Sports cardiologist Harald Jørstad of Amsterdam UMC said that endurance exercise generally benefits blood pressure, the heart, the brain and bones, but that marathon running and the training it requires also carry risks. In research involving 17 first-time Amsterdam Marathon participants in 2021, the runners’ hearts were temporarily fatigued and they were somewhat dehydrated, but none showed signs of heart damage.

Jørstad advised people to build up distances gradually, starting with shorter runs and progressing to a 10-mile race and then a half marathon. He said participants should train with a structured plan and, where possible, in a running group with a trainer, and should be aware of their blood pressure, cholesterol, blood sugar and family history of heart disease. Palpitations, severe shortness of breath, chest pressure or fainting during exertion require immediate medical attention; in the event of fainting, cardiopulmonary resuscitation should be started and emergency services called. He said people with a healthy heart who have trained sufficiently can generally run a marathon, but that running one is not necessary to become healthier.