Your ScanWatch lets you track your sleep without requiring any action on your part. All you have to do is wear your watch to sleep: it will do the rest on its own.

If you do not want to track your sleep, remove your ScanWatch before going to sleep.

How sleep tracking works

Your watch tracks sleep by detecting wrist movement and heart rate. The presence of your heart rate is used to determine if you are wearing the watch or not. 

Below is some important info to aid in more consistent and accurate sleep tracking. 

How movement affects sleep detection

• It can take 15 to 25 minutes of little to no movement while wearing the watch before sleep is detected.
• Even though it can take a few minutes of little movement to detect sleep, once sleep is detected, the sleep tracking is retroactive. This means that if you go to sleep at 22:00, sleep won't be detected until 22:15. Once sleep is detected; however, the watch will show that the first stages of sleep began at about 22:00 to ensure that you are not missing any data.
• It can take 15 to 25 minutes after waking up and moving before the watch exits sleep mode.

How sleep tracking accuracy can be negatively impacted

In order to track sleep the watch needs to detect / confirm it is being worn, but several things can interfere with this and result in inaccurate sleep tracking:

• Wearing the watch too loose can prevent good contact between the HR sensor and the skin, and this can happen more often with metal and leather wristbands. For this reason, it is recommended to sleep with a silicone wristband supplied with your watch.
• Applying too much pressure to the watch (e.g. Under your pillow or under your head or chest)
• Skin perfusion, or how much blood is flowing through the skin, skin and blood properties, can vary among individuals and according to the environment. Any permanent or temporary changes to your skin, such as tattoos, sweat, or even hair on the wrist may affect the measurements.
• Circulatory issues can sometimes cause inaccurate measurements. 
• ScanWatch can sometimes interpret a rest phase as a sleep phase because the watch is almost motionless. Reading a book, for example, comes very close to the watch's sleep detection criteria. If the sleep duration calculated by the watch is not correct, you can edit your sleep data in the Withings App.

Viewing your Sleep Data

The Withings App keeps your entire history, allowing you to easily track how your sleep data evolves over time.

You can view the sleep data collected by your ScanWatch on the Home screen or in the Measure tab in the Withings App.

• Grey or gap: time spent awake
• Medium blue: duration of light sleep
• Dark blue: duration of deep or REM sleep

Tracking Naps and viewing Nap data

Naps are typically periods of time from 10 minutes to a maximum of 2:59 hours.* 

Naps do not appear in the broader sleep data graph. In order to view your naps, follow these steps:

1. Tap on the Sleep Quality card from either the Home or Measure tab.
2. Scroll down to the bottom of the Sleep Quality section under 'More' to find the time and duration of your naps. 
   
   
3. Tap the desired Nap to see a detailed sleep data graph of the nap period, which includes total duration, time in bed, and your heart rate during the nap. 

* Any nap period recorded on a date in which there hasn't been sleep data already collected will be considered sleep data and not nap data. The data can be viewed in the broader sleep data graph at the top of the Sleep Quality section.