BCAAs are Branch Chain Amino Acids.
They are some of the many essential amino acids, including isoleucine, valine and leucine. Leucine is one of the most important amino acids for PROTEIN synthesis and muscle gain.
BCAAs increase the rate of protein synthesis and increase cells' capacity for protein synthesis. When you diet and get leaner, BCAAs can also help prevent muscle and protein breakdown.
BCAAs are can give you an energy boost meaning you can workout harder, and even lose more fat. Between 5-10g should be sufficient, BEFORE AND/OR during your workout.