Fitbit Blog – 11.8.22
Sleep is a beautiful thing. From the moment your eyes roll back at night to the very second you wake up in the morning, your brain goes through different stages of sleep that are pivotal to your health. While each stage of sleep is essential, the king is REM sleep. REM stands for rapid eye movement; as the name states, your eyes move rapidly, back and forth under your lids.
Source: Why REM Sleep is Critical to Your Emotional Health – Fitbit Blog