How to get a better sleep in less time

Get Less Sleep but Still Feel Rested

How to Sleep 8 Hours in 4 Hours: Get Less Sleep but Still Feel Rested
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Medically reviewed by Raj Dasgupta, MD — By Daniel Yetman on October 22, 2020

Getting a full night’s sleep not only feels good, but it also improves your mental performance and boosts your overall health. Most adults need more than 7 hours per night for optimal well-being. Children and teenagers need even more to support their development.

Teens should sleep 8 to 10 hours per night, grade-schoolers 9 to 12 hours, and preschoolers 10 to 13 hours.

Many people wonder if it’s possible to “hack” their sleep so that they spend fewer hours in bed but still wake up feeling rested and productive. The short answer is yes and no — but mostly no.

The quality of your sleep plays a role in determining how rested you’ll feel when you wake. Improving your sleep quality can reduce the number of hours you need to spend in bed.

However, even if your sleep quality is great, sleeping for fewer hours than what’s recommended is detrimental to your health and mental performance. You may be able to do it for a few days, but eventually, the lack of rest will catch up with you.

Keep reading to find out why it isn’t possible to feel rested after getting only 4 hours of sleep per night over a long period. We’ll also look at why some people seem to be able function off much less sleep than others.

For most people, 4 hours of sleep per night isn’t enough to wake up feeling rested and mentally alert, no matter how well they sleep.

There’s a common myth that you can adapt to chronically restricted sleep, but there’s no evidence that the body functionally adapts to sleep deprivation.

Also, people who exercise regularly often need more than the minimum recommended hours to give their bodies time to regenerate from the additional physical stress.

A 2018 study that examined the sleep habits of more than 10,000 people found that regularly getting 4 hours of sleep per night was the equivalent of adding 8 years of aging to the participants’ brains.

Getting fewer than 7 hours of sleep per night over a long period may increase your risk for developing complications like:

  • depression
  • obesity
  • hypertension
  • anxiety
  • diabetes
  • obstructive sleep apnea
  • stroke
  • psychosis
  • cardiovascular disease

Sleep requirement genetic mutation

There’s one caveat when it comes to how much sleep you need: Everybody’s body is different, and some people can thrive off fewer hours of sleep than others.

Scientists have found a rare mutation of the ADRB1 gene in people who are able to feel rested with less than 6.5 hours of sleep per night without any apparent health consequences.

If you carry this gene mutation, it’s possible that you may feel rested even if you consistently sleep less than the recommended number of hours.

Polyphasic sleep

Polyphasic sleep refers to sleeping multiple times in a 24-hour period instead of once per night.

There are many different polyphasic techniques. One of the most common programs involves taking six 20-minute naps spaced equally throughout the day for a total of 3 hours a day.

Many people claim that polyphasic sleep allows you to sleep more efficiently and achieve the same amount of rest in fewer hours. However, there’s no medical evidence that polyphasic sleep is better than traditional sleep.

Sleep deprivation on polyphasic programs likely has the same negative health consequences as other forms of sleep deprivation. However, there’s limited research on these types of programs, since the vast majority of people who follow polyphasic programs only stick with them for a short time.

Chronically cutting your sleep short isn’t a good idea, but life gets busy and sometimes sleeping adequately isn’t possible for a few nights. The more nights you limit your sleep, the more “sleep debt” you’ll rack up. As with financial debt, the more sleep debt you have, the harder it is to pay it off.

There’s no magic way to increase your energy while cutting your sleep. However, the following techniques may help you get through short-term periods of sleep deprivation.

  • Get some light exercise. Exercising lightly can stimulate blood flow to your brain and temporarily make you feel more awake. However, heavy exercise may make you feel even more tired.
  • Avoid screen time for an hour before bed. Screens emit blue light, which may interfere with your body’s natural circadian rhythm and melatonin production.
  • Keep screens and other distractions out of your bedroom. Removing your phone and other potential distractions from your room can help limit idle time in bed that will cut into your sleep.
  • Make sure your room is dark. Bright lights in your bedroom may interfere with your body’s natural production of melatonin.
  • Reduce caffeine intake. Caffeine is a stimulant that acts on your central nervous system and can reduce drowsiness.
  • Eat a healthy diet. Eating an overall healthy diet can potentially give you more energy throughout the day.
  • Avoid alcohol. Alcohol has a sedative effect that reduces activity of your central nervous system and can make you drowsy.
  • Avoid liquids before bed. Avoiding liquids reduces your chances of needing to get up to use the bathroom in the middle of the night.
  • Try napping. Taking short 20-minute naps throughout the day may help give you recharge without causing you to feel drowsy.
  • Spend time in daylight. Exposing yourself to sunlight may improve your focus by stimulating the production of serotonin.

