Can you imagine how incredible it could be to workout while enjoying a voyage on the Parisian river Seine? Italian architect Carlo Ratti is trying to turn that idea into reality with his new design dubbed "The Paris Navigating Gym." The eco-friendly vessel is able to sail down the river by harnessing energy produced by exercising passengers.

By exercising on the so-called ARTIS bikes (a special type of bike that gathers energy and makes it available for further use), participants can contribute to powering the boat. Energy produced by humans will be complemented by photovoltaic cells on the gym's roof. Then, the vessel propellers are activated with electricity, allowing the gym to sail along the river.