Endothelial dysfunction occurs early in atherosclerosis in response to cardiovascular risk factors. The occurrence of endothelial dysfunction is primarily the result of reduced nitric oxide (NO) bioavailabilty. It represents an independent predictor of cardiovascular events and predicts the prognosis of the patient. Therefore, endothelial function has been identified as a target for therapeutic intervention. Regular exercise training is a nonpharmacological option to improve endothelial dysfunction in patients with cardiovascular disease by increasing NO bioavailability.