So normally when you're running on the ground, the ground doesn't "return" any energy, right? Any upward movement is entirely generated by your own muscles, so excess weight will limit the height you reach and therefore how far you can travel forward given whatever forward propelling force you've generated. But if super shoes return energy, doesn't that mean that the excess downward force into the shoe would result in a some proportion of that amount of force returned to the runner? Is this right, or am I an idiot? I have no idea if I'm thinking about this correctly. Let me know!