Speedfit, a human-powered mobile treadmill invented by Olympic medalist Alex Astilean, uses people power to move it forward.

Astilean isn’t planning to stop with a one or two person model. His ultimate goal is to create a public transportation version of the treadmobile that will allow crowdpowered mass transit.

There’s a lot of criticism for this idea, but it doesn’t seem so far-fetched. After all, it works for rowers.

Astilean also has other innovative exercise ideas, like the jump rope alternate: the turbo jump. See the in-depth video below.