Good news for serious runners of a certain age: researchers at the University of Manitoba are convinced that running marathons is no more likely to damage the hearts of people over 50 than it is to damage the hearts of runners between the ages of 18 and 40. Newswise reports that the researchers used blood tests, echocardiography (ultrasound of the heart), CT, and MRI to test healthy volunteers who participated in the 2010 and 2011 Manitoba Full Marathons. They found that elite elderly marathoners over the age of 50 had a transient increase in blood markers and temporary swelling and weakness of the right side of the heart immediately following the 26.2 mile marathon, but they also found that all of the changes returned to normal within a week of the race. “This is the first study worldwide to use cardiac CT in marathoners over the age of 50 to detect the presence of blocked arteries, ” said study author Davinder Jassal, associate professor of medicine, radiology and physiology in the Faculty of Medicine, University of Manitoba and principal investigator at St. Boniface General Hospital Research Centre. “Most importantly, repeated endurance stress does not seem to result in permanent myocardial injury in this patient population.†Read an abstract of the study here.