It has been found that planning your sleep in 90 minute increments will help you get a superior night sleep. You may know that when you sleep, your body goes through five distinct stages of sleep. These stages last a total of about 90 to 100 minutes, they will then repeat continuously until you wake.



Stage One

This stage is where you transition into wakefulness and sleep. Some people consider that this stage only happens once, but it will happen every time that your body enters a state of wakefulness, even if you are not aware that you are awake and including when waking in the morning. This stage lasts for about five minutes before you move onto stage two. People, who suffer from stress or apnea, may continue in this stage for a longer period. The brain waves during this stage are predominantly Theta waves but some Alpha waves also occur. Your eyes may begin to roll slowly during this stage of sleep.

Stage Two

In Stage two sleep peaks of your brain waves become higher these are called sleep spindles. The spindles can be followed by k-complexes (where the peaks suddenly descend and then pick back up). Theta waves can also be found in this stage. Stage two is a period of light sleep and initially only lasts a few minutes. Gradually though, stage two sleep increases to take most the sleep cycle. During this stage your heart rate will impede and your body temperature will decrease as your body prepares to enter a deep sleep.

Stages Three and Four

These two stages make up your Delta sleep and occur when you are at the deepest sleep. These stages are longest in the initial two sleep cycles and are when your body achieves the greatest quantity of restoration. If you have not slept in a while, then this is the sleep that your body will crave. Delta waves will be most ongoing in these stages; however theta waves are also present. It is believed that Stage three is extremely short and will transition into stage four very quickly. In children, delta sleep takes up about 40% of their sleep time and it will be very burdensome to wake them from this stage.

Stage four will then move to stage three and then to stage two before moving onto the next stage.

Stage Five

During this stage your brain becomes very active. Your eyes begin to move rapidly from side to side, your heart rate and respiration speed up, and your muscles (face, fingers, and legs) may twitch. Groups of voluntary muscles may also become paralyzed during this stage and due to increased brain activity, you may begin to hallucinate, or dream. The basic period of this stage five can last ten minutes but this can gradually swell. Beta waves, which are in excessive occurrences while awake, are most universal here during the sleep cycle. After Stage five the body will usually move on to stage two.

Sleep specialists have named the first four stages as Non-REM or NREM and the last stage as REM. REM stands for Rapid Eye Movement and is named due to the increased eye movement during stage five. Your sleep cycle is variable and can be affected by stress levels or certain medication you may take. If you are not consistent with when you go to sleep and how long you sleep, your body might vary the cycles during sleep or even the length of certain stages. It is very important to stick to a schedule, such as going to sleep at midnight and always waking up at 6AM. This is about four sleep cycles and should be enough sleep for your body.

If you have sustained some type of injury or think you may be coming down with a sickness, you may require greater sleep, but always make sure to try wake up during stage two sleep. If you wake during any other stage, especially delta sleep, you will most probably feel as though you have not slept at all.