Sleep Cycles: One rapid eye movement (REM) stage and three non-REM stages that altogether last about 90 to 120 minutes Benefits: Physical and mental recuperation and memory consolidation Disorders: ...

The internet claims waking at the end of a sleep cycle will leave you refreshed, but experts aren’t convinced. By Clarissa Brincat Published Sep 9, 2025 9:00 AM EDT Image: DepositPhotos Get the ...

Sleeping for 7 to 9 hours at night isn't the only way to catch some z's. Here are four alternative sleep cycles -- and they're pretty obscure. Annie Miller Medical Reviewer Annie Miller is a licensed ...

Ever wonder why some mornings you wake up ready to go, and others you feel like a zombie? The difference often comes down to when you wake up during your sleep cycle, and that’s exactly what a sleep ...

“Sorrow can be alleviated by good sleep, a bath, and a glass of wine.” —Thomas Aquinas Getting enough restful sleep is not a basic luxury, it is a biologic necessity. Sleep is far more than about ...

When a person is asleep, their core body temperature drops. Heart rate and breathing also slow down and overall metabolic activity decreases by about 10%. A sleeping body may seem inactive at first ...

Learn facts about sleep, during which the body rests, recuperates and performs essential repairs. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.