People who exercise a ton tend to have more calcium in their heart arteries than couch potatoes—but surprisingly, they don’t have more heart attacks. The calcium buildup doesn’t mean they’re at higher risk.

If you have calcium in your heart arteries, you’re at higher risk for a heart attack—even if you’re a marathon runner. Exercise doesn’t make that calcium harmless.

If you're an adult with early signs of heart disease but no symptoms yet, being very active can help you live longer and avoid heart problems — studies suggest it might delay death by over 30%.

Even though super-fit people have more calcium in their heart arteries, they still live longer and have fewer heart attacks — their fitness seems to protect them from the danger of the plaque.

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.

For older male athletes, doing hard but not extreme workouts (like steady running or cycling) seems to be linked to less calcium buildup in heart arteries over time, compared to doing ultra-intense workouts.