Conventional wisdom says running on concrete is harder on your knees/feet than asphalt, which is harder on you than dirt, which is harder on you than grass, ... than padded track, ... treadmill etc etc.

As an avid runner I see little to no difference between the various surfaces, even barefoot.

Speaking of which: Conventional wisdom says running shoes help you prevent injuries. I disagree. The barefoot running movement has good logic behind it, and my personal experience has supported it. But what do unbiased, objective tests say?

Please confirm or bust.

Thanks,
Jon