Yes, lifelong endurance athletes tend to have more coronary calcium than less active people with similar risk factors. Several imaging studies of middle-aged endurance athletes, most of them men, have found this.
What it means is less settled. The best outcome data so far do not show that very active people with calcium die sooner than inactive people with the same score. But a high score in an athlete is still real plaque, and it deserves the same careful look as anyone else's.
Key takeaways
- Studies of long-term endurance athletes find calcium and plaque more often than in less active peers.
- Earlier research suggested athletes' plaque was mostly the calcified kind, but a newer study did not confirm a more favorable mix.
- In a large cohort of men, high activity with a score of 100 or more was not tied to higher death rates.
- Nearly all of the evidence comes from men, and none of it proves that exercise causes the calcium.
What the studies found
Two studies published together in 2017 set off this discussion. A Dutch study scanned 284 middle-aged men who played competitive or recreational sports and grouped them by lifelong exercise volume. In the most active group, 68% had some coronary calcium, compared with 43% in the least active group.1
A British study compared 152 masters athletes, most of them runners with an average of 31 years of endurance training behind them, with 92 sedentary people of similar age and low calculated risk. Most people in both groups had a normal calcium score: 60% of athletes and 63% of the comparison group.
The difference was at the high end. Only male athletes had scores of 300 or more, which turned up in 11.3% of them, and the number of years of training was the only factor independently tied to a high score or a significant narrowing.2
Is athletes' plaque a different kind?
Plaque comes in forms. Calcified plaque is older and hardened. Non-calcified and mixed plaque contain more soft material and are generally viewed as more likely to cause trouble. Our guide to soft versus calcified plaque explains the difference.
The two 2017 studies both pointed the same way. In the Dutch study, the most active men with plaque had fewer mixed plaques and more often had only calcified plaques than the least active men.1 In the British study, male athletes' plaques were mostly calcified, while inactive men's were mostly mixed. That led to a hopeful idea: athletes have more plaque, but a more stable type.
A larger study in 2023 complicated that picture. The Master@Heart study used CT angiography to compare 191 lifelong endurance athletes, 191 men who took up endurance sport after age 30, and 176 healthy non-athletes, all with low risk profiles. Lifelong athletes were more likely to have plaque of every type, including non-calcified plaque. The authors concluded that lifelong endurance sport was not associated with a more favorable plaque composition than a healthy non-athletic lifestyle.3
The honest summary is that the "more plaque, but safer plaque" idea is plausible and not proven.
Does a high score mean the same thing in an athlete?
The largest study on this followed 21,758 generally healthy men from a preventive medicine clinic in Texas for about 10 years. The most active men were about 11% more likely to have a calcium score of 100 or higher than less active men.
They were not more likely to die. Among men with scores of 100 or higher, the most active group did not have a significant increase in death from any cause compared with the least active group, and the estimate leaned toward lower risk.4 Among men with scores under 100, the most active were about half as likely to die as the least active.
Two cautions keep this in proportion. The very active group was small and had few deaths, so the study could not rule out modest harm. And a score of 100 or more still carried weight: among the least active men, it was linked to about twice the risk of cardiovascular death.
Volume or intensity?
The Dutch team rescanned 289 of their athletes about six years later. Calcium had become more common, rising from 52% of the men to 71%, which is expected with age.
How much the men exercised during those years was not associated with the change. Intensity was. A greater share of very vigorous exercise was associated with a larger rise in calcium score, while vigorous exercise one step below that was associated with a smaller rise.5 The effects were small and come from one observational study, so they are not a basis for changing how you train.
What is still unknown
- Women. Four of the five studies described here enrolled only men, and in the British study the higher plaque burden was found in male athletes. Whether the pattern holds in women is unclear.
- Cause. These are observational studies. They show that calcium and long-term endurance training occur together. They do not show why.
- Events. The outcome data cover death rates over roughly a decade. Long-term data on heart attacks in athletes with high scores are thin.
What gets checked when an athlete has a high score
Being fit does not cancel the ordinary causes of plaque. A clinician looking at an athlete's score will usually go through the same list as for anyone:
- Blood pressure, cholesterol and blood sugar.
- Family history. See our guide to family history of early heart disease.
- Inherited factors a routine panel misses, such as Lp(a).
- Any symptoms during effort, such as chest pressure, unusual breathlessness or a drop in performance you cannot explain.
The last item matters most. In the British study, some male athletes had a narrowing of 50% or more in a heart artery. Symptoms during exercise are a reason for prompt medical evaluation, not a calcium score discussion. Chest pain that does not settle is a reason to call 911.
Your next step
If you train seriously and are weighing a scan, or already have a number, start with our guide to the coronary calcium score and then see what happens after a high calcium score.
You can also answer the three quick questions in the screener on the Cardio Res-Q program page.
Are You a Candidate for Cardio Res-Q?
Three quick questions about the risk factors we screen for. Your answers stay between you and the clinic.
Frequently asked questions
Should I stop endurance training if my calcium score is high?
That is a decision to make with your clinician, based on your whole picture. In the largest study so far, very active men with scores of 100 or more did not have higher death rates than less active men with similar scores. Symptoms during exercise change the situation and need evaluation first.
Does exercise cause calcium in the arteries?
That has not been shown. Studies find the two together in long-term endurance athletes, and one found faster progression with very vigorous exercise, but these are observational results and the mechanism is not established.
Is a score of zero still common in athletes?
Yes. In the British study of masters athletes, 60% had a normal calcium score, about the same proportion as in the inactive comparison group.
Does this apply to women who run or cycle?
It is not known. Most of the studies enrolled only men, and where women were included the excess plaque was seen in the male athletes.
Related reading
This article is for general education and is not medical advice. Decisions about testing and medication should be made with your clinician. If you have chest pain or other symptoms of a heart attack, call 911.
