Oura Ring Q4 2023 — Circles, stress, tags, experiments and more

The last time I exclusively covered the Oura Ring was in Spring 2023, when I mainly discussed the new Chronotype and Body Clock features…

Oura Ring Q4 2023 — Circles, stress, tags, experiments and more

The last time I exclusively covered the Oura Ring was in Spring 2023, when I mainly discussed the new Chronotype and Body Clock features and complained about how long it takes to release a new version of the sleep algorithm.

Oura Ring Q1 2023 updates- chronotype and body clock
While I’m expecting rather significant updates from Circular and RingConn in the smart ring plane, Oura Health has come…

In this article we will follow up on the sleep algorithm and continue with other new features released in the interim, namely:

  • Sleep algorithm moved from beta to production,
  • Social sharing — Circles,
  • some progress on tags,
  • Experiments,
  • Stress.

“Alpha” sleep algorithm

The new sleep algorithm has been eagerly awaited as it promises a dramatic improvement in the accuracy of sleep phase estimation, and Oura in particular speaks to this spirit:

  • 2-phase (wake/sleep) — i.e. a clear distinction between wake and sleep. This lens is said to be 96% accurate.
  • 4-phase (awake, light, deep, REM) — i.e. the determination of sleep phases. Oura achieved 79% agreement with the gold standard, polysomnography.

No two sleep experts can achieve 100% agreement in determining sleep phases based on polysomnography data (brain wave data, eye movement, muscle activity and other metrics). Therefore, I take sleep phase data from ring/wristband type wearables with a large grain of salt.

It is also good to keep in mind that the accuracy of the measurement will not be the same for the whole population, the algorithm may fit better e.g. people with lower HRV etc. A test of the measurement quality was also done by my favourite Rob, directly against the polysomnograph:


The most difficult phase to identify is, not surprisingly, REM, which Oura most often confuses with light sleep. In fact, REM is characterised by features that the smart ring cannot provide — increased brain activity and accelerated eye movement.

Social sharing — Circles

Circles is a very simple feature that allows you to share 3 main metrics with your friends: readiness, sleep and activity.


Tags are a long-standing feature of the Oura ring that is due for a major update. As a reminder, these are tags that you can add on any given day, and they appear primarily in Trends (both in the app and in the cloud view).
We’ve now seen two new additions:

  • Tag Impact,
  • custom tags, and advanced features.

Tag Impact

Oura will now show the impact of selected tags on the user, e.g. “Beer makes HRV worse by 3%”.

I see a big contrast between this level of Oura functionality with Whoop’s wristband competitor and the journal functionality, where you click on relevant information for the day and Whoop then tells you how your actions have affected the relevant metrics, see illustration:

Oura Tag Analysis

Interested in some aggregated impact output from Oura tags? What has the biggest negative & positive impact? I was wondering.

Custom tags, extensions, smart tags

Finally, Oura allows you to create your own custom tags, which you can use in the same way as the standard tags. In addition, you can set a time limit, set a daily recurrence and add a note. There are also new Smart Tags, which are automatically suggested when your sleep score goes up or down significantly:


One of the most interesting recent updates is called Experiments. The Coffee Experiment is currently available. In simple terms, Oura will ask you over a period of 14 days if you drank coffee within 6 hours of going to bed yesterday.
At the end of the period it shows you the results in the form of metrics:

  • Sleep efficiency — a percentage of time spent asleep in bed.
  • Restfulness — the amount of waking and moving during the night.

For my part, I would add that, in my opinion, Oura does not emphasise enough the importance of behaviour consistency during the sleep test. I didn’t see this recommendation in the app, only on the website:


Stress, or daytime stress, is another feature that (in theory) makes the Oura a bit more of a device worth wearing during the day. Historically, the second generation of the ring measured most metrics mainly overnight, with only steps (and secondarily calories) measured during the day, with the third generation adding daily heart rate in the form of a daily curve.
Similarly, you can now see the so-called daily stress curve, which is divided into 4 levels, as shown in the picture:

Oura uses the following metrics to calculate stress: HR, HRV, movement and temperature. Stress is calculated when you are awake and not exercising. It is taken every 15 minutes.

Unfortunately, it is not known what the weight of each metric is, i.e. how important HRV is, what temperature is, etc. If you’re interested in learning more about HRV, you’ll have come across the name Marco Altini. He argues that it’s only worthwhile to measure HRV during the night or first thing in the morning, before you’ve had time to activate all the possible stressors (food, drink, exercise, boss, etc.) into your routine. This is in direct contrast to measuring during the day, which turns out to be the trend with many wearables. At the same time, I think Oura is aware of this (though Marco Altini is one of Oura’s advisors) and their algorithm is more sophisticated than direct HRV reflection.

I will leave some time for further evaluation.
So, personally, I think that Oura is mainly catching up with the trend of competitors and demand. And I have to agree with @drpetertierney who beautifully visualized that stress is not a metric that should be given more importance within wearables (and it is also difficult to measure):

In retrospect, however, it seems to me that on the more hectic days I actually have a “Stressful Day” label, and Oura can also reflect some health issues in this functionality, such as an elevated temperature:

What can we conclude?

It is good to see that Oura is not slowing down and is introducing new and interesting features. Unfortunately, Oura’s roadmap is secret, so we don’t know what’s coming. Follow this link to see what the Oura community is asking for.

There is also growing speculation about a new version/generation of the ring, but nothing is officially announced by Oura. Personally, I think Oura will come up with something this year — 2024 — and the new ring will support contactless payments and I hope there will be a further minimization of the ring body.

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