A Kinetic Future

Most people wouldn't think it, but I believe our future may consist of a lot more energy stemming from physical activity.  For centuries we've tried to find a way to make things physically easier, so that just pushing a button can accomplish most activities.  Now we actually have people who make themselves do work, not for the sake of work, but to burn off all the fat they have stored from not working in the first place.  Why not put that energy to good use and make TVs, computers, and other electrical appliances derive their energy from kinetic sources?  It keeps people thin and conserves non-renewable resources as well.  I mean, if you can operate your computer with a hand crank, then who needs electricity?