3 Things You Should Know About REM Sleep

Sleep is a vital part of good health and optimal function during your waking hours. As you get your much needed, revitalizing rest at night, your body actually goes through various sleep cycles. Each phase of sleep is important and beneficial to your body and mind, but REM sleep is especially fascinating because it increases brain activity, promotes learning, and creates dreams.

Here are three interesting things that you should know about your REM sleep cycles that you experience each night as you rest, rejuvenate, and dream:

What is the Difference Between REM and Non-REM Sleep?

As you sleep at night, you cycle through periods of REM and non-REM sleep. Non-REM sleep occurs in three stages, and then you will enter REM sleep.

Non-REM Sleep

According to WebMD, the three phases of non-REM sleep are:

  • Phase 1: As you first drift off to sleep you are entering phase 1 of non-REM sleep. You are relaxed, but may stir or awake easily for about five to ten minutes.
  • Phase 2: Phase 2 prepares your body for deep sleep. Your heart rate and body temperature will lower as you begin to sleep lightly.
  • Phase 3: Deep sleep begins in phase 3, and you will not be easily woken up as your body works to repair tissue and bones and strengthen your immune system.

REM Sleep

REM stands for Rapid Eye Movement. During this cycle of your sleep, your eyes will move and dart quickly beneath your eyelids. During REM sleep, your brain activity increases, your pulse quickens, and you have dreams. REM sleep first takes place after you’ve been sleeping for around 90 minutes. The first cycle usually lasts about 10 minutes, and each cycle time will increase to as long as one hour in the last phase before you awake.

Why is REM Sleep Important?

REM sleep is important to your sleep cycle because it stimulates the areas of your brain that are essential in learning and making or retaining memories. According to the National Institute of Neurological Disorders and Stroke, a study depriving rats of REM sleep significantly shortened their life span, from two or three years to five weeks. Rats deprived of all sleep cycles lived only three weeks. The importance of REM sleep, in particular, is attributed to the fact that during this phase of sleep, your brain exercises important neural connections which are key to mental and overall well-being and health.

What is REM Sleep Behavior Disorder?

According to the Mayo Clinic, REM Sleep Behavior Disorder is a sleep disorder that causes you to physically act out vivid dreams through erratic and violent arm and leg movements. This disorder can come about suddenly, and impact your sleep several times a night.

During REM sleep, your body usually remains motionless, but the symptoms of REM Sleep Behavior Disorder include:

  • Movements such as flailing, kicking, or punching in response to especially vivid or frightening dreams.
  • Noises such as yelling, talking, or crying while you are sleeping.
  • Ability to vividly remember the dream you were experiencing if you are woken up.

REM Sleep Behavior Disorder can be caused by underlying medical conditions or disease, but can have other triggers such as medications, sleep disorders, or neural problems. If you experience frequent, physical REM sleep disruptions, then a sleep study conducted by a professional sleep expert can help you determine if an underlying sleep issue is present, and help you once again benefit from your important REM sleep cycle.

The Importance of REM Sleep & Dreaming

We typically spend more than 2 hours each night dreaming. Scientists don’t know much about how or why we dream.

Sigmund Freud, who greatly influenced the field of psychology, believed dreaming was a “safety valve” for unconscious desires. Only after 1953, when researchers first described REM in sleeping infants, did scientists begin to carefully study sleep and dreaming.

They soon realized that the strange, illogical experiences we call dreams almost always occur during REM sleep. While most mammals and birds show signs of REM sleep, reptiles and other cold-blooded animals do not.

REM sleep begins with signals from an area at the base of the brain called the pons. These signals travel to a brain region called the thalamus, which relays them to the cerebral cortex — the outer layer of the brain that is responsible for learning, thinking, and organizing information.

The pons also sends signals that shut off neurons in the spinal cord, causing temporary paralysis of the limb muscles. If something interferes with this paralysis, people will begin to physically “act out” their dreams — a rare, dangerous problem called REM sleep behavior disorder.

A person dreaming about a ball game, for example, may run headlong into furniture or blindly strike someone sleeping nearby while trying to catch a ball in the dream.

REM sleep stimulates the brain regions used in learning. This may be important for normal brain development during infancy, which would explain why infants spend much more time in REM sleep than adults.

Like deep sleep, REM sleep is associated with increased production of proteins. One study found that REM sleep affects learning of certain mental skills. People taught a skill and then deprived of non-REM sleep could recall what they had learned after sleeping, while people deprived of REM sleep could not.

Some scientists believe dreams are the cortex’ss attempt to find meaning in the random signals that it receives during REM sleep. The cortex is the part of the brain that interprets and organizes information from the environment during consciousness. It may be that, given random signals from the pons during REM sleep, the cortex tries to interpret these signals as well, creating a “story” out of fragmented brain activity.

The Importance of REM Sleep & Dreaming

Understanding Sleep Cycles: What Happens While You Sleep

Learn what is really going on in your body while you’re getting your zzz’s.

Before the 1950’s, scientists used to believe that as people drifted off to sleep, their brains and bodies would go into “shutdown” mode, entering a passive state that allowed them to recover from the previous day. What researchers have since learned: Sleep is a whole lot more complicated, and it’s a much more active state than you might think. In fact, while you’re getting your zzz’s, your brain goes through various patterns of activity. It’s a predictable cycle that includes two distinct parts – NREM, or Non-REM sleep, plus a REM or “Rapid Eye Movement” cycle.

Check out what happens in your body during each phase of sleep:

Stage One: Within minutes (sometimes even within seconds!) of nodding off, your brain produces what are called alpha and theta waves and your eye movements slow down. This introduction to sleep is relatively brief, lasting up to seven minutes. Here, you are in light stage sleep, which means that you’re somewhat alert and can be easily woken. It’s during this stage of sleep that people often indulge in brief “catnaps.”

Stage Two: During this stage, which is also fairly light, the brain produces sudden increases in brain wave frequency known as sleep spindles. Then brain waves slow down. If you were to schedule a “power nap” you’d want to wake up after this stage of sleep.

