I tried this with my Fitbit, in one of the updates they added "smart alarms". I discovered two things: one, that apparently my range for waking up was too narro

I tried this with my Fitbit, in one of the updates they added "smart alarms". I discovered two things: one, that apparently my range for waking up was too narrow and the alarm was always firing at the last moment, and that a vibration in the wrist will not wake me up at all.