It is accepted that everything within the animal kingdom must sleep, yet the exact purpose and mechanism of sleep are only partly understood.
It always makes for an interesting topic as everyone can relate to it and has plenty of experience of it too.
Understanding sleep, the power of it, and how to get as much high-quality sleep as possible is one of the healthiest things we can do. We can all relate to how a loss of sleep can take its toll on our energy, mood, decision-making, and ability to handle stress.
Sleep should, therefore, be of top priority for our clients, who are typically seeking to improve their bodies and health. Many people try to sleep as little as possible, but just as exercise and nutrition are essential for optimal health and happiness, so is sleep.
No other activity delivers so many benefits with so little effort. It has a direct correlation to the quality of our waking life. This article will look at the true power of sleep, how it works and the importance of it.
The Role Of Sleep
The neuroscience of sleep is the study of the neuroscientific and physiological basis of the nature of sleep and its functions.
Despite sleep being of such importance to the human body, the purposes and mechanisms are only partially understood. It is assumed the key benefits we get from enough sleep have evolved over time, thus creating greater dependence on getting sufficient and quality sleep.
Sleep is a naturally recurring state characterized by reduced or absent consciousness, and the inactivity of nearly all voluntary muscles.
Sleep timing is controlled by the circadian clock, and in humans, to some extent by willed behavior. The circadian clock (also known as circadian oscillator) allows us to coordinate our biology and behavior with daily and seasonal changes in the day – night cycle. This in-built biological clock operates over a 24-hour period and receives daily corrective signals from the environment, primarily daylight and darkness. Circadian clocks are the central mechanisms which drive circadian rhythms.
The term circadian comes from the Latin ‘circa’, meaning ‘around or approximately’, and diem meaning ‘day’. An endogenous (built-in), entrainable oscillation of about 24 hours.
This clock is reset as the environmental changes through our ability to sense external cues of which the primary one is light. This clock is considered to be intertwined with most cellular processes.
When we sleep, the body doesn’t just shut down and switch off. In fact, while we rest, the brain oversees a wide variety of biological maintenance that improves our health markers and aids recovery.
Below is a number of key proposed functions of sleep:
Sleep is restorative, and without it we are not able to work, learn, create and communicate at our highest level. With time, lack of sleep can lead to mental and physical breakdown.
Sleep has also been shown to be linked to the immune system. Sleep loss can impair our immune function, so by sleeping longer we can invest in strengthening our immune system.
Our sleeping brains have been shown to help remove metabolic waste products at a faster rate than during active state, further enhancing the restorative function of sleep. When awake we are exposed to a greater number of factors such as nutrition, stress and toxins, putting greater strain on our detox systems. This can lead to a high level of free radicals in the body. Also, with a higher metabolic rate during the day, which produces greater levels of reactive oxygen species, there is a larger amount of damaging cells within the body when awake.
When we sleep, our metabolic rates reduce and free radical production is decreased, allowing restorative processes to take over.
The metabolic phase during sleep is anabolic, as we see a greater release of anabolic hormones such as growth hormone. This further adds to the restorative processes of sleep
There have been numerous studies conducted to show the correlation between sleep and memory. Furthermore sleep deprivation has been linked to a reduction of ‘working memory’. This is important because it keeps information active for further processing and supports higher-level cognition functions such as decision-making, reasoning and memory.
It’s been suggested that sleep can serve as a ‘preservation and protection’ system to reserve energy and reduce risk.
The Stages Of Sleep
There are a number of stages of sleep that occur every time we get some rest. These stages represent what’s happening beneath the surface, and all play an important part to the benefits that occur from the rest.
There are two main types of sleep:
1. NON-REM (NREM) SLEEP
This is essentially a 3-stage sleep cycle, with each being a deeper level than the previous one.
Stage N1 (Transition to Sleep)
This is a stage between sleep and wakefulness. The muscles are active, the eyes roll slowly under the eyelids, muscle activity slows down and we are easily awakened.
Stage N2 (Light Sleep)
This is considered the first stage of true sleep, and is characterised by an increase in ‘theta’ activity within the brain.
We also become harder to awaken, eye movement stops, heart rate slows and body temperature decreases.
Stage N3 (Deep Sleep)
This stage is also known as ‘slow-wave sleep’, and is characterised by an increase in ‘delta’ activity within the brain. During this time, blood flow to the brain is decreased and passed to the body to enhance its restorative benefits. We are difficult to awaken at this stage.
2. REM (Rapid Eye Movement) SLEEP
REM sleep has been given this name as our eyes can be seen moving back and forth in this stage. It can also be known as ‘dream sleep’ and usually occurs about 60-90 minutes after falling asleep. Eye movement, heart rate and blood pressure increase, yet arm and leg muscles are paralysed.
