L-Valine, an essential amino acid, cannot be manufactured by the body and must be consumed in the diet. Valine is also a branched-chain amino acid, which can be burned for fuel in the cells.
L-Valine is an an essential amino acid, specifically classified as a "branched chain amino acid" (BCAA). BCAAs stimulate protein synthesis directly in muscle tissue. Valine is a major fuel involved in anabolic (tissue-building) reactions, and stimulates muscle protein synthesis.
And what is your point? L-Leucine would be more optimal to get by itself(but not advocating that). It is the one that provides the main signal for protein synthesis.