Bodybuilder’s Guide to BCAAs

Before creatine, arginine and whey protein came to dominate the supplements market, the BCAAs were the most popular muscle boosters among the bodybuilders.

Nowadays the branched-chain amino acids have once again regained their popularity, as it has been proven that they very efficient in stimulating muscle growth, increase the strength and energy, and even promote fat loss. If you are still unsure that you should include them in your supplements plan, we provide you with a detailed account of their benefits.


The BCAAs consist of three vitally important amino acids: valine, leucine and isoleucine. Each of their molecules have a notched extension resembling a branch, hence the name branched-chain amino acids. Although there are about 20 amino acids used for muscle growth, the BCAAs are probably the most important in muscle growth. Namely, these three account for a third of the total aminos found in our muscles.

One of the most interesting properties of the BCAAs is how the liver processes them. When you introduce aminos in your body (whether in their individual form or as protein) it first sends them to your liver where they are processed and used for energy instead for rebuilding the muscle cells. The BCAAs, however, are spared and the liver sends them directly to the muscles where they can be used either as a fuel or for building up muscle tissue.

This property of the BCAAs allows them to perform a twofold function. First of all, they can be used as fuel directly in the muscles.  Their second function is to participate in muscle building during the recovery period. These two function also determine the best timing for BCAAs supplementation. To rip the full benefits, it’s crucial to take them both before and after workout.


Since our muscles use the BCAAs for fuel during the workout they can deplete them of the needed aminos. You can remedy this problem by supplementing the BCAAs immediately before the training. This will improve your energy levels by providing the muscles with direct injection of aminos.

In addition to providing readymade fuel, the BCAAs participate in increasing your energy by influencing another chemical mechanism which involves the brain.  According to a French study, the 5 hydroxytryptamine (5-HT) is signaling the brain that your body is tired, and as a result your strength and stamina are reduced. It’s production is triggered by the amino acid tryptophan, which can be annulled with the valine found in BCAAs. Several studies show that you can reduce the tryptophan’s activity by taking BCAAs before workout, thus reducing the 5-HT levels and resulting sense of fatigue. This will translate in greater capability to workout, which is the first premise for muscle growth.


Although increasing your energy levels is important, it’s the BCAAs capability to boost muscle growth that make them even more interesting for the bodybuilders. They are have an ability to directly stimulate the synthesis of proteins in the muscles, and initiating their build-up.

According to the research, leucine is the most important of the three BCAA’s in terms of protein synthesis. This amino acid unlocks the protein synthesis within the muscles. It also can help in boosting the insulin levels. This hormone is also involved in stimulating protein synthesis, using a slightly different mechanism. In other words, the effect of leucine on protein sunthesis is twofold.

The other mechanism through which the BCAAs stimulate the build up of muscles is by boosting the growth hormone production. An Italian study has proven that BCAA supplementation can increase the levels of both the growth hormone, and of the growth hormone binding protein after workout.  The growth hormone binding protein plays a crucial role in the growth hormone’s transfer through the bloodstream into the muscles.

The BCAAs also suppress the effect of the cortisol. This catabolic hormone has negative effect on muscle growth. According to the research a regular consumption of BCAA can lower the levels of cortisol in your body during and after training.


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