Doctors warn that intense exercise for more than an hour or two can damage the heart, causing the heart tissue to stretch, tear and scar, as well as cause serious changes in heart rhythm.
Two recent studies have confirmed that exercise, like everything else in life, should be moderated.
In one, doctors monitored the health of more than 50 people for 30 years. 14 of them ran regularly and they had a 19 percent higher chance of staying alive during that time period.
However, a closer analysis showed that those who ran between eight and 30 kilometers per week did not benefit from it any more for a longer life than those who did not run at all.
In another study, which was conducted on 20 thousand Danes, it turned out that slow running is the best for health. Physical activity of moderate intensity for at least half an hour five times a week is ideal for heart health, say doctors.
Bonus video:
