Every night, your brain and body experience different phases of sleep, and each one plays an essential role in maintaining your mental and physical health. Use the Oura App to track the quantity and quality of your night's rest, take note of your high points, and identify areas that might need your attention.
What Are Sleep Stages?
Sleep stage data measured by Oura are available in the Sleep tab of the Oura App, and are displayed in color-coded sleep stage graphs called "hypnograms."
The Oura Ring measures four separate stages of sleep:
- Awake: the time you spent in bed before and after falling asleep. This also includes brief awakenings that occur during sleep
- REM: rapid-eye-movement (REM) sleep involves increased brain activity and is often associated with vivid dreaming
- Light: light sleep guides you into deeper stages, and acts as the beginning of or transition between each sleep cycle
- Deep: also known as slow-wave sleep, deep sleep is when your body repairs and restores itself
Every individual's sleep requirements are different, though the recommended amount is 7-9 hours for most adults. This is enough time for your body to go through four to five 90-minute sleep cycles. In general, you spend most of the night in light sleep.
You can find more information on our blog: What Are the 4 Stages of Sleep?
How Sleep Stages Are Measured
Oura uses data from many of your biosignals — including movement, skin temperature, resting heart rate, heart rate variability (HRV), and respiratory rate — to determine which sleep stage your body is in. Here are some of the indicators that Oura looks for at each stage:
- Respiratory rate slows
- Heart rate decreases
- Body temperature drops
- Low movement
- Heart rate and respiration stabilize
- Skin temperature is at its highest
- Respiratory rate increases
- Heart rate increases
Learn more about Oura's sleep measurement on our blog: How Does the Oura Ring Track My Sleep?
Oura's Sleep Staging Algorithm
In May 2023, Oura began rolling out a new sleep staging algorithm for the Oura Ring Gen3. This new algorithm was developed to take advantage of the Gen3 ring's extra sensors and increased memory capacity in order to provide even more refined sleep stage detection.
Using one of the largest sleep datasets-to-date, collected over hundreds of participants across three different continents, Oura's new sleep staging algorithm achieves 79% agreement with polysomnography (PSG) sleep lab tests.
The increased accuracy of the new sleep staging algorithm does not mean that the data from the previous algorithm was incorrect. Independent validation studies have demonstrated that Oura's previous sleep staging algorithm still performed similarly to —or better than — most other consumer wearables.
Find more information about these validation studies and the accuracy of our sleep algorithms on our blog: Oura’s New Sleep Staging Algorithm: More Accurate Than Ever Before
Gen2 rings will continue to use the previous sleep staging algorithm and will not have any data changes. Both algorithms uphold high accuracy standards that Oura has set for itself and continue to provide a comprehensive view of trends in your sleep over time. The new algorithm will not have any impact on any of your data recorded prior to the changeover.