An innovative study conducted at St-Boniface Hospital led by Dr. Davinder S. Jassal, Principal Investigator, St-Boniface Hospital Research and Assistant Professor of Cardiology, Radiology and Physiology in the Faculty of Medicine at the University of Manitoba, shows that running half marathons (a distance of only 13.1 miles) causes short-term cardiac injury, but does not result in permanent heart muscle damage. The study is the first of its kind to examine the effects of marathon running on half marathon participants. It is also the first to use 3D echocardiography (ultrasound of the heart) to show transient changes in heart function post half marathon.
Jassal conducted a study in 2008 with full marathon (26.2 miles) runners from the Manitoba Marathon. His research team used cardiac MRI (CMR) and blood samples to show, for the first time, cardiac abnormalities experienced by long-distance runners. When the results were released in May 2009, and later published in the American Journal of Cardiology, Jassal was already planning a follow-up study with half marathon participants for the 2009 Manitoba Marathon to see if transient cardiac damage was also visible in short distance runners.