If you’re experiencing the following side effects, it’s likely a sign that you need to sleep more. It’s a good idea to prioritize rest for the next few nights until you notice your mental function return to normal.

  • drowsiness
  • irritability and changes in mood
  • changes in appetite
  • frequent yawning
  • poor productivity and focus
  • poor decision-making
  • forgetfulness
  • frequent sickness

Your body cycles through four stages of sleep throughout the night. One cycle takes about 90 minutes.

During a typical night’s sleep, you’ll cycle through each stage four to six times. If you’re limiting yourself to 4 hours of sleep, you’ll only have time to cycle through these stages twice.

The sleep stages are:

  • N1. This is the lightest stage of sleep, lasting 1 to 5 minutes. During this stage, your breathing and heart rate slow down and your muscles relax.
  • N2. This stage lasts about 30 to 60 minutes. Your breathing and heart rate slow down even further and your body temperature drops.
  • N3. The third stage of sleep is also known as deep sleep. This period, which lasts about 20 to 40 minutes, is when your body repairs damaged tissues and cells.
  • Rapid eye movement (REM). REM is the stage most associated with dreaming. Your first REM cycle lasts about 10 minutes and your last one can last up to 1 hour.

Most adults need at least 7 hours of sleep per night to wake up feeling rested and mentally fresh. Limiting your sleep raises your risk for developing many health problems such as diabetes, depression, or cardiovascular disease.

If you have to limit your sleep for a few days, you can potentially increase your energy by spending time in the sunlight, taking short naps throughout the day, and performing light exercise.

For more sleep support, check out our sleep shop.

Last medically reviewed on October 22, 2020

How we reviewed this article:

Healthline has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.

  • Healthy sleep habits: How many hours does your child need. (2018).
  • Patel AK, et al. (2020). Physiology, sleep stages.
  • Sleep and sleep disorders. (2017).
  • Tahkamo L, et al. (2019). Systematic review of light exposure impact on human circadian rhythm. DOI:
  • Wild CJ, et al. (2018). Dissociable effects of self-reported daily sleep duration on high-level cognitive abilities. DOI:

Our experts continually monitor the health and wellness space, and we update our articles when new information becomes available.

Current Version

Oct 22, 2020

Written By

Daniel Yetman

Edited By

Roman Gokhman

Medically Reviewed By

Raj Dasgupta, M.D.

Copy Edited By

Stassi Myer - CE

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Medically reviewed by Raj Dasgupta, MD — By Daniel Yetman on October 22, 2020

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18 Tips to Get to Sleep Faster and Feel Rested

In this day and age of overtasking and multitasking, lots of people wish they could shave some hours off of their nightly need for sleep. If that sounds like you, unfortunately, your body and brain may not agree with your wish.

Most adults feel best when they get somewhere between 7 and 9 hours of sleep a night. Less than that, and you could experience negative effects from sleep deprivation, such as irritability, a weakened immune system, and memory loss.

The amount of sleep you need varies and is based on a number of factors, including age and genetics. Some people are genetically predisposed to be short sleepers, and only require 4 or 5 hours of sleep a night. Others are long sleepers, who feel best when they get 9 or more hours of sleep.

The amount of sleep you need, and how you feel upon waking, may also be clues to your overall health. If you’re worried that you’re sleeping too much, can’t seem to fall or stay asleep, or feel tired even after a full night’s sleep, talk to your doctor.

You can’t change your genes and become a short sleeper, but you can optimize your sleep habits and routine. This isn’t quite the same thing as training your body to need less sleep, but it is an effective way to make the most out of the sleep you get. It will also help you zero in on the exact amount of sleep you need in order to feel your best.

Time spent tossing and turning is wasted time. You can shave off the hours you spend trying to fall asleep through better sleeping and waking habits. Here are some tips to try:

1. Give yourself time to wind down

The goal here is to train your body to fall asleep when you’re tired. One way to do that is by giving yourself ample time to relax at night before lights out. Try turning your home, or at least your bedroom, from a brightly lit, daytime environment to a cozy and restful nighttime one.

