Lights Out

Understanding Sleep Cycles for a Better Nights Sleep

Our Snooze Sleep Consultants believe that understanding sleep stages and cycles can help you to have a better night’s sleep, as it will help you in becoming aware of your body’s rejuvenation process, and how important it is to your general wellbeing.

Sleep is regulated by your internal body clock via cues such as daylight and time of day which indicate when we should be asleep and awake.

Sleep cycles occur and repeat at 90 to 110 minute intervals during the night, as you move between two types of sleep – REM and non-REM (which is divided into four stages).

Non-REM sleep

Stage one: Light sleep

Stage one sleep lasts around 5-10 minutes.  It is the transition between being awake and asleep, and the sleeper can be easily awoken.  Muscle activity slows and most awareness of the surrounding environment is lost.

Stage two: True sleep

Stage two sleep lasts around 20 minutes.  Breathing and heart rates start to slow down and body temperature decreases. All awareness of the environment is lost.  This period accounts for the largest part of human sleep.

Stages three and four: Deep sleep

Stages three and four are where the deepest and most restorative sleep is experienced.

Blood pressure and body temperature continue to decrease, breathing slows, energy is regained and hormones are released for growth and development.

The brain begins to produce delta waves, which are large (high amplitude) and slow (low frequency).  If the sleeper is awakened during deep sleep they may feel groggy and take several minutes to adjust. 

REM sleep

The first rapid eye movement (REM) period generally begins about 70 to 90 minutes after falling asleep.

During REM, the brain is active – more so than during waking hours, dreams occur and the sleeper’s eyes dart back and forth.  Breathing rate and blood pressure increase, but muscles are relaxed.

REM sleep is essential as it provides energy to the brain and body for the day and may contribute to memory consolidation.

After REM sleep, the cycle begins again. The sleeper experiences around three to five REM episodes a night.