The sleeping rhythm of a person is unique. But irregular sleep schedules, jet lag or the time change affect a healthy sleep rhythm. Sleep expert Andreas Eger explains what you can do when your sleep rhythm gets out of sync.
The sleep rhythm under the magnifying glass
In 2007, Briton Tony Wright set a dubious world record: He went 266 hours without sleep – more than eleven days. "This sleep deprivation world record has now even been surpassed", says graduate biologist Andreas Eger, technical director of the sleep medical center in the Helios Amper-Klinikum Dachau. "In official mentions one does not find such records however today any more."
And not without reason: Prolonged sleep deprivation is highly hazardous to health. "The longer being awake lasts, the higher the fatigue, the so-called sleep pressure", says Eger. "Attention, concentration and performance decrease – one degrades motor and mentally." That’s why it’s hardly ethically justifiable to also incite such sleeplessness records.
17 hours awake = 0.5 per mille
The attention after 17 hours awake is about the same as with 0.5 per mille alcohol in the blood. "Then, in normal everyday life, the time dawns when you should go to bed," says the sleep expert.
A important clock for our rhythm is the melatonin. "Melatonin in increased secretion indicates that it is time to go to bed and sleep," says Eger. "So melatonin is not, as originally thought, a fatigue maker, but a time giver."
Those who exceed their usual wakefulness become unfocused, irritable, exhausted and listless, mistakes and wrong decisions become more frequent. This is how many serious accidents and catastrophes can be traced back to misbehavior of overtired people. The notorious "microsleep" – the brief, unintentional falling asleep – is particularly fatal, especially at the wheel. "Most accidents don’t happen in the winter when it snows, but on the way to summer vacations," Eger says. "The danger is always particularly great when people are very exhausted or drive and work at times when they are normally asleep."
Listen to the body’s internal clock
This "normal case" knows our body amazingly well: who has never thought about their own "inner clock"? be amazed when you wake up in the morning just before the alarm clock rings? Many maintain their usual rhythm even when they could actually sleep in: on weekends.
"Men in particular have problems breaking their waking and sleeping rhythms", says Eger. "You wake up at the weekend at the same time as during the work week." Women are generally more flexible and can sleep longer on Saturdays and Sundays, he says. "Men can then go and get bread rolls", smiles Eger.
But what if we are forced to break our biorhythms – for example, because we work at night, travel to another time zone, or change the clocks in fall and spring?
Night work is better for owls
When working nights, you have to distinguish between a permanent night shift and alternating shifts, says Eger. People could usually tolerate permanent night shifts well. "Here, the sleep rhythm simply shifts from night to day." Predestined for such jobs, he says, are the so-called owls, i.e. people who like to be active at night and go to bed late by nature.
The permanent night activity can lead to disadvantages in the social surrounding field, because social contacts can be maintained more heavily. From a medical point of view, however, this is largely harmless.
Andreas Eger, technical manager sleep medical center | Helios Amper-Klinikum Dachau
The situation is different when day and night shifts alternate frequently: "If such shift work is incorrectly planned, it can make you ill over a long period of time, says Eger. In occupational fields with frequently changing night shifts, the recommendation is: no more than three night shifts in a row. "Most people can put this away well", so the sleep expert.
In addition, in these cases, it is important to "go with the flow" Rotate: from the early shift to the next but one late shift, from the late shift to the next but one night shift. So lie enough rest between shifts. Rotating in the opposite direction, i.e. "against the clock", is, on the other hand, more difficult for the body to cope with.
Avoiding jet lag during time change and travel
When flying to a different time zone, Eger says many people cope better with jet lag on the way west, such as a destination in the U.S. Eger: "Heading west, the day gets a little longer. Then a nap on the plane is often enough to adjust to the quite acceptable rhythm."
More complicated for one’s own sleep rhythm is the way eastward , for example to Asia, says Eger. "Because the day gets shorter on the journey east, many have problems falling asleep." His recommendation: "Depending on how long you are traveling, it is best to skip an entire night."
Relatively uncomplicated is against it the time change in the spring and in the autumn. For people who regularly have problems changing their rhythm, Eger recommends: "It’s best to start changing your rhythm one or two weeks before the time change. Go to bed a few minutes earlier or later each day."
Can be "slept on"?
In addition to the time difference, the biorhythm can be upset in other ways when traveling. We know it: The vacation plane leaves early in the morning and we rush to the airport with our suitcases in the middle of the night. In such cases, can we sleep in advance so that we do not arrive on vacation already totally exhausted??
Two things cannot normally be forced: The affection of other people and sleep. You can try to sleep ahead, but to fall asleep yourself you need a certain amount of sleep pressure. Just when you want it badly, it will not succeed.
Andreas Eger, Technical Manager Sleep Medicine Center | Helios Amper-Klinikum Dachau
Sleep deprivation: Can you make up for lost sleep??
Conversely, it is difficult to find "lost" ones To catch up on sleep by simply sleeping twice as long, say after an all-nighter. But that’s not necessary: "The human body regulates the sleep deficit through "deeper" sleep," says Eger. "After a sleepless night, the body gets what it needs most urgently the next time it sleeps: deep sleep."
With a sleep deficit, we do not necessarily sleep much longer the next night, but we do sleep "deeper": The proportion of deep sleep increases significantly within our sleep cycle – especially in the first half of the night.
This is how many weekend workers compensate for their social jet lag: "They have appointments and commitments during the week that often start too early in the morning and often end too late in the evening", says Eger.
Is it possible to trick or train the sleep rhythm??
On a smaller scale, we all adjust our sleep rhythm flexibly. But can you train people to get along on less sleep?? In the 1970s, a California research group led by sleep scientist Laverne Johnson explored this question in a study.
Three "normal sleeper pairs" were examined with a sleep time of eight hours each night. Their nightly sleep time was reduced by 30 minutes from month to month. Although the participants frequently suffered from fatigue during the experiment, their performance remained more or less constant .
Particularly interesting: All three couples maintained a shortened sleep duration of about six and a half hours on average after the experiment. So it seems to be quite possible to train yourself to sleep differently in small steps over a longer period of time – as long as you can put up with the daytime sleepiness as a consequence.
Experiments like these, however, are not advised without expert observation.