By Cristina Goyanes
April 15, 2014

For as many stories as there are touting the benefits of running, occasionally we come across one that says the opposite, such as the recent news of how two seemingly fit 30-something male runners passed away during the Rock 'n' Roll half marathon in Raleigh, NC, last weekend.

Race officials have not released the official cause of death, but Umesh Gidwani, M.D., chief of Cardiac Critical Care at Mount Sinai Hospital in New York City, speculates that it was cardiac arrest that lead to their sudden deaths. The incidence of this occurring is higher in men than women, but still it's very small-about 1 in 100,000. "The likelihood of dying while running a marathon is about the same as having a fatal motorcycle accident," says Gidwani, who would call this a "freak accident."

Two major conditions may have led to these unexpected events, he explains. One is called hypertrophic cardiomyopathy, which is when the heart muscles become thick, obstructing the flow of blood to the rest of the body. The other is ischaemic (or ischemic) heart disease, which is caused by a decrease in blood flow in the artery supplying the heart. This generally occurs in older people or those who have a family history of heart disease. Poor lifestyle habits, like smoking, or having cholesterol problems can also increase the risk of the latter.

Unfortunately, there aren't always symptoms to look out for. "Chest pain or discomfort, unusual sweating, and feeling abnormal heart palpitations are typical warning signs, but these don't always occur before sudden cardiac death," Gidwani warns. Even though there aren't any cues to look out for when runing, you can ask your doctor for a preventative screening in advance, if you have geniune cause for concern.

"An EKG would be able to pick up if there is something wrong with your heart," Gidwani says. Even if there's nothing structurally wrong with your ticker, more specialized tests exist to investigate further. But the odds that you're a candidate for these kinds of tests are slim. "The incidence of sudden cardiac death is so low in young people that it does not help to have widespread screening for it," says Gidwani, adding that these tests are recommended if you have a family history, had chest pains in the past, are a smoker, or have other symptoms.

Typically runners are thought to be in good health. If you're training properly and have the okay from your primary care doctor or cardiologist, then you should be good to go the distance.