At a very rudimentary level I think that efforts like this to make a more productive use out of the energy already being used and released through ordinary foot travel is in one sense brilliant yet in another sense obvious.
I think about this whenever (admittedly on rare occasions) go to the gym and see rows of people peddling and treading but the energy going nowhere. If we could harness it into something substantial that would be cool.
In the same vein, many people like to point to inmates as an idle body of labor going un-utilized.
Food for thought. Happy Monday.