The zero-time exercise series is a set of short tips on ways to exercise or diet that either cost nothing or take no time.

The first tip reflects something I’ve seen only in New York City, and not in any other city in the US or elsewhere: walking up escalators. Sure, walking up the escalator takes effort, but it’s not “zero-effort exercise.” In fact, walking up the escalator actually saves you time, unlike similar suggestions to park your car far away from the office or the mall entrance. If you want to start more easily, start with walking down the escalator. Then, if you’re improving and happen to have slow elevators in your building, walk down the stairs rather than wait for the elevator, from about the 5th floor down, you’ll probably actually save time (you can certainly measure the times and find an optimal solution).

Why don’t I suggest walking up the stairs? Well, when I walk up five flights in a suit, I get a little too overheated and uncomfortable; I don’t want to go into a meeting like that. Sure, walking down doesn’t burn as many calories but that’s not the comparison: the comparison is to how many you would burn standing in an elevator.