Rem Sleep: How Much Is Enough?

Sleep is a complex and mysterious body process that is essential for the rest and repair of the body and brain. Sleep is generally divided into two stages: REM (rapid eye movement) and NREM (non-rapid eye movement). While NREM sleep is characterised by slower brain activity and a more sleep-like state, REM sleep is considered a more \wakeful\ state, with increased brain activity, heart rate, and blood pressure. REM sleep is when most dreams occur, and it plays a crucial role in memory, mental focus, and mood regulation. Understanding the importance of REM sleep can help explain why a solid night's sleep is so important for overall health and well-being.

What happens during REM sleep?

During REM sleep, the brain is highly active, with brain activity resembling that of a waking brain. This is the stage of sleep in which the most vivid dreams occur, and it is thought to be important for learning and memory. The eyes move rapidly behind closed eyelids, and the heart rate and respiratory rate increase. The muscles may twitch, but they are usually paralysed, which prevents us from acting out our dreams.

REM sleep is one of the two main types of sleep, the other being non-rapid eye movement (NREM) sleep. A typical night of sleep consists of four to five sleep cycles, each lasting between 70 and 120 minutes, and each comprising three stages of NREM sleep followed by a stage of REM sleep. The first REM stage is short, lasting about 10 minutes, but each subsequent REM stage gets longer, with the final one lasting about an hour. Overall, for healthy adults, it is recommended that REM sleep makes up 20-25% of total sleep time.

During the first stage of NREM sleep, you are in a light sleep and can be easily woken up. In the second stage, you are in a deeper sleep, and your heart rate and breathing slow down, along with your body temperature. The third stage is the deep sleep stage, during which the body repairs and regenerates tissues, builds bone and muscle, and strengthens the immune system. It is more difficult to wake someone during this stage, and if they are woken, they may experience sleep inertia, a state of confusion or mental fog that can last for about 30 minutes.

While the exact functions of REM sleep are still being studied, it is known to be important for learning and memory. Research has shown that people deprived of REM sleep have trouble recalling things they were taught before falling asleep. REM sleep is also thought to be important for emotional regulation, with some evidence suggesting that insufficient REM sleep can worsen mental health issues like anxiety and depression.

How much REM sleep do you need?

There is no official consensus on how much REM sleep a person needs. However, experts recommend that adults get at least seven hours of sleep per night, with 20-25% of that time spent in the REM stage. This equates to around 90 minutes of REM sleep for every seven to eight hours of sleep.

REM sleep, or "rapid eye movement sleep," is the fourth and final stage of the sleep cycle, during which the brain is highly active and dreams occur. It is important for memory consolidation, emotional processing, brain development, and dreaming.

The amount of REM sleep a person needs can vary depending on individual factors such as age and sleep quality. For example, newborns spend up to 50% of their sleep in the REM stage, while adults only spend about 20-25%. As people age, they tend to spend less time in REM sleep.

If you are not getting enough REM sleep, you may experience symptoms such as trouble coping with emotions, difficulty concentrating, a weakened immune system, and feeling groggy in the morning.

To increase your REM sleep, focus on improving your overall sleep habits and behaviours. This may include sticking to a consistent sleep schedule, avoiding substances like caffeine and alcohol, and creating a relaxing bedtime routine.

Why is REM sleep important?

REM sleep is important for several reasons. Firstly, it aids in memory consolidation by converting short-term memories into long-term ones. This is particularly beneficial for athletes who are learning and practising new technical skills, as a lack of REM sleep can prevent them from retaining what they have learned. Research also suggests that people deprived of REM sleep struggle to recollect things they were taught before falling asleep.

Secondly, REM sleep is important for emotional processing. During this stage, the amygdala (the part of the brain that processes emotions) is activated, and dreams may play a role in this process.

Thirdly, REM sleep is necessary for brain development, especially in newborns who spend most of their sleep time in this stage.

REM sleep may also help prepare the body for waking up. As the night progresses, we spend increasing amounts of time in REM sleep, which may be why we find it easier to wake up during this stage.

Finally, the sleep that occurs during REM is vital for the body's cellular repair and immune system strengthening.

What happens if you don't get enough REM sleep?

REM sleep is important for several mental processes, including memory and learning. Not getting enough REM sleep can have several negative consequences.

Firstly, it can lead to fatigue and irritability, and cause changes in mood, memory, and cognition. You may experience difficulty concentrating during the day and forgetfulness or poor memory. Over time, chronic sleep deprivation can lead to health conditions such as diabetes, depression, obesity, and cardiovascular disease.

Secondly, a lack of REM sleep can affect cardiovascular health and increase the risk of type 2 diabetes. It may also contribute to cancer, stroke, and neurodegenerative diseases like Alzheimer's.

Thirdly, not getting enough REM sleep can disrupt the brain's ability to generate new cells and consolidate memories. This can impair your ability to learn and recall information.

Finally, insufficient REM sleep may cause or contribute to migraines. Additionally, certain medical conditions, such as sleep apnea, can adversely affect the quality and quantity of REM sleep.

In summary, not getting enough REM sleep can have a significant impact on various aspects of your health, including your mood, memory, cardiovascular health, and overall well-being.

How to get more REM sleep

REM sleep is one of the four stages of sleep, along with light sleep, deep sleep, and wake. It is known as the "mentally restorative" stage of sleep, when the brain converts short-term memories into long-term ones. During REM sleep, the areas of the brain responsible for learning and memory are stimulated, and it is also the stage of sleep when you are most likely to dream.

Stick to a consistent sleep schedule

Going to bed and waking up at the same time every day, even on weekends and holidays, can help ensure you get the best sleep and enough REM sleep. Irregular sleep patterns can lead to various issues that impact your physical and mental health, including diabetes, heart failure, and depression.

Keep the bedroom cool, dark, and quiet

Airing out your bedroom before sleeping and keeping the room cool can help you fall asleep faster. Getting blackout curtains can block out street lamps and sunrise rays. A bedroom that is too bright hinders melatonin production, leading to disrupted sleep.

Add aromatherapy to your bedtime routine

Research suggests that inhaling the scent of essential oils like lavender, bergamot, and cedarwood can calm your nervous system and make you sleepier.

Try white noise or earplugs

If you live in a noisy area, a white noise machine or earplugs can help block out sounds that might disrupt your sleep.

Eat more magnesium-rich foods

Magnesium plays an important role in sleep regulation, which can ultimately affect how much REM sleep you get. Pumpkin and chia seeds, almonds, and spinach are all good sources of magnesium.

Cut back on caffeine

Caffeine disrupts your sleep cycle and should be avoided in the second half of the day if you want to improve your sleep quality. This includes not only coffee but also black and green teas and sodas.

Avoid alcohol before bed

Drinking alcohol before bed disrupts your sleep cycle, particularly REM sleep. It takes the body about an hour to process one standard drink, so it's best to avoid drinking alcohol too close to bedtime.

Stay active during the day

Regular physical activity increases the amount of deep, restorative sleep you get, which in turn boosts your mood and energy. Try to exercise outside in the morning, as natural light helps set your body's sleep/wake cycle.

Relax before bed with a bedtime routine

Try listening to soft music, taking a warm bath or shower, or reading a book before bed. However, avoid reading on your phone or tablet, as these devices emit blue light that can interfere with sleep.

Frequently asked questions