Yes, they can. BCAAs, consisting of leucine, isoleucine, and valine, are thought to contribute to protein synthesis, an instrumental process in muscle development. Consuming them, whether through supplements or dietary sources, may contribute to overall muscle growth and improved athletic performance.Yes, they can. BCAAs, consisting of leucine, isoleucine, and valine, are thought to contribute to protein synthesis, an instrumental process in muscle development. Consuming them, whether through supplements or dietary sources, may contribute to overall muscle growth and improved athletic performance.