Just as the Sustainable Dance Club is turning dance steps into energy, French inventor Lucien Gambarota and Wharton grad and entrepreneur Doug Woodring are bringing clean, sustainable energy to the gym using good old-fashioned manpower. The two have joined forces with Hong Kong’s California Fitness, a subsidiary of 24 Hour Fitness Worldwide, to launch a revolutionary concept in which energy burned off by exercisers is diverted and converted to power lighting fixtures, while excess energy is stored in a battery.