Is Running a Marathon Good for Your Heart?

Running a marathon, while a significant physiological stressor, is generally considered beneficial for heart health due to the consistent training it requires, according to exercise physiologists. While headlines occasionally emerge about marathon runners collapsing, these events are rare and often linked to underlying, undiagnosed conditions.

A 2025 study documented 176 cardiac arrests among approximately 29 million marathon finishers in the U.S., highlighting the rarity of such incidents. David Oxborough, professor of echocardiography and cardiovascular physiology, stated that regular moderate-intensity exercise improves cardiovascular risk, reduces mortality, and offers tangible positive benefits.

Running a marathon involves intense physical exertion, and markers of muscle and heart damage can temporarily elevate. However, Oxborough notes that these markers typically return to baseline swiftly and do not appear to be associated with long-term damage. Daniel Muniz, senior lecturer in exercise physiology, emphasized that the consistent training regimen for a marathon carries significant positive effects for both physical and mental health, concluding that "the benefits far outweigh the negatives."

The rare instances of death during marathons are often attributed to specific causes. For individuals under 35, sudden cardiac death is frequently linked to inherited cardiac conditions like cardiomyopathy. In those over 35, acquired diseases such as coronary artery disease are more commonly identified as the underlying cause.

To assess heart health before undertaking marathon training, experts recommend pre-participation cardiac screening. For younger individuals, a 12-lead electrocardiogram (ECG) and a questionnaire can help identify potential inherited diseases. While a diagnosis doesn't necessarily mean ceasing training, it can inform risk management strategies.

For individuals over 35 or 40 considering a marathon, Oxborough advises consulting a general practitioner. Recommended steps include a 12-lead ECG, blood tests to check cholesterol levels, and blood pressure measurement. If these indicate a higher risk, further tests such as an exercise stress test or, if accessible, a CT coronary angiogram may be suggested to establish a baseline understanding of arterial health before intensifying training.

In principle, most individuals can train to run a marathon, provided they engage in appropriate, consistent training over several months or a year. Muniz suggests that gradual progression, starting with shorter running intervals or walk-run programs and gradually increasing duration over months, can enable most people to eventually complete a marathon.