But their are other variables, like the health of the person and pre-existing conditions. It may not be much when calculating an hour's worth of exercise, but it can definitely add up over an 18-hour day, which many of us have. It can be off by several hundred calories.
We'll see what happens with these. I always thought they were a bit silly, but I have known athletes to use and promote silly things. Promoting through Nike is basically like promoting through an athlete without actually having an athlete to promote it. An athlete will use it, spew some BS on how it works, and everyone will follow along.
It's like those energy bracelet thingies that D-Rose started. He fucked his knee up, so you know that shit don't work.