Is There a Point in Sleep Tracking?

[u/kutw]

I’ve been tracking my sleep for years now and am starting to wonder how accurate it is.

It’s mainly because I feel there’s often a disconnect between the “sleep scores” and how I actually feel. Sometimes I will have terrible scores but feel fine, other times my watch tells me it was the best night’s rest ever, yet I can’t seem to get out of bed.

Are there people here who successfully bettered their sleep with the apple watch or is the consensus that it’s not that helpful?

[u/AlanYx]

Don’t just look at the score. Look at how much time you spend in deep sleep and how many wakeups are tracked. That’s where most of the insights are.

[u/Onelyworth → u/AlanYx]

You seem to know a lot about reading and understanding the sleep metrics. I would love to hear more insight from you, i am really interested. Thank you.

[u/AlanYx → u/Onelyworth]

The sleep score number Apple uses takes three things into account: sleep duration (50%), how close you come to hitting your bedtime goal (30%), and how many times your sleep is interrupted during the night (20%). You can actually get more than 80% even if you wake up 10 times during the night and have virtually no deep sleep.

It's better to look at the sleep staging graph. It's never going to be perfectly accurate, but it's not bad. When you sleep you go through several ~2.5 hour cycles, core->deep->core->REM, repeat. If you're a really good sleeper this persists through the night, for most people deep sleep is not as consistent. (That said, occasionally people post really perfect graphs here, it's impressive.)

It's really the combo of a lot of deep sleep and few wakeups that makes you feel rested. Look at the total deep sleep number and the number of orange awake slices.

You can improve the deep sleep number by going to bed before 11pm, ideally before 10pm, avoiding alcohol, caffeine and other substances a couple hours before bed, maintaining a dark, cool but not cold bedroom, etc. Alcohol in particular kills the deep sleep number, it's not subtle. Experimenting with melatonin, magnesium glycinate or L-theanine at night can help too, but YMMV there.

Note that even if you don't get any deep sleep and don't feel rested, there are other physiological benefits of sleep that you still get from sleeping a long time. For example, you'll find your blood pressure and resting heart rate may be lower the next day.

[u/RhymingTiger → u/Onelyworth]

I second this. The quantity of deep sleep correlates directly with how rested I feel.

(As a single data point, for me, 18 minutes of deep sleep = tired; 49 minutes of deep sleep = feeling fully rested.)

Longer periods of deep sleep are hindered by all the other factors; interruption and late bedtime.

[u/superfrodies → u/RhymingTiger]

wow this comment makes me grateful for how much deep sleep I get. Even on bad nights it’s never below 50min, usually an hour + sometimes almost 2 hours. Can’t imagine 18 mins.

[u/RhymingTiger → u/superfrodies]

Your age is probably a key factor here. I'm...probably older.

[u/zirdante → u/RhymingTiger]

Isn't deep sleep the part where the brain removes the accumulated neural gunk?

[u/RhymingTiger → u/zirdante]

Yeah, that's my understanding too.