First some info on BCAA's
BCAA's (Branch Chain Amino Acids)
Leucine, Valine, and Isoleucine are called "branch chain" aminos due to their molecular structure, and are important essential amino acids well known for their anticatabolic (muscle-saving) benefits. They are called BCAA's because they structurally branch off another chain of atoms instead of forming a line. Studies have shown that BCAA's postively affect skeletal muscle growth, enhance fat loss, help to stimulate protein synthesis and inhibit its breakdown, so BCAA's have powerful anabolic and anticatabolic effects on the body. They may also potentiate the release of some anabolic hormones, such as growth hormone. Regular ingestion of BCAA's help to keep the body in a state of postive nitrogen balance. In this state, your body much more readily builds muscle and burns fat. Studies have shown that athletes taking extra BCAA's have shown a loss of more bodyfat than those not taking BCAA's.
BCAAs are used as a source of energy for muscle cells. During prolonged exercise, BCAAs are released from skeletal muscles and their carbon backbones are used as fuel, while their nitrogen portion is used to form another amino acid, Alanine. Alanine is then converted to Glucose by the liver. This form of energy production is called the Alanine-Glucose cycle, and it plays a major role in maintaining the body's blood sugar balance.