Marathon running does not cause sustained heart damage

A study of 167 amateur runners at the 2006 and 2007 Berlin marathons is lowering concerns that this type of activity leads to sustained heart damage, particularly among older competitors. Marathons are becoming an increasingly popular challenge for amateur runners wanting to test their endurance over the classic 26-mile distance. The medical community, however, has long been concerned about how marathons impact the heart - and it has not yet been shown if the effects vary among different age groups or genders.

In an effort to increase understanding of this subject, the Charité-Universitätsmedizin Berlin conducted a study into the effects of marathon running on older amateur runners. The study took place around both the 2006 and 2007 Berlin marathons. In total, 167 older runners with an average age of 50 were monitored. All of whom had previously completed at least one full marathon. They underwent echocardiography tests using the latest equipment, and gave blood samples immediately prior to and after the race. They were monitored again after two weeks. Specifically, measurements were taken of the left ventricular diastolic and systolic functions, the right ventricular systolic function and cardiac biomarkers.

Analysis of the results showed that while there were some notable effects immediately after the race, these had returned to normal after two weeks.  Study lead, Doctor Fabian Knebel, concluded, "The concerns people have about marathon running causing sustained damage to the heart appear to be unfounded.  Our study looked at amateur runners with an average age of 50 - not elite athletes - and it showed that two weeks after a marathon, the key parameters were all back to normal levels."

Immediately after finishing the marathon, there were some significant changes of the parameters of diastolic and right heart function. However, even though these changes were statistically significant, they were all within the normal levels and therefore do not seem to be clinically relevant. All parameters had returned to normal two weeks later, and the most likely cause of the changes were tachycardia and dehydration during the race. Also, for some runners, there was an increase in certain myocardial biomarkers but no correlation could be drawn between this increase and any myocardial dysfunction. It is believed that the temporary increase was probably caused by functional changes of the cardiomyocytes while running and not by myocardial damage.

As a result of this study, it would appear that elderly amateur runners can continue to compete in marathon races without increasing their risk of sustained heart damage.