Objective Investigating the effect and mechanism of resveratrol on cardiac function in exercise induced fatigue rats by regulating mitochondrial energy metabolism. Methods Forty-eight healthy male Sprague Dawley rats (6~8 weeks old) were selected and divided randomly into a blank control (C) group, resveratrol administration (R) group, exercise-induced fatigue (E) group, and exercise-induced fatigue + resveratrol administration group (ER) (n=12 rats per group). Rats in the E and ER groups were subjected to weight-bearing 5% of their body weight for 60 minutes each day and exercise for 6 days per week for 6 weeks. Rats in the R and ER groups received resveratrol 50 mg/kg by gavage, 1 hour after exercise. The biochemical kit was used to detect the indicators of motor fatigue, myocardial injury and mitochondrial energy metabolism enzymes in rat myocardium. The mRNA expression levels of myocardial energy metabolism related regulatory factors were detected by real-time fluorescent quantitative PCR (RT-qPCR). Results Plasma levels of blood urea nitrogen (BUN) and creatine kinase (CK) were significantly increased in rats in group E compared with group C (P<0.05, P<0.05), CK-MB and cTnI activity were also significantly increased (P<0.01, P<0.05), while activity levels of myocardial cytochrome C oxidase (COX) and succinate dehydrogenase (SDH) were significantly reduced (P<0.01, P<0.05). mRNA expression levels of the mitochondrial energy metabolism-related genes silent information regulator 1 (SIRT1), peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α), and estrogen receptor-related receptor α (ERRα) were also significantly reduced (P<0.01, P<0.01, P<0.01). Serum levels of BUN and CK were significantly decreased in the ER group compared with group E (P<0.05, P<0.05), while CK-MB and cTnI activities were significantly decreased (P<0.05, P<0.05), myocardial COX and SDH activities were significantly increased (P<0.01, P<0.05), and SIRT1, PGC-1α and ERRα mRNA levels were also significantly increased (P<0.05, P<0.01, P<0.01). Conclusions Resveratrol can effectively activate the sirtuin 1/peroxisome proliferator activated receptor γ coactivator 1α/estrogen-related receptor α signaling pathway, improve myocardial energy metabolism in exercise-fatigued rats, and protect against myocardial injury.