What Are Sleep Cycles

Have you wondered why some nights are full of dreams and others are not? Or have you ever thought about whether your brain is resting while you are asleep? The brain waves are made up of several sensor waves alpha, beta, gamma and theta. Some of your questions may be answered if you understand the stages of sleep. Sleep has a cycle of different stages. A normal adult requires 6-8 hours of uninterrupted sleep to carry out a normal routine the next day. The duration varies with age.

Stage 1

The beginning stage of sleep is when we just drifting off and experience something similar to day dreaming is when we go through alpha waves and theta waves. These waves vary with people. Some may experience more of these than others, i.e., a state in which some people may experience even through the entire day. People who engage in deep prayers or meditation often experience the resting phase, Alpha. During this phase, people often feel like they are free-falling after which sudden contractions of muscles can be felt. You may also hear noises like the phone or alarm ringing. These are called hypnogogic hallucinations. Following this, we enter the Theta phase which lasts for 5-10 minutes and is a thin line between being asleep and awake. Research shows that it takes 7 minutes for a normal sleeper to fall asleep. This may vary with person.

Stage 2

This is the stage when the brain starts sending short rhythmic, rapid signals called the Sleep Spindles to help the mind and body disconnect from its surroundings. The body temperature and heartbeat rate begin to reduce and this period lasts for around 20 minutes.

Stage 3

This is the intermediate phase amidst light sleep and deep sleep where the brain begins to send Delta waves through the body.

Stage 4

This is known as the Delta Sleep since these Delta waves are fully flourished during this stage. This is the phase where body energy is replenished, stress is reduced, muscles are relaxed, hormones are released and tissue repair and growth occurs. This stage lasts for about 30 minutes. Sleep-walking & bed-wetting occur during this stage of sleep.

Stage 5: REM (Rapid Eye Movement)

This stage is commonly called Paradoxical sleep or REM sleep with reference to the fact that this is the deepest stage of sleep where the brain and body systems increase their activity and the voluntary muscles like the legs, arms, etc. begin to relax or paralyze. This is the phase where the dream actually occurs. This state of paralysation occurs to protect you against involuntarily injuring yourself while you are in your dream which is why you actually can’t run or escape in your dream even if you really wanted to. At this stage your body gets as much deep sleep as possible and this generally occurs 90 minutes after falling asleep.

Cycles

The stages of sleep do not generally proceed through all sequences in order. We start with stage 1 and advance to the next three stages, after which stages 3 and 2 are repeated followed by REM sleep. When the first REM is complete, stage 2 reoccurs and the cycle continues. We go through 4-5 REM sleeps in one night. However, the length of each REM cycle increases as we proceed when compared to the previous. If you are thinking, your dream is taking time. Well then, it is!