...recent studies have shown that pushing your body to run 26.2 miles can cause at least minor injury to your heart.
"We didn't find any gross injuries, such as blocked arteries or blood leakage. But we did find some enzymes leaking through the heart membrane, which is consistent with significant stress on the heart," says Malissa Wood, M.D., the lead author of a 2006 study in the journal Circulation.
The Circulation study found that people who'd averaged at least 45 miles a week in training were significantly less likely to suffer heart damage than those who ran 35 miles a week or less
MY COMMENTS: Food for thought about marathon running. Many of those who run marathons probably should not be doing them.