Myocardial ischemia-reperfusion (I-R) injury is the major contributor to the morbidity and mortality associated with coronary artery disease. Although several factors contribute to I-R-mediated myocardial injury, strong evidence indicates that production of reactive oxygen species and calcium overload are important mediators of this type of cardiac damage. This tutorial lecture will discuss recent experiments examining the effects of endurance exercise training in providing cardiac protection against I-R injury. In this regard, evidence indicates that both short term (days) and long-term (weeks) endurance exercise training significantly reduces I-R-induced myocardial injury. At present, the mechanism(s) responsible for exercise-induced cardioprotection remain debatable. Experiments investigating the role of exercise-induced increases in cardiac antioxidants and ATP-sensitive potassium channels in exercise-mediated cardioprotection will be discussed.