When is the best time to take nap? A sleep doctor reveals the optimal time of day to take a nap in order to feel rested and ...

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

Research suggests that going to sleep between 10pm and 11pm is associated with a lower ... there is a suggestion that the precise time when one retires for the night could carry implications ...