If you love hitting the gym and working out for hours, a new study warns that you could be at a much higher risk for premature death. The study, performed by researchers in Chicago, foudn that white men who worked out at least seven and a half hours per week are twice as lucky to die from heart disease than those who practice moderation in exercise.

The study examined 25-year exercise patterns and found very active white men are 86 percent more likely to see plaque buildup in the heart arteries by the time they reach middle age, a determination that didn’t appear to apply to black men. It’s possible that high levels of exercise puts a lot of stress on the arteries, causing calcification.

That, of course, does not mean you should avoid exercise. Not exercising at all obviously puts you at an even greater risk of heart disease, so as in most things, you should practice moderation.

“White men who exercise at high levels are 86 percent more likely than people who exercise at low levels to experience a buildup of plaque in the heart arteries by middle age, a new study suggests,” reads a statement from the University of Illinois at Chicago. “Led by researchers at the University of Illinois at Chicago and Kaiser Permanente, the study looked at the physical activity trajectories of 3,175 black and white participants in the multicenter, community-based, longitudinal cohort CARDIA study, and assessed the presence of coronary artery calcification, or CAC, among participants. CAC is a clinical measure of the accumulation of calcium and plaque in the arteries of the heart. The presence and amount of CAC, is a significant warning sign to doctors that a patient may be at risk for developing heart disease and a signal to consider early preventive care.”