore, Churchward-Venne and colleagues (245) demonstrated that a BCAA blend was no more effective than leucine at stimulating protein synthesis. It is suggested that this is due to an antagonistic effect between BCAAs, since they compete for absorption (391).

Given these conflicting reports, BCAA supplementation should be left up to the individual until further research can draw more definitive conclusions. From a theoretical standpoint, lifters who engage in fasted training might benefit from supplementing with BCAAs before or during exercise to improve muscle protein balance. However, given the results of Churchward-Venne’s study (245), leucine alone may be more effective.”



As you can see, there is a paucity of evidence regarding the effectiveness of BCAAs for long-term muscle and strength gains.

While the study by Dudgeon et al. has been criticized for discrepancies found in the reported data, the study by Stoppani et al. should also be taken with a grain of salt.

While I ensured that I objectively presented all of the data regarding the topics discussed in the book, from a personal standpoint, the results of Stoppani’s study are quite questionable to say the least.

First off, the study was funded by a supplement company that sells BCAAs. Not a deal breaker by any stretch, but still something to take into account.

More importantly, however, the dramatic muscle growth experienced by the BCAA group compared to the other groups is quite startling.

Not only did the BCAA group achieve twice the amount of muscle and strength gains than the whey protein group, their muscle gains were on par with those achieved by participants administered supraphysiological doses of testosterone (study).

Specifically, the BCAA group gained ~9 lbs of muscle after only 8 weeks of training, which is not far off from a study where the subjects gained ~13 lbs of muscle after being administered supraphysiological doses of testosterone during a 10 week training period.

This drastic increase is not the result of ‘newbie gains’ either, considering all of the subjects had at least 2 years of training experience in the BCAA study.



From an objective standpoint, it is frankly too early to tell if BCAA supplementation is worth it.

However, given their high cost, I would personally advise against supplementing with BCAAs provided you consume enough protein and are not a physique competitor where every little advantage can make a difference.

As mentioned in the book, if you like to train fasted (like myself), then BCAAs would theoretically be beneficial, though to my knowledge, no long-term strength training studies have tested this.

What is clear is that more long-term studies are needed to test the efficacy of BCAA supplementation during a resistance training program, where both groups consume an adequate amount of daily protein.



38. Hackett DA, Johnson NA, Chow CM. Training practices and ergogenic aids used by male bodybuilders. J Strength Cond Res. 2013 Jun;27(6):1609–17.

245. Churchward-Venne TA, Breen L, Di Donato DM, Hector AJ, Mitchell CJ, Moore DR, et al. Leucine supplementation of a low-protein mixed macronutrient beverage enhances myofibrillar protein synthesis in young men: a double-blind, randomized trial. Am J Clin Nutr. 2014 Feb;99(2):276–86.

382. Howatson G, Hoad M, Goodall S, Tallent J, Bell PG, French DN. Exercise-induced muscle damage is reduced in resistance-trained males by branched chain amino acids: a randomized, double-blind, placebo controlled study. J Int Soc Sports Nutr. 2012 May;9(1):20.

383. Jackman SR, Witard OC, Jeukendrup AE, Tipton KD. Branched-chain amino acid ingestion can ameliorate soreness from eccentric exercise. Med Sci Sports Exerc. 2010 May;42(5):962–70.

384. Matsumoto K, Koba T, Hamada K, Sakurai M, Higuchi T, Miyata H. Branched-chain amino acid supplementation attenuates muscle soreness, muscle damage and inflammation during an intensive training program. J Sports Med Phys Fitness. 2009 Dec;49(4):424–31.

385. Shimomura Y, Yamamoto Y, Bajotto G, Sato J, Murakami T, Shimomura N, et al. Nutraceutical effects of branched-chain amino acids on skeletal muscle. J Nutr. 2006 Feb;136(2):529S–32S.

386. Kephart WC, Mumford PW, McCloskey AE, Holland AM, Shake JJ, Mobley CB, et al. Post-exercise branched chain amino acid supplementation does not affect recovery markers following three consecutive high intensity resistance training bouts compared to carbohydrate supplementation. J Int Soc Sports Nutr. 2016 Jul;13(1):30.

387. Stoppani J, Scheett T, Pena J, Rudolph C, Charlebois D. Consuming a supplement containing branched-chain amino acids during a resistance-training program increases lean mass, muscle strength and fat loss. J Int Soc Sports Nutr. 2009 Jul;6(1):P1.

388. Dudgeon WD, Kelley EP, Scheett TP. In a single-blind, matched group design: branched-chain amino acid supplementation and resistance training maintains lean body mass during a caloric restricted diet. J Int Soc Sports Nutr. 2016 Jan;13(1):1.

389. Dieter BP, Schoenfeld BJ, Aragon AA. The data do not seem to support a benefit to BCAA supplementation during periods of caloric restriction. J Int Soc Sports Nutr. 2016 May;13(1):21.

390. Spillane M, Emerson C, Willoughby DS. The effects of 8 weeks of heavy resistance training and branched-chain amino acid supplementation on body composition and muscle performance. Nutr Health. 2012 Oct;21(4):263–73.

391. Szmelcman S, Guggenheim K. Interference between leucine, isoleucine and valine during intestinal absorption. Biochem J. 1966 Jul;100(1):7–11.



  1. yannick says:

    Everyone is different when it comes to supplements and training, i took glutamine at 15g per day which is suppose to be worthless in the studies i have read but i had a better physique then when i took creatine monohydrate that simply bloats me up.

    I have recently added beef isolate protein, beef aminos, whey concentrate and creatine magnesium (0 water retention) i am 45 and all of this is making a huge difference in my recuperation. Go with what is known protein, creatine, multi vit, green tea, and i don’t touch the rest, in a protein powder and if you eat right you have enough BCAA you don’t need to take them separately, if there is one supplement that is expensive its BCAA.