The New Oura Ring
An ‘On-Hand’ Review

The new Oura ring is a second generation wearable health and fitness tracker from Oura Health. This review is based on three weeks with the model Heritage Silver, size 11, and covers the ring, the app, and the website (Oura Cloud). As a frequent traveler, I was also curious how the ring handles time zone changes and recommendations for sleep and recovery.

Note: I bought the ring myself and have not received any payment or incentive for this review.

At a Glance

Look and Feel

The first generation Oura ring had very similar features but it was bulkier and less appealing. The new ring significantly ups the looks, and it also adds some features. My wedding band is a little thinner and slimmer but not by much. Until you remove the Oura ring from your finger, it will easily pass for a regular ring. In fact, I have received compliments on the ring without people knowing it was a smart device.

The ring is made of a coated titanium and comes in several colors, shapes and sizes.¹ You can order a sizing kit and try wearing ‘dummy’ rings first which is recommended to ensure a good and comfortable fit. Any finger should provide a good heart rate reading, as long as the ring is not so loose that it would rotate on your finger.

The ring is much lighter than what a gold or platinum ring of its size would be, which is a good thing. As you would expect, it is also water resistant, so you can safely go swimming (and diving is safe to at least 300 feet). I didn’t find an explicit mention about salt water but the first generation Oura was safe. After close to two months of wearing, there are no scratches or defects. Overall, Oura gets top marks for the look and feel.

Comparison

This review is not a comparison against other products. I am aware of one ring alternative, called Motiv. At the time of my purchase (which was in December 2018),² Oura seemed like a better choice. In the past, I used Misfit Shine (discontinued) and I had been a happy user of Fitbit Alta HR for the past year. Even though I am not explicitly comparing the products, the impressions are inevitably based on my previous experience.

Features

Let’s take a quick look at the sensors the ring has:

Heart Rate

The ring uses infrared light to measure your blood flow. This is a nice improvement over trackers that use green LEDs. For one, no visible light can seep out and disturb you or your partner at night; and, according to Oura, the infrared performs better. In addition to detecting your heart rate, the sensor is accurate enough to infer your respiration rate and ‘heart rate variability’ (HRV, which is the time variation between pulses).

Movement

The ring’s 3D accelerometer and gyroscope track your movement and activity. This seems to work just as well as accelerometers in other devices for detecting the number of steps and intensity of movement.

Temperature

The new ring adds a skin temperature sensor. It measures a relative difference in your body temperature at night. It does not give you an absolute temperature reading but a relative difference between this and previous nights.

To synchronize all this data, the ring connects to a free app on your smart device (iOS or Android) via Bluetooth Low Energy. Oura says the internal memory should be good for several weeks of data (so you can go a long time without syncing with the phone), and the ring’s stated battery life is one week.³ A wireless charger which matches your ring size is included, so there are no exposed charging contacts on the ring, and no cables to connect.

The ring does not include any LED lights, display or vibration motor. This means all communication from the ring goes through the app. While an LED could be likely included without increasing the bulk, I like the fact that Oura went for a pure ring.

That is an impressive feature lineup. Before you start wondering how a ring can do all this for a week without charging, I will call out that the heart rate and temperature monitoring are not running when you’re awake. It is unclear whether the night time heart rate monitoring is continuous or based on sampling. However it is done, it provides more than adequate level of detail and the HR readings matched the Fitbit Alta HR.

Setup and Synchronization

Setup of the new ring on iOS⁴ was quick and easy. Put the ring on the wireless charger, download the app, register using an email and password, and you’re ready to roll.

Syncing the ring has been also seamless. During my use, I had only one sync issue when the app was taking too long to sync because the Bluetooth got disconnected. Tapping on the ring in the phone’s device list did not restore the connection but switching the Bluetooth function off and on made it reconnect. (This could have been an iOS glitch.)

Oura also has an Airplane mode. Since FAA now allows Bluetooth even during takeoff and landing, you should not ever need it. If you do activate it, the ring will continue tracking your activity, but you will need to bring the ring back ‘online’ by placing it on its charger.

To Sleep, Perchance to Dream

Oura Health believes that the quality of our sleep is extremely important for our ability to perform well during the day. The level of attention that went into everything related to sleep reflects this. Every morning, the ring gives you a Sleep Score which is calculated from the following measurements, which you can explore in detail in the app:

• Total sleep time — how long you were asleep.
• Sleep efficiency — length of time asleep compared to time spent in bed.
• Tranquility — the number of times you woke up or were restless (also referred to as ‘disturbances’ in the app).
• Total length of REM sleep and deep sleep based on inferred sleep stages.
• Latency — length of time from bedtime until falling asleep.
• Sleep timing — how well the sleep aligns with the night.

