What's your reason for training for a marathon? Personal sense of achievement? A bet with your buddies? To get a hot body? To improve your heart health? If you answered yes to that last one only, you might consider re-thinking your motivation after recent studies that showed marathoners aren't as heart-healthy as you might think.

In fact, marathoners tend to have higher levels of calcium build-up in their arteries, which can lead to plaques and ultimately heart attacks. The reason? Unknown. What is known is that these findings contradict everything we know about regular running -- it's been shown to reduce cholesterol, lower blood pressure and help in the maintenance of a healthy weight.

The bottom line? I wouldn't stop running just yet if I were you -- it seems the benefits greatly outweigh the risks. But all the same, if you feel compelled to scale back your running routine to, say, half marathons, go for it. Any amount of running is better than none at all.

(Via CalorieLab)