Natural Sleep Cycle

What is Sleep?

Sleep is one of the body`s most mysterious processes. The most significant of sleep facts which differentiates it from the waking state is the interruption of perception. A sleeping person does not see or hear. Additionally, sleep is marked by decreased movement of the skeletal muscles, slowed-down metabolism, and complex and active brain wave patterns.

There are two major types of sleep: rapid eye movement (REM) and non-REM sleep:

Rapid Eye Movement (REM) sleep. It comes and goes throughout the night, and makes up about one fifth of our sleep time. During REM sleep, our brain is very active, our muscles are very relaxed, our eyes move quickly from side to side and we dream.

Non-REM sleep. The brain is quiet, but the body may move around. Hormones are released into the bloodstream and our body repairs itself after the wear and tear of the day.

There are 4 stages of non-REM sleep:

Pre-sleep - the muscles relax, the heart beats slower and body temperature falls.
Light sleep - we can still be woken easily without feeling confused.
Slow wave sleep - our blood pressure falls, we may talk in our sleep or sleep walk.
Deep "slow wave" sleep - we become very hard to wake. If we are woken, we feel confused.

We move between REM and non-REM sleep about five times throughout the night, dreaming more as we get toward the morning. During a normal night, we will also have short periods of waking. These last 1 or 2 minutes and happen every 2 hours or so. We aren't usually aware of them. We are more likely to remember them if we feel anxious or there is something else going on - noises outside, our partner snoring.

How Much Sleep Do You Need?
The amount of sleep each person needs depends on many factors, including age. Some people find that they only need 5-6 hours of sleep, while others need 10-11 hours for optimal performance. The average adult functions best with 7-8 hours of sleep a night. However, it is important to consider how much sleep you need on an individual basis. The signs of inadequate sleep (lack of REM sleep) are low energy levels, drowsiness, irritability, and poor concentration.

Infants and Children. Infants require about 16 hours a day. From 6 months to about 3 years, childrenТs sleep requirement decreases to about 14 hours. Young children generally get their sleep from a combination of nighttime sleep and naps. Children need much more sleep than adults. Growth hormones are released during sleep, so sleep is vital to proper physical and mental development. Tired children are often cranky, fussy and become easily frustrated and difficult.
Teenagers. Teenagers need about 9 hours of sleep a night. Sleep is crucial for teenagers because it is while they are sleeping that their bodies release a hormone that is essential during their growth spurt.
Adults. For most adults, 7 to 8 hours a night appears to be the best amount of sleep, although the amount ranges from 5 hours to 10 hours of sleep each day depending on the individual.
Pregnant Women. Women in the first trimester of pregnancy, and sometimes throughout pregnancy, need significantly more sleep than usual.

Sleep is an important factor in all our lives. Sleep helps the body restore and rejuvenate in many different ways. Sleep enables the brain to encode new information and store it properly. REM sleep activates the parts of the brain that control learning. The parts of the brain that control emotions, decision-making and social interactions slow down dramatically during sleep, allowing optimal performance when awake.

Sleep enables the immune system to function effectively. Without proper sleep, the immune system becomes weak and the body becomes more vulnerable to infection (flu and cold) and disease. During sleep muscle tissue is rebuilt and restored.


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