Other measurements which are indirectly represented in the sleep score are light sleep duration, bedtime start (what time you went to bed) and total bedtime.

Analyzing Your Sleep

Sleep consists of REM (rapid eye movement) and non-REM phases. The non-REM sleep is further divided into four stages based on brain wave activity. The app and the web application categorize all these stages as Light, Deep and REM sleep. While the ring cannot measure your brain waves, it infers the sleep stages based on your heart rate and movement.

There was some criticism after Oura released the new ring that it overestimated the amount of REM sleep. Oura has adjusted their algorithms since. Bear in mind that without an EEG-capable device, the sleep stage durations cannot be absolutely accurate. When I compared sleep stages from several nights between Fitbit and Oura (when I wore both devices), the data were broadly in alignment.

I find the sleep stages provides a meaningful picture of your sleep. Over the year with Alta HR, I learned there’s a clear difference in how I subjectively feel on less than 1 hour of deep sleep.

Over time, Oura also learns what bedtime suits you personally, and starts giving recommendations for your ideal bedtime. I spent a large part of the review period travelling with poor sleep, so for the first month, I was receiving only general bedtime reminders. The suggested best window of time is in the app, but you will not receive a notification on the phone ahead of the bedtime. This wonderful feature is however compromised by the issue described in the next section.

In addition to sleep stages and ideal bedtime, Oura does several extra things, which I cover below under the section about ‘readiness.’

“I Am Afraid I Can’t Do That Dave”

It is currently impossible to make manual adjustments when the software gets your actual bedtime wrong. An example of this issue is when I went out to a movie theater. The ring’s analysis of that night placed the start of bedtime at the start of the movie, despite my moving about during intermission, walking a block to get a ride home, and then getting ready to sleep.

The app has a built-in support chat and the support has been helpful in many areas. In fact, some of small glitches I mention below have been already solved. For editing the bedtime, Oura support commented that “supporting the ability to edit sleep is not a trivial exercise due to the fact that the sleep calculations are all completed on the ring rather [than] in the cloud. As a workaround, you could try removing the ring in the evening while watching TV or reading in bed.”

This workaround is not very elegant: I won’t risk losing the ring by removing it when I’m outside; and at home, I once forgot to to put it back on. The issue shouldn’t be that difficult to solve though: The ring already correctly errs on the side of starting the heart rate monitoring when it suspects you might be going to bed. If, in the morning, the phone were to communicate my manual correction, the ring should be able to override the inferred bedtime start and recalculate all the relevant indicators based on this new information.⁵

This is a fairly big issue: The ring’s primary purpose is to track your rest, not your workouts (if that’s what you’re after, go with Fitbit or some other device). Its purpose is to analyze the quality of your sleep, and recovery, and the vast majority of measurements and scores are significantly affected by the (incorrect) bedtime start.

I don’t expect the ring to get the bedtime right all the time.⁶ But when you cannot correct the ring, it will misunderstand your patterns, and its guidance and trend information will be undermined. The consolation is that it is not a hardware issue.

Naps

The ring also detects ‘rest’ periods throughout the day but is unclear to me how these rest periods are considered. When I was taking naps during and after an international trip, Oura did not seem to include them when scoring my sleep and readiness. If you are from a culture where naps are the norm, or you take naps regularly, this might not be ideal.

Since the ring does a good job of automatically detecting these rest periods, it might be a matter of enhancing the software, so the user can designate some rest periods as actual asleep time, some as meditation, and leave some other simply as rest.

Listen to Your Body

Oura also provides a separate Readiness Score which is different from just the quality of your last night’s sleep. The following indicators influence your readiness:

• Previous night — your last night’s sleep score.
• Sleep balance — the amount of sleep over the past two weeks.
• Previous day activity — your readiness will be lower if you pushed yourself too much the previous day.
• Activity balance — how well you are balancing days of medium and high activity with ‘rest’ days.
• Body temperature — a relative body temperature change. I admit I have a hard time understanding the two charts that are available in the app (trend and 30 days).
• Resting heart rate — the resting (lowest) heart rate during the night compared to your average resting heart rate.
• Recovery index — how long it takes for your heart rate to stabilize at night.

The ring also measures two other important indicators: heart rate variability (HRV) and respiration rate. While you can see these for each night and analyze their trends, these values are not used for Readiness score calculation. The stated reason for this is that they are highly individualized.

Note that a higher HRV is actually a good sign. The more regular your heart beat is the more stressed and tired you probably are. You are likely to see a higher HRV on days with a lower resting heart rate, but the two do not go entirely hand in hand. It would be nice to have HRV in comparison to your average HRV included in the Readiness score.

Too Many Metrics?

