But What Is Good Sleep
While most of us still think of a solid eight hours as being enough sleep, this doesn’t take into account the number of times you wake up, or how much time is spent in each sleep cycle. We also vary, person to person, in how much sleep we need to feel recovered the next day.
A good night’s sleep consists of around five or six sleep cycles. One cycle consists of the following:
Stage 1 The drowsy, relaxed state between being awake and nodding off.
Stage 2 A deeper sleep where your body temperature cools a little and you become disengaged from your surroundings.
Stages 3 and 4 ‘Deep sleep’. It’s harder to wake up from deep sleep because this is when there is the lowest amount of activity in your body. It’s also the part of sleep where your body rebuilds itself and restores energy, and hormones are released. This is the good stuff!
After deep sleep, we slip back into Stage 2 for a few minutes before entering ‘dream sleep’ known as REM sleep. Each cycle lasts around 1.5 hours and we need to experience all four stages in order to wake up rested.
Rem Sleep Rapid Eye Movement
REM sleep is the sleep stage in which dreaming occurs. When you enter into REM sleep, your breathing becomes fast, irregular, and shallow. Your eyes will move rapidly, and your muscles become immobile. Heart rate and blood pressure increase. Men may develop erections. About 20 percent of sleep is REM sleep for adults.
REM sleep is also the phase of sleep in which you dream. This sleep phase begins about 70 to 100 minutes after you fall asleep. The first sleep cycle has a shorter phase of REM sleep. Toward morning, the time spent in REM sleep increases, while deep sleep stages decrease.
Researchers do not fully understand REM sleep and dreaming. They know, however, that they are important in the creation of long-term memories. If a persons REM sleep is disrupted, the next sleep cycle does not follow the normal order, but often goes directly to REM sleep until the previous nights lost REM time is made up.
Sleep And Circadian Rhythms
Circadian rhythms are regular changes in mental and physical characteristics that occur in the course of a day . Most circadian rhythms are controlled by the bodys biological clock. This clock, called the suprachiasmatic nucleus or SCN, is actually a pair of pinhead-sized brain structures that together contain about 20,000 neurons. The SCN rests in a part of the brain called the hypothalamus, just above the point where the optic nerves cross. Light that reaches photoreceptors in the retina creates signals that travel along the optic nerve to the SCN.
Signals from the SCN travel to several brain regions, including the pineal gland, which responds to light-induced signals by switching off production of the hormone melatonin. The bodys level of melatonin normally increases after darkness falls, making people feel drowsy. The SCN also governs functions that are synchronized with the sleep/wake cycle, including body temperature, hormone secretion, urine production, and changes in blood pressure.
When travelers pass from one time zone to another, they suffer from disrupted circadian rhythms, an uncomfortable feeling known as jet lag. For instance, if you travel from California to New York, you lose 3 hours according to your bodys clock. You will feel tired when the alarm rings at 8 a.m. the next morning because, according to your bodys clock, it is still 5 a.m. It usually takes several days for your bodys cycles to adjust to the new time.
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What Do Sleep Trackers Monitor
A wide variety of sleep trackers have hit the market, with more beingreleased all the time. Many are wearable trackers that you can strap toyour wrist. Others clip on your pillow or sit on your bedside table.
Features of these devices vary, but some common capabilities include:
- Sleep duration: By tracking the time youre inactive, the devices can record when you fall asleep at night and when you stir in the morning.
- Sleep quality: Trackers can detect interrupted sleep, letting you know when youre tossing and turning or waking during the night.
- Sleep phases: Some tracking systems track the phases of your sleep and time your alarm to go off during a period when youre sleeping less deeply. In theory, that makes it easier for you to rouse.
- Environmental factors: Some devices record environmental factors like the amount of light or temperature in your bedroom.
- Lifestyle factors: Some trackers prompt you to enter information about activities that can affect sleep, such as how much caffeine youve had, when youve eaten or whether your stress level is high.
What Does a Typical Sleep Cycle Look Like?
During a typical night, you cycle through various stages of sleep:
This cycle repeats every 90 to 110 minutes. As sleep progresses, REM cyclesincrease in length.
Tips For Getting Great Sleep & Improving Sleep Cycles
While there is no simple formula for boosting the amount of time you spend in any of the stages of sleep, there are behaviors you can adopt to give yourself the best chance at an efficient night of sleep. Here are some good practices weve learned from the leading studies on sleep science:
The darker your room, the better you sleep. Light influences the wake stage of sleep so the darker you can get your room, the more time you will get in the restorative stages.
Set your room temperature at or around 68 degrees. You will fall asleep quicker when your bedroom is slightly cool.
Your bed is not a multi-use space. The more you can train your body to associate your bed with sleep, the more adept you will be at falling asleep in that space. As such, avoid work and leisure time spent in your bed.