Around an hour before you want to fall asleep dim the lights, and begin transitioning to your sleep routine. This might include washing your face, brushing your teeth, and getting out of work clothing into pajamas.

2. Turn off your electronic devices

Anything with a screen should get shut off during your winding-down time. This includes:

  • television
  • computer
  • tablets
  • phone

The short-wave emissions of artificial blue light that are generated by these devices inhibit the release of melatonin, a hormone that induces sleep. One exception to this rule are e-ink e-readers, such as the Kindle Paperwhite.

3. Limit alcohol consumption at night

Alcohol is a sedative that can knock you out cold, or at least help you fall asleep quickly. However, it metabolizes in your system over the course of several hours, resulting in sleep disruption and poor sleep quality. Drinking alcohol can also dehydrate you and cause grogginess or a hangover, which affect your ability to wake up refreshed.

4. Avoid caffeine late in the day

Some people can down an espresso after dinner with no ill effects. Others can’t drink coffee after 3:00 p. m. Caffeine stays in your system from 4 to 6 hours. If you suspect that your late-day cola is keeping you up at night, eliminate all forms of caffeine from your diet at least 6 hours before you want to be asleep.

5. Cool down your bedroom

The temperature of your bed and bedroom can affect the quality of your sleep. Being too warm at night adversely affects REM sleep, the period during which your brain is most active. Try turning the thermostat down to around 60 to 68°F (15 to 20°C), or opening up a window to get a better night’s sleep.

6. Reduce noise

External noise, such as traffic or boisterous neighbors, can keep you awake or jolt you awake. If you live in an area where noise is a problem, reduce it by using ear plugs, a white noise machine, or both.

7. Stick to a routine

Dancing till dawn on weekends can be tons of fun on occasion, but maintaining the same sleep and wake times 7 days a week will help you fall asleep faster and wake up feeling more refreshed.

8. Buy a new pillow

Most people hold onto their pillows far longer than they should. The lifespan of the average pillow is 1 to 2 years. Longer than that and they lose their shape, becoming lumpy and unsupportive of your neck and head. This can adversely affect sleep.

Plus, they tend to fill with dust mites over time. Another good reason to treat yourself to a new one, especially if you have allergies.

Shop all expert-verified pillows in our sleep shop to work toward your best snooze possible.

9. Consider a new mattress

If your mattress is uncomfortable, old, or lumpy, your ability to get a good night’s sleep will be compromised. The lifespan of a mattress varies based on quality and other factors. In general, most mattresses should be swapped out for a new one every 7 to 10 years.

Want suggestions? Browse our market, filled with editor-trusted and expert-verified mattress recommendations.

10. Don’t eat a heavy meal late at night

Eating late at night can disrupt your ability to fall asleep, especially if you eat heavy or fatty food, like pizza or cake. If you are hungry or crave a little something, reach for these sleep-inducing foods instead.

11. Take a warm bath

A warm soak in the evening helps your muscles relax, letting you rest more effectively and quickly. Consider soaking about 90 minutes before you hit the sheets.

12. Try aromatherapy

A gently scented room may help you unwind and fall asleep faster. Try these essential oils, which have been linked to better sleep.

13. Read a book in bed

Losing yourself in a good story can help you transition from your day-to-day reality to a restful, slumbering state. Reading helps you reduce stress, letting you fall asleep faster.

14. Get out of bed when you wake up

If you’re addicted to your snooze button, give up those extra 10 minutes to get into a better routine. This may be especially true if you wake up naturally before your alarm goes off. Your body may be telling you that you don’t need any more sleep. You can reinforce that by getting out of bed and starting your day.

15. Change night into day

If you awaken in a dark room, open the blinds and let light in. Natural light will help you wake up, and may reduce your need for more sleep.

16. Create a morning routine

Establishing a reliable morning pattern of behavior can help you feel and be more productive, making you eager to get out of bed in the morning.

17. Exercise daily

Exercising has been shown to reduce insomnia and improve sleep quality. Exercising early in the day may be more beneficial than exercising at night for many people. Try experimenting with the time of day and type of exercise you do.

