Cardiovascular benefits and risks across the physical activity continuum.

PURPOSE OF REVIEW: Habitual physical activity can reduce the risk of future cardiovascular morbidity and mortality. This review evaluates recent publications that have assessed the impact of the dose of physical (in)activity on cardiovascular outcomes.

RECENT FINDINGS: Sedentary behavior, characterized by prolonged sitting, is increasingly prevalent across the globe and increases the risk for cardiovascular events in a dose-dependent fashion. Similarly, the number of individuals performing endurance exercise events has tripled over the last 2 decades, and some studies suggest that the high volumes of exercise training and competition may attenuate the health benefits of a physically active lifestyle.

SUMMARY: Breaking up sitting time or replacing sitting by (light) physical activity are effective strategies to attenuate its detrimental health effects. Low doses of physical activity, preferably at a high intensity, significantly reduce the risk for cardiovascular and all-cause mortality. Larger doses of exercise yield larger health benefits. Extreme doses of exercise neither increase nor decrease the risk for adverse outcomes. Athletes demonstrate a transient cardiac dysfunction and biomarker release directly postexercise. Chronic exercise training may increase the risk for atrial fibrillation, but is also associated with a superior life expectancy compared with the general population.