Could distance running be bad for your health?
It's impressive when someone finishes a marathon. Even more impressive - those who run marathons year after year. But a study of 50 men who all ran the Twin Cities Marathon 25 years in a row has shocking results.
"I thought that we were going to find that I was a very healthy person and no heart disease," said John Tantzen, a study participant.
Instead, the study found those men - including Tantzen - actually had more plaque in their arteries than those who don't run.
"My first perception was, 'Yeah! 90th percentile good!' and it was, like, stunning when I read further into the details and it was 95th percentile bad."
According to Dr. Robert Schwartz, one of the study's authors, "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."
The control group of 25 non-runners included people with diabetes and those who were overweight or smokers. Still, the ultra-marathon runners had more plaque.
As a cardiologist, Dr. Schwartz said he believes that having run for so many years, the subjects likely had higher blood pressure, higher heart rates and metabolic by-products.
Tantzen thinks that for him, it's likely family history and diet.
"It's hard to get enough calories to train that much, and it's so easy to fall into junk food," he admitted.
Dr. Schwartz will continue to monitor the marathon runners to see if their higher plaque affects their long term health. For now, he said it's still too early to say if ultra-marathon runners need to slow down.