Rapid Eye Movement (REM) Sleep

You probably know the feeling of waking up tired, exhausted or bad-tempered. You feel like, even though you got a fair amount of sleep, your body is not rested at all. As a result, you feel worn out throughout the day, have difficulties to concentrate and you can’t perform as well as you’d like to.

But why does this happen? And does it have something to do with the commonly appearing term of REM sleep?

In this article, we will tell you what REM sleep really is and what side effects the lack of said might cause. In addition, we will dive in briefly into the different stages of sleep and how they affect your body.

What is REM Sleep?

Rapid eye movement (REM) sleep, also referred to as paradox or desynchronised sleep is one of the 4 sleep stages.

It is characterized by a distinctive fast eye movement plus an increased blood pressure and heart beat. The brain is almost as active as it is when you are awake, which is why experts say that in this stage it is “all about the brain”.

Usually people enter the REM phase after 90 minutes of sleep (average time of an entire sleep cycle) and do this 4-5 times a night (assuming an eight hour sleep). The duration of the first REM phase is usually around ten minutes, but lasts longer from time to time.

In this stage the body recovers mentally by processing feelings and emotions which is the reason why most of the dreams happen in the REM phase. In order to prevent a so called “acting out” of your dreams, the body enters a state of active paralysation.

Importance of REM sleep

As mentioned before the REM phase is the restorative part of the sleep cycle. However, every person only spends about 20% in REM sleeping states. In a good eight hours of sleep this corresponds to only 1.5 hours.

Getting enough REM sleep is important for a refreshed awakening the next morning and the processing of emotions and feelings.

But these are not the only benefits of a healthy amount of REM sleep. By being more active in this stage our brains remove neurotoxins, which are responsible for diseases, such as Alzheimer and Parkinson. In addition, younger people might experience a stronger sexual desire while older people suffer under memory losses.

A good night sleep is therefore not only beneficial for a good mood during the day, but can even protect you from severe diseases.

Rem Phase – The 4 Stages of Sleep

Our sleep cycle lasts around 90 minutes and consists of 4 stages:

  • Drowsiness
  • Light sleep
  • Deep sleep
  • REM sleep

The first stage is a not restful state of sleep in which just the brain has begun to enter the sleep stage. The rest of the body hasn’t even noticed that you’re sleeping, so this stage isn’t much helpful in terms of recovery and processing of information. The person still maintains a sense of awareness, but already starts to recover and rest. You might experience some muscle jerks or the commonly known “falling sensation”.

This second stage is the one to which people refer to when talking about “Light sleep”. It is not by any means less important than the following stages and takes up more than half of the entire sleep cycle. In this phase the person is fully asleep and the eye movement stops, but can easily be awoken. It is important for the processing of memories & emotions and regulates the metabolism. In this stage the body does a lot of “maintenance” and slightly decreases the heart rate as well as the body temperature. In addition to that, brain waves slow down and only show occasional outbursts of fast waves, which are called sleep spindles.

The third stage is called “Deep sleep” or “slow wave sleep” (SWS), which is characterized by slow brain waves (Delta waves). This state is “all about the body”, since it is responsible for muscular recovery, recharging of energy levels and the releasing of the human growth hormone. The heartbeat, breathing and temperature drop even lower compared to the second stage, which leads to a very relaxing state for the muscles. People who are awakened during this stage might feel sluggish and often need some time to orientate and get a clear thought. In addition, most of the “accidents” of young people, such as night terrors, bedwetting or sleepwalk happen during this stage. This sleep stage is very important for the muscular recovery after very intense physical activities.

The fourth stage is the one covered in this article: The REM stage. When saying, that in the Deep sleep it is all about the body one might say that the REM stage is “all about the brain”. During this stage the body is very inactive and even enters a state of active paralysation. Meanwhile, there is a high brain activity to process feelings and emotions by dreaming.

It is still not fully explained and discovered what role each stage exactly plays, however a lack of any of those might lead to undesired side effects which can rank from minor causes up to serious diseases. Therefore, no one should ever underestimate the important of sleep and every single phase of it, in order to begin the day healthy and well rested.

How much REM Sleep do you need?

As mentioned before at least 20% of our sleep time should be spend in the REM phase. The whole sleep cycle lasts more or less 90 minutes, which means that during an eight hour sleep the body should enter 4-5 REM phases. But since this is the last stage of the sleep cycle, a sleep deprivation often goes along with a lack of REM, which can lead to severe undesired effects and the so-called “REM-rebound”.

Lack of REM sleep

Since the REM phase helps the brain to remove all the dangerous neurotoxins, which are responsible for diseases such as Alzheimer and Parkinson, a lack of REM can lead to an increase of probability of these diseases. Less dangerous side effects, are a feeling of tiredness throughout the day and an “unrefreshed” awakening, which makes it difficult to get a good start into the day.

REM behaviour disorder (RBD)

Is a parasomnia in which the body enters the REM stage but the brain fails to send signals which generate the state of paralysation, which is necessary for the REM phase. Therefore, people start to act out their dreams and show abnormal behaviour. This extends from simple twitches to more complex integrated movement. This movement can be dangerous for both the sleeping person as well as their bed partner. RBD should not be mixed-up with sleep walking, which happens during transitions in the Non-REM stages.

REM Rebound

REM rebound occurs to individuals who are sleep deprived and therefore don’t spend enough time in the so important REM phase. The body shows this lack of REM sleep, by entering the REM phase much quicker and spending more time there. The threshold to determine whether a person is experiencing a REM rebound is above 20% of REM time during an average night.

How to increase REM sleep

As you can see REM sleep is very important for your body and your mind. But what do you do once you figured out you are not getting enough of it or the quality of your REM sleep is very low.
There are lots of different ways to improve and enhance every stage of the sleep cycle, including NREM and REM sleep. These tips might help you to improve your REM sleep:

  1. Sleep enough
    This one might seem very obvious, but most of the time the reason you are not getting enough REM sleep, is simply that you don’t sleep enough. Since REM is the last stage of the sleep cycle, this one is the first you sacrifice if you don’t sleep enough. Thus, always make sure that you at least seven hours per night (7-9 hours recommended for adults) to get an healthy amount of REM sleep.
  2. Create a routine before going to bed
    Having the same bedtime routine every night helps the body and the mind to prepare for sleep. This might help you to fall asleep faster and therefore maximize the amount of sleep. In addition, we recommend avoiding any stressful activities before going to bed, since those will lift up your blood pressure and therefore make it harder to fall asleep, once you are laying in your bed. Things like reading, meditation or listening to relaxing sounds such as alpha waves or ASMR are very effective patterns to include in your bedtime routine.
  3. Don’t drink and sleep
    Lots of people have the false assumption, that they sleep better after drinking alcohol. While, they might in fact fall asleep faster, the consumption of alcohol before bedtime can reduce the number of REM sleep phases experienced per night. Thus, we advise not to drink any alcohol immediately before going to bed.
  4. Get medical help
    This should be the last option you choose in order to improve your REM sleep, but once you tried all of our tips, but neither the quality of your REM sleep nor the amount increases, you should try to seek medical help. There are lots of drugs, which can positively affect sleep quality and impact REM sleep.

We hope this article made you understand better what REM sleep really is and how crucial it is for your wellbeing. Stay tuned and check out our other articles related to the other stages of the sleep cycle. There is more to come!

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