BCAA supplementation is quite the topic when health and fitness advocates talk about the best supplements for recovery and anti-catabolic effects, both while training and fasting. Many benefits have been stated about supplementing with branched chain amino acids (BCAAs), such as a decrease in visceral belly fat mass, improving glucose uptake and insulin sensitivity, muscle and energy production during exercise, and reducing muscle soreness, to name a few. Is there research to back up these claims? Lets take a closer look at the BCAAs and their benefits for muscle, endurance, and fat loss.
As stated above, BCAA stands for branched chain amino acids. Amino acids are the building blocks of protein and protein helps to build muscle, rebuild damaged tissue, and many other physiological functions within the body. BCAAs are made up of three essential amino acids – leucine (known as the “anabolic trigger”), isoleucine, and valine. When we say “essential”, it means that our body cannot make them out of other amino acids and they must be ingested through the food we eat. These essential amino acids make up about 35-40% of the daily requirement of all nine essential amino acids, revealing their importance.
Since amino acids are the building blocks of protein and most protein is consumed through animal products, the highest concentrations of BCAAs can be found in eggs, fish, beef, chicken, and whey protein, as well as other sources. They can also be supplemented, which can be of very beneficial use for athletes.
What does the research say about BCAA supplementation?
In a double blind, crossover design study with male students, aged 19-21 years, they were either given an amino acid mixture or a placebo during their recovery period after a session of eccentric exercise training. The results indicated that the ingestion of the amino acid mixture accelerated the rate of muscle recovery and also produced higher muscle strength during the recovery period, compared to the placebo (1).
In another study done with a group of athletes, they engaged in a 6 month sustained exercise program, in which the distance and exercise intensity was adjusted to compute exercise load. They were split into 3 groups, with one group receiving 2.2 grams of the amino acid mixture, another receiving 4.4 grams, and the last receiving 6.6 grams. The results concluded that the group who received the amino acid mixture at the daily dose of 6.6 grams improved self-assessed physical condition, reduced muscle damage, and improved oxygen-handling capacity (1).
Numerous other studies in humans and animals have shown that the consumption of essential amino acids, BCAAs, or leucine alone, either at rest or following exercise increased skeletal muscle protein synthesis, decreased muscle protein degradation, or both (1, 2, 3).
One study was done by Stoppani et al. where trained subjects were either given 14 grams of BCAAs, a whey protein drink, or a carbohydrate placebo for 8 weeks while participating in a periodized strength training routine. The BCAA group came out on top, resulting in a 4 kg increase in lean body mass, 2% decrease in percent body fat, and a 6 kg increase on the bench press exercise for a 10-rep maximum (4). Although this study does conclude with impressive results from the BCAA group, it was funded by a popular supplement company whose primary product is an intra-workout, BCAA drink, as well as being led by a popular fitness figure and doctor who owns his own supplement company. There’s no way to quantify the degree of commercial bias in this trial.
Nonetheless, it is safe to say that, from the current evidence and numerous studies, BCAAs stimulate protein synthesis and may be able to increase lean mass and strength when added to a strength-training program. More studies need to be done on the effects of BCAA supplementation during meals, following a vegetarian lifestyle, on humans instead of rodents, and on highly trained and experienced athletes and weight lifters.