Stages Three & Four: This stage is the beginning of deep sleep, as the brain begins producing slower delta waves. You won’t experience any eye movement or muscle activity. At this point, it becomes a little harder for you to be awakened, because your body becomes less responsive to outside stimuli. The brain produces even more delta waves and you move into an even deeper, more restorative stage of sleep next. It’s most difficult to wake up during this stage. This is when the body repairs muscles and tissues, stimulates growth and development, boosts immune function, and builds up energy for the next day.

Rapid Eye Movement (REM) Sleep: You generally enter REM sleep about 90 minutes after initially falling asleep, and each REM stage can last up to an hour. An average adult has five to six REM cycles each night. During this final phase of sleep, your brain becomes more active. This is when most dreaming occurs, your eyes jerk quickly in different directions (hence, the name!), heart rate and blood pressure increase, and breathing becomes fast, irregular, and shallow. REM sleep plays an important role in learning and memory function, since this is when your brain consolidates and processes information from the day before so that it can be stored in your long-term memory.

It’s important to note that these phases last for different durations at various ages; an infant’s sleep cycle will look different than that of an adult or elderly individual. On an average night, you move through the stages in a sequential fashion. Most non-REM sleep occurs early in the night and the length of REM periods increases as the night goes on. That’s why there’s a good chance you’ll awaken from a dream in the morning—hopefully, a sweet one!

REM Sleep and Our Dreaming Lives

REM sleep is distinct from sleep’s other stages, and is sometimes referred to as paradoxical sleep. During phases of Non-REM sleep, brain activity slows and changes considerably from its waking state. In REM sleep, the brain becomes highly active. During phases of REM, the brain functions at levels similar to that of a waking brain. At times, levels of brain activity of REM can actually be higher than when you are awake. Heart rate and breathing also increase and become more variable, compared to other stages of sleep. REM stands for Rapid Eye Movement, one of the most marked physical characteristics of this sleep phase. During REM sleep, the eyes move back and forth constantly underneath closed lids.

How much time in REM?

Over the course of a night, you spend approximately 25 percent of sleep in REM phase. REM sleep doesn’t occur all at once. Instead, periods of REM are interspersed among the other stages of sleep as you move through a series of sleep cycles. It typically takes about 90 minutes of sleep to arrive at the first REM period. The first stop of the night in REM sleep is brief, lasting roughly five minutes. Each subsequent return to REM grows longer. REM sleep is predominant in the final third of the night, and the final stage of REM sleep can last 30 minutes. A full night of sleep—typically in the range of seven to nine hours—is necessary to achieve all the restorative benefits of REM sleep.

What is REM atonia?

While the brain is very active during REM sleep, the body is largely immobilized. In REM sleep, a temporary paralysis occurs, known as REM atonia. This immobilization protects the body, preventing the sleeper from acting out physically in response to dreams. It’s possible to wake from this phase of sleep while unable to move or to speak, a phenomenon called sleep paralysis. The effects of sleep paralysis are fleeting, and typically last only a few seconds or minutes. Still, this can be a frightening experience. If you find yourself waking under these conditions, do your best not to panic. Stay relaxed and allow your brain and body to come back into sync.

A time for mental recharge

REM sleep is a phase that’s closely linked with mental recharge. During its time in REM throughout the night, your brain refreshes and restores itself. This is one reason why REM sleep is so important, and why a healthy sleep routine with sufficient amounts of REM sleep is essential to feeling mentally and emotionally well, and to performing at your best during your waking life.

REM sleep is believed to play an important role in learning, memory, and emotion. It is often thought of as the sleep phase during which the brain restores itself. The areas of the brain that are most active during REM sleep are those related to thinking, learning, and decision-making, as well as to emotional regulation. REM sleep is linked to the brain’s ability to make new associations, aiding in the acquisition of new information, problem solving, and creativity. Research indicates REM may play an important role in some forms of memory consolidation, the process by which brain converts newly acquired information into longer-term memory. Evidence also suggests that during REM sleep the brain is at work processing emotions, helping to regulate mood.

The dreaming stage of sleep

Most dreaming occurs during REM sleep. On average, you will spend about two hours per night dreaming. Often those dreams aren’t remembered. If you wake from REM sleep, you’re more likely to recall that you’ve been dreaming.

Dreaming is one of the great mysteries of the human experience, and of sleep itself. Humans have long wondered about the meaning and purpose of dreams, and cultures have connected dreams to their deepest hopes and fears. Many ancient cultures saw dreams as messages, often warnings, from the gods. Throughout history, dreams have been regarded as out-of-body explorations for the soul, as a means to communicate with the dead, and as harbingers of “evil” spirits. Sigmund Freud theorized dreams as a landscape in which to explore the repressed emotions and desires of the unconscious mind. Carl Jung also saw dreaming as a view to the unconscious, but believed dreams manifested the fears and emotions left un-tended in our waking lives.

Why do we dream?

Dreaming remains a scientific mystery even today. Contemporary investigations of dreaming include exploration of both psychological and neurological functions. Theories of the purpose of dreaming continue to cover wide terrain, and often overlap with one another. Some theories posit that dreams are means to integrate new experiences into memory, and to process emotional and traumatic events as a way to regulate mood. Other theories suggest dreaming is the brain’s way of de-cluttering itself after a long, active day of acquiring new information. Some scientists think dreams are a response to stimuli gathered throughout the day, while others contend that dreams are a response to the external stimuli that occurs during sleep itself. Another theory suggests that dreams are the brain’s way of making sense of the electrical impulses that occurs during the brain’s very active REM phase.

