The heart recovers after a marathon

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The question of whether extreme bouts of exercise like marathons do more damage than good to the heart always sparks discussion, thanks to occasional sudden deaths at sporting events (see this Jockology column for a discussion of the issue). Over the past few years, several research papers have found evidence that the heart does sustain damage during prolonged hard exercise — but these indicators are very hard to interpret.

A new study from researchers at the University of Manitoba looked at this question more closely, by using MRI imaging of the hearts of 14 non-elite runners both before and after the 2008 Manitoba Marathon in Winnipeg. Previous studies have used less direct methods to figure out whether the heart was damaged or not. The results provided good news for marathoners:

“By using (MRI), we were able to definitively show that these fluctuations do not result in any true damage of the heart, and the right ventricular dysfunction is transient, recovering one week following the race,” (lead investigator Davinder S. Jassal said).

In other words, just like the rest of your body, the heart takes a pounding during a marathon, but appears to recover soon afterwards. The next step for the researchers is to repeat the study to determine whether running more than one marathon in a given year produces permanent damage.