BCAA's and their use

BCAA (branched chain amino acids) are in short the three essential amino acids - leucine, isoleucine and valine literally. The BCAA are different from the other 17 amino acids in that they are primarily metabolized in skeletal muscle (Layman, 2003) and metabolized at a much lower rate in the liver (Norton, 2005). The rate limiting enzyme in BCAA catabolism is Branched Chain Keto Acid Dehydrogenase, which is much more active in skeletal muscle than in the liver (Norton, 2005). The idea of supplementing with extra branch-chained amino acids (BCAA) in addition to ones protein intake has been around for quite some time. But with all the 'magic elixirs' and 'pump potions' on the market today, BCAA supplementation has never gained popularity outside of the hardcore (as in elite athletes) circles.

One reason for this oversight on BCAA may be that people feel supplementing with additional BCAA on top of an already high protein diet will not be beneficial. Others may simply be uninformed about BCAA.

Because BCAA serve as a "fuel" for skeletal muscle, supplementing with additional BCAA to improve sports performance and to treat various diseases and aliments as been suggested. BCAA have many other roles besides being just a fuel for skeletal muscle.

The Metabolic Roles Of The BCAA Include:

    * Substrate for energy production
* Substrate for protein synthesis
* Precursor for the formation of other amino acids
* Metabolic signals (Primarily Leucine)

Supplementing With BCAA

What is interesting about the BCAA is their ability to participate in the above metabolic processes, energy substrates, substrates for protein synthesis, precursors for alanine and glutamine, and modulators of protein synthesis, is governed by their availability.
Research suggests that first and foremost the BCAA are used for the synthesis of protein structures (Layman, 2003).
Research on leucine shows that once the minimum requirement of leucine for protein synthesis is met leucine can then be used as a precursor for alanine and glutamine or to activate various signaling pathways (Layman, 2003), such as the mTOR pathway. It may sound like leucine is free to exert its powerful effect of mTOR activation, but one must remember that protein breakdown and synthesis is occurring throughout the entire body; the body's protein stores are in a constant state of flux.
The constant body protein flux plus the increased leucine oxidation caused by exercise means that leucine is in high demand and therefore may not be able to participate in muscle growth at its full potential. This is where supplementing with additional BCAA comes into play and importance.
Due to leucine's metabolic properties, many people focus solely on leucine and not the other two BCAAs valine and isoleucine.

Research has shown that leucine-rich diets or administration of leucine alone lead to decreases in valine and isoleucine plasma concentrations and a BCAA imbalance (Shirmomura et al., 2004). While it may be cheaper to supplement with leucine alone instead of all three BCAA, one should supplement with all three BCAA so not to create a BCAA imbalance.
The main question or argument with BCAA supplementation people have is whether additional BCAA supplementation on top of an already high protein intake will produce any benefits, specifically enough benefits justify to the cost of the BCAA. Research and anecdotal findings would definitely suggest yes.
The benefits of free-form BCAA lie in their ability to quickly flood the blood stream and amino acid pools with high amounts of BCAA, specifically leucine. While whey protein is absorbed quickly, ingestion of 10 grams of BCAA from whey does not create the same metabolic response as the ingestion of 10 grams of free-form BCAA.

Once whey protein reaches the gut, it takes about 45 minutes before the amino acids start to be extracted and are absorbed and can be used. This lower absorption means the amino acid pools are not "flooded" with large amounts of BCAA.
the BCAA ability to be utilized in various pathways is governed by their availability. It is my belief that delivering large amounts of BCAA to muscle and keeping BCAA levels elevated will cause a strong and sustained activation of mTOR, leading to skeletal muscle hypertrophy.

The current research available clearly displays that the BCAA (specifically leucine) are very potent stimulators of protein synthesis and have many other beneficial effects to athletes.
In Summary,
The Metabolic Roles Of The BCAA Include:
* Substrate for energy production
* Substrate for protein synthesis
* Precursor for the formation of other amino acids       
* Metabolic signals (Primarily Leucine)
What all this means is ingesting BCAA primes your body for growth (protein synthesis). All of these actions are beneficial to an athlete and should not be overlooked. There is endless research backing BCAA supplementation.

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