The right amount of REM

As with all stages of sleep in your sleep cycle, REM sleep is about balance. Too much and too little REM sleep can have negative consequences for your mood, your alertness and ability to focus, and your capacity to take in new information. There are several factors that can disrupt healthy levels of REM. Alcohol consumption too close to bedtime diminishes time spent in REM sleep. Stress, on the other hand, can extend REM sleep beyond normal levels. Too much REM sleep can actually leave you feeling tired the next day. Ensuring a full night of high-quality rest will help you receive all the benefits of this highly restorative sleep phase.

Does Getting Enough REM Sleep Really Matter?

Photo: / Boophuket

The most important thing you can do for your body-right up there with working out and eating right-is getting enough sleep. The benefits of sleep are as plentiful as the sheep most Americans stay up late counting: It improves your memory, curbs inflammation, aids weight loss, makes you more likely to stick to your workout plans, and even helps you live longer.

But it’s not just about getting the seven or more hours of sleep recommended by the American Academy of Sleep Medicine (which a third of Americans aren’t clocking, BTW). It’s about getting quality sleep-and that means spending enough of your sleep hours in rapid-eye-movement (REM) sleep, the phase when dreaming occurs. Here’s what you need to know about your sleep cycle, the benefits of REM sleep, and how you can bank more of it next time you’re in bed.

What Is REM Sleep?

REM is one of the four stages of sleep, explains W. Chris Winter, M.D., author of The Sleep Solution: Why Your Sleep Is Broken and How to Fix It. “There’s N1, a transitory stage of sleep where you go from wakefulness into sleep; N2, or what we consider light sleep; N3, or deep sleep; and then REM sleep,” he says.

REM gets its name from the rapid eye movements that occur throughout it. The scientists Eugene Aserinsky, Nathaniel Kleitman, and William C. Dement were the first to observe REM sleep in the early 1950s, says Dr. Winter. And it was especially interesting because they also noted that there was almost no movement from the rest of the body during that sleep stage. “From a physiological point of view, it’s almost as if your brain is awake but your body is paralyzed-perhaps to keep you from acting out your dreams,” says Conor Heneghan, Ph.D., lead sleep research scientist at Fitbit.

During the beginning of the night, you’re going to experience a longer period of deep sleep-when your body repairs and regrows tissues, builds bone and muscle and strengthens the immune system-says Heneghan. Most people generally experience their first cycle of REM sleep 90 minutes after falling asleep. “Initially, you get shorter bursts of REM, and as the night progresses and the body satisfies its need for deep sleep, you take in longer periods of REM sleep,” he says.

Over the course of a night, you typically spend about 20 to 25 percent of your sleep time in REM, and you’ll likely go through four or five sleep cycles overall if you’re getting adequate sleep. (Related: 5 Health Benefits You Get from Sleeping Naked)

What Are the Benefits of REM Sleep?

Scientists are still exploring the importance of REM, and it’s not entirely clear what’s going on in our brains during that time, says Dr. Winter. The rapid eye movement that is representative of REM sleep may occur as our brain cycles through new mental images, which, according to a study published in the journal Nature Communications, could be a part of processing new memories. Researchers also found REM to be associated with learning new information and maintaining important neural pathways.

“During sleep, your brain is sort of replaying certain things you’ve experienced and trying to figure out if it should put that experience into your short-term or long-term memory-or to just forget about it,” says Dr. Winter. “Unlike deep sleep, which is really concerned with rest and recovery, REM sleep has lots more to do with concentration, focus, memory consolidation, and pain perception.”

Studies have shown that a lack of REM sleep can affect your memory, mess with your mood, impact your cognitive performance, and screw with cell regeneration. Obviously, that could impact your workday, but it could also eff up your athletic performance, making it hard to perform more complicated activities, Dr. Winter says. Not to mention, if your mood is in the toilet, that could put a serious damper on your workout motivation.

Pain perception has also been linked to REM sleep. “Imagine two people with identical knee injury, but one person is getting good REM sleep and the other person isn’t,” says Dr. Winter. “The person who isn’t sleeping well is going to perceive that pain as being a lot worse. It has to do with the way our brain gates stimuli.” (Related: Is Muscle Pain a Good or Bad Sign?)

How Can You Get More REM Sleep?

The first thing you can do: Get more total sleep. The average American sleeps 6.8 hours a night, according to a Gallup poll-and 40 percent log less than six hours. “If you only have a four-, five-, or six-hour time window to sleep, just by natural physiology you’ll get a higher percentage of deep sleep and a lower percentage of REM sleep,” says Heneghan.

But your sleep habits are also important. “People who go to bed more irregularly tend to actually sleep less than average, and they also tend to see less of the REM than those who are more regular their sleep hygiene,” says Heneghan. (That’s why sleep docs generally advise against trying to “make up for lost sleep” on the weekends.)

In a 2017 study using data from over 6 million Fitbit trackers, researchers found that while sleeping longer can lead to getting more deep and REM sleep, sleeping seven to eight hours gives you the highest combined percentage of time in these stages. (The Fitbit tracks your heart rate, which tends to spike during REM as your body actually responds to the situations in your mind, says Heneghan.) Waking up earlier than usual was also shown to impact the percentage of REM sleep you get.

Lastly, don’t use a glass of wine or a couple beers as a crutch to fall (or stay) asleep. “Alcohol is extremely suppressive of REM sleep,” says Dr. Winter. “Other medications can suppress it, too, like some of the common medications we use for depression. (Related: Did You Know There Are 4 Different Types of Depression?) So talk to your doctor about any prescriptions you’re taking if you’re concerned about your sleep.”

The best thing you can do? Stick to a schedule, and make time for those seven to eight hours so your brain can really go through all the proper cycles of sleep. Not only will you enjoy a better night’s sleep, but it’ll help make your days go smoother as well.

  • By Ashley Mateo @ashleymateo

Whether you remember them or not, dreams are a normal part of sleep. Everyone dreams for a total of about two hours per night, and dreams can occur during any stage of sleep, although they’re most vivid during the REM phase. If you’ve ever woken up from a happy dream feeling relaxed and rested—or a scary one feeling on edge—you might have wondered whether the content of your shut-eye reveries can make a difference in your overall sleep quality. Here’s what’s really going on:

Scary Dreams Linger into the Next Day

Dreams can be positive or negative, and there’s no question that nightmares have ramifications that last even after you wake up. Falling back asleep after awakening from a nightmare is tough, and those scary images can affect your mood and behavior the next day, causing the equivalent of a bad-dream hangover.

