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An electric workout through pedal power

Gyms hook up exercise bikes to TVs, laptops, and batteries to let their patrons power the place.

By Vijaysree VenkatramanCorrespondent for The Christian Science Monitor / November 13, 2008

User-generated: Kendra Johnson demonstrates the pedal-powered laptop that she designed with seven other MIT students as a class assignment for the school’s alumni gym.

Sarah Beth Glicksteen/The Christian Science Monitor

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Cambridge, Mass.

After classes, Sally Peach, a student at the Massachusetts Institute of Technology, has a long list of to-dos.

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She wants to hit the gym, tackle school work, and, as captain of an intramural soccer team and member of a campus health advocacy program, she has plenty of e-mail to respond to every evening.

“Though I know I am being productive, it feels like a complete waste of time to sit there and do just [e-mail replies],” says Ms. Peach.

So, once she arrives at the gym, Peach makes a beeline for a special stationary bike that has a laptop built into the front. The computer is not plugged in. There is an empty space where the battery once fit. But when Peach starts pedaling, the computer fires up. Her spinning workout powers the laptop – and lets her cross off two tasks at once.

Pedal power has been a small-time alternative-energy source for ages. Many innovators have tried to tap the simple motion to power devices – especially those engineered for developing countries, where power grids are unreliable. But few designs have stuck. People aren’t willing to exert much energy just to run simple devices.

But in gyms across the country, ecoconscious patrons are asking why cardio equipment needs to drain power, when the exercisers are already eager to burn calories. Now, fitness centers are beginning to experiment with ways to put muscle strength to good use.

“The idea pretty much sold itself,” says Adam Boesel, a personal trainer in Portland, Ore.

He saw a television report about a Hong Kong gym with human-powered equipment and set out to create an eco-friendly fitness center in his hometown. Mr. Boesel’s Green Microgym opened in late August and has already registered more than 100 members.

The gym chose Team Dynamo stationary bikes, which harness the power of four connected bicycles to generate an average of up to 200 watts per hour. That’s enough to power a LCD television and stereo system for the duration of the ride, according to Team Dynamo inventor Mike Taggett. “And you don’t have to be cycling champ Lance Armstrong to do this because it is a team effort,” he says, referring to how four bikers help charge the batteries.

At Green Microgym, electricity generated by the bikes flows into a bank of batteries, which, in turn, powers devices. Boesel plans to install a “grid-tie” inverter, which allows the generated energy to stream directly into the power grid. This device allows creators of alternative energy, such as solar and wind, to “spin the meter backward” and sell power to their local utility company.

The idea is to meet the gym’s power requirements – kept low by a prudent use of plugged-in devices – with solar panels and an array of energy-producing equipment, says Boesel.

Power bike setups of all sizes
David Butcher, a California Web manager, gets his daily workout on a generator-bike he built three years ago. Pedaling at a steady pace, he charges many appliances at once: the robotic vacuum cleaner, a set of lights, and his laptop. Mr. Butcher webcasts live from his Los Gatos, Calif. basement during these 40-minute sessions. Thanks to the energizing workout, “I feel like a rocket now,” he says, a little breathless from his morning exercise.

Elsewhere, others are testing retrofitted equipment in well-trafficked commercial gyms. A group spinning class can produce a monthly output of 300 kilowatt-hours – enough energy to light six homes for a month and cut 420 pounds of carbon emission, according to Jay Whelan, founder of Green Revolution.

“There is no use it or lose it, or battery maintenance, because the power goes right back to the grid,” says Mr. Whelan, a clean-energy entrepreneur who recently retrofitted bikes for the spin class at the 1,200-member Ridgefield Fitness Club in Connecticut.

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