Running marathons could age men by as much as a decade, research suggests.
The study of males aged 40 and over who had taken part in at least 10 endurance events, found that their major arteries were far stiffer than would be expected for that age group.
Overall, men who regularly took part in events such as marathons, Ironman contests and competitive cycling were found to have a vascular age a decade older than their chronological age, which could put them at greater risk of suffering heart attacks and strokes, experts warned.
However, the study of more than 300 regular athletes found the health of women who took part in endurance events improved. Female athletes had a vascular age that was around the same as their actual age and, by one particular measure, their vascular age was six years younger than their true age.
Scientists said the study, funded by the British Heart Foundation and Cardiac Risk in the Young, could not explain why the impacts of such events differed between men and women.