Each year, more than half a million Americans run 26.2 miles down city streets in one of the country's 1,100 marathons. The chafing and exhaustion induced by all those miles is well-known, but a new study suggests marathons can take a toll even on those who aren't running in them.
A study published Thursday in the New England Journal of Medicine finds that the death rate from heart attacks rises 15 percent on the day of marathons, largely because of delays caused by road closures.
