Quite a few years ago, science established that exercising with weights stimulated muscle protein sythesis. Soon after, we discovered that the presence of the essential amino acids during weight lifting amplified this muscle building response by 100%! That’s important, as a high stimulation of muscle protein synthesis is the mechanism that ensures big gains in muscle mass. Now it appears clear that some of the essential amino acids are more important than others for stimulating muscle growth. The branch chain amino acids (BCAA) are three essential amino acids (those that cannot be synthesized by the body) are the most potent at activating muscle protein synthesis.

A recent study by Hakan Karlsson’s group in Stockholm, Sweden, has revealed that when a BCAA supplement is consumed before, during and after weight lifting, it provides a greater activation of muscle protein synthesis than lifting weights without supplementation. BCAA supplementation and training resulted in a much higher phosphorylation of the 70-kDa S6 protein kinase in muscle. This key signaling protein is a major player in the translation initiation step of activating muscle protein synthesis. A higher phosphorylation of 70-kDa S6 protein kinase means a higher rate of synthesis of muscle proteins.

On a dose per gram basis, BCAA are expensive. High quality whey proteins are the richest known source of BCAA, up to 26 grams per 100 grams of protein and are a much more economical alternative.

The branched chain amino acids (BCAA) (leucine, isoleucine and valine) play a pivotal role in muscle metabolism during exercise. These amino acids undergo increased utilization during exercise, they spare valuable muscle fuel such as glycogen. However, they are also essential for the activation of protein synthesis in muscle after exercise. This is a key aspect of recovery, repair and growth. For these reasons sports scientists are starting to take a closer look at BCAA supplementation to enhance athletic performance.

Studies completed ten years ago showed that supplementation with BCAA can prevent central nervous system fatigue by competing with free-tryptophan uptake from the plasma into the brain. These studies reported that a 2-6 gram dose close to exercise decreased fatigue (measured via perceived exertion) and/or enhanced athletic performance.

One recent study has shown that supplementation with leucine was able to increase power output and time to exhaustion in a group of rowers (outrigger canoeists). Although the researchers examined several aspects of central nervous system fatigue (such as changes in plasma ratio of free-tryptophan to BCAA), they attributed the power and performance benefits from BCAA to a reduction in muscle damage and the preservation of muscle fuel (glycogen).

Whether the beneficial effects of the BCAA resides in their ability to reduce central nervous system fatigue, muscle damage or spare valuable muscle fuel, it’s clear that supplementation with BCAA has the capacity to boost performance particularly during strenuous exercise.

BCAAs are the amino acids leucine, isoleucine and valine. They are 3 of the eight amino acids that fall into the essential category. That is, they can not be made by the body, and must be part of your diet. Research has demonstrated they do enhance protein synthesis, a positive nitrogen balance and help prevent muscle breakdown. Research on BCAA supplementation during exercise does show they: - increase mental alertness and reduce mental fatigue.

In the blood stream BCAAs compete with tryptophan (the tranquilizing amino acid). Tryptophan is the direct precursor to the neuro- transmitter serotonin. This depresses the central nervous system and produces symptoms of fatigue. When you exercise intensely, the ratio of tryptophan to BCAA is altered in favor of increases in tryptophan. This itself makes you fatigued. Several studies with various types of athletes confirm that reasonable does (7-9gms) of BCAAs do reduce mental fatigue and increase mental alertness during their respective events (Bloomstrand et al 1991).

BCAAs are shown to be absorbed far more effectively in this peptide-bound form (Grimble et al.1986). These particular whey protein peptides are shown to be absorbed the more effectively than any other protein chain. They are so low in molecular weight they utilize different cellular pathways. (Silk 1980).

Therefore the combination of whey protein’s naturally high concentration of BCAAs and the incredibly absorption kinetics is a potent one.

Once in the body, most BCAA supplements go directly towards glutamine/glutamate formation. (Neu 1996) A part from the large concentration of BCAAs, whey protein’s amino acid profile is already rich in peptide bound glutamate. This amino acid is also shown to be absorbed far more effectively in peptide-bound form (Silk 1980).