>>120702418When your feet touch the ground, they aren't moving relative to the ground. Friction isn't slowing you down. You _need_ the static friction to impel you forwards, countering losses to air resistance.
Flash (Barry Allen as drawn by Carmine Infantino) ran normally. He didn't make giant strides. In fact, he wasn't aware he was doing anything different; it was the external world which was in slow motion. See his first appearance in Showcase.
They never mentioned how incredibly boring it must be to run 1000 miles; one second to us, but days or weeks for the Flash.
