REM stages and one REM stage. Ideally, you repeatedly cycle through each stage. Learn how long each stage lasts.

It may help the brain wake up or stay awake during tedious activities. One theory is that by moving the muscles in the face and neck, yawning stimulates the carotid arteries in the neck ...

Similarly, teenagers tend to multitask a lot of different activities before bedtime ... to stick to a routine that helps the body and brain wake up. “Do something that signals (that) it ...