At TechRadar, we often pit wearables against each other. Next week you’ll read what happened when I went for a 5km run with my Coros Vertix 2S, Garmin Fenix 8, and Oura Ring Gen 4 at the same time. I ran a similar test while running the 2024 London Marathon when I compared the best smartwatches to Strava.
One aspect of health tracking that has not been group tested is sleep tracking. Fortunately, researchers at Harvard Medical School and Brigham and Women’s Hospital in Boston tested Oura Ring Generation 3 against the Apple Watch Series 8 and Fitbit Sense 2 to see which is the most accurate. He did some preliminary research. To set a benchmark, the three devices were also tested against the gold standard medical-grade polysomnography, a tool used to diagnose and measure sleep disorders.
After studying 35 participants, we found that all devices accurately detected sleep and wakefulness states. However, the Oura Ring was the best at identifying sleep stages, matching polysomnography with about 80% accuracy.
Published in a magazine sensorthe researchers wrote: “Oura’s ring was no different from PSG” [the polysomnograph] Regarding estimation of wakefulness, light sleep, deep sleep, or REM sleep.
“Fitbit overestimated light sleep (18 minutes; p < 0.001) and underestimated deep sleep (15 minutes; p < 0.001). Apple overestimated wake time (7 minutes; p < 0.01) and deep sleep ( 43 minutes; p < 0.001) and overestimated light sleep (45 minutes; p < 0.001).
“In healthy sleeping adults, all devices were similar to PSG in estimating sleep duration, and the devices showed moderate to good agreement with PSG-derived sleep stages.”
All three devices were accurate when it came to tracking wakefulness and sleep, but the Apple Watch was the least accurate when measuring overall sleep stages. It’s worth noting that this test was conducted before the release of the Vitals app in watchOS 11, which changed how Apple tracks sleep using the Apple Watch. The Fitbit Sense 2, on the other hand, hasn’t changed the way it tracks your sleep, so you can expect it to still be accurate so far.
It’s worth noting that with only 35 participants tested, the results may not be statistically significant, but this study is a good indicator of what smart rings can do. . The Oura Ring was the only device that maintained PSG readings through different sleep stages, but the watch was both under- and under-estimating.
This may be due to the ring being placed on the hand rather than the wrist. In a briefing with Jason Russell, Oura’s vice president of consumer software products, putting the ring on your finger is beneficial because the LED has a shorter distance to travel than the sensor would try to pass during blood flow measurements. It was stated. Wearing it on your wrist allows for more accurate measurements overall. The new Oura Ring 4 alleviates this by increasing the “path” the sensor light follows.
If this were true, we would think that all the best smart rings, such as the Samsung Galaxy Ring, would be more accurate than smartwatches at measuring heart rate and tracking sleep. Samsung even reports improved accuracy when using the Samsung Galaxy Watch 7 and Ring together. There is also the aspect of becoming a little more outletless. Wearing a smart ring instead of a smartwatch means you have one less screen in your life, and they tend to last longer than many smartwatches. The usage time of Apple Watch Series 10 is limited to 18 hours, but the Oura Loop Line will run for approximately 7 days.
However, we do not yet believe that smartwatches will be completely replaced. Screens allow a level of granularity and interaction that is very useful to many people. This is especially important when working out. I use the screen on my best running watch to follow preset routes during my runs and check my heart rate and pace regularly. Just because a smart ring is slightly more accurate in terms of metrics doesn’t mean it’s inherently more useful. Pair your watch with one of the best heart rate monitors of all time.
Nevertheless, clinical studies comparing the Oura Ring to medical-grade PSG as well as other wearable devices mean you can trust its nighttime metrics. This is certainly a relief for Oura users. After all, these rings don’t come cheap, and you want to know if the expensive initial purchase (and ongoing subscription) is worth it.
