How much sleep does the human need? A question that is not easy to answer, because the need for sleep varies from person to person. While some never sleep more than six hours during the week, others only feel properly fit and rested after nine hours of sleep. For example, Albert Einstein is said to have slept on average for 14 hours, while Napoleon allegedly slept four hours. But despite the apparently different need for sleep, we have one thing in common: Sufficient sleep is vital to our body.
Function of sleep is controversial
Why exactly we sleep is still a matter of debate among researchers. It is likely that body and mind regenerate during sleep. Thus, the experiences of the day are sorted and stored in the sleep and it grows new nerve connections in the brain. On the other hand, superfluous information is sorted out.
In addition, the immune system should be strengthened during sleep and damaged tissue repaired. In addition, sufficient sleep should also have an impact on the metabolism: those who sleep sufficiently have a lower risk of developing diabetes or being overweight.
How much sleep is enough?
The question of how much sleep we need can not be answered on a flat-rate basis. Some people get along with less sleep, others need more sleep. The difference in sleep duration is largely genetic. An inexplicable indication that you have slept enough, is your own health over the day: Who during the day - with the exception of a small midday low - feeling fit and recovered, has slept enough.
Most people need between six and eight hours of sleep to be efficient the next day. In individual cases, however, four hours may be sufficient or up to ten hours may be needed. The average sleep duration in Germany is about seven hours.
If you are under particular stress, the individual sleep duration can also be prolonged, because the body then requires longer nocturnal regeneration phases. That is why it is particularly important in stressful life phases to sleep sufficiently.
The quality of sleep is also important
However, how much sleep a person needs is not only dependent on sleep duration, but also on the quality of sleep. Who sleeps quietly at night, needs less sleep than someone who sleeps restless and is plagued by sleep disturbances. Therefore, it is believed that "short sleepers" sleep more quietly and thus more effectively than people with a longer sleep duration.
Incidentally, the quality of sleep is independent of the time of sleep. It does not matter if you go to bed in the evening at ten o'clock or at two o'clock in the morning, the body always goes through the same sleep phases. The rumor that sleep before midnight is more relaxing, so is not true.
Just like the duration of sleep, the time of sleep is determined by the genes: while "larks" are born early risers, "owls" rather sleep out.
Lack of sleep has serious consequences
Those who sleep too little on a regular basis quickly suffer from a significant sleep deficit. This brings some far-reaching consequences:
- People who suffer from lack of sleep age faster.
- Since their immune system can not recover sufficiently during sleep, they are more susceptible to illness.
- A sleep deficit is associated with an increased fatigue and a lower ability to concentrate. Because of this, people who suffer from sleep deprivation are also more likely to be involved in road traffic accidents. Work in the office is also harder: you are more irritable, stressed and difficult to make decisions.
However, sleep changes with age: while infants sleep up to 16 hours a day, their need for sleep continually decreases. Schoolchildren should sleep for about ten hours, and adolescents around nine hours. On average, adults only sleep for about seven hours.
Can too much sleep be harmful?
Not only too little sleep but also too much sleep can have a negative effect on our body: those who sleep too much do not feel fresher and happier the next morning, but are often even more tired and battered than usual. Not only that, recent studies also suggest that too much sleep can be detrimental. The studies from the United Kingdom and the United States indicate that both the risk of disease and the mortality rate are increased in long-sleepers.
However, the relationship between too much sleep and an increased risk of disease exactly is not yet clear. However, it is believed that the duration of sleep affects the metabolism of the organism and that a significantly too short or too long sleep time can lead to certain diseases.