The Power of Sleep - The Four Stages of Sleep

Every human body is different, and the amount of sleep we need varies from person to person. The general guidance is 7-9 hours. Sleep is a dynamic process and healthy adults experience 3-5 sleep cycles per night. There are four sleep stages; Light, Deep, Rapid Eye Movement (REM) and Awake.  

The Four Types of Sleep

Light Sleep

This sleep is the physiological process to transition to deep sleep. It has minimal restorative impact and you can be easily awakened during it. Your body is more responsive to its environment in this stage.

Deep Sleep

This is the time when your muscles repair and grow. Your heart rate and respiratory rate decrease significantly. During this stage the body produces 95% of its daily supply of growth hormones. As an athlete, training breaks down muscle tissue so that it can rebuild and grow during deep sleep. Deep sleep also strengthens the immune system and detoxifies the brain. 

REM Sleep

This is when the brain is restored. Ideas and skills acquired during the day are converted to long-term memories. For athletes, if you have practiced a technical skill, the consolidation and retention of that learning happens during REM sleep. Unlike deep sleep, the brain is very active during REM sleep, it’s when most dreams occur. 

Awake

It’s natural to be awake for brief periods of time in the night. You can wake 10-20 times per night. They often only last a few minutes and you may not be conscious of them. You can lose upwards of an hour of sleep in the wake stage due to these disturbances.

Sleep Cycles

Sleep is entered through light sleep, transitions to deep within about 10 minutes, then to REM sleep somewhere around 90 minutes after falling asleep. When you wake, a new sleep cycle will begin. A normal night of sleep contains 3-5 of these cycles, depending on how long you are asleep for. 

Your first period of deep sleep each night generally lasts between 45-90 minutes. As the night progresses, deep sleep becomes shorter in each subsequent cycle. Your first period of REM sleep only lasts about 10 minutes, with each episode getting longer as the night progresses. The final one may last roughly an hour. 

Time in Each Stage

The amount of time a person will spend in each sleep stage varies night by night. In general, a healthy breakdown (based on 7-9 hours sleep) is:

• Light 50%
• Deep 23%
• REM 22%
• Awake 5%

When you’re sleep deprived, deep sleep becomes your body’s priority. Both deep and REM sleep decrease with age.

Tips for Sleep Hygiene

Sleep hygiene is practicing behaviours that facilitate sleep and avoiding behaviours that interfere with sleep.

• Sleep in a dark room. Light will influence the wake stages of sleep so a darker room helps you get more restorative sleep.
• Cooler room temperature helps you to fall asleep quicker (18-20 degrees celsius is recommended). 
• Maintain your bedroom as a sleep space, where possible.
• Limit screen time before bed. 
• Refrain from caffeine at least four hours before bed. 
• Plan ahead when consuming alcohol. It makes it harder for your body to move into deep sleep. 
• Consistent sleep and wake times each day.  This can improve the quality and efficiency of your sleep.

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