Danish scientists monitoring more than 1,000 healthy joggers and non-joggers over a 12-year period discovered that it was best to jog no more than three times a week or for 2.5 hours in total. People who jogged more intensively - particularly those who jogged more than three times a week or at a pace of more than 7mph - were just as likely to die as those who did no exercise at all.
"You don't actually have to do that much to have a good impact on your health,” said Researcher Jacob Louis Marott, from the Frederiksberg Hospital in Copenhagen."And perhaps you shouldn't actually do too much - currently no exercise recommendations across the globe mention an upper limit for safe exercise, but perhaps there is one."
While the accurate reasons behind these results are not yet known, scientists suggest that it’s possible that it is the effect extreme exercise can have on the heart that would make too much of it a bad thing.
Maureen Talbot, senior cardiac nurse at the British Heart Foundation, has said: "This study shows that you don't have to run marathons to keep your heart healthy. Light and moderate jogging was found to be more beneficial than being inactive or undertaking strenuous jogging, possibly adding years to your life.”