The Xiaomi Watch 2 supports sleep monitoring. When you wear the watch while sleeping, it automatically detects when you fall asleep and wake up. The watch records data on deep sleep, light sleep, rapid eye movement (REM) sleep, wakefulness, sleep oxygen levels, and sleep heart rate using its sensors. Sleep sessions lasting less than three hours are recorded as naps. However, nap records do not support detailed sleep stage analysis.
Note:
The historical sleep data is not stored on the watch. To avoid data loss, synchronize your sleep data with the Mi Fitness APP regularly. This ensures that your sleep information is preserved and accessible for future reference.