As you can see, the ring gives you a lot of metrics and scores. Initially, I was skeptical and felt this might be an attempt to make the ring seem more feature-rich by rehashing a handful of underlying data points in more ways than is warranted. This is not the case though, and a seemingly ‘superfluous’ metric can surface an important fact and provide a good guidance. I am including an example of this in the section on travelling.

HR Yes, Just Not 24 x 7

An expected but still somewhat disappointing step back from what I’d been used to is the lack of continuous heart rate monitoring. The Oura ring would be an easier purchasing decision if the ring had an option for HR sampling throughout the day. The battery power is definitely there.⁷

It is possible that a 24-hour HR tracking is omitted because movement affects the accuracy of the reading. If this inaccuracy was tolerable though⁸, a 24-hour HR monitoring option would provide valuable insight for people who want it. As long as the user’s expectations around the accuracy and effect of enabling such feature are managed, the ring’s battery and memory are more than capable of handling it.

Basic Activity Tracking

Oura’s emphasis is not on tracking physical activity but on quality of sleep. At the same time, it tracks activity because it is an important part of understanding your overall readiness and balance. While I respect that sleep receives more attention from Oura, the feature gap between Sleep and Readiness and Activity is quite large.

Oura tracks the following indicators related to your activity to give you an Activity Score for each day:

• Inactive time – how many hours you were stationary during the day.
• Move every hour — periods of inactivity longer than an hour.
• Meet daily targets — how well you did over the past 7 days.
• Training frequency — how good is your mix of medium and high intensity exercise.
• Training volume — amount of exercise you got over the past 7 days.
• Recovery time — checking if there are days when you take it easy.

The app will also show you the usual (and less usual) statistics for the day: the number of steps, total calories burned, activity burn (calories burned during exercise), and walking equivalency (your activity burn converted to walking distance).

Activity Goals

The Oura app and website explain that your daily activity goals are based on your age, gender and your daily readiness. This is a significant improvement over static goals offered by many activity trackers. When I was exhausted from jet-lag, the app didn’t make me feel guilty by setting a goal that I would be unable to complete.

At the same time, the goals are an example of the ring not taking in users’ input. While the activity goals matched my circumstances during the review period, other people will want challenges that go above the ‘minimum.’⁹ If that will be your case, you will have to disregard the rewards (shown as crowns) for achieving the defined activity goal, and hold yourself accountable to a self-imposed number that goes beyond filling up the activity circle.

This could be easily improved: The app could allow the user to manually specify a percentage multiplier; or the app could automatically increase the goal based on the user’s past week’s average activity. Both would provide a more challenging framework for people who are as interested in staying fit as in their sleep.

Manually Added Activities

There is no way to manually track a physical activity and there currently isn’t a plan to allow tracking your heart rate during exercising. To compensate, Oura allows you to fill in an activity after you’re done with the exercise: You choose the type of activity, enter a start time, duration and intensity (low, medium, hard). The app then calculates the burned calories and overrides the data measured by the ring’s accelerometer.

If you have a separate source of information about how many calories you burned, check that the number is similar, or tweak the activity’s intensity or duration.

It is not very elegant — the ring could maybe try to help by guessing the start and duration — but it does work as a way to enter activities where the ring couldn’t measure the effort even approximately (e.g. riding a bicycle) or when you couldn’t wear the ring.

A comparison with trackers with, and even without, HR monitoring (Fitbit, Misfit) is currently not in favor of Oura. Do not expect to see a wealth of data augmented with phone’s GPS readings, and rich visualizations that are the staple of activity trackers.

Update: Importing Activities from Apple Health

On September 19, Oura released an update that allows iOS users to import activity information from Apple Health. The information includes the type of workout, duration and burned calories.

Apple users who have a way to get more precise activity data into the Health app can now avoid the manual entry, and get accurate activity info within the Oura app.

Inactivity Alerts

You can also turn on hourly notifications that are displayed when you were inactive for an hour. While this is a nice feature, in practice, I have been receiving no more than three such notifications per week. This could be either because the ring mistakes typing and reading for movement, or because there is an issue with the notifications. However, since the metric for Long Periods of Inactivity shows me failing only 2 times per week, the problem seems to be with the movement sensitivity.

Compared to a wrist-worn tracker, the challenge for Oura is how to recognize and ignore activities such as typing. I assume a lot of Oura users are information workers, so it is important that Oura should not treat the time spent typing and moving a mouse as light activity. But the movement ‘signature’ of using a computer should be quite distinct from walking etc.

Interestingly, a separate metric, Inactive Time, is measuring with ruthless precision that on average, I am not moving eight hours per day. So it is hard to understand why I do not get notifications when many of these hours are not broken up by activity. The ring does not need to insist on taking 250 steps every hour but Oura usually ‘overlooks’ inactivity even when I don’t get up from my chair at all. Again, this is something that can be easily addressed with software, especially since the inactive time metric works.