Dreams Don’t Change Sleep Structure

Despite how it may feel, though, disturbing dreams don’t always have a significant effect on your sleep architecture, meaning they won’t necessarily change how much time you spend in the different stages of sleep or the number of times you awaken. What they can change: How long it takes to fall asleep at night and how challenging it is for your body to switch between non-REM and REM stages of sleep, which may leave you feeling less rested.

Does Good Sleep Equal Happy Dreams?

The relationship between dream quality and sleep quality could be likened to the old chicken-and-egg scenario: No one is sure which comes first. Research shows that good sleepers often describe their dreams as being more pleasant and joyful, while people who suffer from insomnia tend to have fewer positive emotions associated with their dreams, but whether or not a happy or sad dream means you’ll sleep better or worse still isn’t clear.

Dreams Reflect Reality

Dream content often relates back to what’s happening in your waking life. If you’re experiencing low stress and plenty of satisfaction in your day-to-day life, you may have more positive dreams. By contrast, if you’re depressed or anxious during the day, you may have more unpleasant dreams and compromised sleep quality at night.

The good news is that while you cannot control your dreams directly, you can work on improving your state of mind during the day. This, in turn, may help improve the quality of your dreams—and perhaps sleep—at night.

During a typical eight hour sleep pattern, an adult spends only around one and a half hours in REM sleep. REM sleep is sometimes referred to as paradoxical sleep, due to its neurological and respiratory similarities to wakefulness. But in other ways, it’s the deepest stage of sleep, and incredibly important to maintain healthy brain function in particular.

Note: The information on Sleepopolis is meant to be informative in nature and is not written by medical experts. Please consult a healthcare professional if you experience chronic sleep issues that may be linked to a medical condition.

REM is a mnemonic of Rapid Eye Movement. It’s the stage of sleep where eyes are darting back and forth, or “rapidly moving.” During REM sleep, blood flow towards the brain is decreased while blood flow to the muscles increases. It’s also estimated that REM sleep is where 80% of dreaming happens. It takes a while after falling asleep for REM to be attained, and it’s extremely important particularly for maintaining good brain health.

The Sleep Cycle

REM is the most brain-restorative part of sleep. A sleep cycle consists of around three stages of non-REM sleep before REM is reached. This cycle is important to help retain your circadian rhythm. If REM is disrupted, the next night your body may fall immediately into REM rather than following the sleep cycle. This can lead to feelings of grogginess, tiredness and lack of concentration – all of the typical side-effects associated with lack of sleep.

An infographic outlining the different stages of sleep and sleep cycles

  • Stage One – The Transitional Stage. This is the changeover period between wakefulness and sleep. Heart rate, breath and eye movements all slow down, and the muscles relax and may twitch slightly. Brain waves also begin slowing.
  • Stage Two – The Light Stage. This is a period of light sleep. Body temperature and muscle movement drop, and the brain waves slow apart from quick bursts of electrical activity.
  • Stage Three – Slow Wave Sleep. This is a deeper sleep, during which heart rate and breath are at their slowest and muscles at their most relaxed. It can be difficult to wake someone from this stage.
  • Stage Four – Deep Sleep. This is the deepest sleep stage, similar to tage three but with even less brain activity and a similarly low heart rate and rate of breath.
  • Stage Five. This is REM sleep, categorized by quickening of eye movements. Brain waves become more similar to those during wakefulness. This is where the majority of dreaming occurs. Breathing and heartbeat speed up, and muscles become stiff to stop you acting out your dreams.

During NREM (Non-REM) sleep, the body repairs itself – in particular the bones, body tissues and immune system. It seems that REM sleep is more important for repairing of the brain. It improves memory recall and reduces mental fatigue, alongside having emotional benefit.

Many people think of REM sleep as “dreaming sleep.” Most people dream for around two hours per night. While some dreaming does occur in other stages of the sleep cycle, it’s true that the majority of dream happen during REM sleep. There is still some uncertainty about the actual cognitive function of dreams, but some researchers postulate that dreams are where the brain organizes thoughts, feelings and emotions, which helps regulate mood and boost brain function.

Why We Need REM Sleep

Without REM sleep, no matter how long you’re actually sleeping for, you won’t wake up feeling refreshed and invigorated. It’s absolutely essential in order to avoid feelings of daytime sleepiness and fatigue, and to ensure maximum concentration and work performance.

REM sleep is also important for repairing and protecting the brain. Without it, pathways through which memories are formed and stored can become damaged. It seems REM sleep is hugely beneficial to brain creativity, too. Immediately after waking the brain is “hyper-associative” – meaning likely to perform better at creative problem solving, anagrams and puzzles.

REM Sleep Deprivation

REM sleep deprivation, simulated in studies, has been shown to cause mild psychological disturbances like anxiety, erratic mood swings, low concentration and even mild hallucination. Appetite also tends to increase. Generally REM sleep deprivation seem to have similar symptoms to sleep deprivation in general. Even if you’re getting enough hours of sleep, if your circadian rhythms are disrupted and REM sleep is prevented, you will likely not feel as well rested and refreshed.

How To Boost REM Sleep

An infographic detailing was to improve REM sleep

As we age, the amount of the sleep cycle spent in REM sleep drops. Babies spend as much as 50% of their time asleep in REM, while adults only around a third. And as we age, that can drop to eve lower than 20%. REM sleep is hugely important for mental and physical health – so here’s how to make sure you’re getting the most you can.

