The Nike+ FuelBand SE tracks your movement whether you're awake or asleep. Just like when you're awake, the Nike+ FuelBand SE can track your movement as you sleep.
Identical to how the Nike+ FuelBand SE tracks other activity sessions, tracking a "Sleeping" session will let you know how much NikeFuel you earn while you sleep and also keep track of the duration of your session. Over time, you can see your averages as you save more sessions.
Learn how you can start a session by clicking here.
Note: Sleep sessions can only be tracked with the Nike+ FuelBand SE.