Sometimes you are working out so hard at the gym that it feels like you could power the entire place with your own energy – well now maybe you can. A new human-powered gym just opened in the Portland, Oregon. It's a gym that runs partly on energy generated by people working out.

Here’s how it works: as people pedal on stationary bicycles, a small motor connected to the bikes charges batteries that run the gym’s television and stereo system. Another machine, called the Team Dynamo, connects hand cranks and foot pedals to a generator to capture as much human output as possible.

Although the amount of energy created by people is still relatively small, the gym’s owners say they still feel good knowing they are making a difference.

Technology like this is also being used in other parts of the world, the Netherlands has a Sustainable Dance Club. The dance floor of the club is a movable surface composed of small modules. As people dance, the movement of the modules is converted into electricity that lights up the floor, and an energy meter allows dancers to see the amount of energy they are creating.

Learn more about how you can conserve energy [1].