I recall a while back there were advertisements for a device that could stimulate your muscles directly, making them stronger without you even having to go to the gym. However, it was discovered not to long after their release that usage over a long term caused the nerves in the area to atrophy. People were completely losing the ability to contract their muscles normally; the muscles would only contract when under the influence of the device. I am not a physician, but I would be very cautious about using a device like this unless it were proven beyond a shadow of a doubt.<p>EDIT: Now that I think about it, I remember seeing advertisements for these devices in middle school and they suddenly stopped. I asked someone (probably another student) what happened, and they told me about the nervous atrophy thing. So there's a good chance it's made up, sorry for not checking my sources first.