Exercise-induced reduction in myocardial infarct size after coronary artery occlusion in the rat.

Chronic exercise (E) has been thought to be beneficial to the cardiovascular system by increasing energy production and utilization, improving myocardial contractility and increasing myocardial vascularity; whether or not any of these effects are beneficial to ischemic myocardium is uncertain. In this study, rats were forced to swim one hr/day, 5 days/wk for 5 weeks. They were sacrificed and the myocardial capillary bed was perfused with carbon black.