Marathon running puts heart under strain, say researchers, who urge sufficient training
- Strain imposed by running 42km race is much greater than when running shorter distances, Spanish study shows
- Researchers find no evidence of increased risk of heart attack or heart disease, but say runners should make sure they train enough for the longer distance
A new “Research Letter” published in the American Heart Association’s journal Circulation raises the old fear that running long distances – particularly the 42.19km marathon – could be bad for amateur runners.
But according to several experts, including the paper’s author, would-be marathoners should not worry that they are on the road to a heart attack or heart disease, though it is smart not to attempt the marathon distance until you have trained sufficiently.
A group of Spanish physiologists reported that “the strain imposed on the myocardium by competing in a full marathon is much greater compared with other distances such as the half-marathon or 10km races”. They came to that conclusion by measuring the same proteins in runners’ blood that doctors look at to diagnose heart attacks. The biomarkers – cardiac troponins – were elevated in all 63 runners (39 women and 24 men, with an average age of 37) after completing their races, but particularly so among the marathon runners.
But the Spanish team made no claims about heart attack or heart disease risks among the marathon runners. Indeed, the Letter notes that “the release of cardiac troponins after exercise may not be indicative of any cardiovascular dysfunction”.
This is precisely the finding of other studies published over the last decade, including a handful in Circulation, a scientific journal published for the American Heart Association.