18. Wake up with cool water

A cool shower is invigorating, and can help you wake up energetically. Anecdotally, some people also feel that drinking cold water first thing in the morning helps them wake up more fully. Try having a cold glass of water before you reach for your first cup of coffee and see how you feel.

If you consistently need to sleep more than 8 or 9 hours a night, you may be oversleeping. This can be caused by a number of conditions, including depression, thyroid conditions, and heart disease. Some medications may also cause oversleeping.

Oversleeping is sometimes temporary, and may be your body’s reaction to an oncoming illness.

If you oversleep nightly for a prolonged period of time, it may be time to visit your doctor.

Everyone has a bad night’s sleep every now and then, where you wake up feeling tired or exhausted. If you rarely or never feel rested in the morning, you may be experiencing short periods of wakefulness that you’re not aware of, due to alcohol use, indigestion, or other issues.

You may also have a condition such as restless leg syndrome or sleep apnea. Try improving your nighttime routine and see if it helps you wake up feeling refreshed instead of tired.

If you are unable to change your sleeping habits, and find yourself unable to get out of bed with less than 10 or 12 hours of sleep a night, talk to your doctor.

You should also see your doctor if you always feel tired in the morning, regardless of how much sleep you had.

Chronic insomnia is a medical condition that can be treated. If lifestyle habits are not enough to improve the quality of your sleep, a doctor may be able to help.

It may not be possible to train your body to need more sleep. However, good sleep hygiene and a proactive morning routine can help you get the most out of sleep, and reduce the amount of time you spend trying to fall asleep.

6 ways to improve sleep and improve daily routine

Understanding how many hours you need to sleep to be healthy and active. And what to do if the quality of sleep leaves much to be desired.

On average, a healthy adult needs 8 hours of quality sleep. Studies show that one in three adults do not get enough sleep. This is due to our hectic lifestyle and the abundance of gadgets that we use on a daily basis.

Technology is an integral part of our lives, but it can have a bad effect on our sleep. And sleeping pills can cause drowsiness during the day and are usually not suitable for long-term use. Fortunately, today there are other ways to deal with insomnia. nine0007

☝What is described in this article is often referred to as sleep biohacking. However, it is rather a set of life hacks and recommendations that will help improve the quality of sleep.


  • Start monitoring your sleep
  • Find the right temperature
  • Reduce exposure to blue light
  • Get ready for bed
  • Move on
  • Stick to the schedule
  • Note
  • What else can be done? nine0018

1. Start monitoring your sleep

First of all, it is important to understand what is wrong with your sleep. Sleep monitoring can help with this. Thanks to monitoring, you can find out if you have problems falling asleep, whether you wake up in the middle of the night, whether you sleep lightly.

If you are serious, you can sign up for a study in a special sleep laboratory and consult a somnologist. Polysomnography is the gold standard for detecting sleep disorders. Doctors use these tests to diagnose restless leg syndrome, sleep apnea, insomnia, and other conditions. nine0003

However, today there are many cheaper and smaller devices that can help with sleep monitoring. If you have a smartwatch, there are apps that can track sleep patterns based on your heart rate. The watch can also record sounds, which will help you detect snoring or external stimuli that prevent you from deep sleep. For example, loud noises from the street in the early morning. It is much easier to conduct such a “research”, but its accuracy will be much lower. nine0007

Please note ☝ There are varying data on the effectiveness of sleep monitoring applications. Some studies suggest that the readings of smartwatches and trackers are quite reliable. Other studies indicate that such devices often overestimate the duration of sleep. There is also evidence that for some people, smartwatches and similar gadgets can cause additional anxiety that impairs sleep.


Find the optimal temperature

Body temperature drops from outside and rises before waking up. Too low or too high temperature in the bedroom can affect the quality of sleep. It is believed that for optimal sleep, it is best to keep the temperature in the room between 18 and 24°C. It must be remembered that body temperature is affected not only by the temperature in the bedroom, but also by bedding and pajamas. nine0003

It is believed that for a comfortable sleep your room should be like a cave - it should be dark, quiet and cool. To do this, you can open windows, turn down the heat if possible, or use a fan, for example.

3. Reduce exposure to blue light

Blue light from electronic devices can interfere with sleep quality. That is why the habits of scrolling the feed on social networks or watching TV shows before bed are not the healthiest. Blue light affects natural circadian rhythms. nine0003

The easiest way to minimize the negative impact of blue light is to stop using gadgets 1-2 hours before bedtime. An alternative could be a paper book, talking to loved ones, or any hobby that doesn't require a phone or computer.

