In June, the NBA announced that all players returning to play in Orlando, Florida, would have the option to receive an Oura Ring, a tiny, titanium device that you wear on your finger and that tracks a host of data about your body. The league made the ring available based on evidence in early studies indicating that its ability to chart temperature, heart and respiratory rates, sleep patterns, and more could help detect coronavirus infections before symptoms occur.
Despite the coronavirus connections, the Oura Ring is mostly a sleep tracker, a device designed to help its owner feel as refreshed and ready for the day as possible. I’ve worn the ring continuously (save for a few charging sessions) for more than two months, and I’ve found it to be a cleverly designed and reasonably comfortable tool that gives fascinating (to me) data and performs near the level of our best sleep-tracking apps. But one of the key things that set the Oura Ring apart from those apps is its ability to track your heart rate and heart-rate variability (HRV) with high precision and to show how those vital signs change when you sleep, meditate, and go about daily activity, as well as to give you concrete suggestions for improving your sleep based on that data.
The Oura Ring told me more about my body than any of the sleep trackers we’ve tested, and over time I did become more conscious about my lifestyle choices. And unlike the bulkier fitness trackers we tested, the Oura Ring felt light, compact, and stylish. But the ring costs $300 (or more, depending on the finish). Is it worth that investment? Unfortunately, it isn’t a great fitness tracker, so if logging workouts is important to you, this ring probably isn’t a good fit. But if you want to dive deep into your sleep and health data, the Oura Ring may give you some eye-opening insights into your body and well-being.
The Oura Ring does more than a conventional sleep tracker, providing highly accurate heart-rate monitoring and solid information on your sleep cycles. But it’s more expensive than many sleep trackers, and its fitness tracking capabilities are poor.
Why you should trust us
I’m Wirecutter’s associate staff writer for sleep, and I’ve spent over 200 hours researching and sleeping with various sleep-tracking apps. I’ve been testing the Oura Ring for more than two months, and I’ve spent more than 10 hours speaking to company representatives, researchers, and independent scientists—including Seema Khosla, MD, medical director of the North Dakota Center for Sleep, and Jessilyn Dunn, PhD, assistant professor of biomedical engineering at Duke University—about sleep tracking and wearable technology. As someone who has struggled to get the recommended seven to nine hours of sleep per night, I’ve sought out tools to help me fall asleep more easily and get better-quality rest.
What is the Oura Ring?
The Oura Ring is a wedding-band-like sleep tracker that collects data about your body, activity, and sleep using optical heart-rate monitoring, a common technology in fitness trackers. Made of titanium, the Oura Ring goes on your index, middle, or ring finger. Oura launched in 2015 with a Kickstarter campaign for the first-generation ring (which was bulkier than the current version). The second-generation ring came out in 2018. The ring shines infrared light beams through your skin and uses sensors that capture changes in the reflected light beams to track your respiratory rate (how many breaths you take per minute), your heart rate, and—perhaps most important—your heart-rate variability. The Oura Ring uses those data points, along with an accelerometer to detect movement, to track your sleep and activity, transmitting your results to an accompanying app via Bluetooth. The ring also includes two sensors that measure your skin temperature.
The app uses this data to build three scores: Sleep, Activity, and Readiness. Oura’s Sleep score is mostly equivalent to the scores you can see in the sleep-tracking apps we recommend. Like those scores, it’s pretty straightforward: The more total sleep you get per night, and within that, the more time you spend in REM sleep and deep sleep, the higher your score will be. Your sleep score also takes into account factors such as your sleep efficiency (total time lying down in bed divided by the total amount of sleep detected) and how correlated your sleep is to the fall and rise of the sun. The Activity score, too, is what you might expect: The more you move around during the day, the more your score goes up. But if you exercise strenuously, to maximize your score (and the impact of your workout) you should sprinkle in a few recovery days, as well, since the Oura Ring factors recovery time into the score.
The Readiness score is the catch-all, principal score the Oura Ring gives you. It combines elements of your Sleep and Activity scores to build a metric that measures your “readiness” for the day. Each morning, it’s the first score you see once you open the app, and it’s the score that (supposedly) encapsulates your general health best. In addition to elements from sleep and activity, included in this score are your resting heart rate, your heart-rate variability, and your skin temperature.
