What is the reason for jet lag

Overcoming jet lag: symptoms, duration, 16 prophylaxis tips

Anyone who travels a lot, especially long air travel, knows the problem: jet lag. By quickly crossing several time zones and the time difference, the sleep-wake rhythm and biorhythm get out of step. Regardless of whether you are flying west or east, your internal clock is disturbed when you arrive at your destination. The body then needs two times to adjust to the new rhythm - on the outward journey as well as on the return journey. It is therefore difficult to arrive relaxed and fit after a long-haul flight. After all: There are a few tips and tricks on how to overcome or prevent jetlag ...

➠ Content: This is what awaits you

➠ Content: This is what awaits you

Jet lag causes

The term “jetlag” is derived from the English word for airplane (“jet”) and time interval (“lag”). If you cross several time zones, the day and night rhythm shift compared to the country of origin. The internal clock initially continues to run as usual, but over time it gets more and more confused - with corresponding consequences.

The reason for this is our biorhythm. It controls all physical and mental functions in the usual 24-hour cycle. This internal clock ticks differently in every person. When crossing several time zones, however, the internal and official clock no longer match. The daily rhythm is shortened for flights to the east and lengthened for flights to the west.

Jet lag symptoms

According to studies, around two thirds of people suffer from typical jetlag symptoms as soon as they cross more than three time zones by plane. The rest of them have slight or no problems at all. The type and severity of jet lag symptoms can also vary from person to person. Typical jet lag symptoms are:

➠ fatigue
➠ insomnia
➠ dizziness
➠ Difficulty concentrating
➠ circulatory problems
➠ headache
➠ irritability
➠ Power reduction
➠ loss of appetite
➠ digestive problems
➠ mood swings

In fact, people react differently to the shift in their sleep-wake cycle. Women and older people are usually stronger, men and younger people often synchronize faster with the new time zone. In addition, it seems that night owls (so-called “owls”) and people who change their sleep-wake rhythm more frequently (due to shift work) find it easier to deal with jetlag or get used to the new time zone more quickly.

After an adjustment phase of three to 14 days at the latest, however, all of the symptoms of the time change mentioned should have disappeared and the internal clock should have leveled off.

Jet lag duration

How long the jet lag lasts depends on you, the direction of flight and the extent of the time difference. Our bodies can cope with time differences of up to three hours. But if more time zones are flown over, the jet lag has a stronger effect. If you travel to the USA, for example, it takes around a week for your body and mind to adjust to the local daily rhythm again. Before that, you are usually tired during the day and tend to be awake at night. Likewise, you will not (yet) get your usual appetite at the local meals.

The hormonal processes that control our body functions continue to run relatively self-sufficiently in the old rhythm - that is, regardless of new light changes, eating and sleeping times. They also need time until they have leveled off again and adapted to the new time zone or time change. As a rule of thumb, you can remember:


For each time zone flown over, you have to reckon with an adjustment period of half a day to a full day.



When flying west, this adjustment is around 20 percent faster after flying east. Reason: Our organism is not set to an exact 24-hour rhythm, but a little longer. According to studies by scientists at the University of Maryland, our bodies find it easier to lengthen a day than to shorten a day.

Overcoming jet lag: 5 tips

The following tricks and behaviors can help overcome jet lag more easily. Frequent flyers in particular should familiarize themselves with these tips:

  1. Adjust rhythm in good time
    If your schedule allows, get your body used to the new time zone a few days before the flight. This is how it works: On flights to the west, you stay awake a little longer in the evening, while on flights to the east you go to bed earlier.
  2. Change the clock
    To get used to the new local time, you should set your watch as early as possible. You can do this at the gate at the departure airport, for example, and prepare for the new time during the flight. In concrete terms: Meals are only eaten when the time comes at the destination. The same goes for sleeping, of course.
  3. Drink a lot
    You should drink as much as possible on board. The air in the aircraft cabin is usually dry and thus dries out our mucous membranes - and dried out mucous membranes are more susceptible to pathogens. In combination with the disturbed day-night rhythm, these are ideal conditions for a cold. However, drinking a lot does not mean that you should consume alcoholic beverages. On the contrary. Alcohol can make it harder for you to adapt to the new rhythm in the destination country. It is better to drink water or diluted fruit juices. Because you should also avoid coffee and tea.
  4. Take it easy
    Give your body the time it needs to get used to the new conditions. Provided the job allows it. Exercise and other strenuous activities should be avoided for the first few days. If you have trouble falling asleep, a carbohydrate-rich diet can help - or our tips for falling asleep.
  5. Fill up with daylight
    Natural light plays an important role in regulating our internal clock. If you spend a lot of time in the fresh air and get as much daylight as possible, your body will produce less melatonin. And less melatonin means you are less tired.

By the way: If you only stay in the destination country for a short time (one or two days), you shouldn't try to change your internal clock. Instead, stick to your normal rhythm - if the reason for your trip allows it. Otherwise, you put a lot of stress on your body until the internal clock has synchronized itself twice with the new and old local time.

