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Even though endurance athletes have more fatty deposits in the main heart arteries—especially the soft, unstable kind—they don’t have the dangerous features that usually make plaques burst and cause heart attacks.
Correlational
Men who have trained for decades as elite endurance athletes, like cyclists or marathoners, tend to have more fatty deposits in their heart arteries than healthy men who exercise moderately—even when both groups are fit and have normal cholesterol and blood pressure.
Even though endurance athletes have less dangerous plaque overall, about 1 in 6 still have a major blockage in their heart arteries — meaning exercise doesn’t completely prevent heart disease.
Descriptive
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.
When given a medicine that opens up heart arteries, endurance athletes show a much bigger increase in artery space relative to heart muscle size than non-athletes, which might mean their arteries respond better to the drug.
People who train hard and regularly for endurance sports are less likely to have dangerous, unstable plaque in their heart arteries that could suddenly cause a heart attack.
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.
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.
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.
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.
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 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.
Older male athletes who do the most extreme workouts are more likely to develop hardened, calcified plaques in their heart arteries over time, compared to those who train less intensely.
For older male athletes, how much they exercise overall doesn’t seem to affect whether their heart arteries get more clogged over time—it’s more about how hard they push during workouts.
For older male athletes, doing a lot of hard but not extreme exercise—like fast running or cycling—seems to be linked to less calcium buildup in heart arteries over time, compared to doing super intense workouts.
For older male athletes who work out really hard—like sprinting or intense cycling—doing more of this super intense exercise over time seems to be linked to more calcium building up in their heart arteries, which could be a sign of plaque growth.
Even though belly fat is often blamed for heart problems, in young, active adults, it doesn’t seem to directly affect artery thickness — fitness and triglycerides matter more.
In young men, being fitter and having lower triglycerides both link to healthier arteries, but in young women, only fitness matters — triglycerides don’t seem to affect artery thickness in this group.
Whether young adults are normal weight or overweight, better fitness is just as strongly linked to thinner artery walls — meaning being fit helps your arteries even if you carry extra weight.
Among young, active adults, high levels of triglycerides (a type of fat in the blood) are the only blood marker that consistently links to thicker artery walls — more than cholesterol, blood sugar, or belly fat.
Young adults who can run 3000 meters faster tend to have thinner artery walls in their necks, which is a sign of less early artery damage, even if they’re overweight or have other risk factors.
Being fit as a teen didn’t seem to protect against hardening of the neck arteries when people got older.
Teens who were more aerobically fit had fewer heart arteries with a dangerous mix of soft and hard plaque when they got older.
Teenage boys who were both strong and fit had the lowest risk of serious heart artery blockages when they became middle-aged.