The Green Microgym in Portland Oregon captures the energy produced from gym goers working off those holiday calories.
This gym and its original concept makes you feel very good at the end of your work out: you burned those extra-calories and released stress and you also reduced your footprint.Gyms are some of the biggest energy suckers, with their treadmills, bikes, elliptical machines, and flat-screen TVs. Not the Green Microgym.
They use humans to power the equipment through their exercise. Movement on the gym’s stationary bikes contributes power to batteries, which generates electricity for the TV and stereo. The Human Dynamo spin bikes can generate 350 watts of continuous and useful energy.
The energy output is relatively small, but Adam Boesel, the gym’s owner, has visions of bigger, greener ideas. “Our goal is to someday create 100 percent of the electricity we use in the gym,” he told ABC News. “The short-term goal is to get all of the electricity we can out of the machines.” 
The gym’s features include SportsArt EcoPowr treadmills which use 30% less electricity than others, solar panels that generate an average of 8 kilowatt hours per day and a 4-person machine with hand cranks and foot pedals which can generate up to 100 watts of electricity an hour.
Video The Green Microgym
 ABC News. Sweat Fuels Electricity at Gym http://abcnews.go.com/Technology/SmartHome/Story?id=5754828