Screens are stimulating and keep you awake. Avoid using your phone or computer in bed, screen time makes it more difficult to fall asleep.
Set a cut-off time for caffeine intake. Caffeine has a lingering presence for many hours after consumption. For greater sleep efficiency, consciously refrain from caffeine consumption at least 4 hours before bed.
Plan ahead when consuming alcohol. Just as caffeine intake impacts the body hours after consumption, so too does alcohol. Keep this in mind on a night out so that your sleep performance doesnt suffer.
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Analyzing Sleep Stages & Trends With Whoop: Slow Wave Sleep Vs Rem
The long-term sleep trends accessible on the WHOOP web app give you the opportunity to unpack nighttime habits that either help or hurt your sleep efficiency. Heres an example of one WHOOP athletes data:
When looking at the 2-week average breakdown below, we see plenty of time in bed. However, the ratio of time spent in REM and SWS shows where this athlete is coming up short:
For REM, the athlete is getting 1 hour and 16 minutes on average per night. This is 13% of the total time in bed, glaringly low in comparison to the goal of roughly 22% each night. To assess a root cause, the athlete might look at the night statistics from Feb 3, 4, 5, and 11 pictured in the bar graph above. For this athlete, a drinking event preceding each low REM sleep seems to be the common thread .
For SWS, this athlete is getting 1 hour and 43 minutes a night. Measured against the average total time in bed, this means that 18% of their sleep is spent in the SWS stage. This is a healthy ratio, but if the athlete hopes to investigate behaviors that could contribute to this trend it would be appropriate to select Jan 31, Feb 9, and Feb 10 to see if anything stands out. Here, it appears that the athlete got less than his or her average total amount of sleep on those nights and, on 2 of the 3 occasions, the sleep was following a very high strain day.
What Is A Sleep Debt
If you havent slept well or long enough for a few days, you might create a sleep debt. Once your debt builds up, you may feel physically and mentally exhausted. Try to make sure you get enough sleep every night to avoid creating this debt. You cant necessarily make up your debt by sleeping a lot on the weekends. Its best to get enough sleep all week long.
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What Is The State Of The Science Involving Narcolepsy
In the past few decades, scientists have made considerable progress in understanding narcolepsy and identifying genes strongly associated with the disorder.;
Groups of neurons in several parts of the brain interact to control sleep, and the activity of these neurons is controlled by a large number of genes.; The loss of hypocretin-producing neurons in the hypothalamus is the primary cause of type 1 narcolepsy. ;These neurons are important for stabilizing sleep and wake states.; When these neurons are gone, changes between wake, REM sleep, and non-REM sleep can happen spontaneously.; This results in the sleep fragmentation and daytime symptoms that people with narcolepsy experience.
However, it is important to note that these gene variations are common in the general population and only a small portion of the people with the HLA-DQB1*06:02 variation will develop narcolepsy.; This indicates that other genetic and environmental factors are important in determining if an individual will develop the disorder.
How Does Sleep Work
There are two distinct states of sleep. These are rapid-eye-movement sleep and non-rapid-eye-movement sleep . Generally speaking, the average adult will spend around 75 percent of their sleep duration in NREM sleep and around 25 percent of their sleep duration in REM sleep.
Sleep usually begins after a period of quiet wakefulness that can last up to half an hour. When we first fall asleep, we typically enter NREM sleep followed by REM sleep.
NREM sleep has three distinct stages that occur in the following order:
What Are The Symptoms
Narcolepsy is a lifelong problem, but it does not usually worsen as the person ages. ;Symptoms can partially improve over time, but they will never disappear completely.; The most typical symptoms are excessive daytime sleepiness, cataplexy, sleep paralysis, and hallucinations.; Though all have excessive daytime sleepiness, only 10 to 25 percent of affected individuals will experience all of the other symptoms during the course of their illness.
- Sleep paralysis. ;The temporary inability to move or speak while falling asleep or waking up usually lasts only a few seconds or minutes and is similar to REM-induced inhibitions of voluntary muscle activity.; Sleep paralysis resembles cataplexy except it occurs at the edges of sleep.; As with cataplexy, people remain fully conscious.; Even when severe, cataplexy and sleep paralysis do not result in permanent dysfunctionafter episodes end, people rapidly recover their full capacity to move and speak.
- Hallucinations. ;Very vivid and sometimes frightening images can accompany sleep paralysis and usually occur when people are falling asleep or waking up.; Most often the content is primarily visual, but any of the other senses can be involved.;
Additional symptoms of narcolepsy include:
What Is A Sleep Cycle
In short, the sleep cycle is the process your brain and body goes through to repair and restore your physical and mental state when youre asleep. It consists of these 4 stages:
Here is a more scientific definition from Wikipedia:
Now youre aware of the four stages, lets take a look at how long each one lasts
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What Are The 5 Stages Of The Sleep Cycle
Non-REM Sleep of the Sleep Cycle
- Stage 1 Sleep. Stage 1 of the sleep cycle is the lightest stage of sleep.
