Optimal Running Dose and Cardiovascular Risk.

The cardiovascular benefits of regular exercise are well established. A mortality benefit has clearly been demonstrated for those that participate in light and moderate exercise. Less is known regarding the long-term effects of vigorous regular running over an extended period. In recent years, myocardial fibrosis, arrhythmias, and coronary artery calcium have been demonstrated in high-intensity exercisers. However, the prognostic implication of these findings remains unknown, and thus, there is insufficient evidence, and potentially not a need, to recommend a maximal running dose or limit for healthy individuals who already train intensively. For those otherwise healthy individuals who wish to run for cardiovascular health benefits, following the standard guidelines of 150 min of moderate-intensity exercise or 75 min of vigorous exercise weekly is recommended. Prevention and screening remain as key to lowering morbidity and mortality in all individuals.