Fatigue　is　a　common　health　issue　in　today＇s　society　worldwide.　Finding　anti-fatigue　functional　substances　seems　warranted　to　alleviate　fatigue-related　issues.　The　Lateolabrax　japonicus　peptides　(LPH)　obtained　via　enzymatic　hydrolysis　were　identified　being　rich　in　Glu,　Gly,　and　hydrophobic　amino　acids,　which　exhibited　antioxidant　properties.　However,　other　biological　functions　of　LPH　have　yet　to　be　reported.　This　study　main　goal　was　to　investigate　the　anti-fatigue　effects　of　LPH　via　a　fatigue　mice　model,　and　further　to　elucidate　its　underlying　mechanism　using　in　vivo　assay.　The　results　indicated　that　LPH　exhibited　strong　antioxidant　activity　and　stability　in　vitro.　Meanwhile,　LPH　significantly　extended　the　swimming　time　of　mice,　while　also　decreasing　fatigue　marker　levels　(LA,　BUN,　CK,　and　MDA)　in　serum　concurrently　by　increased　levels　of　antioxidant　enzymes,　blood　glucose,　and　Na+-K+-ATPase.　Histopathological　examination　revealed　that　LPH　effectively　improved　tissue　damage　caused　by　fatigue.　Mechanistically,　LPH　upregulated　the　gene　and　protein　expression　of　Nrf2　and　AMPK,　indicating　its　regulatory　role　in　Keap1/Nrf2　and　AMPK/SIRT1/PGC-1　alpha/NRF1　signaling　pathways.　Furthermore,　the　study　demonstrated　that　LPH　could　modulate　the　abundance　and　balance　of　fatigue-related　gut　microbiota　(Butyricimonas,　Helicobacter,　Monoglobus,　and　Turicibacter).　In　summary,　these　findings　indicated　that　LPH　exerted　its　anti-fatigue　effect　by　improving　energy　metabolism　and　reducing　oxidative　stress,　suggesting　its　potential　as　a　promising　functional　anti-fatigue　nutraceutical　in　food　industry.