Those things are crap.
I for one never fell for any of those fitness gadgets but friends of mine have
All in the approach.
If you believe it is an accurate device in lieu of genuine medical lab data - your an idiot. Of course it cannot replace real sleep studies etc. Nor can it provide/replace a nutritional study by a nutritionist. Nor does it have the value of a real exercise plan developed for you by a doctor or a physical trainer.
So then what is it good for?
It is a motivator. By measuring not only how many steps you walk, but accurately shows how sedentary you are. It knows the difference between sitting/standing/lying down. And with reasonable accuracy of your heart rate...it can also show you how many calories you are burning in whatever activity to are involved in.
Other than that....there is always "that guy" who makes a statement like yours.
