AP PSYCHOLOGY

Detailed explanation-1: -Each sleep cycle consists of four stages, with each having varying effects on the body. On average, adults go through 4–6 sleep cycles per night and spend 90 minutes in each sleep cycle stage.

Detailed explanation-2: -“There’s an idea that everyone sleeps in 90-minute cycles but that’s an average, not a rule, ” says Winter. “That means your REM cycle might be longer or shorter than 90 minutes. So you shouldn’t feel like you’ll wake up feeling more restored if you wake up five minutes later or earlier.” Phew.

Detailed explanation-3: -So, the 90 minute sleep cycle refers to the time it takes for our body to complete one cycle of sleep, made up of the different stages of sleep including NREM, NREM2, and NREM3. When we hit the hay each night, our bodies go through the various light/deep/REM sleep states in a fairly consistent 90-minute cycle.