If we don’t sleep brain it stops working, and if the brain stops working, we die. Sleep is an essential activity that allows our mind to reorder its wiring, and tackle the next block of wakefulness with the maximum guarantees of freshness and alertness.. The hours of sleep they are therefore not a waste of time, but rather an investment in the short and long term.
Sleep helps our body to stay healthy and avoid diseases of all kinds, due to a disturbance of rest. It also affects our mental abilities (concentration, calculation, creativity…) and motor skills (driving, playing a soccer party…).
Sleep can be equated in importance to what is oxygen or water. Despite sleeping since the beginning of our species, the biological process of sleep remains a mystery because It affects all the tissues and systems of our body: brain, heart, lungs, metabolism, immune function, mood, disease resistance…
What is the recommended amount of sleep time?
exist different recommendations on the appropriate number of hours according to our age. Since we are just a few months old and it is recommended to sleep between 14 – 17 hours per 24 hours, until we reach the age of older adults (>65 years) and the range is reduced to 7 – 8 hours per 24 hours.
In the middle of these stages are small children from one to two years old (11 – 14 hours per 24h), preschool children from three to five years old (10 – 13 hours per 24h), school-age children from six to thirteen years (9 – 11 hours per 24h), adolescents between 14 and 18 years (8 – 10 hours per 24h) and adults up to 65 years (7 – 9 hours for every 24 hours).
We can observe how the role of sleep varies according to the stage of life in which we find ourselves, being vital throughout life, but essential during the development of our brain until the end of adolescence. But why do we sleep?
Circadian rhythms: why we are sleepy
What do you do when your mobile runs out of battery? You plug it in to charge. Sleep is the daily charge we need to keep our batteries charged. If we don’t sleep, just as the mobile doesn’t turn on if we don’t charge it, we will also be turned off and out of coverage.
Just as the hands of our watch go through 24-hour cycles, we have another internal clock that is responsible for letting our body know when it is time to wake up, and when it is time to go to sleep. If these circadian rhythms are correctly aligned, our body will carry out complex physiological mechanisms throughout the day.
One such mechanism is that our brain releases adenosine throughout the day, peaking when our eyes send information to a region of the brain to tell it that it is night, based on the light they receive. Do you know what drink blocks adenosine? If you have been “awake” you will have guessed that it is coffee, tea and the like.
Another hormone that is released as natural light fades at night is melatonin. when those Cardiac rhtyms they are perfectly aligned, the mechanisms work correctly and there is no sleep disturbance.
When adenosine, melatonin and other hormones are released it makes us sleepy and we have to sleep. But if we go to bed at a different time each day and start the day by suddenly interrupting sleep with an alarm clock, we will alter those biological processes for whom sleep and a healthy lifestyle are essential.
Sleep architecture: stages we go through every night
Before explaining why we sleep, or rather what we sleep for since why is still a mystery as we said at the beginning of the article, it is interesting to understand what is sleep. Every night when we close our eyes and start to sleep they alternate four stages cyclically until we wake up. Each cycle generally lasts between 90 and 120 minutes.
Within each of those cycles we go through four stages, three of them known as non-rapid eye movement (NREM) sleep and a final stage called rapid eye movement (REM) sleep. NREM sleep occupies around 80% of each cycle, leaving the rest to REM sleep.
If we do calculations, and as adults we should sleep between seven and nine hours, knowing that each phase lasts about an hour and a half or two hours, we go through about four or five complete cycles.
Why is it necessary to perform several complete cycles?
REM sleep begins about 90 minutes after falling asleep. In that time we go through all three NREM stages, but it is the fourth stage, the REM stage, that is the icing on the cake. It is this REM sleep that is related to such important aspects as memory consolidation, and many others that we will describe below.
In addition, sleep cycles have different durations as the night progresses. In the first cycle it is shorter, while the later ones are usually longer. The amount of time we spend in deep sleep phases also increases as time asleep progresses.
The REM phases they are especially lengthened in the second half of the night, going from a first REM stage of a few minutes, to stages in that second half of the night that can last up to an hour. That is why it is so important to reach those recommended minimums and not cut off sleep after a few hours, when the most effective sleep begins.
