Bioactive peptides rich in branched-chain amino acids (BCAAs) are an effective way to alleviate fatigue conditions, but the deep mechanism remains unclear. This study investigated the anti-fatigue effect of branched-chain amino acid-enriched egg white peptides (BEWPs) through the gut-muscle axis by gut bacteria and untargeted metabolomic analyses. The results demonstrated that BEWPs enhanced exercise endurance and strength by also promoting gastrocnemius development in mice. Furthermore, there was a reduction in oxidative stress, inflammatory response, and the accumulation of unexpected metabolites generated under fatigue conditions. The intake of BEWPs increased the abundances of