I am not sure the ends justifies the means with this concept. You would have to spend more money on the energy storage apparatus then you would have spent on all of the gym equipment and your standard power bill combined. If you didn't want to store the power you could have something like a television or radio powered directly by an exercise bicycle. Many gym components today are either free weights, with no way to harness the energy, or equipment that needs its own power supply to operate- a modern tread mill for instance.

A conventional rowing machine isn't powered, nor is a cycling machine. They could potentially generate far more power than is needed for just a TV. And surely the point is that the principle works, and the inventions follow? Yes, building a prototype would be costly, but a decent, cost-effective product could be developed and sold given enough enthusiasm.

I think this is a great idea. Maybe there is a way to create a portable device that you could easily attach to different fitness machines to collect the power. Or perhaps there's a way to feed the power that you generate right into the electrical system in your house.

This is a fantastic idea. It can monitor calories burned and dollars saved! (J Strauss)