Adults' Rem Sleep: How Much Is Enough?

Sleep is a complex and mysterious process that is essential for human health and well-being. While asleep, the body and brain undergo a range of restorative functions, including energy conservation, self-repair, and brain maintenance. The quality of sleep is just as important as the quantity, and this quality is determined by the different stages of sleep. During the rapid eye movement (REM) stage, the eyes move rapidly, and the brain is active, similar to when awake. Dreams typically occur during this stage. In contrast, during the non-rapid eye movement (NREM) stage, the brain is less active, and the body's physiological functions slow down. Adults need around 7-9 hours of sleep per night, with REM sleep accounting for about 20-25% of this.

REM sleep and dreaming

REM sleep, or rapid eye movement sleep, is one of the two types of sleep humans experience, the other being non-rapid eye movement (NREM) sleep. During REM sleep, the eyes move rapidly behind closed eyelids, and brain activity is similar to that of wakefulness. Most muscles become temporarily paralysed during REM sleep, which stops us from acting out our dreams, although we may experience occasional muscle twitches.

The amount of time spent in REM sleep differs depending on age. Newborns tend to get the most REM sleep, which makes up 50% of their sleep. In contrast, older adults tend to need less REM sleep than younger adults, children, and babies. On average, REM sleep should make up around 20-25% of a person's total time asleep. For adults sleeping for eight hours a night, this equates to about one hour and 45 minutes to two hours of REM sleep.

REM sleep is the sleep stage most commonly associated with dreaming. Dreams during REM sleep tend to be more vivid and unusual, whereas dreams during NREM sleep are more grounded in reality. REM sleep is believed to be essential for cognitive functions such as memory, learning, and creativity. Studies have shown that taking a nap and reaching the REM sleep stage leads to improvements in working memory. REM sleep may also play a role in emotional processing and recovery from stressful events.

If you are not getting enough REM sleep, there are several things you can do to increase your chances of sleeping well. These include:

• Developing and maintaining a sleep schedule by going to bed and waking up at the same time every day, even on weekends.
• Treating any sleep disorders that may be disrupting your sleep.
• Stopping the use of sleep aids, as certain medications can reduce or suppress REM sleep.
• Avoiding alcohol, caffeine, and tobacco, as these substances can interfere with normal progression through the sleep stages.
• Adopting good sleep hygiene habits, such as exercising regularly, maintaining a cool, dark, and quiet bedroom environment, and establishing a regular bedtime routine.

How to increase REM sleep

REM sleep is the final stage of the sleep cycle, which we enter about 90 minutes after falling asleep. During this stage, the brain is highly active, and the eyes dart back and forth behind closed eyelids. We tend to dream during this stage, and it is thought to be important for learning, memory, and processing emotions.

If you want to increase your REM sleep, the best way to do so is to focus on improving your sleep quality and duration overall. Here are some tips to help you get more REM sleep:

• Stick to a consistent sleep schedule: Try to go to bed and wake up at roughly the same time every day, even on weekends. This helps to regulate your body clock and ensure you get the best sleep.
• Create a relaxing bedtime routine: Develop a soothing pre-sleep routine such as taking a warm bath, listening to classical music, or reading quietly.
• Keep the bedroom cool, dark, and quiet: A cool, dark bedroom can help you fall asleep faster. Block out any unwanted light with blackout curtains or an eye mask.
• Avoid stimulants: Caffeine and nicotine are stimulants that can interfere with your sleep. Avoid consuming them, especially in the second half of the day and close to bedtime.
• Limit alcohol consumption: While alcohol may make you feel sleepy at first, it actually disrupts your sleep, particularly REM sleep. Try to avoid drinking alcohol, especially before bed.
• Exercise regularly: Aim for about 30 minutes of exercise per day, but make sure to do it several hours before bedtime so as not to interfere with your sleep.
• Create a suitable sleep environment: Keep your bedroom dark, cool, and quiet. Avoid watching TV or working on your computer in bed. Also, make sure to keep gadgets and screens out of the bedroom.
• Get up if you can't sleep: If you find yourself lying awake in bed, get up and go to another room. Do something quiet like reading or listening to relaxing music until you feel sleepy again.
• Replace your pillows: Consider replacing your pillows if they are old and uncomfortable. This may help you sleep better.
• Meditate: Meditation can help calm your mind and body, making it easier to fall asleep and improve your overall sleep quality.
• Aromatherapy: Try using essential oils like lavender, bergamot, or cedarwood in a diffuser or sprinkle a few drops on a piece of fabric near your pillow.
• White noise or earplugs: If outside noises disturb your sleep, try using a white noise machine or app, or simply use earplugs to block out the sounds.
• Eat magnesium-rich foods: Magnesium plays an important role in sleep regulation. Include more magnesium-rich foods in your diet, such as pumpkin and chia seeds, almonds, and spinach.