4. Get ready for bed

It's a good habit to just get ready for bed - make sure that all the urgent things are done, plans for tomorrow are made, and you are ready to relax. Here are some tips that might come in handy:

  • take a warm but not hot bath - this will help your body reach the ideal temperature for relaxation
  • write a to-do list for the next day - this will help organize your thoughts and get rid of any distractions
  • do relaxation exercises, for example , light stretching, but do not do intense workouts before bed,
  • listen to calm music,
  • read, but not from a phone or computer.

Meditation can also help you get rid of anxiety, pay attention to your breathing and just relax. Research shows that meditation and mindfulness practices ( mindfulness ) can help you deal with minor sleep disturbances quickly. Other studies have found that people who do these practices are less likely to suffer from insomnia and depression, and to experience less fatigue.

Important☝ If you have had insomnia for more than four weeks, you need to see a doctor. nine0012

5. Get moving

We know that exercise improves the composition of the microbiota, improves mood and helps maintain physical and mental health. But besides that, according to research, exercise can have a positive effect on sleep.

In particular, physical activity helps to improve the quality and duration of sleep, and also helps with insomnia. It is best to exercise in the morning or afternoon, so that by night the body is ready for a good sleep. Avoid strenuous exercise two hours before bedtime. And before going to bed, you can do light stretching exercises. nine0007

6. Stick to a schedule

The circadian rhythm, also known as the internal body clock, affects sleep and wake schedules. Ideally, we should feel most awake early in the morning and ready for bed when it gets dark. The circadian rhythm is affected by unstable sleep patterns, jet lag, irregular work schedules, and overwork.

How to improve the situation:

  1. Go to bed and wake up at the same time every day. For children, you need to establish a daily routine and bedtime. Do not use the child's bedroom as a place for time-outs or punishment. nine0018
  2. Try to keep the same sleep schedule on weekdays and weekends.
  3. It is worth giving up a heavy dinner a couple of hours before bedtime (snacks are possible), as well as alcohol and nicotine.
  4. If possible, try to walk every day and be physically active in general.


Lack of sleep is harmful to health: it increases the risk of obesity, diabetes, cardiovascular disease and cancer, affects the mental state, reduces life expectancy. nine0003

Sleep is necessary for the recovery of the body and its normal functioning. When we sleep poorly, our productivity decreases, our ability to concentrate and learn, our memory and mood deteriorate.

To improve sleep, you need:

  1. Give up gadgets for 1-2 hours before bedtime.
  2. Maintain an optimal temperature in the bedroom.
  3. Go to bed and wake up at the same time every day.
  4. Do not forget about physical activity. nine0018
  5. Cut down on alcohol and nicotine before bed and avoid heavy meals a couple of hours before bed.

Warning☝ This article is for educational and informational purposes only and should not be used for diagnosis or treatment, or as a substitute for professional advice.

What else can you do?

Genetics can also influence sleep patterns. Scientists have found that insomnia can be inherited. Researchers have also established a genetic link between insomnia and type II diabetes. Various DNA tests, including the Atlas Genetic Test, can analyze the genetic predisposition to insomnia. nine0007

There is also growing evidence that gut microbes can affect sleep quality. Having a more diverse microbiome (with different types of bacteria) is associated with better sleep, according to a 2019 study. The diversity of the gut microbiota and other important parameters of a healthy gut will help determine the Atlas test.