The Oura Ring’s ability to detect heart-rate variability is of particular interest. Heart-rate variability (HRV) is a measure of the regularity (or irregularity) of the time between pulses. For example, if your heart beats in sync with a metronome, your HRV is close to zero. But if the time between pulses frequently differs slightly beat to beat to beat, your HRV is high. Perhaps counterintuitively, more variability in the time between beats may suggest you’re more relaxed and well; several decades’ worth of research has shown that low HRV could be associated with physical or emotional stress. After using the Oura Ring for a while, you’ll have a reliable baseline for your HRV. If you then notice an exceptionally lower-than-normal HRV measurement, it could be a sign your body is under stress.
Josh Hagen, PhD, director of the Human Performance Innovation Center at the West Virginia University Rockefeller Neuroscience Institute, has partnered with the maker of the Oura Ring to study its applications for athletes and the military. He told me that he is a proponent of using HRV to monitor performance because it can approximate a person’s recovery from the previous day and their training capacity for the upcoming day. If your HRV is higher than normal, Hagen told me, you may be able to handle a heavier physical workload for the day; if your HRV is lower than usual, it might be a good day to rest up.
Lower-than-normal HRV can also signal an immune response to an illness, so several wearable-tech companies—including Oura and Fitbit—have partnered with researchers to determine if their HRV-tracking devices can detect COVID-19 cases before symptoms start. Researchers at West Virginia University paired the Oura Ring with a specialized app to track COVID-19 symptoms among healthcare workers. In May, they announced, based on early results from the study, that the Oura Ring could detect COVID-19 “up to three days” before symptoms started with 90% accuracy. (Though the study was funded by the university, Oura worked closely with researchers in providing access to data.) The study is now open to the general public.
Most fitness trackers (including the trackers we recommend) use green light beams to measure your pulse; the Oura Ring, in contrast, uses infrared frequencies. “You have a faster fluctuation in the signal [in the green light],” Jessilyn Dunn, PhD, a researcher at Duke University studying the COVID-19 applications of wearable devices, told me, “and that faster fluctuation has a lesser chance of being attenuated by a substance that it’s flowing through.” In other words, shorter, green wavelengths produce a clearer signal and are more “robust” against movement. However, although green wavelengths can withstand movement more easily, Dunn told me that green light is “more sensitive to components of the tissue.” For example, melanin absorbs green light more effectively than it does infrared light. Because infrared light has a longer wavelength, it can penetrate deeper into the skin, but the signal is also weaker, so it’s more easily dispersed by motion. As a result, any measurement of heart rate or HRV during movement with infrared is worse than a measurement with green light. And because of that, the Oura Ring doesn’t measure heart rate, HRV, or body temperature while you’re active.
What we like about the Oura Ring
The Oura Ring is a well-made device that can be useful if you’re looking to improve your sleep. Weighing just 4 to 6 grams (depending on your ring size), the Oura Ring is particularly light; I’ve barely noticed it on my finger. Compared with wrist wearables like the Fitbit Charge or Apple Watch, it’s more compact and discreet—the ring looks like a minimalist wedding band. (It also comes in other colors and finishes, including a $1,000 version with diamonds.) Considering how small the Oura Ring is, the battery lasts a long time. I was able to wear the ring continuously for a week before needing to charge, which takes about 60 to 80 minutes from empty depending on your ring size (on a par with our top fitness tracker picks).
The accuracy of the Oura Ring’s sleep-tracking data was close to that of other sleep trackers we’ve tested, but it didn’t stand out from the pack in this regard. In the company’s most recent validation study (PDF), conducted on its first-generation model in 2016, the Oura Ring’s sleep staging agreed with polysomnography, the gold-standard sleep analysis you’d receive at a sleep lab, about 66% of the time (though the company has said its sleep staging has likely improved with the second-generation ring, it has not released any new findings regarding validation of that model). According to the validation study (PDF) for SleepScore, our sleep-tracking app pick, SleepScore agreed with polysomnography 73% of the time, a result that suggests slightly higher accuracy. Of course, company-led validation studies need to be taken with a grain of salt, but in our own unscientific comparisons, we also noted that the Oura Ring didn’t capture as much REM sleep as SleepScore did. However, given the large uncertainty in sleep tracking (particularly without looking at brain waves), it’s more important to examine trends rather than raw data anyway.
