LA CROSSE, Wis. (WKBT) -

A new study is showing too much running could be hazardous to your heart.

A Minnesota Cardiologist compared the risk of heart disease in marathon runners versus non-runners. He found long distance runners actually have a higher build up of plaque inside their coronary arteries than their counter parts.

The rise in blood pressure while they run can cause stress inside their blood vessels leading to plaque and calcium to build in and around their arteries.

Doctors say running long distances on a regular basis can be harmful, but there are precautions every runner should take. "If you are just getting into running a routine and you have health issues, you might be a little bit overweight, it wouldn't hurt to see your primary physician before just immediately starting some marathon training program you got on the internet or saw with a friend," said Gundersen Exercise Physiologist Eddie Stenger.

The study did show long distance runners had lower blood pressure, body mass, and cholesterol.