Who would have thought a marathon runner could be damaging his heart? The notion sounds ridiculous, but a controversial new study is raising questions about the true health benefits of distance running.
This comes after a study of 50 men who all ran a major marathon 25 years in a row, revealed shocking results.
"I thought that we were going to find that I was a very healthy person and no heart disease," says study participant, John Tantzen.
"We would have expected they had less plaque because these are very fit people typically good healthy lifestyle lots of exercise of course healthy eating habits, in fact they had slightly more plaque, a big surprise," adds researcher Dr. Robert Schwartz.
The study found those men, including John Tantzen, actually had more plaque in their arteries than those who don't run.
Cardiologist Dr. Robert Schwartz of the Minneapolis Heart Institute is one of the study's authors. He says what they don't know, is why. And for that reason, it's too early to tell ultra marathon runners to slow down.
But, it is remarkable that the control group of 25 non-runners they included in the study all were people with diabetes and who were either overweight or smokers, and even so, it was the other group, the ultra marathon runners who had more plaque.