What sets the Oura Ring apart from other sleep trackers is its ability to measure your heart rate, HRV, and skin temperature while you sleep. The company says these measurements can provide clues about how well you’re sleeping, how rested you’ll feel in the morning, and possibly your stress levels and emotional well-being or even whether you’re coming down with something. Generally, when your body is working harder, whether due to physical exertion, fighting an infection, or emotional stress, your heart rate increases, your HRV decreases, and your skin temperature rises. The company’s validation studies (PDF) have shown the Oura Ring’s measurements of heart rate and HRV to be 99.9% and 98.4% accurate, respectively, in comparison with an electrocardiogram.
Those extra data points give the Oura Ring’s analyses more nuance compared with what most sleep trackers offer. For example, I moved from Virginia to New York in July. Leaving wasn’t easy; except for a semester of graduate school, Virginia has always been home. I was worried about living alone in the big city, about being so far from family, and about the pandemic ravaging the nation. As my move approached, my anxiety went through the roof. Unsurprisingly, at that time, my Oura Ring recorded a sudden decrease in my HRV.
At its nadir, on my first night in New York, my HRV was over 30% lower than my baseline, but it quickly rebounded to normal levels within two days, mirroring my feelings as I got more accustomed to my new surroundings. Interestingly, both my resting heart rate and my skin temperature increased, too, but those changes were longer lasting, as neither returned to normal levels until I finally installed my air conditioner five days later (New York was in the midst of a heat wave). Once my apartment cooled down, my heart rate and temperature declined precipitously. I slept better, too.
To be clear, the Oura Ring didn’t exactly clue me in to some unknown phenomenon—I knew I was stressed, and I knew my new apartment was an unusually warm environment for sleep. But I appreciated how the ring validated my impressions with concrete data. I’m not sure how common a problem this is, but when I go to the doctor, I often struggle to articulate how I’m feeling, even if I know something is wrong. (My anxiety always spikes when the doctor asks me: “Can you rate the pain on a scale from 1 to 10?”) Having a tool that creates easy-to-understand metrics could be useful if you often have a hard time identifying how you’re feeling on the outside and connecting it with what might be happening inside your body, or vice versa.
The Oura Ring also gave me more detailed information about my sleep quality and how to improve it, which helped me feel more in control of my body. Other sleep trackers, whose data sets were more limited, would simply log the duration and stages of sleep I experienced each night and then offer generic suggestions for how I might improve. The Oura Ring, by contrast, could pinpoint specific physical factors that may have impacted my sleep and how rested I felt. For example, one morning the app informed me: “Looks like something kept your heart rate up last night. To give your body the rest it needs, try taking it easy today… An intense training day, a late night workout, elevated body temperature, or heavy meal just before bed can keep your [resting heart rate] elevated during the night.”
The ring identified a problem with my sleep, suggested why that might have happened, and presented advice on how to fix it. For that reason, I seemed to change my habits far more based on the Oura Ring’s data compared with how I reacted to other sleep trackers. On some days, especially on weekends when I went to bed late, I would wake up short on sleep, see that my scores were too low for my liking, and go back to sleep for a while, whereas otherwise I would’ve just started my day. Over time, this awareness led me to just go to bed earlier instead. I started working out more, and I began monitoring my food and drink consumption more closely. I can’t say whether the Oura Ring has made me healthier, but it has made me more health conscious.
Oura’s app also has a meditation feature, called Moment, which provides both guided and unguided meditation sessions while collecting physiological data. I’m not much of a meditator, but I found the Moment meditation feature useful, especially since it could detect how my heart rate, HRV, and skin temperature changed during the session, something that other meditation apps can’t do. The guided sessions are similar to what you can find on Headspace, our pick for the best meditation app, but the options are far more limited. Although it’s a nice feature, I wouldn’t recommend buying the ring if what you’re mainly looking for is a meditation guide.
