Yesterday Inhabitat reminded us about that River Gym idea that was, er, floated back in 2005 as part of New York Magazine's contest for forward-thinking gym concepts. Dr. Mitchell Joachim and Douglas Joachim's idea for a floating gym is premised on "transforming wasted human mechanical energy into a useful kinetic gymnasium." Their eco-friendly gym would harness the energy usually lost during New Yorkers' workouts and use it to power boats back and forth across the Hudson and East Rivers.

So whatever happened to that? Well, nothing in New York, but Dr. Joachim, an adjunct professor at Columbia, tells us that the idea of utilizing exercise energy is catching on elsewhere. He writes:

It seems they copied the River Gym in Hong Kong. And now the Swiss are making offers to us. Although, we have no protection there either. As far as I'm concerned the River Gym is an elective and free design concept, that anyone willing may interpret for their own use. However, they should hire us for the expertise in making it possible.

Indeed, a non-floating gym in Hong Kong called California Fitness is using cycling and cross-training machines to generate electricity. The owner asserts, "One person has the ability of producing 50 watts of electricity per hour when exercising at a moderate pace….If a person spends one hour per day running on the machine, he/she could generate 18.2 kilowatts of electricity and prevent 4,380 liters of CO2 released per year."

Given the Bloomberg administration's big talk about sustainable energy, fitness, and reducing traffic congestion, the River Gym would seem like a no-brainer. And if the cabaret laws are ever relaxed, maybe we can get one of those Sustainable Dance Clubs, like the one that's opened in London!