Review: Oura Ring, The One to Rule Them All?

Collecting health data to help your training is not a new phenomenon. Since Polar launched the first consumer heart rate monitor in the early 1980s it has become endemic among almost all professional athletes. In the beginning, athletes simply recorded their heart rates while training to understand how hard they were working, but in recent years the focus has widened collecting data away from the bike to understand how the body responds to training and how it recovers. As the technology advanced, further measures like HRV, the minute differences between each heartbeat, became possible to measure with consumer tech and sports scientists began to research what this long-used medical marker can tell us about our performance and condition. Today there are a few options on the market that record a range of metrics with the goal of optimising your performance and/or health, and the Oura ring is at the forefront of the current generation of advanced health-focused wearables.


The ring itself starts at $299 USD for the the standard version and charger. The standard ring is available in two profiles - Balance or Heritage - and comes in silver or black. If you are feeling fancy, you can upgrade the Heritage version to a stealth or gold version finish for a little over $100 more and the Balance has a diamond-studded option at $999. It is worth noting that the tech remains the same throughout the range - the price increases are for fancier finishes and precious metals. Unlike its main competitor, the Whoop strap, there is no monthly subscription or further cost and the app is free to use. This means that over a year the standard Oura ring comes out a little cheaper than the Whoop strap, which is $30 per month.




Getting Started

Before you purchase an Oura ring they send you a free-of-charge fitting kit with plastic rings to check your finger size. I have fairly average-sized hands (I'm usually a 9 for gloves) and the size 9 ring was the closest for me. With hindsight I wonder if I could have done with a slightly smaller ring as fit on the finger is important to get good readings. I appear to have relatively big knuckles and thin fingers - so although the 9 was a little loose on my finger I could not get the 8 over the knuckle, and if I could I almost certainly would have not been able to get it off again, which would make charging impossible.

Out of the box you need to pair the ring to the app. For the first use this needs to be done with the charging stand and app, once you have made the connection and charged the ring, simply slip it on your finger and let it get on with working. Reading online reviews there seems to be some hint that it is better to wear the ring on your non-dominant hand, although I was not aware of this at the time. My wife does not mind what wedding ring I wear, providing I wear one on my left ring finger, so I chose that as it is the only finger I am used to have a ring on and I cannot wear a ring on my right ring finger after crushing it under a concrete block as a teenager.

You will immediately have activity data and will begin receiving scores after your first night sleeping with the ring on. When it is active you can quickly check in on your progress through the day via the app. Oura say that the ring needs a little time at first to get to know you, they say a couple of weeks to set up baselines, then it will continuously learn and improve the longer you wear the ring. While it establishes your baselines, your scores are based on a proxy with similar metrics to you.


The main choice to make with the app is do you allow notifications? If you do allow them it will send you updates about your progress on the days activity goal, inactivity, bedtime and battery levels for the ring. If you do not want to receive these updates you can either choose to disallow notifications or place the ring in airplane mode which disables the ring's connectivity and you need to place the ring in the charger to re-establish a connection with the app (this is also worth keeping in mind if you are visiting anywhere you are concerned for your digital security).

The most complicated area with setup is if you wish to pull in data from other sources. For instance, if you are out riding the ring may register occasional heart rate readings and the movement, but it is nowhere near as in depth as you would record with a cycling computer, which then means a large part of your daily health information is not recorded and cannot be taken into account when the app is putting together your scores. To access this data becomes complicated because Oura will not pull data directly from third-party apps such as Strava or Garmin Connect. To import data from these sources on an iPhone you need to first connect your activity app to Apple Health, then connect the Oura app to Apple Health and get all the read/write permissions in order to share the sports data from your tracking app to Oura via Apple Health. With this many steps in the process it stood out in the setup process as being particularly tricky to get working correctly, especially because the rest of the setup ran so smoothly. The ring was only tested with an iPhone, but the Oura website states that you can set up similar links with Android to bring in outside data.

