Dr. Spencer Nadolsky is a practicing medical physician. He is based in Suffolk, Virginia.
Amino acids are commonly described in layman terms as the building blocks of protein. More than 500 types are known but only a select few are used in protein synthesis and so considered essential nutrients for the human diet. Most of these can be synthesised by your body from other compounds, however, there are nine amino acids that can not be made from scratch so instead we must consume from our diet.
The nine amino acids we can’t synthesise are: phenylalanine, valine, threonine, tryptophan, methionine, histidine, leucine, isoleucine and lysine. It’s the last three on this list in which we are interested because together they are known as the branched chain amino acids (BCAA). Leucine, isoleucine and lysine account for around 35% of all essential amino acids in muscle proteins and consequently have been heavily marketed as a key workout supplement to induce protein synthesis. However, in reality, their actual effectiveness has been blown out of all proportion.
Is supplementation necessary?
BCAAs do play a role in building muscle, but remember that whenever you consume protein you’re consuming BCAAs because they are the constituent parts of protein. So is supplementation necessary? The evidence suggests that BCAAs have a very limited effect on exercise performance in well-fed individuals.
Supplementation was found to relieve cognitive fatigue during exercise that lasted more than two hours, so could be beneficial for athletes who need to maintain hand-eye coordination over a long game, such as tennis, hockey or American football players.
BCAAs play only a small role in enhancing physical performance, and do not increase power output, reduce fatigue, or improve muscular endurance. However, if you can not use whey protein supplementation – for whatever reason – then BCAAs can be a very beneficial addition to your supplement regime.
How to take it
If you consume enough dietary protein then you likely have all the essential amino acids you need. However, if you do want to take on additional BCAAs before or during your workout, then supplementation can be a better option that dietary protein, which is harder to digest so can cause cramping and nausea during training.
To supplement BCAAs take 10g before exercise. The most-commonly marketed ratio is a 2:1:1 ratio of leucine, isoleucine, and valine, but there is no research to support this. They can be added to a carb-based drink or taken with water.