Are Competitors in Long-Distance Running Races at Increased Risk for Cardiac Arrest?

When a news announcer reports that a runner has experienced cardiac arrest during a road race, many people become anxious about exercising. To provide much-needed perspective on the cardiac risk of participation in long-distance running races, investigators used a prospectively compiled database to assess the incidence and outcomes of cardiac arrest during and immediately after marathon and half-marathon races in the U.S. from January 2000 through May 2010. Cardiac arrest was defined as a state of unconsciousness, without spontaneous respiration and pulse, documented by a medical professional.

Of almost 11 million runners in the database, 59 experienced cardiac arrest (mean age, 42 years; 86% men), an incidence of 1 per 184,000 participants.…