Energy supply issues, ATP+PC, anaerobic glycolysis, product accumulation, lactic acid, mechanical failure of muscles to contractions and nervous system changes contribute to fatigue. The goal of this study was to determine whether 70% ethanol and aqueous extracts of Rusa unicolor antler from East Kalimantan, Indonesia, can reduce fatigue in male mice. A total of sixty-four male mice aged 2-3 months (20-30 g) were randomly assigned to eight groups (negative control, positive control and 3 doses of treatments for each extract). After that, the swimming endurance time was assessed, and blood glucose levels were measured before and after the test. Mice's tiredness is demonstrated by their head remaining submerged for 4-7 s while their tails and legs are stretched. One-way ANOVA was used to statistically analyze the data. The results showed that there were significant differences between all treatments with the negative control group (p<0.05). At a dose of 1.3 mg/kg BW of 70% ethanol and aqueous extract of Rusa unicolor antlers were able to maintain the stamina of male mice in swimming for 2 hrs 37 mins. Both extracts improve endurance training, delay tiredness, and promote recovery after exercise. Hence, Rusa unicolor antler extract can significantly improve athletic ability and facilitate recovery after exercise in male mice by increasing endurance training capacity and delaying tiredness.