Marathon running can increase your risk of cardiac arrest in the short term, but it also lowers the overall likelihood that you will experience cardiac arrest or other heart problems, according to science, statistics and sports cardiologists. Exercise does not prevent heart disease altogether, though, he said, and the hearts of marathon runners, like those of sedentary people, can harbour fatty plaques that can break free and block an artery, causing cardiac arrest. Thompson was a co-author of a 2012 study that found that, between 2000 and 2010, 59 people racing a full- or half-marathon in the United States experienced a cardiac arrest. Another 2012 study, using survey data from marathon medical directors, concluded that the overwhelming majority of cases of cardiac arrest during races involve middle-aged men, most of whom collapse in the final four miles of the course. Still, while middle-aged male runners’ relative risk of a cardiac arrest rises while they are completing 26.2 miles compared to when they are not, their absolute risk of cardiac arrest, even then, remains reassuringly low, Thompson said.

Source: The Irish Times June 08, 2019 15:56 UTC