Copyright © 2009 The Author(s)

Abstract: Epidemiologic studies have consistently identified a strong inverse association between coronary heart disease (CHD) and regular, predom-inantly moderate-intensity physical activity and cardiorespiratory fitness. Supporting evidence of causative rela-tionships has been provided by aero-bic exercise training studies in both animals and humans. This research demonstrated multiple plausible cardio-protective biological mechanisms. These include direct antiatherosclerotic effects by improving artery endothelial func-tion and reducing inflammation and indirectly via modification of other risk factor components of the metabolic syn-drome, by reducing risk of a coronary thrombotic occlusion (antithrombotic effects), by decreasing myocardial oxy-gen demands and increasing its vascu-lar supply (anti-ischemic effects), and by improving cardiomyocyte electrical stability and autonomic nervous system adaptations (antiarrhythmic effects). Although much additional research is needed to better define and estab-lish optimal dose-response relationships, clearly these pleotropic effects strongly suggest that aerobic exercise can atten-uate the risk of CHD at all stages of the underlying atherothrombotic process