Using the Ring

The idea with the Oura ring is that you check in each morning to see how you are doing. On the main screen you are presented with your readiness score in the home page with brief summaries of three areas: readiness, sleep and activity. You can then follow each of these areas into a separate tab in the app to get a more detailed breakdown of the contributing factors. Readiness is calculated based on resting heart rate, HRV, respiratory rate and body temperature. It is worth mentioning here that the temperature reading is based on a skin measurement and should not be considered useful for medical diagnosis - I had COVID while wearing the ring and ran a fever for several days, but this was not picked up by the ring.

Oura claim that their tiny device has 99.9% correlation to a medical ECG device for heart rate and 98.4% for HRV, although there is little information about sampling rates and the resting heart rate consistently came in higher than on the Garmin HRM strap I use to take a manual HRV reading each morning. I have been taking manual HRV readings with the iThlete app using a Garmin/Polar strap since 2016, so I have a good background and have established a reasonable correlation between the scores I get on that app and how my body is recovering or responding. My readiness score and HRV readings from the Oura app did not correlate well with my manual readings and often how I felt. With the discrepancies like this between the two platforms it was a case of choosing which one to follow for a given day as they frequently told me quite different things. That said, maybe this is was an unfair situation for the Oura ring as I only used it for three months, compared to five years with iThlete. If I had stopped iThlete and focused on Oura the situation maybe it would have improved but as the ring was only with me to test I did not want to abandon my long-term health tracking.


The sleep section looks at your total sleep time, time in bed, sleep efficiency (ie. quality) and resting heart rate. The Oura calculates your sleeping based on movement and heart rate, a technique called actigraphy, that has in-built limitations in differentiating between sleep phases. As part of the sleep information the app calculates what it thinks would be your ideal bedtime based on your recent sleep, although it continually recommended I head to bed at 8pm, which is early even for me. It is with the sleep score where I had my biggest issue with the Oura ring - it consistently under-recorded my sleep. On many nights it would register me going to bed at the correct time, but then decide that I was awake for up to an hour and a half after I was out cold. Talking to Oura technical support staff they tracked this down to my heartrate being consistently elevated in the evening and dropping slowly over the course of the night. That (relatively) high heart rate meant the sensor gave me low sleep efficiency and latency scores, reducing my sleep score and dragging my overall readiness score below my perceived levels and the levels extrapolated from my manual HRV reading. Reading online I have seen people suggest that the some other devices use an electrodermal sensor to improve accuracy on sleep tracking, but at present that is not something Oura offer.

Finally there is activity which is pretty self-explanatory as it is not so different from a $25 Fitbit-alike or the motion sensor built into your smartphone, counting steps and periods of inactivity. This was surprisingly valuable to me as the fact the Oura is a ring meant I had it on 24/7 while I would habitually leave my phone elsewhere and take my Garmin watch off when I was not training. That said, I did not turn on notifications for the movement updates as I have moral issues with about being told when to move by a gadget.

Limitations

From what I can work out, I did not have a typical experience with the Oura ring. Talking to a friend who used one for several years, he reported a far higher quality of data, which lead me to scrutinise the cause of my problems. I am open to the possibility that I have weird physiology - I have a bony lump in the base of my wedding ring finger, my resting pulse rate is very low (I have clocked it around 35bpm some mornings) and maybe my knuckle to finger width ratio means I cannot get a ring tight enough to the skin to get good readings. Unfortunately with my mangled right ring finger I could not simply swap the ring to the other hand for a comparison. In some online reviews testers have talked about differences between units but when I raised my concerns with Oura I was not offered an alternate test unit to rule out that possibility. After my time with the ring I discovered that it is recommended you take the ring off for hard physical work where the ring could be damaged such as trail building or hitting the gym. There was no change in the data to suggest this was the case, but as I could not rule it out I do not want to omit that possibility here.

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Pinkbike's Take