Sleep Tracking

mjposner

So I have been using the watch to track my sleep and either its me or the watch but every day I get the same statement: “you didn’t sleep very well.” I sleep at least 7 hours a night, and except for getting up to pee I seem to sleep fine. How accurate is this sleep tracking?

@mjposner for me it’s accurate… But we are different, so… Many factors influence the sleep tracking ALGO! Two different watches can show X values on the same app… You must trust your watch…Or you can go & get most accurate data in polysomnography lab…

@mjposner said in Sleep Tracking:

So I have been using the watch to track my sleep and either its me or the watch but every day I get the same statement: “you didn’t sleep very well.” I sleep at least 7 hours a night, and except for getting up to pee I seem to sleep fine. How accurate is this sleep tracking?

It doesn’t depend just on amount of sleep, but also on quality - amount of sleep in each of the sleep stages. You are probably not getting enough of deep sleep.

@mjposner What’s your sleep score for those nights?

Look at the phase break up. Normally REM and deep sleep should account for about 40% of one’s sleep. Likewise, the less awake time you have and shorter it is, the better. Last but not least don’t forget about restfulness of your sleep, i.e. amount of movement in your sleep. All these are factors that are weighted along with the duration of your sleep to arrive the sleep score, from which then a textual description is given.

Nigel Taylor 0

https://www.firstbeat.com/en/blog/a-good-nights-sleep-what-does-it-mean/

The Firstbeat metric also uses HRV, so even drinking alcohol or eating relatively close to bedtime will likely result in lower quality score.

Jamie BG

@mjposner
Getting up to go to the toilet during your sleep period already suggests that your sleep isn’t as good as you think it is, as you aren’t getting good deep/rem sleep (necessary to produce the chemicals that prevent urination).

Take a look at your sleep chart on the phone, and make sure that you put average HR against it. Check and see how that tallies against your normal resting HR.

Note: these are all based off my stats and observations and could be very wrong - but seems to be the way its working for me:
I have also found that min and average HR play a huge roll in how the watch (firstbeat) determine how good your sleep is, along with the duration. Basically the HR seems to determine the % of good sleep, which is then applied to the duration, especially whether under/over goal, with 6hrs seeming to be a sort of minimum qualifier to get under/over 50% quality.
For example my quality last night was 33% - ave HR was 69bpm & min was 57bpm, duration 5h24min --> compared to 76% quality were Ave HR was 64bpm & min was 52bpm, duration 6 hrs. I say that duration seems to feed in as I have one where ave 70bpm, min is 60bpm, quality is 51%, but duration is 6h09mins (similar deep sleep, but REM was higher for this one, so not sure how much of a factor stages also play).

What we really need is also the ability to track food/drinks etc time against this to get a better idea of how far ahead, and how much of an impact that may play too.

Getting up to go to the toilet during your sleep period already suggests that your sleep isn’t as good as you think it is, as you aren’t getting good deep/rem sleep (necessary to produce the chemicals that prevent urination).

In all honesty, we don’t know how old OP is. After certain age, as melatonin production drops and it no longer sustains deeper sleep levels, it becomes quite normal for one to wake up and have bathroom breaks, especially for men given other physiological changes.

Waking up at night may also be a result of merely a bad routine, such as drinking a lot of water close to bedtime.

mjposner

@nickk Let’s start with the fact that I am 60 so peeing every night is normal at my age. Also, I do not drink alcohol (hardly ever), and I try not to eat too late.

Here are my stats:

54 bpm average heart rate
43 bpm minimum
Awake 27 minutes
Rem 51 minutes
light 5.59 hours
deep 34 minutes
Quality 70%

@nickk Let’s start with the fact that I am 60

That’s exactly what I said to another poster, didn’t I? By drinking I didn’t mean alcohol, but fluids in general.

Now, looking at your stats… There’s far less restorative sleep (deep/REM) for the duration you have and almost half an hour of awake time. Both of these could be perfectly normal for somebody who’s 60, but I’m not sure Firstbeat algos necessarily got the memo.

To give you a point of comparison, my sleep today was only 6 hours, but REM was 1:14 and deep was 1:13, and awake time less than 10 min. Hence the score was 83% no doubt affected by the shortness of sleep. I think I could have done better, but let’s blame it on a second shot of vaccine and all the excitement.

