If you run marathons, cycle long distances, train for Ironman events or log countless miles each week, you are doing something extraordinary for your health. Exercise remains one of the most powerful interventions for longevity and cardiovascular protection. Compared with sedentary individuals, endurance athletes have lower rates of obesity, hypertension, metabolic syndrome, diabetes and premature death.
But there is an important message emerging that must not be overlooked in the world of prevention: Elite fitness does not equal immunity from cardiovascular disease.
In fact, some of the most compelling cardiovascular research over the last decade has focused on a surprising observation: Lifelong endurance athletes often have more coronary artery plaque than expected (often more than their sedentary peers), even when they appear exceptionally healthy.
One landmark study of endurance athletes (average age 54, averaging 31 years of endurance training) found that male marathon runners had nearly double the prevalence of coronary plaque compared with healthy non-athletes (44% vs. 22%). Even more striking, 11% of male athletes had coronary artery calcium (CAC) scores greater than 300, a level generally considered high risk in the general population. Significant arterial narrowing (>50% stenosis) was also identified in 7.5% of male athletes who otherwise considered themselves healthy. (https://pubmed.ncbi.nlm.nih.gov/28465287/)
This finding has now been replicated across multiple studies: lifelong endurance athletes — particularly marathoners, cyclists, competitive cross-country skiers and triathletes — often demonstrate higher coronary artery calcium scores and more coronary plaque than expected for their age and traditional risk profile. (https://pmc.ncbi.nlm.nih.gov/articles/PMC13027719/)
However, there is an important nuance here. The plaque seen in athletes is often more heavily calcified, which indicates plaque that is likely more stable than the mixed or soft plaque more commonly seen in sedentary individuals. This means these plaques are generally less likely to rupture. However, stable plaque is still plaque. Fitness may modify risk, but it does not erase biology.
Furthermore, while still poorly understood, the physiologic demands of endurance athletics likely play a role in the development of arterial disease. Theories such as exercise-induced oxidative stress, poor sleep, chronic inflammation from overtraining, micro-trauma and arterial wall stress/shearing and the impact of performance-enhancing substances all likely hold some truth and contribute to this phenomenon. While researchers are still working to understand the interplay of genetics, endurance sports and disease, we must not be inappropriately reassured that exercise negates traditional cardiovascular risk factors (like family history, high cholesterol and high blood pressure).
This brings us to one of the most important truths in prevention: Cardiovascular disease does not discriminate.
Approximately 1 in 5 people worldwide have elevated Lp(a), often without symptoms or awareness. High levels substantially increase the risk of premature heart attack, stroke, and aortic valve disease, even in people who maintain excellent fitness and nutrition. Lifestyle habits, including endurance athletics, cannot significantly lower Lp(a) or its associated risk.
We routinely care for highly trained athletes with markedly elevated risk profiles, including elevated LDL cholesterol, ApoB, familial hypercholesterolemia or elevated lipoprotein(a). Sadly, we often meet these athletes only AFTER they experience a cardiovascular event; after being told that their obvious risk factors were outweighed by their athletic endeavors. This unfortunate bias often leads to inappropriate screening practices and delayed diagnosis in athletic individuals.
Here is what we want every patient to hear: Cardiovascular disease does not discriminate, and the only way to know if you have it is to get appropriately screened; even if you run marathons.
If you are an athlete, having elevated cholesterol, high Lp(a), silent plaque or prediabetes despite “doing everything right” is not failure, it is information. Too often, heart disease becomes apparent only after an event, especially in people whose habits seemingly outweigh their inherent genetic risk factors. Don’t become a statistic simply because no one looked for disease.
We encourage patients to know their numbers and understand their personal risk. Depending on your history and goals, this may include:
Know your numbers. Know your risk. Protect the future you are training so hard to enjoy.