Running helps your heart, but can it also make you less anxious? Maybe so, if rats on little treadmills are any indication. From the Well Blog in the New York Times:

The “cells born from running,” the researchers concluded, appeared to have been “specifically buffered from exposure to a stressful experience.” The rats had created, through running, a brain that seemed biochemically, molecularly, calm.

Submitted by the cool, calm, and collected MadMayo Runner Jack. Thanks, Jack!