This question is about Running
Branched-chain amino acids (BCAAs), also known as valine, leucine and isoleucine, are known for their role in promoting muscle repair and growth, decreasing muscle soreness and increasing power output [ 1 2
While runners can supplement their routine with BCAAs, they are actually found abundantly in whole foods, so if you eat a well-balanced diet, it’s not necessary to take BCAA supplements. Animal proteins (such as poultry, fish, pork, and beef) contain all nine essential amino acids, including the BCAAs. If you’re a vegetarian or vegan, it’s more difficult to get all three BCAAs from a singular plant-based protein; however, a combination of these proteins will result in adequate intake.
VanDusseldorp TA, Escobar KA, Johnson KE, et al. Effect of Branched-Chain Amino Acid Supplementation on Recovery Following Acute Eccentric Exercise. Nutrients. 2018;10(10):1389. Published 2018 Oct 1. doi:10.3390/nu10101389
Gervasi M, Sisti D, Amatori S, et al. Effects of a commercially available branched-chain amino acid-alanine-carbohydrate-based sports supplement on perceived exertion and performance in high intensity endurance cycling tests. J Int Soc Sports Nutr. 2020;17(1):6. Published 2020 Jan 20. doi:10.1186/s12970-020-0337-0