  • Keep A Regular Schedule. It’s generally accepted that going to sleep and waking up at the same time each day helps preserve circadian rhythms and allow for better quality REM sleep.
  • Have A Soothing Night Time Routine. Gently signalling to the brain that sleep is coming can help it come more easily. Things like having a bath, reading a book or meditating can act as this sort of signal.
  • Avoid Alcohol And Rich Food Before Bed. Both alcohol and rich food can stop the brain from achieving REM sleep, and can actually make it difficult to fall asleep at all.
  • Ban Afternoon Caffeine. Any caffeine consumed after lunchtime can interfere with the brain’s ability to switch off, and prevent good quality sleep.
  • Keep Mental Health In Check. Anxiety, depression, stress and other mental health problems can cause issues with sleeping. Trying to maintain stable moods and meditation can help – although if the problem is truly affecting your sleep and your life, consult with a doctor.
  • Get Your Environment Just Right. Many environmental factors can inhibit REM sleep, such as noise pollution, light pollution or an uncomfortable bed. Ensuring your environment is one which offers your personal maximum comfort will help sleep come easier and be of higher quality.

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Annie Walton Doyle

Annie Walton Doyle is a freelance writer based in Manchester, UK. Her work has appeared in The Huffington Post, The Daily Telegraph, Professional Photography Magazine, Bustle, Ravishly and more. When not writing, she enjoys pubs, knitting, nature and mysteries.

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Why Sleep Is So Important

Many hard-charging managers pride themselves on their ability to work long hours and get by on 5 or 6 hours of sleep. But the truth is that they’re shortchanging themselves — and their companies.

“Sleep is not a luxury,” says Dr. James O’Brien, medical director of the Boston SleepCare Center in Waltham, Mass. “It’s a necessity for optimal functioning.”

When you sleep, your brain catalogues the previous day’s experiences, primes your memory, and triggers the release of hormones regulating energy, mood, and mental acuity. To complete its work, the brain needs 7 to 8 hours of sleep. When it gets less, your concentration, creativity, mood regulation, and productivity all take a hit.

How sleep works
To understand why the right amount of shut-eye is so important to performance, it helps to know how sleep works.

Healthy sleep is divided into four-stage cycles. As we progress through stages 1 and 2, we become increasingly unplugged from the world until we reach the deep sleep that happens in stage 3. In deep sleep, both brain and body activity drop to their lowest point during the cycle, and blood is redirected from the brain to muscles.

The fourth and final stage is named for the rapid eye movement — REM — that is its defining characteristic. Our brains become busily active in REM sleep, too, even more so than when we are awake. Dreaming happens during this stage.

In a full night’s sleep, we experience three or four such cycles, each lasting 60 to 90 minutes.

The work sleep does
Different yet equally important restorative work happens during deep sleep (stage 3) and REM sleep (stage 4).

Deep sleep is crucial for physical renewal, hormonal regulation, and growth. Without deep sleep, you’re more likely to get sick, feel depressed, and gain an unhealthy amount of weight. According to the National Sleep Foundation’s 2008 Sleep in America poll, those who sleep less than 6 hours per night on workdays are significantly more likely to be obese than those who sleep 8 hours or more (41% vs. 28%).

In REM sleep — stage 4 in the sleep cycle — the brain processes and synthesizes memories and emotions, activity that is crucial for learning and higher-level thought. A lack of REM sleep results in slower cognitive and social processing, problems with memory, and difficulty concentrating. The same 2008 sleep poll found that people who sleep less than 6 hours per night during the workweek are twice as likely as their better-rested colleagues to report difficulty in concentrating.

A deficit in sleep leads to deficits in work performance
Performing complex tasks and navigating complicated relationships — the heart and soul of a manager’s work — both become much harder to do when REM sleep suffers. And when you cut back on sleep, your REM sleep suffers the most.

There are two reasons for this:

  1. Your brain, when confronted with sleep deprivation, opts for lighter sleep and hence less REM sleep.
  2. Later sleep cycles tend to have longer REM periods than cycles earlier in the night. When you sleep through only one or two cycles instead of three or four, your REM sleep is disproportionately affected.

When your brain is starved of REM sleep, concentrating on a single activity is challenging. Multitasking — an inescapable bane of managerial work — becomes exponentially more so.

A deficit of REM sleep also makes it tougher to pick up on nuances in discussions or negotiations.

“When you’re trying to understand the subtext of what someone is saying, your brain needs to use a bunch of programs at the same time,” says Dr. Gandis Mazeika, head of Sleep Medicine Northwest in Seattle. “If you’re sleep deprived, that’s hard to do.”

In addition, recent research shows that sleep deprivation takes a toll on decision-making ability.

Getting more from the sleep you get
Given the demands facing managers today — working in a 24/7, always-on environment is a big one — a full night’s sleep is sometimes an impossible dream. Fortunately, there are ways to get more out of the time you do manage to spend in sleep:

  • Avoid caffeine. Cut out caffeinated coffee, tea, and soda ideally 10 hours before bedtime — and chocolate, too. When you sleep, make it a commitment.
  • Try to nod off quickly. To fall asleep fast, you can occasionally use a sleeping supplement. But be careful. For example, the much-prescribed Ambien is specifically for sleeping seven to eight hours. If you don’t have that much time, don’t use it. Although some antidepressants can help you feel drowsy enough to fall asleep, they also tend to compromise REM, says Dr. O’Brien. A more healthful approach for some is to meditate a half-hour before hitting the bed.
  • Darken the room completely. Your brain creates a hormone called melatonin that senses when it’s dark out and primes you for sleep. If you try to sleep amid too much light, your brain may decide you’re not ready for bedtime after all. So turn off the TV, shut down the computer, turn the clock to the wall, and close the blinds tightly. Use an eye mask if you’re sleeping during the daytime.
  • Sleep in a restful environment. Make sure the room is quiet and your BlackBerry is out of hearing range. Sleep on a comfortable mattress; Dr. Mazeika advises you get a new one every five to 10 years.

Exploit the power of power naps
Don’t forget that brief day-time naps can be helpful. If at all possible, close your office door (if you have one) and try to doze for 10 to 20 minutes.

