Sleep analysis with Polar and Garmin

I’ve been wearing during the last two weeks both Garmin 945 and Polar Vantage V at the same time – this maybe being one of the side effects of not interacting with the others – you don’t look that weird wearing one watch on each hand.

So, besides a 24/7 wear comparison between the two watches, I thought of highlighting one of the aspects a lot of people look after when they are choosing Polar at least – the sleep analysis. Actually, to be completely honest, I was very much excited when Polar announced Ignite and detailed sleep analysis ( and even more excited when I heard that eventually that will make its way to Vantage as well.

Regarding Garmin, they never made so much noise around their ability to analyze your sleep – you’ll find some references here ( but Garmin doesn’t explicitly mention their sleep analysis function with the more advanced wearables – I’ve seen something on Venu’s page .. but not the strongest feature that they advertise.

Anyway .. let’s look over the data available after a night of sleep (actually for the Polar Nightly Recharge you need to wear the watch for 3 nights to create some data trends). If you look in the web platforms after one night, you’ll see something like below (like my last night):

Garmin Connect (Web) sleep info – night of 4th of April 2020
Polar Flow (Web) sleep info – night of 4th of April 2020

So actually you may say that Polar’s view is not that “advanced” and deep – that’s true somehow, because they didn’t mirrored the Sleep Plus Stages entirely in Flow Web, but they offered only a glimpse in the details … at least compared with what they offer on the watch and mobile Flow app.

You can still see some details about the sleep on 4th of April, hovering on Flow Web

If you looked at the data above, you already might have seen that the wake up hour is the same, but the fell asleep is not .. Polar is more close to reality than Garmin in this particular instance, but we will look over the last week data to see that this kind of a difference is not happening every day.

Garmin Polar
DateFall asleepAwakeDurationFall asleepAwakeDuration
Sleep stats collected by Garmin and Polar
Usually the nightly sleep duration measured by Garmin is higher (overall with 1.6%) – [1h21m over 11 nights]

Though is not easy to say for sure when you fall asleep, I would say that Polar is more accurate than Garmin in measuring sleep duration. I can take for example last night, when Polar says I fell asleep 5 minutes after a let my phone down, being already in bed, whereas Garmin says that I fell asleep 9 minutes before a let my phone down. So, if those 14 minutes count for you (or sleep analysis accuracy) – Polar is the way.

Now, when it comes to what you can do with that information, or the details of your sleep stages, then Polar wins again because it assigns a Sleep Score (up to 100) for all nights just to give you an idea how well you slept.

Garmin gives the same level of detail regarding sleep phases, it doesn’t matter if the percentages of REM, deep or light sleep are the same (they are not, obviously) but it’s up to you to use that information somehow and correlate it with your habits. For example, I know for sure that if I have a larger meal with a drink or two later in the evening, my deep sleep period will diminish – that’s a fact highlighted by Garmin and Polar as well.

What Polar adds is the Nightly Recharge ( which is giving you some insights about your quality of regeneration based on ANS and sleep.

The information is also available on your mobile Flow app, but not not that much on the web Polar Flow (unfortunately).

Garmin comes here with something somehow similar – Body Battery which also uses the HRV from the optical heart sensor and the algorithms from First Beat to give you an insight about your “energy status” during the day (and not only during night, or the first 4 hours of your sleep like Polar). Usually, I found Body Battery to reflect pretty well my status or evolution at least.

Garmin considers that my body battery was recharged okish during the 4th of April sleep

When it comes to wearing comfort, especially during night – for me both of them are fine, easy to wear, with a slight edge to Garmin which has a less intrusive sensor. But they watches are light and I didn’t feel that they are a burden to wear in bed.

The Polar sensor leaves some marks, unless you keep the watch pretty loose

Garmin does a better job with displaying the information (as detailed as it is) both in the mobile and web app, not that much on the watch itself, where the sleep information is not available in any of the widgets.

I don’t have the Pulse Ox feature on because it drains the battery and I didn’t feel like is that accurate to give me something back for the battery percent it eats.

Garmin has extensive reporting in their web app, but the development teams (product teams) are not very in sync, so you’ll get for week/month/6 months/year a graph with your sleep duration but that’s it.

Garmin Connect web dull (from my perspective) report for longer period sleep time trends

Polar has a more unbalanced approach – it displays the sleep data (and nightly recharge) on the watch with great details, does the same (even more) on the mobile app, but less in the web app – which may say something about their development team bandwidth or priorities. Usually, the Flow web app is considered the flagship of Polar ecosystem – maybe they were just “pushed” to have something available on the market and didn’t get as much time to make that available on their web interface.

One thing that annoyed some people used with Polar’s sleep analysis before Ignite was released is that Polar decided that you can’t edit the sleep start/end moments yourself, letting everything on Polar’s algorithms – that might be an issue for those that have a restless sleep or wake up in the middle of the night for a period .. I don’t have that problem, but this might be a concern for some. Garmin allows you to alter the sleep duration, if that’s important for you.

I didn’t alter the sleep duration to see how this affects the phases stats, but I imagine that they are simply cropping of existing data.

One other thing worth of being mentioned is that both Polar and Garmin don’t treat well your over day naps – they need at least 4 hours of continuous sleep to do something with the, from this perspective I’ve seen in various forums complaints from people used with Fitbit’s more flexible approach.

Conclusion – if you’re interested in your sleep analysis, and that’s important for you, Polar does a better job (in my opinion and based on my measurements) than Garmin at measuring your sleep and providing you feedback. Garmin has a more cohesive approach at displaying data in all platforms (watch/mobile/web) but doesn’t do something with the data to help you understand what’s important and how. Polar has developed the algorithms to measure sleep and has some nice stats to display, but also correlated with Nightly Recharge you can act on the data.

Some interesting references:

Garmin 945 FW 4.2.0 (and 4.2.9 beta)

Polar FW 5.1.4

Author: Liviu Nastasa

Passionate about software development, sociology, running...definitely a geek.

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