I frequently get asked whether or not you really need to supplement with BCAAs. Aside from their delicious taste, the answer ultimately comes down to two things: the type of exercise you do and your performance goals.
Branched-chain amino acids (BCAAs) are made up of three essential amino acids: leucine, isoleucine, and valine. They're deemed "essential" because the body can't make them, so they must be consumed through food. While you could stick to whole foods like chicken, beef, and eggs for your BCAA needs, supplementation has its advantages, because pure BCAAs bypass the liver and gut and go directly into your bloodstream.
BCAAs are particularly important for people with muscle-building or muscle-maintenance goals. BCAAs, especially leucine, help regulate protein metabolism by promoting muscle protein synthesis and suppressing protein breakdown.
But is that reason enough to take a scoop before training? The answer is a bit more complicated.
BCAAS: The Science
Previous research has found that BCAA supplementation before your workout can help increase rates of protein synthesis, suppress muscle protein breakdown, reduce markers of muscle damage, and lessen the symptoms of delayed-onset of muscle soreness (DOMS).[1-5] Sounds pretty impressive, right?
Well, I hate to be Debbie Downer, but these findings haven't necessarily proven increases in strength or muscle mass. If your goal is to add size and strength, and you're already meeting your daily protein needs through whole foods and protein shakes, additional BCAAs probably won't do much for you.
Don't throw away your shaker bottle just yet, though! BCAAs may not stimulate hypertrophy on their own, but taking 6-10 grams pre-workout can help you to hit the weights with enough consistent intensity and volume to stimulate muscle growth and get you back in the gym sooner by promoting faster recovery.
Also, BCAAs are broken down during exercise and used as an immediate energy source. A decline in circulating BCAA levels leads to an increase in serotonin concentrations in the brain, which is thought to partly contribute to fatigue during exercise. This is especially true for endurance-based exercise.
Adding a scoop or two of BCAAs to your intra-workout drink can also be helpful if you follow a low-carb diet or train in a fasted state, because they may reduce fatigue and enhance fat utilization during exercise in a glycogen-depleted state.
- 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, 20(3), 236.
- Coombes, J. S., & McNaughton, L. S. (2000). Effects of branched-chain amino acid supplementation on serum creatine kinase and lactate dehydrogenase after prolonged exercise. Journal of Sports Medicine and Physical Fitness, 40(3), 240.
- MacLean, D. A., Graham, T. E., & Saltin, B. (1994). Branched-chain amino acids augment ammonia metabolism while attenuating protein breakdown during exercise. American Journal of Physiology-Endocrinology And Metabolism, 267(6), E1010-E1022.
- Nosaka, K., Sacco, P., & Mawatari, K. (2006). Effects of amino acid supplementation on muscle soreness and damage. International Journal of Sport Nutrition and Exercise Metabolism, 16(6), 620.
- Tipton, K. D., Rasmussen, B. B., Miller, S. L., Wolf, S. E., Owens-Stovall, S. K., Petrini, B. E., & Wolfe, R. R. (2001). Timing of amino acid-carbohydrate ingestion alters anabolic response of muscle to resistance exercise. American Journal of Physiology-Endocrinology And Metabolism, 281(2), E197-E206.
- Shimomura, Y., Murakami, T., Nakai, N., Nagasaki, M., & Harris, R. A. (2004). Exercise promotes BCAA catabolism: effects of BCAA supplementation on skeletal muscle during exercise. The Journal of Nutrition, 134(6), 1583S-1587S.
- Newsholme, E. A., Acworth, I. N., & Blomstrand, E. (1987). Amino acids, brain neurotransmitters and a functional link between muscle and brain that is important in sustained exercise. Advances in Myochemistry, 1, 127-133.
- Gualano, A. B., Bozza, T., De Campos, P. L., Roschel, H., Costa, A. D. S., Marquezi, M. L., ... & Junior, A. H. L. (2011). Branched-chain amino acids supplementation enhances exercise capacity and lipid oxidation during endurance exercise after muscle glycogen depletion. The Journal of Sports Medicine and Physical Fitness, 51(1), 82-8.