Our favourite words of the day: Good Night

Sleeping and waking up follow a natural rhythm. We sleep in different phases during the night. And our organism is extremely sensitive to irregularities. One of the key messages we need to appreciate is:

You can’t do without sleep

Even if there are people who try to prove the opposite in all sorts of experiments: at some point they will all close their eyes. We need sleep. To thrive. To feel content. To focus. To concentrate. And to simply be alive.

It is no secret anymore that sleep deprivation can trigger lack a long list of disorders: Starting from lack of focus & concentration and reduced mental performance. If sleep deprivation continues over a longer period of time, people have experience a lack of sleep will become increasingly irritable, moody to the point of changing their personality and suffer from personality disorders and suicidal thoughts. Muscle tension, breathing, heartbeat, blood pressure, body temperature, hormones, metabolism and other functions become confused if the natural rhythm of sleeping and waking is disturbed in the long term. It is serious! And we should not feel obliged to feel proud if we worked again through the entire sleep and been coping on little to no sleep.

The normal sleep rhythm follows the alternation between day and night

A large part of the processes in the body adapt to the alternation between day and night (circadian rhythm over 24 hours) and enable us to wake up in the morning and tired in the evening. Certain groups of nerve cells in the brain, which have connections to the optic nerves and also to other brain areas, play an important role. Day and night, light and dark have a direct influence on the sleep-wake rhythm.

The coordinated nerve signals regulate the ups and downs of hormones, body temperature and certain chemical substances that are also involved in the immune system. At night, for example, the hormone melatonin and growth hormones are released, which promote sleep. They decrease in the morning when the hormone cortisol increases, which makes us wake up. Thus you don’t need a coffee first thing in the morning, as you are still ‘high on cortisol’.

Simultaneously, the body temperature also increases. It sinks again towards evening so that we can sleep better. Incidentally, the body temperature also shows a brief interim low during the day, in the early afternoon. Ever feeling sleeping during the early afternoon? Many people feel tired at this time, and it is a normal natural rhythm that our body goes through. Those who like and can take a short lunch break – go for it! It is natural and you do yourself a favour. However, most people are not able to as it doesn’t fit into our modern lifestyle where we need to be constantly on alert and wide awake.


The stages of sleep: light sleep and deep sleep alternate. In between, first shorter, then longer, are the REM phases (red lines)

In summary

Sleep is essential to us humans. And yet, we dismiss is as we believe it takes away productive hours we could use to work. But as so often one needs to step away from work, and slow down before one can be productive again. As always it is a balancing act. There is a reason, why we need to close our eyes to allow our body to recover and regenerate. If we don’t do this, important processes in our body & mind will shut down.

There are two basic stages of sleep: REM and NREM

Sleep is characterized by two basic stages in which the central nervous system and various body functions are correspondingly active or less active, in order to enable relaxation and regeneration during sleep.

In one of these sleep stages, the sleeper quickly moves their eyes back and forth under the closed lids. Doctors therefore speak of REM sleep (rapid eye movement). At this stage we dream particularly vividly. That is when we talk about dream sleep. Adults spend about 20 percent of their bedtime in REM sleep, while babies spend about half.

The other stage is NREM sleep (non rapid eye movement), which is divided into four phases: two light sleep phases and two deep sleep phases. These phases replace each other with REM sleep several times at night, REM sleep and light sleep phases predominate towards morning (see graphic above).

Our brain is therefore the one who does not come to rest at night. However, it redirects its activities and uses bedtime for important cleaning and repair work. Scientists are still researching for more precise processes. The brain is yet such an undiscovered area like space. A cast space where still lots to explore. According to experts, nerve cells that have been subjected to heavy stress during the day and are subject to many influences can shut down and regenerate during sleep.

The confusion and the illusions that often appear after long periods of sleep deprivation can possibly be explained by the fact that the nervous system is constantly overloaded if it has no chance of getting rid of unnecessary ballast and sorting out what has been experienced in peace. In other areas, new connections are created between the nerve cells at night. Newly learned things are thus consolidated and anchored in the memory. Those who sleep well learn more easily and sustainably.

Each phase is important for the recovery function of sleep. Essential body processes such as blood pressure, digestive activity or muscle tension also change at night, depending on the stage in which the sleeper is. Blood pressure, for example, drops in deep sleep. If the sleep is interrupted several times, the non-sleeper must even get up, and the blood pressure rises again. AS a result, prolonged sleep problems can promote high blood pressure.

The various stages of sleep are controlled by finely tuned nerve signals in the brain. Anything that affects or changes this interaction also disrupts the natural sleep rhythm.

For example, luxury foods such as coffee, nicotine or alcohol as well as certain medications can influence REM sleep and deep sleep. This also applies to diseases that affect cardiac and respiratory activity, nerves, muscles or metabolism.

The psyche plays an important role. When thoughts about worries, fears, unresolved problems, stresses and conflicts revolve, stress hormones continue to be released, the entire organism does not come to rest. Hormones, such as serotonin and norepinephrine, are also important for the sleep architecture, as experts call the course of the different phases. They come into imbalance in depression. Sleep disorders, especially waking up early in the morning, may indicate depression.

Five or ten hours – how much sleep do we need?

Regardless of the eternal discussions between late risers and short sleepers, early risers and night people: the amount of sleep and sleep times vary to a certain extent, but differ from person to person. The disposition, age and habits play a vital role.

The decisive factor is ultimately how relaxed a person feels in the morning, whether they are tired and lacking concentration during the day or whether, apart from natural lows, they spend most of the day full of energy and mentally and physically fit. Some do this after six hours of sleep, others only after nine hours. People who tend to sleep less often tend to take a quick nap during the day (power napping). However, a sleep like this cannot compensate for a permanent lack of sleep or a bad night’s sleep.

Most effective: About seven to eight hours of sleep

Scientific studies indicate that a good night sleep of seven to eight hours of sleep is most effective. In studies of sleep and obesity, people who slept less than six hours a night gained weight faster than normal sleepers with seven to eight hours. However, those who stayed in bed for nine hours or more gained more pounds. Other tests that looked at sleep duration and life expectancy also suggest that an average measure is the best fountain of youth.

Adolescents generally need more sleep than adults. They are also more of a late riser. After puberty you will find your personal normal size. In old age, this is reversed for many. Early risers predominate here. The amount of sleep remains mostly unchanged, however, it is spread over day and night, as older people take a nap more often during the day. In addition, sleep becomes more superficial and the deep sleep phases decrease.

The trend in our society is towards less sleep, since many believe that they can no longer afford or want to sleep. Lack of sleep and sleep disorders often cause serious problems for health and everyday life. Many traffic accidents happen, for example, because the driver is tired and therefore less concentrated or falls asleep.