Runner's High is Real

German researchers have found scientific evidence for what humans have known since the first caveman sprinted away from a saber-toothed tiger: running can make you feel pretty darn good.

The so-called "runner's high" can range from a general feeling of peacefulness to all-out euphoria and is associated with many types of high-octane exercise, reports the New York Times. But not all runners seem to reap the benefits - more research may show why some people are prone to post-run pink cloud bliss, while others merely want to throw up.

The biochemical mechanism behind runner's high was long an unproven hypothesis. We knew it probably had something to do with endorphins, but we weren't sure what. Now, scientists using PET scans to examine the brains of long distance runners before and after a two-hour run have found that endorphins produced during running can indeed attach themselves to the brain centers associated with emotion. The limbic and prefrontal areas, the parts of the brain activated by romantic love, appear to be especially affected. So get off match.com and go for a 5K!

What about you? Do you run for the high? Or just to justify your double cheeseburger habit?

--Emily Matchar