Polar SleepWise™
Polar SleepWiseTM shows how your recent sleep boosts your daytime alertness level and readiness to perform. This is what we call Boost from sleep. In addition to the amount and quality of your recent sleep, we also take the effect of sleep rhythm into account by looking how well your sleep-wake rhythm aligns with your body's internal circadian rhythm.
To ensure personalized feedback, please make sure that your Preferred sleep time setting matches your real sleep need.
SleepWise is completely automatic and all you need to do is to track your sleep with Sleep Plus Stages compatible Polar watch.
Minding your sleep rhythm can help you get enough good quality sleep on regular basis, and thus greatly improve your chances of living a healthy, productive life.
SleepWise provides simple visual and numeric feedback on any changes in your sleep rhythm. This way, you can easily recognize if the changes are for better or for worse. This helps you understand how the effects of sleep accumulate in the long run. It makes the impact of sleep debt and irregular sleep-wake rhythm visible.
It helps you reach and maintain a healthy sleep rhythm so that you can face your daily challenges sharp and ready. Better alertness adds up to better readiness to perform by improving reaction time, accuracy, judgement and decision-making.
Note that you need to have at least five sleep results within the last seven days in order to see your Boost from sleep forecasts. In case you haven't worn your watch or if the sleep tracking was not successful, you can also add sleep times manually in the app to increase your sleep result count.
To see your Boost from sleep forecasts in the Polar Flow app, choose Boost from sleep from the menu or get a glance of the daily Boost from sleep forecast from the card in the Diary. Tapping the card opens the daily Boost from sleep view.
Boost from sleep view opens:
In the morning, you can see a forecast for how your sleep boost is expected to vary throughout the day, and plan alertness boosting activities accordingly (such as naps, coffee, or a walk outside).
Boost score summarizes the daily forecast into one number in order to make it easy to compare between days. Your boost score may be excellent, good, fair, or modest. Excellent boost score means that you get all the benefits of good sleep to support your day. Your boost score may be modest if you, for example, have a lot of sleep debt. You might see repeating patterns in the trend, for instance, because of weekends.
Sleep gate anticipates the time when your body is ready to fall asleep. However, your body's internal rhythm might not always align with your everyday commitments. That's why your sleep gate is not always your ideal bedtime in real life. This could be the case, for example, when you go back to work after a break – be it a longer vacation or just a weekend break.
The daily Forecast graph shows how your recent sleep is expected to boost you throughout the day.
The lighter the shade and higher the bar, the higher the boost level. It means you're likely to feel sharp and ready to perform. The darker the shade and lower the boost. It means you may feel less alert – even drowsy.
Please notice that our forecast is based on sleep only. It doesn't react to anything else you might or might not do during the day. In other words, the graph won't react to the cups of coffee you might consume or the cold showers or brisk walks you might take. Inner motivation also plays a role in how sharp you feel. No matter how high your sleep-based boost level, you're likely to start feeling drowsy during the course of a very boring lecture. On the other hand, you might feel quite sharp even after a bad night's sleep, if you have a truly interesting task at hand. By following the daily forecast, you'll learn that your boost level tends to dip in the afternoon for some time and then go up again. There's no reason to worry about this afternoon slump though. It's regulated by your internal rhythm and is natural to all human beings. By studying the course of your past forecasts, you can learn how today's boost levels are not only affected by last night's sleep but also your recent sleep history. Staying up late on weekends, for example, can affect several days.
In the Weekly sleep view you can compare and analyze your Sleep details from different nights. Tap the calendar icon to access it.
Boost from sleep graph shows how your sleep has affected your days lately. Based on this, you can consider making changes to your sleep schedule.
Sleep & Internal rhythm graph shows how much your actual sleep rhythm deviates from your body's internal circadian rhythm.
Syncing these two rhythms – actual and internal – has many health benefits. Sticking to regular bedtimes and wake-up times can help you sync them. You can see how your behavior affects your internal rhythm. For example, staying up late on weekends or traveling over time zones may upset the sync of your rhythms.
Sleep gate anticipates the time when your body is ready to fall asleep. However, your body's internal rhythm might not always align with your everyday commitments. That's why your sleep gate is not always your ideal bedtime in real life.