- Stage 2 Sleep. Stage 2 usually follow Stage 1 and represents deeper sleep.
- Stage 3 and 4 Sleep Deep Sleep. Stage 3 and Stage 4 sleep of the sleep cycle are progressively deeper stages of sleep.
- Dreaming during NREM.
Tips For Improved Sleep
All stages of sleep are important and your body naturally regulates your sleep cycles to make sure you get what you need.
Tools like the Oura Ring can help you monitor your sleep patterns and generate a Sleep Score each night to help you improve your sleep.
Check out these patterns to see if your sleep is being disrupted:
- Increase in deep sleep after a hard workout: Exercise can increase your bodys prioritization of deep sleep the night after an intensive workout.1
- Higher REM rebound after sleep deprivation: When you recover from a period of sleep deprivation, your body prioritizes deep sleep for the first few nights to repair your body and prepare for action. After several nights of sufficient deep sleep, REM sleep rebounds; to focus on your brain.
- Interrupted sleep cycles after caffeine:Caffeine can increase the time it takes for you to fall asleep, cutting your sleep period short. Shorter sleep periods disproportionately cut down on your total REM sleep, as REM cycles are more likely to occur in later sleep cycles.
We all have those days when we just need our coffee. However, taking a look at your nightly patterns and acting on your desire to improve your sleep can help you face those days well rested.
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Why Is Sleep Important
The physiological changes that occur during sleep help to regulate different bodily functions, including:
Brain function: Each distinct sleep stage helps to restore cells in the brain and optimize its daytime performance. The brain will essentially reorganize itself and create new pathways to help you learn new information and consolidate memories. At the same time, it flushes out “toxic” byproducts that can negatively impact brain health and performance.
Sleep At Different Ages
Babies, children and teenagers need different amounts of sleep.
Also, sleep patterns change as babies and children get older. For example, as babies grow, they begin to sleep less during the day and more at night. And children generally need less sleep as they grow older.
Childrens sleep needs and patterns vary, so the information below is just a guide. Your childs sleep might be different.
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What Should Sleep Cycles Look Like
Are you worried that you dont get enough sleep and how that in turn, is affecting your life? Do you know how much sleep you should be getting? Did you know that for efficient snooze, you should be repeatedly moving through five stages of sleep? If youre in a daze when it comes to the answers to these questions, read on for more information.
How much sleep should I get per night?
We spend over a third of our lives in bed so its essential that we get to bed on time and catch enough zzzs. Sleep is a good indicator of health and wellbeing. Adults should aim to get between eight and nine hours nightly.
What are sleep cycles?
Each night while we are asleep, we move through a number of 90 minute sleep cycles. Each sleep cycle contains five stages of sleep.
During the initial four stages, you pass through non-rapid eye movement sleep. The last stage is when rapid eye movement sleep happens.
- Stage 1: This is a very light sleep, where you can be woken easily and you may experience hypnic jerks
- Stage 2: Again, a light sleep, where you dont dream but you can easily be woken up
- Stage 3-4: It is harder to wake up in this period and if you do, you will feel groggy and confused. While no dreams are had at this stage, sleepwalking sometimes occurs
- Stage 5: This is the deepest stage of sleep when dreaming occurs. Deprivation of this stage means you will be unable to form long term memories
Effects of sleep deprivation
- Weight Gain
- Lack of Ability to Form Long-term Memories
Toddlers: When And How Much They Sleep
Toddlers need 11-14 hours of sleep every 24 hours. Usually this is a sleep of 10-12 hours a night, and a nap of 1-2 hours during the day.
Some toddlers arent keen on going to bed at night. Often this is because theyd like to stay up with the family. This is the most common sleep problem reported by parents. It peaks around 18 months and improves with age.
Less than 5% of two-year-olds wake three or more times overnight.
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Things That Can Disturb Your Sleep
Getting enough sleep is essential to your health and wellbeing. There are different ways to improve your sleep and treat insomnia.
Many things can make sleeping difficult too, like alcohol, drugs and medication. Mental or physical illness can reduce your quality of sleep just as much as stress or working shifts at odd hours. Some people’s sleep is disturbed by nightly pauses in breathing or restless legs syndrome. Others wake up several times each night to go to the bathroom. During menopause many women find that their sleep is interrupted by hot flashes.
Grinding your teeth , talking in your sleep or sleepwalking can also affect how well you sleep. Nightmares can also make you wake with a start and influence how long and deeply you sleep. Jetlag is another factor that can really confuse your sleep-wake cycle for a while. Almost half of us snore. You often do not notice it yourself, but it can disturb others’ sleep.
Lack of sleep not only affects your quality of life. It can also be dangerous because it increases your chances of having accidents. This makes it important to find out the underlying cause if you are regularly sleeping poorly.