Branched Chain Amino Acid Supplements 

Branched chain amino acid supplements aren't as widely used as other supplements like creatine and protein powder.  The BCAAs include the three indispensable amino acids valine, leucine and isoleucine, which make up one-third of muscle protein. 

The theory is that since they are so abundant in the muscle tissue, consuming them in supplement form may help reduce the chance of muscle tissue breakdown-similar to glutamine supplements.

What BCAA supplements do

BCAA supplements may help prevent the break down of muscle tissue, particularly during high intense aerobic activity.  The body converts the BCAAs into two other amino acids (glutamine and alanine) which are then released in large amounts throughout the body.  The muscles may also be able to use BCAA's as a source of fuel when muscle glycogen levels are depleted.

The evidence

A study conducted in my home town of Guelph, Ontario demonstrated that supplementing with 4 grams of BCAAs before and after exercise can reduce muscle tissue breakdown (MacLean et al., 1994).  They also appear to help maintain muscle tissue in athletes that consume a diet that is low in carbohydrates (Williams, 1998).

How Can a Bodybuilder Benefit from BCAA Supplements?

Theoretically BCAAs could be beneficial to a bodybuilder on a fat loss program to help maintain lean body mass.  Keep in mind that there are a limited number of published studies that prove their effectiveness over the long term (I didn't even bother looking at the studies conducted by supplement companies).  Also, they've been around for quite some time now, and haven't attracted much attention from bodybuilders or athletes.

Conclusion 

Like HMB supplements, BCAA haven't really proven themselves as an essential supplement in a bodybuilder or athletes supplement regimen.  Furthermore, most bodybuilders and athletes already consume meal replacement and protein powder supplements that contain ample amounts of BCAAs.  If you are taking a high quality protein powder, You may not need BCAA supplements.

With that being said, some people find that BCAA's do help them make decent muscle gains.  Here are a few real reviews from BCAA users that have bought the supplements:

My advice; give Optimum's BCAA 5000 Powder a test run if you have extra cash.  If not,  only go for the following  proven supplements:

• Creatine
• EFA supplements
• Glutamine
• Multivitamin & Mineral supplements
• Whey protein powder