my philosophy for running. Also add to this quote - if you run til you pass out it won't hurt at all, just find someplace soft to land before you do. Finally, if you run til you puke then that's even more calories you 'burned' in your workout!
Feeling sad or angry? Don't reach for the ice cream. Lace up those running shoes and hit the streets. The pound on the pavement will satisfy your frustration, the fresh air will give you time to think, and the endorphins will help calm your emotions.