Jet lag and flight direction

Jet lag is less a problem of flight duration than of the direction of flight. The further we fly east or west, the greater the difference in the respective time zones. The most important tip against jet lag is: Be sure to adjust to the time in the destination country, no matter how difficult it is at the beginning: hold out until the evening - without sleeping in between. Those who can should book night flights on long-haul flights or arrive at least one day earlier. This gives the body time to get used to the time difference.

In principle, jet lag can occur both on flights to the west and on flights to the east. In general, the body can cope with traveling westwards more easily than flights to the east. According to studies, people experience the strongest jet lag with a time difference of eight to ten hours to the east. Depending on the direction of flight, you can still counteract or prevent jetlag in different ways:

Prevent jet lag: flights to the west

  • If you fly west, ideally stay awake, preferably before. You can make this easier by staying up late in the evening.
  • Plan the trip so that you arrive at noon if possible. The flight extends the day and makes you particularly groggy on the first evening. The endurance is usually rewarded the next morning by a natural form of time change.
  • Move. On the long-haul flight, keep walking back and forth in the cabin and try to stay awake. If you sleep on board, you will find it harder to find the new rhythm.
  • For flights to the west, a protein-rich food on board - i.e. meat, cheese, eggs or fish - is recommended. This suppresses tiredness and helps you stay awake longer.
  • Above all, use the morning sun at your destination to get used to it.
  • If you are flying west, you should schedule important appointments or meetings in the destination country in the morning - you are still fittest there.

Prevent jet lag: flights to the east

  • For flights to the east, on the other hand, it is exactly the opposite and sleeping (on board) is the better alternative.
  • Always go to bed a little earlier the week before the flight and get up earlier than usual.
  • Eat mostly fruit, potatoes or pasta on board. Carbohydrates help you to stimulate the natural need for sleep.
  • What also helps to get used to the new era quickly: lots of daylight. Sun rays at the target location activate the release of stimulating hormones. Use the evening sun on flights to the east, it will help you get used to it even faster.
  • In the eastern destination country, you should schedule appointments and meetings especially in the evening.

You can - as usual - download the tips against jet lag given here as a PDF free of charge and use it as a checklist before a long business trip or vacation trip.

Jet lag and melatonin

The so-called sleep hormone melatonin significantly controls our sleep-wake rhythm. The antagonist to this is cortisol: the hormone is released in the morning to wake us up. However, especially in connection with jet lag, the effects of melatonin have been studied intensively. Some subjects reacted well to corresponding preparations, others less so. There is no clear result. Even more: a wrong time of intake can prolong the symptoms.

Accordingly, melatonin preparations are not yet approved in Europe. What you can buy are mostly products from the USA, which are classified as dietary supplements there and are freely available in drug stores. After a long-haul flight, some swear by an intake dose of 0.5 to a maximum of five milligrams shortly before going to bed around 10 p.m. at the destination. They fall asleep faster and supposedly find their way into the new time zone earlier.

However, caution is advised: the controls of dietary supplements in the USA are significantly more lax than those of drugs. If you have persistent headaches, nausea or diarrhea, or if you are depressed, you should consult a doctor anyway. Many doctors also advise against sleeping pills. We also recommend natural sleep aids against jet lag, such as sleeping masks, neck pillows and quiet music from your own smartphone.

What is weekend jet lag?

The so-called "weekend jetlag" has nothing to do with travel jetlag. Rather, scientists understand it to mean that many employees fall asleep particularly poorly and sleep through the night on the evening before Monday. Reason: The weekend messed up your usual sleep-wake cycle. Some also speak of “social jetlag” in this context - due to weekend parties or hobbies.

Tips on how to sleep better on the plane

Do you have a tight schedule and would like to take a rest on the plane before going straight to your business meeting? But finding a suitable sleeping position is not that easy. You just turn from side to side and after several hours on the plane you get off with a stiff neck and unrested. It gets worse if you suffer from jet lag. You should actually be in top shape. The day has just started on site, but you just want to go to bed. What helps?

There are people who can sleep practically anywhere. You could sit on a fully booked vacation plane full of noisy children and still fall asleep as soon as you were seated. Other people want to sleep, but cannot find rest. If you are of the latter type, these tricks may help you:

  • Don't put yourself under pressure.
    If you convulsively think that you only have a few hours to rest, your sleep will not work out. Take the pressure off and try to relax. If you don't want to sleep well, read something and wait until the tiredness sets in on its own.
  • Find a good seat.
    When choosing a seat, make sure you get a window seat if possible. Then you don't have to get up every time one of the other passengers has to go to the toilet. In addition, you can close the shutters and lean on them.
  • Bring a neck pillow.
    There are small and handy neck pillows that you can stow in your hand luggage. On the plane, you are then happy to have a way to rest your head comfortably on your shoulders.
  • Ask not to be disturbed.
    If you want to sleep and are not constantly asked by the flight attendants whether you want something to drink or something to eat, briefly inform the aircraft staff about it. To avoid being woken up every time the seat belt signal lights up, cover up first and then buckle up. The aircraft crew can then see that you are buckled up and do not have to wake you up.
  • Create your quiet zone.
    If you want to sleep even though it is light outside and you cannot close the shutters, it helps to have a sleep mask with you. With it you can create the desired darkness yourself. If you find the noises around you annoying, you can block them out with music.

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