Men who train extremely hard for endurance sports like marathons or triathlons for many years tend to have more calcium buildup in their heart arteries than men who exercise moderately, even though they’re otherwise healthy.

Men who exercise moderately — like running a few times a week — tend to have less calcium buildup in their heart arteries than men who don’t exercise much.

Men who have trained for decades in marathons and endurance sports are more likely to have calcium deposits in their heart arteries than men who don't exercise much—even if they're otherwise healthy and have no heart disease risk factors.

Men who train extremely hard are more likely to have moderate levels of calcium in their heart arteries than men who train less, but women who train just as hard don’t show this increase.

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.

Women who train hard for endurance sports — even very hard — tend to have less calcium buildup in their heart arteries than women who don’t exercise much.