Which factors influence sleeping habits?

Jet lag, night shift, time change: listen to your rhythm

Understand the rhythm of sleep

A person's sleep rhythm is unique. But irregular sleep times, jet lag or the clock change affect a healthy sleep rhythm. Sleep expert Andreas Eger explains what you can do if your sleep rhythm gets out of step.

The sleep rhythm under the microscope

In 2007, the Briton Tony Wright set a dubious world record: He stayed 266 hours without sleep - more than eleven days. "This sleep deprivation world record has now even been surpassed," says biologist Andreas Eger, technical director of the sleep medicine center at the Helios Amper Clinic in Dachau. "However, such records are no longer found in official mentions today."

And not without reason: Long sleep deprivation is a major health hazard. "The longer you are awake, the greater the fatigue, the so-called sleep pressure," says Eger. "Attention, concentration and performance decrease - you lose motor and mental health." That is why it is hardly ethically justifiable to incite such sleepless records as well.

17 hours awake = 0.5 per thousand

The alertness after 17 hours of wakefulness corresponds approximately to the same level of alertness as with 0.5 per mille of alcohol in the blood. "Then in normal everyday life the time comes when you should go to bed," says the sleep expert.

A Melatonin is an important clock for our rhythm. "Increased levels of melatonin indicate that it is time to go to bed and sleep," says Eger. "So melatonin is not, as originally thought, a tired man, but a timer."

Those who exceed their usual wakefulness become unfocused, irritable, exhausted and lacking drive, mistakes and wrong decisions pile up. Many serious accidents and disasters can be traced back to misconduct by overtired people. The notorious “microsleep” - the brief, unintentional falling asleep at the wheel - is particularly fatal. "Most accidents do not happen in winter when there is snow, but rather on the way to summer vacation," says Eger. "The danger is always particularly great when people are very exhausted or drive and work at times when they normally sleep."

Listen to the body's internal clock

Our body knows this "normal case" surprisingly well: Who has never been amazed at their own "internal clock" when they wake up shortly before the alarm goes off? Many keep their usual rhythm even when they could actually sleep in: on the weekend.

"Men in particular have problems breaking their waking and sleeping rhythm," says Eger. "They wake up at the same time on the weekend as they do during the work week." Women are usually more flexible and can sleep longer on Saturdays and Sundays. "Men can then go and get bread," smiles Eger.

But what if we are forced to break our biorhythm - for example because we work at night, travel to a different time zone or change the clocks in autumn and spring?

Night work is more suitable for owls

When working at night, you have to differentiate between permanent night shift and changing shifts, says Eger. Long-term night shifts could usually be tolerated by people. "Here the sleep rhythm simply shifts from night to day." The so-called owls are predestined for such professions, i.e. people who like to be active at night and who naturally go to bed late.

The permanent night activity can lead to disadvantages in the social environment because social contacts are more difficult to maintain. From a medical point of view, however, this is largely harmless.

Andreas Eger, Technical Director of the Sleep Medicine Center | Helios Amper Clinic Dachau

The situation is different if day and night shifts frequently alternate: "If such shift work is incorrectly planned, it can make you sick for a long time," says Eger. In professional fields with frequently changing night shifts, the recommendation therefore applies: no more than three Night shifts in a row. "Most people can put up with that," says the sleep expert.

In addition, it is important in these cases to rotate "with the clock": that is, from the morning shift to the late shift after the next, from the late shift to the night shift after that. So there is enough relaxation between the shifts. on the other hand, it is more difficult for the body to cope with.

Avoid jet lag when changing time and traveling

When flying to another time zone, according to Eger, many people cope better with jet lag on the way west, for example at a destination in the USA. Eger: “The day gets a little longer to the west. Then a nap on the plane is often enough to adjust to the perfectly acceptable rhythm. "

The way eastwards, for example to Asia, is more complicated for your own sleep rhythm, according to Eger. "Because the day gets shorter on the journey eastwards, many have problems falling asleep." His recommendation: "Depending on how long you are traveling, it is best to skip a whole night."

In contrast, the time change in spring and autumn is relatively uncomplicated. Eger recommends people who regularly have problems changing their rhythm: “It is best to start changing your rhythm one or two weeks before the time change. Go to bed a few minutes earlier or later every day. "

Is it possible to "fall asleep"?

In addition to the time difference, the biorhythm can be disrupted in other ways while 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. Can we sleep late in such cases so as not to arrive on vacation completely exhausted?

There are two things that you can't usually force: other people's affection and sleep. You can try to sleep early, but you need some sleep pressure to fall asleep yourself. If you really want to, it won't work.

Andreas Eger, Technical Director of the Sleep Medicine Center | Helios Amper Clinic Dachau

Lack of sleep: can you catch up on lost sleep?

Conversely, it is difficult to catch up on "lost" sleep by simply sleeping twice as long, for example after a night of wakefulness. But that is not necessary either: "The human body regulates the sleep deficit through a" deeper "sleep," says Eger. "After a sleepless night, the body gets what it needs most urgently during the next sleep: deep sleep."

With a sleep deficit, we don't necessarily sleep much longer the next night, but "deeper": The proportion of deep sleep increases significantly within our sleep cycle - especially in the first half of the night.

In this way, many employees compensate for their social jetlag at the weekend: "During the week they have appointments and obligations that often start too early in the morning and often end too late in the evening," says Eger.

Can you trick or train the sleep rhythm?

On a smaller scale, we all adapt our sleep rhythm flexibly. But can you specifically train people to get by with less sleep? In the 1970s, a California research group led by sleep researcher Laverne Johnson investigated this question in a study.

Three "normal sleeper pairs" with a sleep time of eight hours per night were examined. Their night sleep time was reduced by 30 minutes from month to month. Although the participants often suffered from fatigue during the experiment, their performance remained roughly constant.

Particularly interesting: After the experiment, all three couples maintained a reduced sleep duration of around six and a half hours on average. So it seems to be quite possible to train yourself to sleep differently in small steps over a longer period of time - provided you endure daytime sleepiness as a result.

However, it is not advisable to conduct experiments like these without being observed by an expert.

Last updated on October 21, 2020