Originally Posted by Phatman
I think the reason for the impact being lessened is that your foot doesn't fall as far. think about running downhill, your foot has to travel farther, and can pick up more speed before it hits the ground.
Yeah!
Actually, I'm positive there's less impact on an incline; that's why I used to do it. This is probably a dodgey analogy (I can't be bothered thinking it through
), but compare running up stairs to running on a flat road or a slight decline -- I'm sure the pounding varies.