Ōura Ring

A ring that measures sleep, activity and readiness

By Irene van den Broek in Sleep Activity

September 26, 2021

What is the Ōura Ring?

A pretty piece of jewelry on the outside with a variety of sensors hidden on the inside! The Ōura Ring is a Sleep and Activity tracker that measures heart and breathing rate, skin temperature, and motion. Without any effort, and with very little non-wear time, I have already collected a wealth of data over 928 days. Here, you can read all about my experiences collecting, analyzing and visualizing my Ōura Ring data!

How to get your data?

All daily activity and nightly sleep data are stored on your (free) Ōura cloud account. Both the Ōura cloud platform and the Ōura app have some nice features to view daily, weekly or monthly trends in your data. However, if you (like me 😄) want to analyze and visualize your own data, you can get the data in your own hands by either:

  1. Export your data as a.csv or .json file from the Oura cloud account; or
  2. Connect through Ōura cloud API using a personal access token.

The available data from the Ōura Ring is summarized below. A detailed description of all measured parameters can also be found in the Ōura Ring API documentation.

Sleep and Activity Data

In the below panels you see an overview of all numeric data values measured with the Ōura Ring during sleep (Fig. 1) or daily activity (Fig. 2).

Sleep

Distribution of daily sleep metrics measured wih the Ōura Ring, including the durations of various sleep phases (Rem, Deep and Light), the total sleep time (Total), the time in bed (Duration), the time awake (Awake), the time to fall asleep (Onset Latency), as well as the percentage of time asleep (Effciency) and the percentag of time that motion is detected (Restless). In addition, the average breathing rate (Breath Average), the average and lowest heart rate (Hr Average and Hr Lowest), the average heart rate variability (Rmssd) and the average skin temperature deviation (Temperature Deviation) are provided.

Figure 1: Distribution of daily sleep metrics measured wih the Ōura Ring, including the durations of various sleep phases (Rem, Deep and Light), the total sleep time (Total), the time in bed (Duration), the time awake (Awake), the time to fall asleep (Onset Latency), as well as the percentage of time asleep (Effciency) and the percentag of time that motion is detected (Restless). In addition, the average breathing rate (Breath Average), the average and lowest heart rate (Hr Average and Hr Lowest), the average heart rate variability (Rmssd) and the average skin temperature deviation (Temperature Deviation) are provided.

Activity

Distribution of all daily activity metrics measured wih the Ōura Ring, including active and total calories (Cal Active and Cal Total), step count (Steps), distance moved equivalent (Daily Movement), the duration of Non Wear, Rest and Inactive time as well as active time (Total) with Low, Medium, or High intensity, and the metabilic equivelent minutes as daily average (Average Met) or as total during Inactive time or time with Low, Medium or High intensity activity.

Figure 2: Distribution of all daily activity metrics measured wih the Ōura Ring, including active and total calories (Cal Active and Cal Total), step count (Steps), distance moved equivalent (Daily Movement), the duration of Non Wear, Rest and Inactive time as well as active time (Total) with Low, Medium, or High intensity, and the metabilic equivelent minutes as daily average (Average Met) or as total during Inactive time or time with Low, Medium or High intensity activity.

Sleep, Activity and Readiness Scores

Based on the Sleep and Activity metrics, the Ōura Ring calculates a daily Sleep, Activity and Readiness score. In Figure 3, you see the distribution of my scores over 928 days, whereas the panels underneath show the distribution in the individual scores used to calculate the total scores.

Distribution of daily Sleep, Activity and Readiness Scores measured wih the Ōura Ring.

Figure 3: Distribution of daily Sleep, Activity and Readiness Scores measured wih the Ōura Ring.

Sleep

The daily Sleep Score is based on the individual scores for the total amount of sleep (Total), the amount of REM and Deep sleep, the percentage sleep from the time in bed Efficiency, the time it takes to fall asleep (Latency), the amount of restlessness (Disturbances) and the sleep timing (Alignment).

Figure 4: The daily Sleep Score is based on the individual scores for the total amount of sleep (Total), the amount of REM and Deep sleep, the percentage sleep from the time in bed Efficiency, the time it takes to fall asleep (Latency), the amount of restlessness (Disturbances) and the sleep timing (Alignment).

Activity

The daily Activity Score is based on the amount of Recovery Time, the amount and regularity of physical exercise (Training Volume and Training Frequency) and the frequency of reaching the daily activity goals (Meet Daily Targets) during the last seven days. In addition , the activity scores take into account the avoidance of (long periods of) inactivity (Stay Active and Move Every Hour) during the last 24 h.

