No one doubts that training longer and harder will improve your marathon performance. But will it make you healthier? The question is particularly germane for older runners, since increasing age brings on higher disease risks.
German cardiologist Stefan Mohlenkamp has been studying the cardiac risks of marathon runners older than 50 for almost a decade. His early papers reported an “unexpected atherosclerotic burden” among male marathoners. Now he has followed a group of those over-50 runners for 6.5 years – it’s the first study to do so – and compared their heart attack and death rates to a control group of nonrunners with similar risk profiles.
His conclusion? Marathon running confers no protective benefit. The “cardiac events” and mortality rates between runners and nonrunners are the same.
The 108 marathon runners studied by Mohlenkamp were all over 50 at the beginning of the trial period, had run at least five previous marathons, and had no history of heart disease. Most of them completed the Dusseldorf Marathon in 2006, finishing with an average time of 4:10.
In the next 6.5 years, three of the runners died – one from a heart attack, one from a brain tumour and one from non-Hodgkin lymphoma. Seven other runners had cardiac events of one kind or another. None of these occurred during a marathon, but one happened at 7K of a 10K race, and the death happened near the end of an easy 20K training run.
“A lifelong runner with a continuously low risk factor profile may never develop any atherosclerosis in his life,” Mohlenkamp writes. “Yet, if he does for any reason, his risk of a coronary event seems as high as that in other persons with a comparable atherosclerosis burden.”
Mohlenkamp measured the heart disease of his marathon subjects and controls with a coronary artery calcium (CAC) test. The two groups had equivalent scores. As CAC scores increased, coronary events increased by the same amount in both groups.
The results are similar to those reported recently between Boston Marathon runners and their nonrunning spouses. That study used a carotid IMT test to measure atherosclerosis. It found no difference between the 21 male and 21 female Boston marathoners, and their non-running spouses.
Principal author Beth Taylor commented that her Boston Marathon research should prove reassuring to marathoners, because it revealed no increase in atherosclerotic risk. On the other hand, marathoning also provided no apparent benefit.
Mohlenkamp reaches the same conclusion: “All cause mortality in marathon runners is similar to that in risk factor-matched controls.”
An abstract of his new paper can be found here.
