Can you power a house with a ShakeWeight?

You found the energy produced by your linear generator, which is only a minute fraction of the energy you put into the ShakeWeight. Most of it went in the springs in the ShakeWeight; that's what it's meant to do - absorb energy. If you want to generate electricity with a ShakeWeight, do what mechanical flashlights do: remove the Springs and use a big coil and magnet. I think you'd probably be able to produce tens of watts. You are not 200000 times weaker than a horse.