“Power naps are real and help you feel refreshed,” says Dr. O’Brien.

But keep the naps short, he warns. With a longer nap, you’re likely to wake up while in deep sleep and feel worse than before. It can take up to 30 minutes to feel fully alert after awakening from deep sleep.

By keeping your nap to 10-20 minutes, you should be able to achieve stage 2 in the sleep cycle and wake up energized rather than groggy. A short power nap should provide enough of a boost to keep your performance going strong the rest of the day — and is more effective (as well as healthier) than a cup of coffee.

REM sleep is important because it is the restorative part of our sleep cycle. Typically, you begin the sleep cycle with a period of non-REM sleep followed by a very short period of REM sleep. The period of non-REM sleep is made up of stages 1 to 4. Each stage can last from 5 to 15 minutes. A completed cycle of sleep consists of a progression from stages 1 to 4 before REM sleep is attained, then the cycle starts over again.

However, if your REM sleep is disrupted even one night, your body won’t follow its normal circadian sleep cycle (“inner clock”) progression. Instead, you will slip directly into REM sleep as a result of not getting the right amount of sleep the night before. You will also go through extended periods of REM sleep until you “catch up” on this stage of sleep. Poor sleep cycles can cause grogginess, a lack of concentration and more.

People often associate REM sleep with dreams. While dreams can occur in other deep sleep stages, most dreams occur during REM sleep. Researchers are still trying to learn exactly why people need REM sleep, why we dream, and what purpose our dreams serve. However, some researchers theorize that dreams are the ways in which the brain processes emotions, information, memories, and stress.

Changing your way of life so that every night you can get the proper sleep you need is key. Here are a few tips you can do to increase your chances of a good night’s sleep:

  • Keep a regular sleep schedule
  • Create a relaxing bedtime routine
  • Manage your thoughts
  • Stay away from big meals at night
  • Avoid alcohol before bed
  • Eliminate caffeine after lunch

If you’re looking for extra aid in improving your sleep, try Azumio’s Sleep Time app. Sleep Time measures your sleep efficiency and REM cycles as well acts as an alarm clock that will wake you up during your lightest sleep phase. See what thousands of users are raving about by downloading Sleep Time today!

Sleep Time is a free app available on iOS and Android. For more information, visit or follow us on Twitter and Facebook. If you have any questions, please email us at [email protected]

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How Much Deep, Light, and REM Sleep Do You Need?

In healthy adults, about 13 to 23 percent of your sleep is deep sleep. So if you sleep for 8 hours a night, that’s roughly 62 to 110 minutes.

However, as you get older you require less deep sleep.

During deep sleep, a variety of functions take place in the mind and body:

  • memories are consolidated
  • learning and emotions process
  • physical recovery occurs
  • blood sugar levels and metabolism balance out
  • the immune system is energized
  • the brain detoxifies

Without deep sleep, these functions cannot take place and the symptoms of sleep deprivation kick in.

On the other hand, there doesn’t seem to be any such thing as too much deep sleep.

How much REM sleep should you get

Although there’s no official consensus on how much REM sleep you should get, dreaming is most common during this stage. Experts believe that dreaming helps you process emotions and solidify certain memories.

For most adults, REM takes up about 20 to 25 percent of sleep, and this seems to be healthy during average sleep cycles. However, sleep research is raising some interesting questions. One recent study suggested that higher amounts of REM sleep may be associated with depression. But don’t go making sudden changes in your sleep habits — it is not clear which is the cause and which is the effect.

How much light sleep do you need?

Although sleep scientists believe that light sleep is good for you, there is no minimum to strive for. Light sleep is usually the default stage, one that is nearly impossible to avoid if you are asleep at all.

Too much overall sleep on a regular basis, however, is linked to obesity, depression, pain, heart disease, and even increased risk of death.

How much deep and light sleep do children need?

Babies and children need more sleep than adults. Babies need the most, spending about 16 of every 24 hours asleep. Approximately 50 percent of their slumber is spent in the REM stage, while the other 50 percent is divided between stages 1 through 4 and NREM sleep that cycles between light and deep.

As children grow older, the amount of sleep they need varies:

  • toddlers: 11 to 14 hours
  • preschoolers: 10 to 13 hours
  • school-aged children: 9 to 12 hours
  • teens: 8 to 10 hours

With enough sleep that appears to be restful, it’s likely that the light, deep, and REM ratio is exactly where it should be in young people.

If they’re having trouble with falling asleep, staying asleep, or sleeping well, or if they are sleeping way too much for their age, children may be irritable, could have learning and memory problems, or may be more susceptible to illness.

Sleep Basics

What happens when you sleep?

When you sleep, your body rests and restores its energy levels. However, sleep is an active state that affects both your physical and mental well-being. A good night’s sleep is often the best way to help you cope with stress, solve problems, or recover from illness. Sleep is prompted by natural cycles of activity in the brain and consists of two basic states: rapid eye movement (REM) sleep and non-REM (NREM) sleep, which consists of 4 stages.

During sleep, the body cycles between non-REM and REM sleep. Typically, people begin the sleep cycle with a period of non-REM sleep followed by a very short period of REM sleep. Vivid dreams tend to occur during REM sleep.

What is REM sleep?

The period of REM sleep is marked by extensive physiological changes. These include:

  • Accelerated respiration
  • Increased brain activity
  • Eye movement
  • Muscle relaxation

Usually, REM sleep occurs 90 minutes after sleep onset. The first period of REM typically lasts 10 minutes, with each recurring REM stage lengthening, and the final one lasting an hour. Polysomnograms (sleep readings) show wave patterns in REM to be similar to stage 1 sleep. In people without sleep disorders, heart rate and respiration speed up and become erratic during REM sleep. The face, fingers, and legs might twitch. Intense dreaming occurs during REM sleep as a result of heightened cerebral activity, but paralysis occurs simultaneously in the major voluntary muscle groups. REM is a mixture of encephalic (brain) states of excitement and muscular immobility. For this reason, it is sometimes called paradoxical sleep.

