Even though you are at rest, not every part of your body is resting and quiet. In particular, the brain is a busy little beaver sitting out all sorts of signals, which are helping to control the stages of sleep through which you are passing. Muscle activity and rapid eye movements change throughout the various stages of sleep as well.



Currently there are five different stages of sleep which have been identified by researchers throughout the years. And on a good night of sleep you will travel through each and every one of the five stages of sleep. In fact you will pass through them several times during the night. While there are five distinct stages of sleep, the first four stages of sleep are logged to gather and are known as the State non--rapid eye movement or NREM. The fifth and final stage of sleep is the stage known as rapid eye movement or REM sleep.

The various states of NREM and REM are distinguished by the changes in the brain wave activity that takes place during sleep. REM sleep is also characterized by irregular but rapid breathing and heartbeat, an increase in blood pressure, an increase in brain activity and essentially absent muscle activity.

NREM and REM sleep take place throughout the time you are asleep. Typically during the time that you are sleeping during the first one third of the night will consist of NREM sleep, while the sleep you enjoyed during the last one third of the night is typically REM sleep. It is from this stage of sleep from which you generally awake.

During the stages of sleep the first stage of sleep is known as a transitional period. During this time you can be quite easily awakened and will experience the repeating cycle of falling asleep and waking up several times. It is during this first stage of sleep that you began to feel more sleepy and begin to lose control over your body's muscles. It is also during this time that your eye movements begin to slow. Some people even experience a sudden jerking of the muscles during this stage of sleep.

The stage of sleep that takes up the majority of the night is known as stage two. It is during stage two that your eyes stop moving, your heart rate slows, your body temperature lowers and your brain waves slow. There may also be short bursts of eye movement during stage two as well.

Once the body reaches a deep sleep this is known as stages three and four. During these two stages of sleep the brain waves are extremely slow. During this stage the muscles and eyes are also completely still.

Always following a period of NREM sleep, the REM stage takes place throughout the sleep period and makes up approximately a quarter of the total sleep period. The first REM occurs at the end of Stage 1 and lasts about 10 minutes and the final REM stage lasts around 60 minutes. So ff you sleep for 8 or 9 hours, then you will generally experience REM sleep 4 or 5 times.

Repeating throughout the sleep period, numerous sleep cycles take place during a single sleep episode. So as you continue to progress through the sleep cycles during a sleep period, the amount of your REM sleep naturally increases.

The important thing to remember is that your body requires uninterrupted movement through the sleep cycles in order to achieve the best-quality sleep that your body needs. So know that you understand the sleep cycles, you can determine what works best for you to get your best night of sleep.