Oura Cloud

The data collected by the ring is available in the app and, in greater detail, in a web browser.

Oura App

The app is well designed and has a clean and friendly UI. It displays all the information described above, and also allows you to review your trends in the various categories and measurements under the Sleep, Readiness and Activity categories.

In addition, the app allows you to manually add tags (such as “late coffee”) and text notes as you go through your day.

Oura has redesigned the app for the second-generation ring and since it is fairly new, I noticed some cosmetic issues. Update: Some of them have since been fixed.⁹

• The calendar view visualizes reached goals (readiness, sleep, activity) with three dots under each day. However, their order is meaningless: the left-most dot is lit up if you reached any one goal, etc. You need to open the details of the day to find out which goals you reached. The order should be fixed, and the dots could be color coded.
• In one instance, the app recorded two ‘rest’ periods with overlapping times. Oura support confirmed this is a known issue under investigation.
• (Cosmetic) The timeline on the main screen has a label that says ‘Score’ in bold letters followed by the numerical score displayed in a thin weight. It would be more sensible to show the number, not the label, more prominently.
• Note that the Android version is in Beta so the experience might not be identical yet, but I expect Oura is aiming for parity on both platforms. (Except OS-specific features such as the integration with Apple Health.)

Again, these examples are minor issues which I expect to be ironed out soon. I am including them for the sake of completeness.

Looking Deeper in the Cloud

The web version has more rich features for displaying and correlating the trends of the various measurements. You can plot the various metrics and juxtapose e.g. your resting heart rate with the amount of exercise you did. And you can put multiple such charts below each other for even more insight.

A shortcoming is that the tags and notes you make for individual days are not shown. Nor can you use the tags and comments for filtering or searching. This means that while you can juxtapose things such as HRV and length of High Activity exercises, you cannot compare your Sleep Score on days tagged with “late coffee” against days which are not tagged that way.

Handling Time Zones

As a frequent traveler, I was curious to see how the app handles big time zone changes. This is not a trivial problem because your day is either shorter or longer than 24 hours. For example, my Fitbit would overwrite hours of data when the tracker was synced to a new time zone on westward journeys. I was also curious to see how good the ring’s recommendations are going to be when my sleep is disrupted by jetlag.

A ‘Time Travelling’ Ring

The following observations are based on my trip from West Coast of the United States to Europe, with a time zone difference of 9 hours. While I couldn’t decipher how exactly Oura stores your data internally, it supports big time zone changes gracefully.
When travelling eastbound, there was no problem at all. A 3-hour nap on a transatlantic flight was logged using the last synced time zone (PDT in this case) and analyzed and displayed as a regular sleep for that night.

The activity chart for each day is visualized on a 24-hour scale from 4am to 4am, and after I synced the ring with the phone using the new time zone, the ring skipped ahead and started charting my activity from 9:35am of the following day, with the last previous entry in the previous day at 12:35am. That is ideal.

On the way back (westbound), the activity chart continued to be plotted using the original (CEST) time zone even after I arrived and synced the ring to the PDT time zone. This is a smart decision because the data would otherwise overwrite the previous 9 hours. It still means some activity is not going to fit because the chart stretches to 4am (corresponding here to to 7pm). The ‘overflow’ cannot be recorded into the next day because the ‘new’ 4am is then correctly snapped to the PDT time zone. Finally, the sleep is recorded using the local times from start to finish, including heart rate.

It sounds complicated, but the bottom line is, this is as good as I can imagine it can get. Daylight saving time changes probably happen gracefully in a similar way.

Useful Insights when Travelling

Let me close the review with a nice example from my travel: After the first night of sleep (7 hours with the help of melatonin), the app advised me that “easy does it” and brought to my attention that “[my] lowest resting heart rate occurred late last night.” The app was able to tell me that because it tracks Recovery Index, which measures “how long it takes for your resting heart rate to stabilize during the night.”

The minimum and average heart rate values and the length of sleep did not paint a particularly bleak picture on their own. Yet, the warning reflected the shape of the HR chart, which was very different from my other nights. I was exhausted and my body started winding down based on my internal clock only in the morning. The recovery index captured this in a numeric form, and because of how Oura calculates Sleep and Recovery, it notified me something was wrong as soon as I woke up.

Conclusion

Oura ring is a sophisticated tool for tracking your sleep and to help with balance between activity and recovery. I would hesitate to recommend it as your sole device if what you are looking for is tracking workouts and trainings. People who are very serious about their physical exercise as well as recovery should consider using a device designed around workouts (such as an HR chest strap) in addition to Oura.

If you want just one device and are looking for a something that does a decent job tracking your activity throughout the day and a superb job in looking after your sleep and readiness, then Oura should earn your consideration.