The Branched Chain Amino Acids are Leucine, Isoleucine and Valine. They are sometimes included as components of intra-workout supplements because they can help spare muscle tissue during extended training. A study published in The Journal of Sports Medicine and Physical Fitness tested their ability to attenuate decreases in power production after strength training.
Researchers assessed the countermovement jumping and seated shot put throwing performance of 11 men with weight room experience. Some were given 20 grams of BCAAs while others received a placebo before and after a session of compound barbell exercises. Although there were no differences in muscle soreness 24 hours after training, BCAAs did help reduce typical decrements in functional power a day after the workout.