Running is a primal exercise, so essential in a well-rounded fitness regimen. In a hostile world the expression “survival of the fittest“ is most directly related to the animal that can outrun its predator. You don’t last long if you can’t dust your toothy competitors. It’s also supreme for developing a strong core.
Don’t simulate running on some clunkety hamster wheel. Get out! Pound the variegated turf, push into the headwind, bask in the immense energy of the radiant sun. Feel, feel, feel!
http://www.chacha.com/gallery/4160/5-reasons-not-to-run-on-a-treadmill
http://www.chacha.com/gallery/4974/why-is-running-outside-better-than-a-treadmill
Grass Is Greener Fitness 