Every time we sleep we are likely to go through all stages of this sleep cycle. Our bodies move back and forth between REM and N3 sleep to form a complete sleep cycle. Each cycle typically lasts about 90 minutes and repeats four to six times over the course of the night.
Typically, the majority of deep sleep occurs in the first half of the night, with REM stages becoming longer with more light N2 sleep later into the night.
This is why may people report waking up after a number of hours sleep, as their sleep is getting lighter and they are easily awakened.
Each sleep within this sleep cycle has potential benefits to the sleeper. A normal adult spends around 50% of total sleep time in stage 2 sleep, 20% in REM sleep, and 30% in stage 1 and 3 sleep.
Stage N3, deep sleep, is considered one of the most important for making us feel energized and refreshed from resting. It is heavily involved in maintaining our health, providing growth and development, repairing muscles and tissues, and boosting the immune system. It essentially renews the body.
REM sleep renews the mind and is important to ensure a healthy memory and learning ability. During REM sleep, the brain consolidates and processes the information we have learned that day while forming neural connections to strengthen the memory. It also replenishes its supply of neurotransmitters including feel-good chemicals like serotonin and dopamine.
It’s evident that we need a mixture of all sleep stages for optimal health and restoration.
How Much Sleep
With modern lifestyles people are sleeping less than ever, with the average person getting less than 7 hours per night.
While sleep requirements vary from person to person, this average is not enough for most, and is leading many people into chronic sleep disorder.
Most people sleep as much as they need, not as much as they should for optimal health and performance. In reality, most healthy adults need between 7.5-9 hours of sleep per night for best results. Young adults and children are considered to require even more.
There is no system or protocol to show how many hours we should get exactly, and the best way is to evaluate how we feel throughout the day. If energy is low, memory is poor and we don’t feel alert, then chances are we need more sleep.
Everyone experiences trouble sleeping from time to time and this can be the result of a number of different factors.
A problem may occur when regular disturbances happen frequently and these can begin to affect daily life too. This can lead to a sleep disorder.
Sleep disorders are not just a simple diagnosis of lack of sleep, but all the negative symptoms that can be associated with it, namely poor energy, mood, and health markers.
Many sufferers from sleep disorders tend to have an underlying medical or mental health problem, while those with sound health tend to sleep well.
This problem alone can lead to a number of health problems, and even a minimal loss of sleep can affect health and performance.
Just like eating disorders, many people go untreated and have difficulty linking their symptoms to a problem. Also, for those who cannot resolve their sleeping habits themselves, they should seek out the help of someone trained in sleep medicine.
SIGNS AND SYMPTOMS
Everyone will have the odd poor night’s sleep leaving them sleep-deprived for a short time, but if this becomes a chronic problem then a sleep disorder is likely.
You may be sleep deprived if you:
• Need an alarm clock in order to wake up on time
• Rely on the snooze button
• Have a hard time getting out of bed in the morning
• Feel sluggish in the afternoon
• Get sleepy in meetings, lectures, or warm rooms
• Get drowsy after heavy meals or when driving
• Need to nap to get through the day
• Fall asleep while watching TV or relaxing in the evening
• Feel the need to sleep in on weekends
• Fall asleep within 5 minutes of going to bed
We may all feel these symptoms from time to time, but if it leads to regular occurrences of the below effects, the person is likely to be chronically sleep deprived.
The effects of sleep deprivation include: –
• Fatigue, lethargy, and lack of motivation
• Moodiness and irritability
• Reduced creativity and problem-solving skills
• Inability to cope with stress
• Reduced immunity; frequent colds and infection
• Concentration and memory problems
• Weight gain
• Impaired motor skills and increased risk of accidents
• Difficulty making decisions
• Increased risk of diabetes, heart disease, and other health problems
Types Of Sleep Disorders
Insomnia is the most common type of sleep disorder and is essentially the inability to get enough sleep to feel fully rested and energized. It can typically be linked to underlying problems such as stress, anxiety, depression, or lifestyle choices such as medications, jet lag, nutrition choices, or family issues.
Many cases of insomnia can be resolved following the simple changes recommended in the ‘how to sleep better’ section of the article.
Common symptoms of insomnia include: –
• Difficulty falling asleep at night or getting back to sleep after waking during the night
• Waking up frequently during the night
• Your sleep feels light, fragmented, or exhausting
• You need to take something (sleeping pills, nightcap, supplements) in order to fall asleep
• Sleepiness and low energy during the day
2. Sleep apnoea
Sleep apnoea occurs when the upper airways become blocked, forcing breathing to temporarily stop. The result is that the person awakes, but often they never remember doing so. This constant and regular waking leads to poor overall sleep and the negatives associated with it.
