[ellacraig]

I don't know what you're talking about with a rebounder... I've always had difficulty trying to walk/jog/run in place without actually moving... Back when I was in grade school and that was part of phys ed occasionally instead of having us run actual laps I'd always wind up actually going forward quite a ways without even realizing it, and before I'd realize it was happening, I'd be almost bumping into someone else.

Well honestly you get a good workout with Leslie's vids. You need to be able to take a few steps forwards and sideways.
A rebounder is a mini trampoline