  • NHS: Why lack of sleep is bad for your health – Sleep and tiredness
  • NHS: How to get to sleep – Sleep and tiredness
  • Tomas Chamorro-Premuzic, “How Much Is Bad Sleep Hurting Your Career?”, Harvard Business Review Home
  • Kelly Glazer Baron et al., “Orthosomnia: Are Some Patients Taking the Quantified Self Too Far?”, 2017
  • Dalva Poyares et al., “Fitness Tracker to Assess Sleep: Beyond the Market”, 2015
  • Janna Mantua et al., “Reliability of Sleep Measures from Four Personal Health Monitoring Devices Compared to Research-Based Actigraphy and Polysomnography”, 2016
  • Kathleen E. West et al., “Blue light from light-emitting diodes elicits a dose-dependent suppression of melatonin in humans”, 2011
  • National Heart, Lung, and Blood Institute: Sleep Deprivation and Deficiency
  • Mark R. Rosekind, “The Cost of Poor Sleep: Workplace Productivity Loss and Associated Costs”, 2010
  • David S. Black et al., “Mindfulness Meditation and Improvement in Sleep Quality and Daytime Impairment Among Older Adults with Sleep Disturbances: A Randomized Clinical Trial”, 2015
  • Kline, C, E., “The Bidirectional Relationship Between Exercise and Sleep: Implications for Exercise Adherence and Sleep Improvement”, 2014
  • Yujiro Yamanaka et al., “Physical exercise accelerates reentrainment of human sleep-wake cycle but not of plasma melatonin rhythm to 8-h phase-advanced sleep schedule”, 2010
  • Smith, R, P et al., “Gut Microbiome Diversity is Associated with Sleep Physiology in Humans”, 2019
  • Stein, M, B et al., “Genome-Wide Analysis of Insomnia Disorder”, 2018
  • Celia Vimont, “Should You Be Worried About Blue Light?”, 2021

Optimizing sleep: how to sleep less but better

  • David Robson
  • BBC Worklife

Image copyright Getty Images

Scientists have already learned how to deepen and speed up the recovery processes that occur in our brain during sleep. Will it make us feel better even when we go to bed too late and wake up too early? nine0193

We often talk about our sleep difficulties with some pride. After all, they testify that we lead an extremely busy life.

Let's remember Thomas Edison, Margaret Thatcher - yes, the same Donald Trump. All of them are famous for their short night rest - 4-5 hours of sleep, much less than the 7-9 hours recommended by doctors for adults.

  • We cut our own sleep, and the consequences are very disturbing
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  • How long can one go without sleep?

Many of us seem to follow suit: according to the US Centers for Disease Prevention and Control, more than a third of US adults regularly lack sleep.

The consequences are known - from memory impairment to increased risk of infectious diseases, from difficulty making decisions to obesity. But they are often ignored. nine0007

Alas, when our work needs exceed our normal daily schedule, the first thing we sacrifice is hours of sleep.

But if we could optimize the hours we spend sleeping, make them more efficient? Would we then need less time to sleep, and would it be deeper?

This possibility is closer than we think. Techniques for optimizing sleep already exist, and experiments around the world are proving that we can improve the efficiency of our brains at night. nine0007

First, we speed up our deep sleep, and then we increase the quality of our rest.

Do you think it sounds too nice to be true? Let's figure it out.

Slowing down the rhythm

During a normal night, the brain goes through different stages of sleep, each with its own characteristic "brain wave" pattern. At the same time, neurons in different areas of the brain work synchronously, in a certain rhythm (like a large crowd chanting something in unison). nine0007

During the phase of REM sleep, also called the phase of rapid eye movements (REM), the rhythm of neurons is relatively fast - at this time we usually dream.

But at certain moments our eyes stop moving, dreams stop dreaming and the rhythm of brain activity drops to one "beat" per second.

And here we plunge into that very deep unconscious state, which is called the phase of slow sleep.

It is this stage that is of most interest to scientists studying the possibilities of optimizing sleep. nine0007

Image copyright, Getty Images

Image caption,

Margaret Thatcher, among other things, was known for getting four to five hours of sleep a night, at least during her years as British Prime Minister

Research since the 1980s has shown that non-REM sleep is critical to maintaining normal brain function. During it, the corresponding areas of the brain translate memories of what happened during the day from the category of short-term memory to long-term - so that we do not forget what we have learned and learned. nine0007

"Slow-wave sleep facilitates this transfer of information," says Jan Born, Head of the Department of Medical Psychology and Behavioral Neuroscience at the University of Tübingen (Germany).

  • How some people manage to get by with little to no sleep
  • The best recipe for a broken heart or clouded mind is to take a nap

Slow-wave sleep also triggers blood and spinal fluid flow to the brain, thus "flushing out" potentially damaging neurons. blockages". nine0007

At the same time, levels of cortisol (hydrocortisone, the “stress hormone”) are lowered, which helps to restore the immune system, preparing it for future attacks of infections.

Image copyright, Getty Images

Image caption,

Many companies are now working to develop methods to help their customers achieve deeper NREM sleep, much like children do.

