Consuming protein after exercise is important for two reasons. Firstly, protein provides the amino acid building blocks with which muscles and connective tissues are repaired and built. Secondly, the ingestion of amino acids provides the stimulus that tells your body it’s time to start muscle protein synthesis. In relation to providing this stimulus, not all proteins and amino acids are created equal. L-Leucine is one of the three branch chain aminos, and of all the amino acids it plays the most important role in stimulating muscle protein synthesis. Continue reading to find out how and why this happens.