The percentage of REM sleep is highest during infancy and early childhood. During adolescence and young adulthood, the percentage of REM sleep declines, and the percentage decreases further in older age. In many cases, older people enter REM sleep more quickly and remain in REM sleep longer.

What is NREM sleep?

The period of NREM sleep is made up of stages 1 to 4. Each stage can last from five to 15 minutes. Stages 2 and 3 repeat backwards before REM sleep is attained.

Stage 1

Polysomnography shows a 50 percent reduction in activity between wakefulness and stage 1 sleep. The eyes are closed during stage 1 sleep. However, if aroused from this stage of sleep, a person might feel as if he or she has not slept. Stage 1 might last for five to 10 minutes.

Stage 2

This is a period of light sleep during which polysomnographic readings show intermittent peaks and valleys, or positive and negative waves. These waves indicate spontaneous periods of muscle tone mixed with periods of muscle relaxation. The heart rate slows and the body temperature decreases. At this point, the body prepares to enter deep sleep.

Stages 3 and 4

These are deep sleep stages, with stage 4 being more intense than stage 3. These stages are known as slow-wave, or delta, sleep.

During NREM sleep, the body repairs and regenerates tissues, builds bone and muscle, and appears to strengthen the immune system. As you get older, you get less NREM sleep. People under age 30 have about two hours of restorative sleep every night, while those over 65 might get only 30 minutes.

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Exploring the Mystery of REM Sleep

“To sleep, perchance to dream”

What role does REM sleep play in humans and animals? And why do we dream at all? Ever since the 1950s, researchers have known that sleep occurs in different stages and that the deepest part of sleep, which usually happens in the early hours of the morning, can be recognized by rapid, random eye movements.

This stage of sleep is now known as REM (rapid eye movement) sleep and is linked to extremely vivid dreaming. Among the different theories about REM sleep’s function are that it helps in forming new memories, stimulates the central nervous system, and restores brain chemistry to a normal balance.

Along with rapid eye movements, REM sleep is also recognized by low muscle tone and a rapid, shallow EEG pattern. In most adults, REM sleep can happen four or five times on average each night making up only 25% of the total time spent sleeping. Researchers have also found evidence of REM sleep in almost all land-based mammal and bird species and even some aquatic mammals such as dolphins.

As for how REM sleep first evolved, a recent article published in the journal Dreaming has suggested an intriguing new hypothesis. Written by Ionnanis Tsoukalas of Sweden’s Stockholm University, the article suggests that REM sleep, and dreaming in general, evolved out of an ancient defense mechanism still seen in many species. This defense mechanism is known as tonic immobility, or the faint response.

When rabbits react to apparent threats, they suddenly become rigid and unmoving. In fact, they can often seem completely dead which is usually their last line of defense when “fight or flight” is no longer an option. By “playing possum”, a rabbit can avoid a fatal bite by blending in with the surroundings and possibly escape.

Tonic immobility is seen in a wide range of land-based and aquatic species, including sharks, lizards, and many small mammals and birds. Researchers have managed to trigger tonic immobility using electric shock, or even gentle stroking in some cases. Reports of “animal hypnosis” dating back to the 17th century have been based on the tonic immobility responses in animals such as rabbits and chickens. Though some researchers have suggested that it also can occur in humans experiencing extreme trauma, this remains controversial.

According to Tsoukalas’ hypothesis, REM sleep shares many common features with tonic immobility, including inability to move while sleeping, also known as sleep paralysis. As he points out in his article, “A fearful stimulus can induce the fight-or-flight reflex—which increases the muscle tone of the extremities—but it can also induce tonic immobility—which results in a gradual or sudden decrease in muscle”. This leads to what he refers to as a “fight-flight-or faint reflex”.

Among other ways that REM sleep and tonic immobility are similar are:

  • Both states show a similar EEG pattern with additional “theta” waves linked to the brain’s hippocampus (which plays an important role in memory and spatial perception)
  • Both states show strong loss of muscle tone and suppression of reflexes
  • Both states show changes in heart and breathing rate
  • Both states affect the body’s ability to regulate body heat
  • Both states show changes in the brain’s biochemistry including increased acetycholine and decreased serotonin and norepinephrine in the brain stem
  • Significant changes in eye movement, facial twitches, and jerking limbs in both states
  • Also, both states rarely last longer than a few minutes, varying from five seconds to 20 minutes

Both tonic immobility and REM sleep appear to be linked to parts of the brainstem involved with sleeping, eating, and breathing. They also appear to have very similar roles in helping the body recover from traumatic experiences. As an emergency reaction to extreme danger, tonic immobility prepares the body to cope with trauma and heal afterward. This happens through the release of brain chemicals such as acetycholine to reduce pain and increase drowsiness. Research into REM sleep has found many of these same biochemical markers which suggests that the vivid dreaming experienced during REM episodes plays a strong role in helping the body cope with stress and trauma.

One of the most intriguing suggestions that Tsoukalas raised was that the link between tonic immobility and REM sleep might provide evidence for the threat rehearsal theory proposed by evolutionary psychologists. Basically, the theory proposes that dreaming can be used to simulate threatening events to provide dreaming animals and humans with a way to review different ways to avoid these threats when awake. In the same way tonic immobility allows animals to avoid extreme threats, REM sleep may well let us practice how to cope successfully, as well as giving our bodies the chance to “recharge our batteries”. Even the rapid eye movements we show during dreaming can reflect the need to gather as much information as possible about our surroundings, much as we would if we were awake and in a dangerous situation.

Though Ionnanis Tsoukalas’s hypothesis raises fascinating questions about the origin and purpose of dreaming, more research is still needed to test the relationship between REM sleep and tonic immobility. Along with learning more about why we dream, new research can help us understand why our perception of reality is so distorted when we sleep and possibly to discover more about less-understood phenomena such as “near death experiences”, and “waking dreams”. As we learn more about dreaming, we might develop better tools for dealing with sleep disorders as well as better ways of helping the body heal after trauma.

