Objective To study the effects of maca extract on exercise endurance and blood hormone levels in the rats. Methods Wistar rats treated with maca extract (2.0, 4.0, 8.0 g/kg body weight) were freely swimming in the circulating water flow daily for 15 days. On the 16th day of experiment, the exercise endurance and blood noradrenaline (NA), estradiol (E2), and testosterone (T) levels of the rats were determined.Results The rats administered with maca extract at the doses of 2.0, 4.0, 8.0 g/kg body weight for 15 d showed that the swimming time before sinking was increased by 32.51%, 60.04%, 106.52%, the total swimming time was extended by 16.99%, 56.50%, and 101.73% respectively (P<0.01); while the number of sinking was decreased by 18.89%, 35.89%, and 58.06%, respectively (P< 0.01), compared with those swimming rats without maca extract treatment. The noradrenaline level in the blood of rats treated with maca extract 2.0, 4.0, 8.0 g/kg body weight was increased by 3.30%, 6.60%, and 16.50%, respectively, compared with the control group, and increased by 42.49%,47.05%, and 60.70%, respectively, compared with the swimming rats without extract treatment; the E₂ level was increased by 132.83%,102.72%, and 62.26% (P<0.01)respectively, compared with the control group, while decreased by 23.88%, 33.72%, and 46.95% (P<0.01) respectively, compared with the swimming rats without extract treatment. The blood testosterone level was increased by 5.11%, 37.65%, and 123.16% (P<0.01) respectively, compared with the control group, and increased by 28.98%, 68.92%, and 173.85%, (P<0.01) respectively, compared with the swimming rats without extract treatment.Conclusions The results of this study demonstrate that maca extract has effect to resist fatigue and enhance exercise capacity in rats. The mechanism is associated with reduced blood E₂, and increased noradrenaline and testosterone levels in the blood of rats.