Even though endurance athletes have less dangerous soft plaque, their amount of hard, calcified plaque in the heart arteries is about the same as in people who don’t exercise.

Even though endurance athletes and healthy non-athletes have about the same amount of calcium in their heart arteries, the athletes’ calcium levels are higher than 90% of people their age, suggesting their arteries are aging faster from exercise.

Women who train hard for endurance sports like marathons don’t show more calcium buildup in their heart arteries than women who don’t exercise much — and some evidence suggests they may have less.

If an athlete has a high calcium score on a heart scan (over 100), doctors should treat them like someone with early heart disease — lower their bad cholesterol and test how their heart handles exercise.

People who regularly do long, intense workouts like running or cycling tend to have less dangerous types of plaque buildup in their heart arteries than people who don't exercise much.

For older male athletes who exercise a lot, doing very hard workouts (like sprinting or intense cycling) seems to be linked to more calcium buildup in the heart arteries over time, while moderate hard workouts might not have the same effect.