Could Running Marathons Be Bad For Your Health?

Some 55,000 runners are descending on New York City for Sunday's marathon, the world's largest. For years, we've been told that being active and maintaining a healthy weight actually lowers cancer risk. But a new study shows long distance running could be linked to colon cancer. Dr. Lynn O'Connor, Chief of Colon & Rectal Surgery at Mercy Hospital, explained the science behind the study to Inside Edition's Alison Hall.