Fitbit Surge the other big advance is that fitbit can finall automatically detect when you’re asleep that means no more remembering to prees a button to tell the wearable it s bedtime and as mentioned before if you don’t turn on sensitive mode the sleep tracking is actually pretty accurate from there you can dig through the collected data and start looking for those disturbing trends like the fact that I average about four and a half hours of sleep a night during the week and that it takes me almost an hour to really settle into a result sleep and so good fitbit surge.