Born and other scientists wondered if we could to improve the quality of sleep and, in particular, the phases of non-REM sleep so much that it will improve our daytime functioning? nine0007

One of the most promising techniques is to use a kind of metronome for the sleeping brain. Participants in the experiments put on a kind of helmet on their heads, which captures the phases of their brain activity during sleep - including when they are immersed in the slow phase.

And then the device begins to reproduce short impulses, barely audible sounds with a frequency that coincides with the brain impulses of the non-REM sleep phase.

These sounds are not loud enough to wake up a sleeping person, but a person subconsciously perceives them. nine0007

Bourne came to the conclusion that such gentle sound stimulation is sufficient to ensure that the correct brain rhythms enhance the state of deep sleep.

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    The signals sent by the device changed the hormonal balance, helped to reduce the level of cortisol in the body.

    To date, none of the participants in the experiments have reported adverse effects or side effects of such brain stimulation, Born says.

    For sound sleep - to the store

    Most of the experiments to deepen the non-REM sleep phase involved small groups of young and healthy volunteers. So, in order to be fully convinced of the benefits of such techniques, research should be wider and in groups with more diverse composition. nine0007

    But the technology has already made its way into some household devices, mostly in the form of headbands worn at night.

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    The French start-up Dreem, for example, produces such a headband (costs about 400 euros), as in the experiments described above, stimulating the brain with sound pulses that immerse a person in the slow sleep phase. The effectiveness of this device is confirmed by a peer-reviewed scientific study. nine0007

    The French gadget comes with a mobile app that analyzes your sleep and offers practical tips and exercises to improve it - including meditation and breathing exercises.

    Philips, the manufacturer of the SmartSleep device, makes it clear that it wants to help alleviate the negative effects of sleep deprivation.

    The device is for those people "who, for whatever reason, simply can't afford to get as much sleep as their body needs," says David White, Chief Scientist at Philips. nine0007

    Image copyright, Getty Images

    Image caption,

    Philips joined the research to improve sleep efficiency with its own device for sleep deprived people

    Launched in 2018. Like the Dreem, it's a headband that detects electrical brain activity and periodically sends out short beeps to stimulate the vibrations that are characteristic of non-REM sleep.

    The gadget relies on software that offers the optimal level of stimulation for a particular person (SmartSleep is currently only available in the US, its price is 39$9).

    David White agrees that such devices are not a complete substitute for a good night's sleep. But, he says, those who suffer from sleep deprivation are extremely difficult to convince of the need to change their lifestyle. And the device should at least help them feel better during the day.

    Philips' own research has reportedly confirmed that SmartSleep stimulates slow-wave sleep in those who are regularly sleep deprived and mitigates the impact of this sleep loss on the effectiveness of nighttime memory consolidation. nine0007

    No doubt, in the future, new experiments will lead to new devices and innovative ways to optimize sleep.

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    Auror Perrault of Concordia University (Montreal) recently tested a bed that gently rocked back and forth every four seconds - much like a cradle with a baby.

    According to her, her colleague suggested this after she had a baby and had to rock him to sleep. Scientists have a question: but will it work with adults too? nine0007

    Image copyright Dreem

    Photo caption

    French startup Dreem's device uses sound brain stimulation to improve sleep quality. Similar products are beginning to appear on the market

    Indeed, it turned out that the participants in the experiment fell into slow sleep faster and spent more time in it. Their brains synchronized with external movement.

    As expected, they reported feeling more rested afterwards. In addition, this was accompanied by positive effects on their memory. nine0007

    If such a bed is available for sale, it will perform the same function as head-mounted devices.

    Perro is particularly interested in whether she will help the elderly. As we age, the amount of time we spend in non-REM sleep decreases, and memory problems may be associated with this.

    Perrault hopes that the gently rocking bed will help counter this.

    Sleep anyway

    While such studies are at the very beginning of their journey, they are nevertheless promising. Perrault and Bourne are optimistic about the potential of commercial products that use sound pulses for health purposes. nine0007

    Perrault emphasizes that more research is needed on the effectiveness of such methods - and no longer in the laboratory. "It's great that they keep trying to use external stimulation - we know it works," says Perrault.

    Image copyright, Getty Images

    Image caption,

    Some research has found that long-known environmental stimuli, like bed rocking, can help adults sleep better too

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