Treadmills, ellipticals tap into natural power

Nothing would seem to be more "green" than exercise, which gives off sweat and smell but not pollution. But if you get your cardio on a machine, you're not completely eco-clean unless you use one that doesn't plug into a wall socket, which is at least partially powered by fossil-fuel-burning power plants. Aside from a few categories -- rowing machines, spinning bikes and some high-end self-generating exer-bikes -- there have been no other electricity-free treadmills and ellipticals available until just a few months ago. Here's the first look at the workout world's newest green machines.

By Roy M. Wallack

November 16, 2009