Solving one of the fundamental mysteries about how and why REM sleep occurs may truly be such stuff as dreams are made of.

Strengthen your brain by resting it

New research on the potential benefits of sleep–including stronger memory and longer attention spans–were the focus of research presented by psychologists at the Western Psychological Association’s 84th Annual Convention in Phoenix, April 22-25. The association’s conference dedicated several sessions to discussing sleep, its effects on health and impact on social policy.

The conference featured leading experts in sleep research such as Cheryl Spinweber, PhD, of the Scripps Mercy Sleep Disorders Center, Richard Bootzin, PhD, of the University of Arizona, and Tracy Kuo, PhD, of the Stanford Sleep Disorders Clinic, who discussed a range of topics, including sleep’s relationship to mood and Americans’ pervasive sleep debt. James B. Maas, PhD, a professor and former chairman of the psychology department at Cornell University, headlined one session that discussed sleep’s many benefits–such as improved health and memory.

“We have a crisis in America,” said Maas, author of the best-selling book “Power Sleep” (Villard Books, 1998). “Most adults are moderately to severely sleep deprived, and it affects their productivity, their work and their relationships. If we treated machines like we treat the human body, we would be accused of reckless endangerment.”

Maas stressed that good sleep isn’t a luxury, but a necessity. “Your alertness, energy, performance, thinking, productivity, creativity, safety and health will be affected by how much you sleep,” he said. “Good sleep is the best predictor of life span and quality of life.”

Sleeping and learning

Besides boosting alertness, sleep–particularly rapid eye movement (REM) sleep–is a way for the brain to store new information into long-term memory, said Maas. The brain, he explained, accomplishes this through a phenomenon that researchers have only recently come to understand: sleep spindles.

Sleep spindles–one- to two-second bursts of brain waves that rapidly wax and wane at strong frequencies, so-called for the spike image they form on an EEG reading–occur during REM sleep. The REM phase usually takes place toward the end of the night, between the sixth and eighth hours of sleep, when people are most likely to dream. In fact, Maas said, the brain’s neural patterns during REM sleep resemble those of its awakened state.

During REM sleep, the brain busily replenishes neurotransmitters that organize neural networks essential for remembering, learning, performance and problem solving, he explained. Conversely, he says depriving the brain of sleep “makes you clumsy, stupid and unhealthy.”

For example, say you take golf lessons on a Wednesday to improve your swing before your next round on Saturday. After seeing progress, you sleep six hours each night for the rest of the week–about the median amount of sleep American adults get nightly.

However, “by the time the weekend comes around, you’re worse off than if you had not taken the lesson at all,” Maas said.

Why? During REM sleep, the brain transfers short-term memories in the motor cortex to the temporal lobe to become long-term memories, Maas said. Research suggests sleep spindles fire away as the temporal lobe makes sense of new information and stores it in long-term memory.

Yet sleeping fewer than six hours may block sleep spindles and stop new information from entering long-term memory, which helps acts such as a golf swing become automatic, Maas said.

While researchers have known of the spindles’ existence for some time, only in recent years have they posited this theory, Maas said. For example, he noted that psychologists Matthew Wilson, PhD, of the Massachusetts Institute of Technology, and Alan Hobson, MD, of Harvard, have recently published breakthrough research on the subject by measuring the neural patterns of sleeping rats that had run a maze earlier that day. They found that the rats’ brain patterns during sleep were nearly identical to the patterns they exhibited while running the maze. The patterns were so similar, in fact, that the researchers could tell what part of the maze the rat was dreaming about.

However, rats whose REM sleep was blocked did not navigate the maze as well during a second run as did rats with REM sleep. Some researchers contend that the results do not conclusively demonstrate that REM sleep is essential for short-term memory. Some studies find that antidepressant drugs that inhibit selective serotonin in the brain, which interferes with REM sleep, still do not disrupt learning and memory. But Maas said the research indicates that dreams are more than just abstract thoughts. Rather, they represent the brain’s attempts to make sense of daily events, he explained.

“Practice during sleep is essential for later performance,” Maas said. “If you want to improve your golf game, sleep longer.”

Subjective sleep

Other research presented in Phoenix suggests that just as important as how long a person sleeps is how recuperative a person perceives their sleep as being.

Robert Hicks, PhD, professor emeritus at San Jose State University, said his research has found that some people say sleep completely rejuvenates them, while others feel they can’t sleep enough–even though the two groups sleep the same amount. Hicks presented research he conducted using a self-report questionnaire that asks participants to rate whether they agree with statements such as “I feel I cannot think clearly,” “I have trouble maintaining physical effort for long periods” and “I am less able to deal with emotional problems.”

He found that participants scoring in the highest and lowest 20 percent slept nearly identical periods of time each night, but that 62 percent of low-fatigue people were satisfied with their sleep, while 68 percent of high-fatigue people were dissatisfied with it. And when he asked them how many additional hours of sleep they felt they needed each night to awake fully rested, the high-fatigue group reported that it needed about one and a half more hours, while the low-fatigue group reported needing only about an hour.

“They’re sleeping almost the same, but they’re perceiving the value of their sleep in a very different way,” he said.

Why the difference? Hicks surveyed the two groups and found they varied in one unexpected area: The high-fatigue group reported suffering more frequently from post-traumatic nightmares and night terrors in which they relived awful, traumatic past experiences. These types of dreams are commonly associated with intense emotions even during sleep and can cause the dreamer to wake up frequently at night.

While Hicks continues to research this area to see if night terrors actually do contribute to the dreamers’ perceptions that they did not sleep enough, he said that the effect of sleeping through emotionally intense night terrors might lead people to report that their sleep was not recuperative–even though they still slept the same amount as those who did not have traumatic nightmares.

Benefits of rem sleep

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