Here we have one night of my sleep; last night. For once I would class it as a good night’s sleep. It was just me and my teddy bear.
It was a very late night but that was work-related rather than party-related. And it was enjoyable work rather than the usual stressful stuff.
I have done these comparisons before for my own benefit but never with 4 devices. So here I am sharing it with you.
EMFIT and OURA both claim to be able to offer HRV insights. Indeed, for the same night (I can show it if you want), both devices broadly agreed with each other for RMSSD and rHR.
You can perhaps spot some ‘vague similarities’ in how EMFIT+OURA assign my time to the various sleep classes but, perhaps, ‘vague similarities’ is being generous.
Nevertheless, as you can see, below, they both agreed with each other on the first BED exit event at 7am. Garmin did NOT EVEN SPOT THE BED EXIT event and yet would still like you to believe that it can correctly assign my sleep classes?
Polar DO spot the bed exit but do not pretend to try to guess my sleep classes. Instead preferring to give me a measure of sleep continuity. At least THAT scores quite highly as a ‘hmmm’ RATHER THAN a ‘meh.
Please feel free to click and closely examine the charts (but I wouldn’t waste your time) and then read on afterwards
Garmin Forerunner 935
Summary Table & Intricate Analysis
I determined a few correlation coefficients but then decided that the best conclusion was that “I got about 7 and half hours sleep” 😉
If you can make any better conclusions on the charts, above, or the sleep stage data, below, I’d love to know
|Garmin 935||not stated||04:00||05:41||9:41|
|Polar||not stated||not stated||not stated||7:15|
When I decided to get up, I did a Polar Orthostatic Test – which told me I was ‘good to go’ like it usually does these days (via ‘Recovery Pro’). And I even got blast-from-the-past BioforceHRV to agree that I was ‘good to go’.
Hey. One night’s sleep and all that. Sample of one.
- The Garmin data is just simply wrong. It can even get the 70kg (ish) of me getting out of bed and traipsing off to the toilet right. How on earth can it possibly distinguish my deep sleep stages? No doubt your Garmin data is more accurate than mine.
- Polar gets the basic ‘hours’ right in a probably more honest approach. At least they don’t pretend to know the stuff that the major fitness companies pretend to know – and I include the likes of Fitbit et al in that sweeping statement (specifically: sleep stages)
- EMFIT and OURA both seem plausible to me. I secretly hoped they would agree with each other. But I didn’t expect that they would. I reckon one of them is the most accurate device at a deeper level and properly able to determnie sleep classes….I just don’t know which one it is 🙁 – you can be sure that both will have their own studies saying it is them!
- EMFIT and OURA did broadly agree on the night’s HRV trend and rHR trend, which I did find vaguely (& pleasantly) surprising. From that I would have expected similar conclusions on sleep stages. However EMFIT has the advantage of being better able to detect ‘gross’ body movements, some of which OURA might miss. Historically that’s why I have tended to trust EMFIT as one of my indicators of readiness (through other measures it produces)
Take Out: Don’t work late, get a blue light, don’t drink alcohol, coffee or have a good time [insert your own unsubstantiated conclusion here] 🙂
These opinions are all my own. Let’s face it nobody else would want them. If YOU have any opinions other than ‘Eesh’, I’d love to hear them