Figure 5: The daily Activity Score is based on the amount of Recovery Time, the amount and regularity of physical exercise (Training Volume and Training Frequency) and the frequency of reaching the daily activity goals (Meet Daily Targets) during the last seven days. In addition , the activity scores take into account the avoidance of (long periods of) inactivity (Stay Active and Move Every Hour) during the last 24 h.

Readiness

The daily Readiness Score is based on the activity level of the Previous Day as well as the sleep quality of the Previous Night. In addition, the readiness score takes into account the deviation of the nightly values for HRV (HRV Balance), resting heart rate (resting HR), and Skin Temperature (Temperature) compared to their normal ranges. The readiness score furthermore measures the balance between low, medium and high intensity activities (Activity Balance), the long term sleep pattern (Sleep Balance) and how long it takes for the resting heart rate to stabilize during the night (Recovery Index).

Figure 6: The daily Readiness Score is based on the activity level of the Previous Day as well as the sleep quality of the Previous Night. In addition, the readiness score takes into account the deviation of the nightly values for HRV (HRV Balance), resting heart rate (resting HR), and Skin Temperature (Temperature) compared to their normal ranges. The readiness score furthermore measures the balance between low, medium and high intensity activities (Activity Balance), the long term sleep pattern (Sleep Balance) and how long it takes for the resting heart rate to stabilize during the night (Recovery Index).

Daily Timestamps

In addition to the daily aggregates, the Ōura Ring data also consists of a few time-related values (Fig. 7).

The Ōura Ring data includes timestamps for the time at which you go to bed (Bedtime Start), the time that you get up (Bedtime End) and the time in the middle of your sleep (Midpoint),used to calculate the Alignment score for sleep timing.

Figure 7: The Ōura Ring data includes timestamps for the time at which you go to bed (Bedtime Start), the time that you get up (Bedtime End) and the time in the middle of your sleep (Midpoint),used to calculate the Alignment score for sleep timing.

Nightly Time Series

For a few metrics the Ōura Ring data provides data with higher granularity. During the night, heart rate, HRV and the sleep hypnogram are recorded in 5 minute intervals (Fig. 8 - Fig. 10).

Hypnogram

The Ōura Ring records the sleep phase classification (Awake, Deep sleep, Light sleep or REM sleep) for every 5 minutes during the entire sleep period.

Figure 8: The Ōura Ring records the sleep phase classification (Awake, Deep sleep, Light sleep or REM sleep) for every 5 minutes during the entire sleep period.

Heart Rate Variability

The Ōura Ring records the heart rate variability (HRV) as rmssd for every 5 minutes during the entire sleep period.

Figure 9: The Ōura Ring records the heart rate variability (HRV) as rmssd for every 5 minutes during the entire sleep period.

Heart Rate

The Ōura Ring records the heart rate for every 5 minutes during the entire sleep period.

Figure 10: The Ōura Ring records the heart rate for every 5 minutes during the entire sleep period.

Daily Time Series

In addition, during the entire activity period (from 4 am in the morning to 4 am the next day) the activity level classification is recorded in 5 minute intervals as well as the average MET level in 1 minute intervals (Fig. 11 - Fig. 12).

Metabolic Equivalent Minutes

The Ōura Ring records Metabolic Equivalent Minutes for every minutes during the entire day.

Figure 11: The Ōura Ring records Metabolic Equivalent Minutes for every minutes during the entire day.

Activity Level

The Ōura Ring records the Activity level (Low, medium and high intensity as well as non-wear, inactive time and rest) for every 5 minutes during the entire day.

Figure 12: The Ōura Ring records the Activity level (Low, medium and high intensity as well as non-wear, inactive time and rest) for every 5 minutes during the entire day.

Conclusion

The Ōura Ring stands out for it’s data accessibility and the ease of wearing.

Although the Ōura Ring isn’t cheap, it’s fashionable look and compact size, make the Ōura Ring easily worn day and night, collecting a wealth a data with little to no missing data points! The Ōura ring fully charges in about 1-2 hours and lasts for almost 4 days. As a sleep tracker, the Ōura Ring is great for tracking your sleep pattern and nightly body functions. However, the Ōura Ring is not very accurate in sleep staging, particularly in differentiating laying down from actual sleeping.

Ōura Ring - Pros:

  • Good data visualization options in app and cloud platform.
  • Data is fully accessible through file export or API.
  • No bluetooth connection during inactivity or sleep.
  • Can be worn day and night without noticing.
  • Little “non-wear” time due to charging.
  • Fashionable look.

Ōura Ring - Cons:

  • Not cheap (price starts at $299).
  • Not very accurate in sleep stage detection (certainly not able to differentiate laying still from actual sleeping).
  • Be careful; you don’t want to lose or damage the ring!
  • Skin temperature and breathing rate data are only available as a nightly average.
  • Meditation data is recorded but not accesible.

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