PSYCHOLOGY OF EMOTIONS

Detailed explanation-1: -The sleep cycle: A sleep cycle lasts about 90 minutes, and during that time we move through five stages of sleep. The first four stages make up our non-rapid eye movement (NREM) sleep, and the fifth stage is when rapid eye movement (REM) sleep occurs.

Detailed explanation-2: -In a typical night, a person goes through four to six sleep cycles. View Source . Not all sleep cycles are the same length, but on average they last about 90 minutes each.

Detailed explanation-3: -Each cycle lasts 90 minutes on average, and the recommended sleep time for adults is 7-8 hours. You can fit five complete 90-minute cycles during that time. If you sleep more or less, you risk interrupting these cycles and not resting well enough.

Detailed explanation-4: -Sleep cycles across the night are only approximately 90 minutes in length. There are lots of individual differences in cycle length and the variation may be from around 60 to 110 minutes.