Because everyone sleeps differently (and in different locations: cars, planes, boats, camping, etc.), the sensitivity of the sleep analysis may need to be adjusted to better fit your sleep style.
1. From the main page, swipe right to the "Settings" page.
2. Choose a sensitivity ranging from 0-3 (default is 1). With 0 being the least sensitive to labeling your movements as sleep — great for deep sleepers, or those who get up a lot at night. And level 3 being the most sensitive to labeling your movements as sleep — great for light sleepers, or those who may toss and turn when sleeping, though still be asleep.*
3. The sensitivity selected will be used during the analysis, not during the tracking. Meaning if you feel the data synced to your phone is inaccurate, selecting another sensitivity from the watch and tapping “Sync Again” at the bottom of the "Settings" page will compute your data with the new sensitivity and replace the sleep report in the iOS app. This may be helpful for those coming from another sleep tracker wanting to match those results.* (Note this can only be done with the previous night's sleep. Once another sleep is started, the previous night's data is deleted from Apple Watch, though remains in the iOS app.)
* Sleep Pulse is meant to be used while sleeping. The sleep algorithm is relative across all its data for your sleep. The algorithm learns your motion from the start point for the rest of your night so it is tailored to you. Which is why when you start a sleep, it says "In Bed" with the time. As it assumes you are in bed, Sleep Pulse should be started in bed. *Sleep must be started when In Bed, and not before each night, Sleep Pulse's algorithm tracks only sleep and any attempt to try and "auto track" your sleep before being In Bed will provide inaccurate results of your sleep.*