This is a common yet very serious disorder that will need treatment with the help of medical professionals. This is usually done so via Continuous Positive Airway Pressure (CPAP), which delivers a constant stream of air to the person via a mask while they sleep.
Common symptoms include: –
• Loud chronic snoring
• Frequent pauses in breathing during sleep
• Gasping, snorting, or choking during sleep
• Feeling exhausted after waking and sleepy during the day, no matter how much time you spent in bed
• Waking up with shortness of breath, chest pains, headaches, nasal congestion, or a dry throat
3. Restless legs syndrome (RLS)
RLS is the constant moving or shuffling of legs or arms due to discomfort, aching, or irritable sensations. Common symptoms include: –
• Uncomfortable sensations deep within legs, accompanied by a strong urge to move them
• The leg sensations are triggered by rest and get worse during the night
• The uncomfortable sensations temporarily get better when you move, stretch, or massage your legs
• Repetitive cramping or jerking of the legs during sleep
Narcolepsy involves excessive, uncomfortable daytime sleepiness which can result in the person falling asleep at any given time. This is due to the dysfunction of the brain mechanisms that control sleeping and waking.
Common symptoms include:
• Seeing or hearing things when you are drowsy or starting to dream before you are fully asleep
• Suddenly feeling weak or losing control of your muscles when you are laughing, angry, or experiencing other strong emotions
• Dreaming right away after going to sleep or having intense dreams
• Feeling paralyzed and unable to move when you are waking up or dozing off
Our biological clocks can sometimes be knocked out of sync, which can throw our typical sleeping patterns off. Jet lag, insomnia, and shift work are common ways to disrupt this system.
How To Sleep Better
Those people with poor sleeping habits or disorders commonly share the same bad habits.
There are a number of sleep-promoting techniques and considerations that can be easily integrated into someone’s evening routine.
GET A ROUTINE
Syncing with the body’s natural clock, the circadian rhythm is one of the most effective methods we have to getting a good night’s sleep.
Getting into a strict and consistent routine of going and getting out of bed at the same time each day can have huge benefits.
It’s also important to experiment with different sleep and wake times, as various setups will benefit people differently. So not only find the ideal length of sleep but also the times this sleep should start and finish.
CONTROL THE SURROUNDING
On top of finding the best sleeping routine, we can naturally encourage the body to feel more alert or relaxed. A hormone known as melatonin is released when we are in dark surroundings, as it helps the body regulate the sleep-wake cycle.
If we are exposed to little to no sunlight during the day, we can release melatonin making us sleepy during the day.
In a bright environment, melatonin production is stopped. The same occurs at night when we do want a release of melatonin to induce sleep. If we are exposed to bright light or electrical equipment just before bed, it can slow down the release.
The goal should be to spend more time in daylight during the day, with less exposure to it (including artificial light) at night.
KEEP THE BEDROOM FOR SLEEP
Ensuring the bedroom is optimized for relaxing, unwinding and sleeping is essential. The bedroom should, therefore, become a place to be associated with sleep which will send a powerful signal to help us nod off.
Other important factors here are:
• Eliminating any noises that may disturb our sleep
• Keeping the bedroom at the right temperature
• Removing any electronic equipment
• Ensuring the room is dark enough
• Ensuring the bed is comfortable enough
IMPROVE NUTRITION AND EXERCISE HABITS
Good nutrition habits can drastically improve sleep quality, particularly in the last hours before bed. Some important considerations are:
• Avoid eating large meals before bed
• Avoid drinking too much liquid
• Avoid caffeine in the latter part of the day
• Avoid alcohol before bed
A small bedtime snack containing a balance of protein, fat and carbohydrates can be ideal to help people fall asleep, as that feeling of being satisfied can help the body rest.
Daily exercise can also lead to improved sleep, while exercising too late may disturb the body’s natural wake-sleep cycle as it can act as a heavy stimulus on the body.
REDUCE STRESS AND RELAX
Stress-related to family, money, work, or other day-to-day difficulties can be a common sleep disruptor. Managing these stressors and using pre-bed relaxation techniques can be effective in aiding a better night’s sleep.
Some common techniques are:
• Write down any problems or issues
• Conduct some deep breathing techniques
• Use progressive muscle relaxation techniques
• Avoid any stressing tasks or thoughts before bed
• Keep the bedroom clean and tidy
• Have a hot shower or bath
• Do something you enjoy before bed
We now know the impact sleep can have on the body and health. By educating our clients on this important topic, we can see drastic improvements in those with sleep disorders and those who are sleep deprived.