There are some interesting products in the article. I like the stool that wobbles slightly to make you use your muscles to stay on.
But, it starts with a really dumb example with the elevator (oops, I mean intervator). The way to get people to take the stairs is not to go one floor lower than they want and then tell them to walk up a flight. Then, everyone would just learn to choose the floor above where they want to go. The best way to get people to use stairs is to design buildings so that people see the stairs before the elevators. Right now, you walk in a building and see a bank of elevators, but you have to search for the stairwell, which is often hidden. If you have stairs in plain sight, then move the elevators to a less visible location, more people would use stairs.