Sleep is a necessary process of nearly all life on earth. As night follows day, sleep is initiated, a fundamental part of our circadian rhythm. This rhythm describes the pattern of which our bodies cycle between alertness and sleepiness. This is sometimes referred to as our 'body clock'.
We spend around 1/3 of our lives sleeping, a subsequent indication of its importance. It is advised that adults get between 7-9 hours of sleep per night, including multiple stints of deep and REM sleep.
A common misconception of sleep is that it is a complete body switch off, a time when not much happens other than maybe a few dreams. Sleep is actually the time when the mind and the body are working their hardest, carrying out processes essential to health, such as cell regeneration, hormone production and the formation of memories.
What is the most important stage of sleep?
Unknown to most, the time between falling asleep and waking up is not comprised of a single stretch of time in the exact same state. There are actually multiple stages of sleep, each with their own purpose and characteristics.
The 5 stages of sleep.
The first and shortest stage of sleep lasts only the duration of around the first 5-10 minutes. This stage is referred to as light sleep. When starting to drift off into light sleep, a slowing down of the mind and body is initiated. This triggers the body into winding down and gearing up for a busy night of rest ahead.
It is relatively easy to wake up from light sleep, as you are somewhat drifting in and out of both states. Movement and sound in close proximity will most likely wake you up.
The second stage of sleep is still referred to as light sleep. Muscle activity, eye movement and brain waves decrease as the body starts to prepare for deep sleep.
Stage 2 of light sleep is observed as the bridge or transitional stage between a semi-conscious state and being properly asleep.
In stage 2 light sleep, sudden spikes in brain waves occur, called spindles. This sudden increases in brain activity is the consolidation of memories and the processing of information from the previous day. Because of this, stage 2 sleep is incredibly important for memory formation and character development.
Stages 3 and 4.
Known as slow-wave sleep, stages 3 and 4 are the stages in which the body becomes fully relaxed, experiencing a significant decrease in breathing, heart rate, and body temperature.
In both stages (3 ; 4), the body produces hormones responsible for growth and development, as well as regulating the functionality of the immune system, and development/repairs of muscle tissue using recently metabolised amino acids.
Stages 3 and 4 are often categorised together because they share such similar characteristics, but it should be noted that stage 4 is a 'deeper' state of sleep where more activity and functional processes take place, with more efficiency.
What is REM sleep?
The fifth and final stage of sleep.
Whilst stages 3, 4 and 5 are all stages of deep sleep, 3 and 4 are geared more towards the healing, recovery and development of the body. Whereas stage 5 is more focused on the mind.
Stage 5 is known as the REM stage of sleep and demonstrates multiple neurological and physiological responses that are very much similar to that of being awake.
REM stands for Rapid Eye Movement and describes what is going on behind closed eyes. When in REM sleep, the eyes move very quickly back and forth, in an almost twitch like erratic fashion.
During REM sleep heart rate, blood pressure and body temperature return back to normal levels, breathing however can become more frequent and shallow. Despite this, the body puts itself is put into a temporary state of paralysis to stop you from performing involuntary movements from dreams. Demonstrations of sleep talking and sleepwalking happen exclusively in stage 5 sleep.
The processing, consolidating and storing of information into the long term memory are carried out when in REM sleep, as such REM sleep is absolutely essential for the brain's ability to learn and why this stage of sleep is so vital to our well-being.
REM vs Non-REM sleep.
Stages 1 through to 4 are all examples of non-REM sleep. Non-REM sleep is no less important for you than REM sleep, but the processes that happen during these stages are different.
Getting adequate amounts of both REM and non REM sleep are essential for a good nights rest and overall well-being.
In REM sleep, there is more focus on processes in the brain and in non-REM sleep, there is more attention on processes in and around the body.
The importance of deep sleep.
Deep sleep, stages 3 to 5 are the most important stages for brain health and functionality, during this time the brain can also detox and recover, replenishing energy in the form of glucose.
