And who says that steps is the only way to measure "activity"? Before starting to use Actifit, I was using Runtastic (I still do). That one will measure activity in different ways. If you're doing a weight lifting session, you won't get many steps, but you'll be doing something that is just as demanding physically, maybe more. Or if you're riding a bicycle, you're getting activity, but no steps. "Proof of activity", my foot!