The ring has a two-year limited warranty, which is standard for a wearable (though if you have to replace your first Oura Ring within the warranty window, your second ring is covered for either the remainder of your original warranty or only 90 days, whichever is longer). It covers “defects in material and workmanship” but doesn’t cover minor scratches and dents or damage related to misuse or accidents.
What about data privacy and security?
The Oura Ring is compliant with GDPR (the European Union regulatory standard for data and privacy, widely considered a stronger standard than US privacy laws), so all data is de-identified, anonymized, and aggregated.
|Is data encrypted?||Yes.|
|Does Oura Health share or sell data?||Oura will never sell your data. It will share data only with third parties that have privacy and security standards at least as rigorous as its own.|
|What biometric data does the Oura Ring collect?||Heart rate, HRV, respiration rate, skin temperature, and movement.|
|Can you delete data?||You can access any data the Oura Ring has collected and request removal of some data.|
Flaws and potential dealbreakers
Although the Oura Ring is a solid sleep tracker, it’s a mediocre fitness tracker. As we mentioned above, the infrared light that the Oura Ring uses for optical heart-rate monitoring is less accurate during movement compared with the green light used in fitness trackers, so the Oura Ring simply doesn’t collect much fitness data—including heart rate, heart-rate variability (HRV), or respiration rate data—while you’re exercising. The ring isn’t marketed as a fitness tracker like our picks for the best fitness tracker and the best GPS running watch are, but it’s tough to justify paying $300 or more for a wearable with such limited fitness data, especially when the Fitbit Charge gives you both sleep and fitness tracking (albeit without HRV) and costs around $100.
The Oura Ring is also very expensive compared with sleep-tracking apps. The Premium version of SleepScore, our favorite sleep-tracking app, costs $50 per year; the Premium version of Sleep Cycle, another app we recommend, costs $30 per year. You’d have to own the ring for six or 10 years, respectively, before it would pay for itself compared with those apps (as stated above, the warranty lasts only two years). And the Oura Ring lacks the smart wake-up alarms that even the free versions of both apps offer, which go off when they detect you’re in light sleep during a specified wake-up window. I found that the apps’ smart alarms made a big difference in how refreshed I felt in the morning.
Duke University’s Jessilyn Dunn told me that one of the biggest issues her team had with the Oura Ring was the inflexibility of the material. Because your finger changes size slightly throughout the day and night, your ring might be slightly loose when you go to sleep but be especially tight in the morning. She suggested that the ring might eventually be made of a flexible material so that the fit would be more consistent and comfortable.
This might be a small thing, but because the ring is so, well, small, I lost it all the time. Sometimes I’d mean to take it off for a few minutes and not be able to find it again for hours. Usually it was somewhere stupid like in my pants pocket or on a coffee table, but I would misplace it at least two or three times per week (which actually affected my activity score, since the ring couldn’t collect data when I wasn’t wearing it). If you spend $300 on anything, the prospect of misplacing it that many times is pretty anxiety-inducing. Another concern: The company told me that wearers should remove the ring before activities, like weight lifting, that could damage the ring, suggesting that it may not be durable in all situations (it is water resistant up to 100 meters).
Harpreet Rai, CEO of Oura Ring, phone interviews, May 7, 2020, May 15, 2020, September 1, 2020
Josh Hagen, PhD, director of the Human Performance Innovation Center at Rockefeller Neuroscience Institute at West Virginia University, phone interviews, May 15, 2020, May 26, 2020
Seema Khosla, MD, medical director at North Dakota Center for Sleep, phone interviews, May 19, 2020, June 12, 2020
Jessilyn Dunn, PhD, assistant professor of biomedical engineering at Duke University, phone interviews, June 17, 2020, August 28, 2020
About your guide
Justin Redman is an associate staff writer covering sleep for Wirecutter. A poor sleeper for many years, he hopes to help others (and himself) reap the benefits of better, more comfortable sleep. He has previously been published in The Hill and The Credits, and he has blogged about the NBA for WizardsXTRA.