While I think there are plenty of reasons to run, another bonus of running just crossed my path. New research from Yale University found that endurance athletes have a higher resting metabolism than their unfit counterparts (read: couch potatoes). This means that runners, even when they are not exercising, burn energy faster than sedentary people. In this study endurance athletes were defined as men running four or more hours a week. On a cellular level, these men burned 54 percent more calories at rest than men that did not run at all.
While many of us aren't endurance athletes, I think this could be motivation to dedicate four hours a week to serious cardio. What about you?
To read the science behind the study, which might require you recall elements of your high school biology class (like mitochondria, the power plant of cells, and the conversion of fats and sugars into ATP molecules, which move energy around the cell), check out New Scientist.