Branch Chain Amino Acids or BCAAs are the most rapidly absorbed of all amino acids; in fact 70% of BCAAs immediately pass through the liver and are 'pushed' into muscle tissue where the majority of the metabolism takes place. BCAAs are also responsible for muscle production and energy production. Muscle production is supplied by an increase in protein synthesis. Energy production is caused when BCAAs assist in the production of L-alanine, a primary pathway to muscle energy, causing both increased protein synthesis and increased energy sources. BCAAs may also be of benefit to you during extreme dieting by lessening the catabolic (breaking down) effect of muscle tissue. You can see why BCAAs are so important in your quest for muscle growth and recuperation. Your body can not manufacture its own BCAAs. They must be supplied through your diet.