![You Should Probably Stop Running Marathons — They Might Kill You](http://townsquare.media/site/47/files/2012/12/Stockbyte.jpg?w=980&q=75)
You Should Probably Stop Running Marathons — They Might Kill You
You know that friend of yours, the one who's really into running? He might actually be running himself right into an early grave: new research has discovered that too much exercise can be bad for your heart.