No deep sleep?

The first one looks more correct as it's "normal" to have around 1 hour of awake time with an 8 hour sleep time...normally, that 1 hour should be spread across the whole night so can't really say how much the Epix is accurate but i can say that, most probably, the vivoactive 3 is missing some awake sleep.

Garmin was always underestimating the awake time and they were recording only "noticeable" awake time like when you get up for few minutes or you really awake and you can remember but since a month or 2 they started to update the sleep algorithm and they are starting to show more and more awake time.

On the other hand, stages between the 2 devices look pretty different except the middle deep part and a portion of the biggest REM part..can't say anything about it as i don't pay too much attention at stages and i have no knowledge in them.

bigwillystyle99 said:

Interesting to note the differences in REM sleep, Awake time and Total Sleep. I wonder which one is more accurate?

What is your feeling about the awake time? Normally that is very accurate for me and easy to verify since I know if I'm awake ;-)

I doubt you would transition into deep sleep as quick as the Vivoactive shows and also transition between deep sleep and awake several times as shown between 10:30pm and 11:00pm

I definitely wake up multiple times in the night but not for as long as the Epix Awake Total is showing.

The Epix often shows deep sleep for me after I have just dropped off (just not last night) and only normally ever in my first four hours of sleep but never more than 75 minutes of deep sleep in 8 hours. 

I think the best thing to me is not to read into it too much. However I would like to know if others record deep sleep of over 75 minutes and REM over 90 minutes in 7-8 hours.

It would be interesting if someone had two Epix one on each wrist to see if they read the same.

Normally, i have lower deep sleep but a lot of REM sleep(it happens that i exceed the recommended range too). Don't have many examples with 8 hours window.

Coincidentally I apparently had a good amount of deep sleep last evening. IIRC it was only a few minutes the night before. I don't take too much notice of the sleep phases as I am not convinced they tell me anything much. However, the my sleep start and finish times are generally very close to reality.

bigwillystyle99 said:

It would be interesting if someone had two Epix one on each wrist to see if they read the same

While it might be interesting there are differences between the vasculature of the wrists that might render any comparison moot. And certainly for me the fact that I usually have my head on my pillow with my right arm underneath (I have the watch on my left wrist) would also induce some differences due to restrictions in the blood flow of my right arm.

Well, for me Garmin’s algorithm does not work concerning deep sleep. Wore a Suunto 9P, an Oura 3 and the Epix this night and the Suunto and the Oura report twice as much deep sleep than the Epix. So thumbs up for you guys getting good results and enjoy it, I think I will have to wait until (if ever ) Garmin gives us some update! 

I just don't know why garmin won't use the same algorithm has the vivomove sports which has better accuracy.

The sleep tracking on this is rubbish, in fact terrible.  My AW was superior.  But, in the end it tells me how many hours I've slept and that's good enough for me.   Most important for me is.  Hours asleep, resting heart rate, sleeping SPO2.   Those work fine.

Really makes me laugh. Kudos for Quantified Scientist for what he does, but as he himself mentions there are loads of issues with his test methodology. The reality is that all of these are based off a device that is only 86% accurate to start off with (and ignores that some of the older devices weren't assessed against his EEG either, the number of nights he uses as a basis etc). A prime case in point is that he actually retested the Fenix 7 at a later date and it was significantly better. And I suspect it will continue to do so as the firstbeat algorithms improve and Garmin/firsbeat continue to work with more data from the elevate 4 sensor.

Stating that I find that the firstbeat sleep algorithms are improving and are pretty consistent with with what my CPAP machine provides i.e. when I have a loose mask which will cause apnea events which will reduce deep sleep - I see that impact. The duration ties in pretty well with my CPAP records. I also find that it is all pretty consistent with a positive reaction in changes to lifestyle and habits i.e. when I change them it reacts i.e. don't eat/drink 2hrs prior to sleep my stats improve - when I do they get worse; drink alcohol and I see the impact, same with spicy food etc. In a lot of ways this is far more important than an estimate of sleep stages being accurate. 

Naps - seem to be people's biggest issue - they are recorded, however not as sleep (which they aren't) but rather as a recharge to body battery which is correct. Naps should be short less than 40mins, the idea being a quick recharge. You don't want them included as part of sleep as it will impact the % deep and % REM per overall sleep duration. Ideally we should be within certain percentages as per the sleep score breakdown.