Harnessing the Energy of Exercise

A few months back I wondered why human exercise machines weren't used for power generation. Well, someone else has been wondering the same thing and made an art project out of it. It turns out that one reason that the idea hasn't taken of may be:

Except in extreme cases of highly fit athletes, the limit for stationary bicyclists seems to be in the range of 75 watts to 150 watts, Wilson said.

Not huge but enough to run your computer and a handful of CFL lightbulbs ... so could pay it's way in a gym, I'd have thought.
See also and here.
Wired News: Harnessing the Energy of Exercise:
Filed in: power, generation, exercise, human