Sleep gate recognizability
Your sleep gate may be clearly recognizable from your data, or not. Irregular sleep rhythm or unusual sleeping hours can mess your internal rhythm and make sleep gate less prominent. You can expect your sleep gate to be clearly recognizable (3/3), if your sleep rhythm is regular. In case your sleep rhythm changes drastically, your sleep gate is difficult to recognize (1/3).
Your body's internal rhythm means there are times when your body naturally wants to be asleep or awake. The purple lines in the graph show your sleep window – the time span when your body would've naturally wanted to be asleep. The blue bars show your actual sleep rhythm. Syncing these two rhythms – actual and internal – has many health benefits. It promotes cardiovascular and metabolic health and supports your immune system. Sticking to regular bedtimes and wake-up times can help you sync them.
Many people working office hours tend to stay up late and sleep in on weekends. This is how they end up shifting their sleep gate towards staying up late on Sunday night as well. In this very typical case of social jet lag, trouble falling asleep on Sunday night may result in starting a new working week sleep-deprived. Going by the book, the trick to avoid Sunday insomnia and sleep-deprived Mondays is to go to bed and get up at the same time every day. However, if you've ended up staying up late, you should rather compensate that with a nice early afternoon nap instead of sleeping in.
When your watch detects that you've woken up, it will show your Boost from sleep forecasts on the Boost from sleep view. Navigate to the Boost from sleep view by swiping left or right from the watch face.
You can also stop the sleep tracking manually if you watch has not yet summarized your sleep. Zzz is shown on the Boost from sleep view when your watch has detected a minimum of four hours of sleep. Already awake? appears if you tap the display. Confirm by tapping 
and the watch summarizes your sleep instantly.
The information displayed on the Boost from sleep view includes:
- Boost from sleep graph shows how your recent sleep is expected to boost you throughout the day. The lighter the shade and higher the bar, the higher the boost level. Tap the display to see more details.
- Boost score summarizes the daily forecast into one number in order to make it easy to compare between days. Your boost score may be excellent, good, fair, or modest. Excellent boost score means that you get all the benefits of good sleep to support your day. Your boost score may be modest if you, for example, have a lot of sleep debt. You might see repeating patterns in the boost score trend, for instance, because of weekends.
- Sleep time tells you the total duration between when you fell asleep and when you woke up.
- Sleep score (1-100): A score that summarizes your sleep time and sleep quality into a single number.
- Sleep gate anticipates the time when your body is ready to fall asleep. However, your body's internal rhythm might not always align with your everyday commitments. That's why your sleep gate is not always your ideal bedtime in real life.
- Sleep gate recognizability (1/3, 2/3 or 3/3): You can expect your sleep gate to be clearly recognizable (3/3), if your sleep rhythm is regular. In case your sleep rhythm changes drastically, your sleep gate is difficult to recognize (1/3).
Humans are hardwired for sleeping at night when it is dark and being active and alert during the day when the sun is shining. Sleep is regulated by two systems: circadian system and homeostatic system. The circadian system generates your body’s internal circadian rhythm that is roughly but not exactly 24 hours. External cues such as light, physical activity, and mealtimes help keep the body’s internal circadian rhythm set to a 24-hour cycle. The homeostatic system balances a time spent awake and a need for sleep. The homeostatic sleep pressure builds up during awake and dissipates during sleep. The amount of sleep you need to remove sleep pressure depends on your personal sleep need. The interaction of the homeostatic and the circadian systems contribute to the timing, amount, and quality of your sleep and to your alertness levels during waking hours.
Polar biomathematical model
Polar SleepWise feature utilizes biomathematical modeling for predicting daytime alertness based on how one has slept recently. Our biomathematical model evaluates your sleep amount, quality, and timing against your personal sleep need and your body’s internal circadian rhythm. Your internal rhythm is defined using your sleep timing. It takes from 1 to 2 weeks for SleepWise to collect enough data to reach full reliability.
Scientific proof
Polar SleepWise feature is built on a solid foundation. Biomathematical modeling is a generally accepted means to predict how different sleep schedules impact on alertness during waking hours. Our model is based on the elements presented by several biomathematical models that have been validated and applied also in real-life settings. The outputs of the models have typically been validated against a simple reaction time task. Results from such a task are known to correlate with maintaining attention, problem solving, and decision making.