Forerunner 935 sleep tracking

Forget about sleeptracking. It doesn’t work.

Last sunday I got up at 7, doing some house cleaning, and my 935 reported I slept deep unit 10. Yeh, sure.

(That’s just one example of many where the start and/or end time is completely wrong)

Garmin's sleep stages are VERY experimental and so is sleep detection in general. The main problem here is that Garmin only makes use of the movement information and heart rate. HRV does not seem to be used in any meaningful way if at all.

This means, if you are sitting on your couch or in bed late and reading a book or watching a movie, the watch may detect that as sleep. When you are actually sleeping but your sleep is not calm, your watch may detect that as awake periods.

For me, the sleep information with the current Garmin algorithm is useless.

However there have been some reports recently that the Fenix 6 has an improved algorithm which works better. This feature however is not (yet?) available to the FR935.

Thanks Elbo. Love 935. Glad its not just my watch. Maybe Garmin will find fix

Thanks Humodda. My Vivoactive HR was a lot more accurate. Only showed deep and light sleep, no REM. Sleep accuracy is something I can live without with the 935 doing great otherwise. Happy it’s not just my watch

How much deep sleep, light sleep and rem sleep you have might seem interesting, but actually it's not. There isn't much you can do about it (except for not drinking alcohol). Also there is no way to tell if your watch is right. 

The thing that is interesting is the amount of sleep and whether you are awake during the night. That's something you can do something about (in worse cases with help) Unfortunately, this is where Garmin not excels, like humodda says.

Thanks Elbo!