REM sleep and memory

REM sleep is important for memory consolidation. Memory consolidation is the process of stabilising recently acquired information into long-term storage.

During REM sleep, the brain repairs itself and processes emotional experiences, transferring short-term memories into long-term memories. REM sleep is also when dreaming occurs, and experts believe that dreaming helps us to process emotions.

The hippocampus, the memory region of the brain, is active during REM sleep. This is when theta rhythm-dependent processing of hippocampal place cells occurs, which is believed to be integral to memory consolidation.

The amount of time spent in REM sleep changes as we age. Newborns spend up to 50% of their sleep in the REM stage, while adults spend only about 20% in REM.

REM sleep and emotional processing

REM sleep is important for emotional processing. It helps to regulate emotions and cope with emotional stress. REM sleep deprivation can increase negative emotional reactivity and decrease positive emotional reactions to positive events. It also increases amygdala reactivity to aversive emotional information.

REM sleep and sleep disorders

Sleep is a complex and mysterious body process, and while it may seem simple, it is anything but. During sleep, the body "powers down" and most body systems, including the brain, become less active. However, the brain remains active during sleep, and there are two main types of sleep: REM (rapid eye movement) sleep and non-REM sleep.

REM sleep is characterised by rapid eye movement, and the eyes move rapidly behind closed eyelids. Brain activity during REM sleep consists of smaller, faster waves, called theta waves, that are similar to brain activity during wakefulness. Most muscles become temporarily paralysed during REM sleep to prevent sleepers from acting out their dreams, although individuals may display occasional muscle twitches. Dreams tend to occur during REM sleep, and they are often more vivid and unusual compared to dreams during non-REM sleep, which tend to be more grounded in reality.

REM sleep is important for several mental processes, including memory and learning. Studies have shown that taking a nap and reaching the REM sleep stage leads to improvements in working memory. REM sleep may also play a role in brain development, and the muscle twitches experienced during this sleep stage may contribute to motor learning. The sleep period of newborn babies consists of 50% REM sleep, supporting the theory that REM sleep is important for brain development. REM sleep may also foster emotional processing and creativity, and obtaining larger amounts of REM sleep after a traumatic event may reduce the chances of developing post-traumatic stress disorder.

There are several ways to increase the amount of REM sleep you get. Firstly, it is important to get enough sleep overall, as REM sleep occurs mostly during the second half of the sleep period. Developing and maintaining a consistent sleep schedule, even on weekends, can also help to regulate REM sleep. This is because longer periods of REM sleep tend to align with the dip in body temperature that occurs in the early morning hours, which is regulated by the circadian rhythm. Disrupting this balance by keeping irregular sleep-wake times may confuse the body and interfere with REM sleep regulation.

Treating any sleep disorders can also help to increase the amount of REM sleep. For example, studies have shown that treating obstructive sleep apnea with continuous positive airway pressure (CPAP) therapy resulted in REM rebound sleep, accompanied by better mood and higher-quality sleep overall. Stopping the use of certain antidepressant and antipsychotic medications may also help, as these can reduce or suppress REM sleep. Avoiding alcohol, caffeine, and tobacco can also help to increase REM sleep, as these substances can interfere with normal progression through the sleep stages, especially if consumed in the evening or close to bedtime.

Finally, adopting good sleep hygiene habits can help to improve sleep quality and increase the amount of REM sleep. This includes exercising regularly, maintaining a cool, dark and quiet bedroom environment, and establishing a regular bedtime routine with soothing activities such as reading or taking a warm bath. Keeping gadgets and screens out of the bedroom is also recommended, and if you are unable to sleep after 20 minutes, it is best to leave your bed and do something else in another room until you feel sleepy.

While there is no official agreement on how much REM sleep is needed, adults need at least seven hours of sleep every night, and REM sleep should make up around 20-25% of total sleep time.

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