Why do we sleep, and how does sleep affect our well-being and health?
If we don’t sleep, we die. It is an important reason to sleep. They knew that for many centuries, and for this reason they used it as torture to prevent people from sleeping, which led them to madness and death. An insufficient amount of sleep can have serious repercussions.
Memory consolidation and long-term memories
Have you ever gone to an exam without sleeping and have a blank? By not sleeping you have not consolidated that information in memoryin addition to having reduced your ability to access other information that was stored there.
It’s what is known as “pillow talk” where we go to bed with a problem that we haven’t been able to solve all day, and the next morning, we open our eyes and suddenly the light bulb goes on and eureka , problem solved.
Sleep converts learned experiences into long-term memories. That is why it is becoming more and more popular the sandwich method of retaining information. It consists of waking up, studying and after a while taking a nap or a snooze to store that information, and continue studying afterwards. Studying is in the middle of that sandwich, where bread is the dream.
Put our hourglasses back to zero: patience and creativity among many others
Do you have the same patience with your partner, children or friends after a long day, as at the beginning of that same day? Are you able to solve simple tasks such as calculating the return of the purchase in the same way first thing in the morning as at the end of the day?
The dream orders “all the junk” that we have been leaving through the brain throughout the day, and we wake up with everything in order and with the counter at zero. Specifically, deep sleep is essential for creativity and insightful thinking. That is why it is advisable to place the most cognitive and creative tasks at the beginning of the day.
sleep well too resets our ability to alert, our state of mind and our willpower. It is easier to avoid a traffic accident first thing in the morning, to take a traffic jam in a better mood on the way to work than to return from it, and to say no to an ultra-processed food for breakfast than for dinner.
It is because that adenosine, and other substances that accumulate in the brain as we spend sleepless timelimit our attention, our humor and our decision making.
Prevent illnesses and medical conditions, both physical and mental
Not sleeping the recommended hours and with the necessary quality affects our mental and physical well-being. Metabolic diseases such as obesity, type 2 diabetes and high blood pressure, as well as mental and neurological diseases such as depression, even stroke, are connected to rest.
Sleep makes sure that all our systems work perfectly, avoiding problems with insulin or glucose, and helping our brain to receive its corresponding charge each night to reset us and prepare us for another wake cycle.
This function of sleeping is closely related to the improvement of depression symptoms, control of anxiety disorders, etc. The opposite happens when we suffer from insomnia and sleep little, thus entering a vicious circle in which we are increasingly depressed, anxious and stressed.
This constant sleep deprivation, combined with other factors, can lead to neurodegenerative diseases such as Alzheimer’s or Parkinson’s, and even increase the risk of premature death.
Repair and regeneration
If you are a professional athlete, or train to improve your body composition, you should keep in mind that sleep time counts as training time. The stimulus that we bring to our body is the seed, and sleep is the watering and the sun that makes that seed flourish.
The deepest stages of sleep are often called restorative sleep, and it’s literally true. Our body is here where it repairs the damage caused by our strength and resistance training, and regenerates the parts involved, leading to improved performance and muscle growth.
The immune system is also included in this section since sleep reinforces this system and other key processes in this regard. Have you ever had a bad headache or an upset stomach and after sleeping it disappeared? Everything has been a dream”.
And of course, the dealer gets the best part. The brain eliminates thanks to sleep all the toxins that have been accumulating during the day. It is for what we have commented on a couple of occasions that we sleep why we must reset the system to start a new day.
We could go on, but we have to go to sleep
The list of the role that sleep plays in our life and well-being is endless. Almost all diseases are prevented and improved with proper rest. Health, understood as physical, mental and social well-being, depends directly on our quantity and quality of sleep.
On a physical level, it helps our physiological mechanisms to be well oiled so that all systems do their job. At the mental level, it is responsible for preventing mental disorders and illnesses, as well as helping our brain to order the experiences and classify them to be able to dispose of them.
And restful sleep also interferes with our social relationships, making us be in a better mood, and with more energy to make plans with family and friends, instead of being “too tired to go out”.
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