Troubleshooting Polar Sleep Plus Stages™
The sleep tracking in your Polar watch is fully automatic. The Sleep Plus Stages measurement is based on recording the movements of your non-dominant hand with a built-in 3D acceleration sensor and recording your heart’s beat-to-beat interval data from your wrist with an optical heart rate sensor. Continuous heart rate tracking needs to be enabled for Sleep Plus Stages to function.
Although we, and others, have found the Sleep Plus Stages algorithm pretty accurate, it's important to acknowledge the challenges of the automatic sleep detection technology. It’s possible that your watch will not be able to properly recognize your sleep every night, or that the detected times you've fallen asleep or woken up sometimes differ from your perceived sleep times. Within this document, we’ll explain why this can happen and what the challenges of automatic sleep detection are.
The Polar Sleep Plus Stages feature has been developed for tracking healthy sleep. The metrics measured can help you better understand your sleep habits, and through that, find ways to optimize your sleep. The feature is not intended for use in the diagnosis or treatment of sleep disorders or other related conditions.
Sleep Plus Stages metrics are missing for some nights
If your Sleep Plus Stages metrics are missing it means that the Sleep Plus Stages calculation has failed. This can be due to one or more of the following reasons:
- Continuous heart rate tracking needs to be enabled for Sleep Plus Stages to function. To enable Continuous HR tracking go to Settings > General Settings > Continuous HR tracking and select On or Night-time only.
- Make sure that you wear your watch correctly. Tighten the wristband firmly around your wrist. The sensor on the back of the watch must be in constant touch with your skin. For more detailed wearing instructions, see The what and how of Polar's wrist-based heart rate measurement.
- You slept less than 4 hours. Your sleep time, in other words the duration between when you fell asleep and woke up must be at least 4 hours to get Sleep Plus Stages metrics.
- Your watch detected less than 4 hours of sleep, even though you actually slept longer than that. The automatic sleep detection may be challenging on nights when you are very restless and move a lot during your sleep, and therefore the data may be less accurate. The Sleep Plus Stages calculation may fail, for example, if the detected time you’ve fallen asleep is later than the actual time and/or the detected time you’ve woken up is earlier than the actual time, and as a result, the length of sleep detected may be insufficient for Sleep Plus Stages calculation.
- Automatic sleep detection is based on the fact that there is at least some movement during sleep, and as mentioned earlier, the sleep detection in your watch is based on recording the movements of your hand. If you are very still for long periods of time, it may be challenging for your device to ascertain that it is being worn. This might lead to inaccurate and insufficient sleep data in certain cases.
- Taking the device off immediately after waking up, or putting it on only for bed may confuse the Sleep Plus Stages calculation.
If the Continuous heart rate tracking is not enabled on your watch, you won't get the full sleep feedback. Sleep score, feedback on sleep themes (amount, solidity and regeneration) and sleep stages information can't be recorded if the Continous heart rate tracking is disabled. However, you’ll get basic sleep data that includes sleep time, interruptions, actual sleep and the continuity of your sleep.
Fell asleep / Woke up time is incorrect
If the detected time you've fallen asleep or woken up seems inaccurate, please check the following for possible reasons for inaccurate results.
- If you are very restless and move a lot during the start of your sleep, it may be challenging for your Polar watch to recognize when you fall asleep, and therefore the detected time you’ve fallen to sleep may be later than the actual time.
- If you are very restless and move a lot during the end of your sleep, your Polar watch may mistakenly detect that you’re awake when you’re actually still asleep, and therefore the detected time you’ve woken up may be earlier than the actual time.
- If you’re lying relatively motionless but not asleep for long periods of time before falling asleep or getting up in the morning (for example, while reading a book or watching TV), your Polar watch may have trouble determining whether you are awake or sleeping, and it’s possible for your Polar watch to falsely record sleep.
- If you’ve not worn the product for a while and you put it onto your wrist just before you go to bed, the device may not have enough data to ascertain that it is being worn. Try wearing your Polar watch well in advance (about an hour and a half) of going to bed.
- If you disagree with the detected times you've fallen to sleep or woken up, you can manually edit the times in the Flow app to better reflect your time asleep
My Polar device doesn’t measure my Sleep Plus Stages metrics at all
Try if resetting the device to factory settings would help. Running factory settings removes all personal data and settings from the device. You will need to set it up again for your personal use. All data that you have previously synced from your Polar device to your Flow account is safe. After reset you get sleep stages information (light sleep, deep sleep, REM sleep) and sleep score after one night, including feedback on themes (amount, solidity and regeneration). After third night, you get comparison to your usual level.
For instructions on resetting your Polar Ignite, Polar Ignite 3, Polar Grit X, Polar Grit X Pro, Polar Unite, Polar Vantage M, Polar Vantage M2, Polar Vantage V or Polar Vantage V2, follow the links below.
How do I reset the Ignite? (User manual)
How do I reset the Ignite 3? (User manual)
How do I reset Polar Unite? (User manual)