REM Sleep Explained: Why It Matters and How to Get More

Understanding REM sleep is key to optimizing your mental recovery and cognitive performance.

REM sleep plays a critical role in memory consolidation, learning, and emotional regulation. If you've noticed a low REM percentage in your sleep data, understanding what it means and how to improve it can significantly impact your cognitive performance.

This guide explains what REM sleep is, why it matters, how much you need, and what you can do to get more of it.

What is REM sleep?

REM sleep, which means "rapid eye movement sleep," is one of the 4 stages of sleep (along with light, deep and wake) that your body's sleep cycles consist of. It is known as the "mentally restorative" stage of sleep when the brain converts short-term memories into long-term ones. Your brain is very active during REM sleep and it is when the most vivid dreams occur.

The sleep stages

Something many people don't realize is that REM sleep and deep sleep (also referred to as slow wave sleep) are very different stages of sleep. Deep sleep is the "physically restorative" stage when muscles repair themselves and cells regenerate. It follows light sleep and precedes REM sleep in a normal sleep cycle, and unlike REM when your heart and respiratory rate speed up, during deep sleep they both slow down.

Why is REM sleep important?

REM sleep is the time when new learnings from the day are committed to long-term memory. For athletes, this means technical skills practiced during the day are retained during REM sleep. Without adequate REM sleep, you may not see the full benefits of your training.

More generally speaking, there's been research to suggest that when people are deprived of REM sleep they have trouble recollecting things they are taught before falling asleep.

Not getting enough REM sleep can negatively impact your brain's ability to learn and create new memories. Because most REM sleep occurs at the end of the night, a lack of it often signals overall sleep deprivation.

Chronic sleep deprivation has been linked to greater risk of obesity, Type 2 Diabetes, dementia, depression, cardiovascular disease, and cancer.

There has also been research to show that insufficient REM sleep may cause migraines, and some medical conditions (sleep apnea for example) can have adverse effects on it.

The following physiological changes occur during the REM stage of sleep:

• Eyes move rapidly back and forth behind closed eyelids
• Heart rate and blood pressure rise to levels nearly as high as when you're awake
• Respiratory rate speeds up and becomes erratic
• Brain consumes more oxygen and its activity increases significantly
• Face and limbs may twitch

Below is a chart representing brain waves measured by an EEG when a person is awake, in REM sleep, and in non-REM sleep:

Your brain is almost as active in rapid eye movement sleep as when it's awake, which is why most dreaming happens during this time. As a precautionary measure, part of the brain also sends signals to immobilize your arms and legs in order to prevent you from acting out your dreams (REM sleep behavior disorder). For these reasons, REM sleep is sometimes called paradoxical sleep.

How much REM sleep do you need?

You first enter REM sleep within 90 minutes of falling asleep, and this initial period lasts about 10 minutes. You'll go through 3-5 REM cycles per night, with each episode getting longer. The final cycle may last roughly an hour.

For healthy adults, a good goal is to spend about 22% of your time asleep in the REM stage. If you get 7-8 hours of sleep, around 105 minutes of that should be REM, which is the average for WHOOP members.

The normal amount of REM sleep also declines with age, beginning with infancy (when it may be greater than 50% of total sleep time) and extending all the way through adulthood.

Learn More:

How Much REM Sleep Should You Get a Night?

How Much Time Should You Spend in Each Stage of Sleep?

How to get more REM sleep

Improving your sleep habits will help you get more REM sleep. Start by spending more time in bed. Here are 45 tips to help you sleep better.

Two factors stand out for increasing REM sleep. The first is sleep consistency—going to bed and waking up at the same time each day.

Your body functions more efficiently on a regular schedule. We analyzed sleep data from 25,000 WHOOP members and found a significant rise in REM sleep as sleep consistency increased:

The second big thing is to stay away from alcohol before bed. When your body is forced to process alcohol during sleep, it has difficulty getting past light sleep and into the deeper stages.

Learn More: Tips to Increase REM Sleep

How WHOOP measures REM sleep and helps you improve it

WHOOP monitors your sleep in detail, showing exactly how much time you spend in each stage. You can track trends in your restorative sleep over time to identify what impacts it.

The app also features a Sleep Planner that uses your own circadian rhythm to recommend daily bed and wake times to optimize the quality of your sleep.

WHOOP will let you know how much REM sleep you're getting and help give you a better understanding of what you can do to get more of it.

THE WHOOP APP DISPLAYS HOW MUCH TIME YOU SPEND IN REM SLEEP EACH NIGHT.

Understand and improve your sleep with WHOOP

Understanding your sleep is the first step toward improving it. By measuring your sleep stages and tracking how your behaviors impact them, you can make targeted changes to improve mental recovery and cognitive performance.

WHOOP provides the data and insights to help you build better sleep habits.

Frequently asked questions about REM sleep

What is REM Sleep good for?

Yes, REM sleep is beneficial for memory consolidation, emotional regulation, and learning. However, a healthy sleep pattern requires adequate amounts of both REM and non-REM sleep stages.

Which is better, REM or deep sleep?

Both REM and deep sleep are important stages of the sleep cycle, and each has its own unique functions and benefits. Deep sleep is crucial for physical restoration, while REM sleep is important for cognitive and emotional processing. Therefore, it is not a matter of which stage is better, but rather, a healthy sleep pattern requires adequate amounts of both REM and deep sleep.

Can you get too much REM sleep?

The amount varies based on individual factors like age and sleep quality. However, consistently high REM sleep may signal an underlying health condition, and you should seek medical evaluation.

What happens if you wake up during REM sleep?

Waking up during REM sleep can cause grogginess or disorientation, known as sleep inertia. Because your brain is highly active during this stage, abrupt awakenings feel jarring. You're also more likely to vividly remember your dreams.

Occasionally waking during REM is normal, but consistently doing so may indicate a disruption in your sleep cycle.

This feature is for wellness purposes only and not for medical use. If you have concerns about a medical condition, please consult your doctor.