How Much Deep Sleep Do You Need?

Sleep is by its very nature elusive, and can be a source of stress for a lot of people.

Now we all know that a bad night’s sleep can make for a tough next day...we have all been there.  But what kinds of sleep stages are there, and just how much sleep do we need in each? 

Also, not all sleep is good sleep either. Your lifestyle habits can have a huge impact on how rested you will feel, even if you don't always get as many hours of sleep as you would like.

Types Of Sleep

Sleep can be separated into two categories: REM sleep, and non-REM sleep. 

Non-REM Sleep

Non-REM sleep is also known as slow wave sleep or deep sleep, and is called as such because the brain waves are slowest during this time, as are the breathing, heart rate, and eye movements.

There are 3 stages of deep sleep:

  • The first stage is a transitionary period where the brain and body change from a state of wakefulness to one of sleep. This lasts only a few minutes, and is the period of sleep which can be most easily disturbed. The rhythm of the whole body begins to slow down, first with the body and then the brain.
  • Stage 2 of the deep sleep cycle is another period of transition. Still light in essence, the 2nd stage sees the sleeper progress from light sleep into deeper sleep. This is the longest part of the sleep cycle, where the heart and breathing slow down even more.The muscles are relaxed, the body temperature drops, and the eyes stop moving, although electrical signals to the brain are still fired sporadically in small bursts. 
  • Stage 3 is the deepest sleep, and despite the cyclical nature of the human sleep pattern, this stage of sleep is more present and lasts for longer towards the beginning of the night. During this stage the heart and breathing are at their lowest, the brain has become much slower, and the eyes and muscles are completely relaxed. Due to its nature, this stage sees the most sleep disorders (like sleepwalking), as the brain is almost completely shut down, making the sleeper difficult to wake up.

REM Sleep

REM, or rapid eye movement sleep is known as paradoxical sleep, and is the fourth stage of the sleep cycle.

It happens for the shortest amount of time during a sleep cycle, and is a strange state, responsible for high brain function and the occurrence of dreams.

As the eyes and brain move more rapidly, and brain waves begin to resemble the waking state more and more. 

Only found in mammals and birds, REM sleep is better for promoting creativity, and people who are awakened from REM sleep can often give more detailed accounts of their dreams.

REM sleep is also associated with desynchronized and fast brain waves and eye movements.

As well as loss of muscle tone and suspension of homeostasis, the balance of internal, physical, and chemical balance in the body.

How Much Deep Sleep We Need

How Much Deep Sleep We Need

Whilst all stages of the sleep cycle are important to human beings, we especially need deep sleep for improved brain health and functions.

This is the portion of sleep where the brain is least active, and so important maintenance is done during this time to make us ready for another day.

Think of the brain as an office. The busy workers are thoughts and brain waves, accomplishing multiple tasks every minute and operating to a high level of efficiency.

Sleep is when all of these workers start to go home, and deep sleep is when the office closes and the cleaning staff arrive. 

This is when the light bulbs get changed, the floors get vacuumed, and the waste paper baskets get emptied.

A lot of this maintenance goes unseen, but if it were to stop, then the office would quickly become an unpleasant place to work.


The human brain also needs this time as rest from a day of thinking. This allows us to replenish energy in the form of glucose, preparing us for another day.


Hormone balance is partially supported by good, deep sleep. The pituitary gland secretes human growth hormone during deep sleep, leading to faster tissue repair and cell regeneration. 


Deep sleep also plays an important role in the retention and storage of new memories, and poor sleep (especially deep sleep) can result in bad short term memory and an inability to properly retain information.

So, How Long?

Most experts recommend 7-9 hours of generalized sleep for a human adult.

This varies in age of course, and teenagers especially require longer periods of sleep to function at full capacity.

7-9 hours of sleep will ensure the best opportunity for several periods of deep sleep to occur, making you feel rested and ready for a new day.

Encouraging Deep Sleep

Woman exercising outdoors, exercising regularly promotes deep sleep

The main method for promoting better sleep is vigorous exercise like jogging, swimming, or cycling.

Not only is this beneficial for tiring you out and burning off energy, it also has wider benefits throughout the body, and is important for long term health.

A diet with less carbohydrates can lead to better sleep, especially if replaced with healthier fats, such as avocado, nuts, or seeds.

Spa treatments have also been seen to promote better sleep.

Anything that warms the body’s temperature really, including saunas, warm baths, or spending time in a hot tub.

Final Thoughts

If there is one thing to take away from this article, it is that sleep is not only vital, but extremely complex and interlinked with our overall bodily health. 

Not only is it important for restoring brain function, but it is when we undergo general maintenance to make us our best, bubbly, and attentive selves at the start of another long day.

If you are struggling with sleep, or are having some problems establishing a pattern.

Then try some of the sleep encouraging methods described above, and most importantly try to establish a bedtime routine.

Your brain and body will certainly thank you later.