Deep sleep plays an essential role in overall well being, and without it, the body would no longer be able to produce balanced hormones, form memories or repair damaged tissues, amongst many other things.
For these important processes to take place, it is necessary for an individual to get enough hours sleep total, in order to facilitate enough time for deep sleep. 7-9 hours is the recommended amount for the average adult, and should offer plenty of time for the body to carry out the numerous stages of deep sleep.
Benefits of deep sleep:
- Efficient regeneration of energy stores.
- Healthy cell regeneration.
- Boosting muscle blood supply.
- Promotion of the growth and rehabilitation of tissues and bones.
- Improved immune system resilience.
- Balanced hormone production.
- Accurate memory formation.
- Brain detoxification and replenishment.
Habits to promote a better nights sleep.
- Avoid bright lights - Reducing screen time, and avoiding brightly lit areas when getting closer to bet time is a great way to get your body into sleep mode. Our eyes communicate with our body clock, so when we're seeing lots of light, we are almost tricking our body into thinking its daytime.
- Keep a dark room- Closely connected to the previous point, sleeping in darkness will help trigger the bodies auto-response of sleepiness when it experiences darkness. If you are uncomfortable sleeping in complete darkness, try a very softly lit night light. Lights with a red hue are thought to help with relaxation.
- Restrict caffeine- Drinking too much caffeine throughout the day, or too late in the evening can make it very difficult to get to sleep, and maintain an uninterrupted sleep. Caffeine is a stimulant that increases levels of adrenaline and raises blood pressure that keeps you alert. If you enjoy hot drinks later in the day opt for decaffeinated alternatives such as calming camomile tea, or warm malted milk.
- Avoid eating late- Having a bloated stomach full of food waiting to be digested, is a sure-fire way to keep you up at night. Avoid eating large meals at least 3 hours before you intend on going to sleep. Laying down with a full stomach can lead to indigestion and heartburn.
- Reduce stress- Stress has many effects on both the mind and body, one of which being falling and staying asleep. Racing thoughts and mental stress can leave you feeling fatigued, but still unable to sleep. To reduce stress try mindful practices such as meditation and yoga. Another good tip is to focus on your bedroom being a stress-free zone. By associating your bedroom with positive thoughts and calmness, a designated place where you can get away from the stresses of life will help to set the tone. Making it easier for you to unwind, switch off and get a proper nights rest.
- Figure out a sleep routine- Naturally, humans are creatures of routine. As a whole, we find comfort in the familiar and build daily routines sometimes without even realising. Brushing your teeth, going to work and eating periodically timed meals are all everyday examples. Applying a routine to your sleep can help massively in ensuring a good nights rest.
It is good practice to work backwards when figuring out your sleep routine. First, establish when you need to wake up, then minus your recommended 7-9 hours. From here you can establish what time you need to be fully asleep.
Approximately an hour before you plan to be asleep, your routine can start. Have a hot bath or shower, put on some comfortable sleepwear, and enjoy your favourite decaffeinated hot beverage. Followed by 20-30 minutes reading or mindfulness practice. After this turn down the lights and any noise distraction, TV off, phone on silent etc. You are now ready for sleep.
Over a short period of time, your body will associate this routine with sleep and as a result will allow you to become far more relaxed in the process, making it easier to fall asleep.
Sleep is a natural part of life that most take for granted. Sleep is an essential aspect of maintaining a healthy lifestyle and without it, your body will be unable to function to its full potential, eventually falling into a state of sleep deprivation. Deprivation from good quality sleep leads to a host of negative symptoms and side effects which are detrimental to overall well-being.
By getting enough uninterrupted quality sleep you are giving your body all the tools it needs in order to go through all the sleep stages, including REM sleep.
Eating a nutritionally dense and well-balanced diet, along with a considered exercise program will also aid in getting a proper nights sleep, essential for maintaining a healthy body and mind.