From what I read, restorative sleep should comprise at least 40-45% of your total sleep duration. Needless to say, it becomes hard to accomplish as we age.

Jamie BG

Mine from last night: 47, overweight and trying to get fitter, hypertension 2 so am also on 2 blood different blood meds (family history of high blood pressure), also I use a CPAP machine (so have already noticed duration looks pretty good as a norm):
68bpm ave
55bpm min
Awake: 0
REM: 1:12h
Light: 2:38h
Deep: 1:14h
Total: 5:04h
Quality 62%
HR was higher about 5bpm higher than usual - not sure why as didn’t really do/have anything to cause it to be higher.
Sleep duration was lower than usual, as was REM, but deep about the norm.

CPAP: 5:21hrs, mask leakage 4l/min (no biggie), Apnea 7/hr (anything below 14 means good sleep).

So based on this don’t think Firstbeat is doing too badly on their analytics. Probably about right considering they are basing it off HRV only.

So based on this don’t think Firstbeat is doing too badly on their analytics. Probably about right considering they are basing it off HRV only.

I don’t think it’s HRV only, not to mention they’d need a decent HR to begin with to derive HRV from beat intervals as they don’t run EKG on you. They most definitely utilizing accelerometer too.

Regardless, I doubt phase analysis is really correct. No wearable out there scores too high, even those few who had third parties publish validation studies. That’s why I personally just look at restorative sleep (REM and deep) vs light sleep. I also think it’s far more important to look at duration trends and schedule consistency, two things which Suunto app makes very easy to do with their ingenious little chart.

mjposner

I just got a Google Nest Hub with sleep tracking so I thought I would compare the results:

Google Nest:

Asleep Time: 6h 57 min
Efficiency 88% (this is just time in bed versus sleep time)
Heart Rate Average 61 bpm
Respiratory Rate 12 rpm

Say two awake period looks like around 1 and at 4

Suunto:

Asleep Time: 7h 06 min
Quality 33%
Heart Rate Average 60 bpm
Awake: 25 min
Rem 1:11h
light 5:36h
deep 19 min

@mjposner So, the both got your sleep time correctly, figured you had some awake time (I’d trust a watch on your hand more), and were roughly accurate on your average heart rate. Beyond that, sadly, they report different things.

Jamie BG

Have been using a Fenix 6x Pro Solar (F6) for the last couple of nights. Uses all the same firstbeat algorithims as S7 except for the quality and then the calc of your body resources recovery - they are using their own info based on their years of data.
F6 & S7 are pretty much matching and getting very similar readings, however the quality on the F6 is much higher and seems to be far more realistic, especially when I add in respiration, Ox and movements readings which all show my quality is much higher than the S7 shows. This also ties in more with my CPAP machine and can see the impact on my quality of sleep matching CPAP apnea score against respiration and Ox changes - which are all tying in and accurately reflecting in how I feel and what I am getting as quality.

Certainly suggests that firstbeat need to review their quality calc.

Jamie BG

@mjposner we have the same sleep respiration rate.

@jamie-bg I have F6X too. Usually get the same quality, 80% and higher from either F6X or S7. In fact they are roughly in agreement, on sleep times, phases, and quality.

Jamie BG

@nickk they should be as they are both using the latest firstbeat sleep metrics, only difference is the quality calc, which Garmin is using their own.

@jamie-bg Not sure Garmin has much left of their own. The homegrown sleep tracking was always abysmal to say the least. My understanding is that most of their product line is now using Firstbeat algos or is being converted to use them.

Also, there’s a difference in sleep quality implementation between Fenix 6 line and newer Venu2, which not only gives you the score but also explains which aspects of your sleep contributed to it. The big number remains the same, but now comes with some context.

Jamie BG

@nickk F6 does give some context - main result of widget - Short but continous sleep.
Final widget screen - full comment: You sleep less than recommended but continously, which helps you have more energy and be more alert - bit of Duhhhhh…
But yes would be helpful to see how it breaks down the quality score.

@jamie-bg No, that’s just a short summary. Venu2 has literally entire screen explaining the score, breaking it into duration, REM and deep phases duration, restfulness, and what not.

I’m sure one of the next updates will add this to F6 too. Garmin’s been pushed hard by COROS to play nice with older watches.