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.

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.

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 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 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.

Older athletes who train hard for many years tend to have more calcium deposits and fatty buildups in their heart arteries, but these buildups are usually hard and stable, not soft and dangerous.