目的 探讨不同强度运动对心肌线粒体功能的影响及与运动性疲劳的关系。方法 以不同时间游泳为运动模式，观察了 90 min运动、力竭运动和力竭运动后 24h心肌线粒体脂质过氧化水平、抗氧化能力、游离钙浓度及磷脂酶 A2活性的变化。结果 90 min运动后心肌线粒体各项指标未见明显变化。力竭运动后心肌线粒体脂质过氧化水平显著提高，抗氧化能力和游离钙浓度显著下降，磷脂酶 A2活性显著增高 (P Objective To investigate the effects of exercise with different intensity on myocardial mitochondrial function and the relationship with exercise-induced fatigue. Methods Swimming at different times was used as the exercise mode. The changes of myocardial mitochondrial lipid peroxidation, antioxidant capacity, free calcium concentration and phospholipase A2 activity were observed at 90 min, exhaustive exercise and exhaustive exercise. Results There was no significant change of myocardial mitochondria after 90 minutes of exercise. After exhaustive exercise, myocardial mitochondrial lipid peroxidation level was significantly increased, antioxidant capacity and free calcium concentration decreased significantly, phospholipase A2 activity was significantly increased (P