Long-haul flights involve crossing several time zones. The most obvious jet lag symptoms come from flying from west to east. When you fly westward, on average, one day is needed to adapt to two hours of time difference. When traveling east, your body and internal clock usually on average needs two days to adapt to three hours of time difference.
Adapting to the time difference is individual. With fast adapters, recovery from three time zones is successful in one day, while slow adapters need three days to slowly adapt to the time difference.
Adapting to the five-hour time difference therefore takes two to four days, depending on the flight direction and the individual variation and adapting to a ten-hour time difference from three to seven days.
Symptoms of jet lag
Symptoms of jet lag are among others e.g. fatigue, generalized malaise, slowed reaction times, difficulty concentrating, irritability, insomnia, bowel dysfunction and related fluid balance disorders. The most common sleep disorders associated with jet lags are interrupted sleep, waking up in the early hours and difficulty falling asleep. Symptoms such as trouble falling asleep and morning fatigue are signs of jet lag while traveling eastwards. Typical symptoms when traveling westwards are premature awakening in the morning and fatigue in the early evening.
During the flight, the passenger is already exposed to viral and bacterial infections that are spreading in the air. Jet lag causes sleep deficit and reduces resistance to illness. If the hotel is air-conditioned overnight, the risk of getting a respiratory infection continues to increase.
How to recover from jet lag?
There is no patent solution to speed up the recovery from jet lag. The leaders and experts of many international companies always travel on long flights in business class, depending on the airline, the seats are either fully or almost completely reclining. This ensures a better position and sleep. Unfortunately, only a small number of passengers can afford to travel in business class. The quality of airline economy seats varies, as well as the ability of passengers to sleep in a seated position. As a side-note, there is an interesting theory of sleeping in sitting position, according to which early childhood sleeping habits could have an effect on it. If a person has slept as a child in a sitting position, it is also easier as an adult. However, sleeping on an airplane seat is never a quality sleep.
Flight schedules are also of great importance. From Europe to the United States it is advisable to fly at daytime, arriving in the afternoon or evening. During the day flight you can drink coffee, stay awake late at night and not go to bed too early. While flying east, it is better to go on a flight in the evening and sleep during the flight.
Excessive alcohol consumption should be avoided. On a day flight, alcohol is tiring, and on night flight it degrades sleep quality and increases urine secretion.
The significance of light in jet lag
Staying outdoors in bright blue light at the right time can also affect time difference adaptation and alertness. Evening light moves biological rhythms to a later stage, and early morning light brings them forward. Exposure to light at the wrong time makes it difficult to adapt to the new time. Blue light exposure can be reduced by using orange or red sunglasses that filter out blue light.
Jet lag while traveling to the West
When traveling westward, your own internal circadian rhythm should be moved backwards or delayed. Delaying the sleep-wake rhythm is always easier than bringing it forward. If we decide to stay awake to two o’clock in the morning, it will probably be easier than if we decide to go to bed at 20 o’clock and sleep well until the morning.
The circadian rhythm can be shifted backwards in relation to the target country by staying in bright light in the evening after arriving. So you shouldn’t go to sleep the first night too early, because it only aggravates the early morning awakening. When you fly west, you should stay awake and go to bed until late at night. In the afternoon and evening you should get a lot of light. It is theoretically useful to start light timing even before the trip, but it may be difficult to implement in practice.
Jet lag while traveling to the East
When traveling eastward, your own internal circadian rhythm should be moved forward, ie to advance. After traveling east, you should stay in light in the morning and in the day, but avoid bright light in the evening after 6 pm. When traveling eastwards, the morning light also helps to advance internal rhythms. However, bright light should be avoided on the day of arrival too early in the morning.
After the first day of arrival, the time of departure must also be taken into account. A stay in the bright light immediately after arrival can delay the rhythms instead of getting ahead.
Bright light therapy for jet lag
The effect of bright light therapy on the circadian rhythms is transmitted through the base of the eye, from which the retinoic hypothalamus traverses the supracasmic nuclei, where the central clock of the brain is located. From the supercasmic nucleus, the noradrenaline mediated nerve pathway travels to the pineal gland located at the back of the brain, secreting dark hormone or melatonin. Light transmitted through the eyes inhibit the secretion of melatonin. In a jet lag bright light therapy should usually be scheduled for the morning.
Melatonin, sleeping pills and jet lag
Melatonin can also be used to speed up recovery from time difference. The timing of melatonin is simpler than the timing of bright light. Melatonin should always take at least 22 in the early evening at the time of destination. According to some studies and recommendations, it would be good to start taking melatonin a few days before the trip. Such is not always easy to implement, and some may also experience fatigue before the day of departure. Thus, it has been found that in practice, perhaps the most effective way is to start medication either on the day of departure or the next night.
Melatonin should always be taken approximately one hour before bed time, but always at least 22 o’clock at the time of destination. At the right time, the dose of melatonin can be 0.5 to 1 milligram. The most common dose is 2 to 5 milligrams for a total of two to four days.
Some studies suggest that taking short-acting sleeping pills one or two nights may also make it easier to fall asleep and sleep a little longer. However, the use of sleeping pills is always accompanied by the possibility of harm, which is why they should only be resorted to in difficult sleep disorder associated with jet lag.
Some people take sleeping pills in an airplane to sleep during the flight. It is not recommended. The use of sleeping pills on an airplane has sometimes led to incidents. When a flight attendant has to wake a sleeper on an airplane that has taken a sleeping pill, the passenger may be confused and aggressive towards the flight attendant and other passengers. Such a traveler can also hurt himself when he walks and falls, because under the influence of sleeping pills, the balance is usually weakened.
Restless legs and jet lag
For a person with restless legs syndrome, a long flight in an economy class is very painful and sleeping is not easy during flight. In this case, jet lag symptoms also become more pronounced. A small dopamine-like medication (dopamine agonist) can bring relief. The right use of light is also important. Melatonin can help to relieve jet lag symptoms, but unfortunately it can also worsen the symptoms of restless legs, as well as motion sickness and sedatives.