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We have all experienced jet lag at least once. On a recent trip to Southeast Asia, with a twelve hour time difference, it was difficult to get on top of the feeling of being run down or tired, at least for the first few days. Naps morph into fourteen hour sleep-fests wihout you even knowing it. The bad news is that if you travel, you will have to deal with it. The good news is that there are some things you can do to lessen the severest effects of jet lag.
According to Emad A. Yanni at the CDC, “Jet lag is a temporary disorder among air travelers who rapidly travel across three or more time zones. Jet lag results from the slow adjustment of the body clock to the destination time, so that daily rhythms and the internal drive for sleep and wakefulness are out of synchronization with the new environment.
Eastward travel is associated with difficulty falling asleep at the destination bedtime and difficulty arising in the morning. Westward travel is associated with early evening sleepiness and predawn awakening at the travel destination. Travelers flying within the same time zone typically experience the fewest problems, such as nonspecific travel fatigue. Crossing more time zones or traveling eastward generally increases the time required for adaptation. After eastward flights, jet lag lasts for the number of days roughly equal to two-thirds the number of time zones crossed; after westward flights, the number of days is roughly half the number of time zones.
Here are some symptoms and preventative measures:
- Jet-lagged travelers may experience the following symptoms:
- Poor sleep, including delayed sleep onset (after eastward flight), early awakening (after westward flight), and fractionated sleep (after flights in either direction)
- Poor performance in physical and mental tasks during the new daytime
- Negative subjective changes such as increased fatigue, frequency of headaches and irritability, and decreased ability to concentrate
- Gastrointestinal disturbances and decreased interest in and enjoyment of meals
- Travelers can minimize jet lag by doing the following before travel:
- Exercise, eat a healthful diet, and get plenty of rest.
- Begin to reset the body clock by shifting the timing of sleep to 1–2 hours later for a few days before traveling westward and shifting the timing of sleep to 1–2 hours earlier for a few days before traveling eastward.
- Seek exposure to bright light in the evening if traveling westward, in the morning if traveling eastward (although it requires high motivation and strict compliance with the prescribed light–dark schedules).
- Break up a long journey with a stopover, if possible.
Travelers should do the following during travel:
- Avoid large meals, alcohol, and caffeine.
- Drink plenty of water to remain hydrated.
- Move around on the plane to promote mental and physical acuity, as well as protect against deep vein thrombosis.
- Wear comfortable shoes and clothing.
- Sleep, if possible, during long flights.
Travelers should do the following on arrival at the destination:
- Avoid situations requiring critical decision making, such as important meetings, for the first day after arrival.
- Adapt to the local schedule as soon as possible.
- Optimize exposure to sunlight after arrival from either direction.
- Eat meals appropriate to the local time, drink plenty of water, and avoid excess caffeine or alcohol.
- Take short naps (20–30 minutes) to increase energy but not undermine nighttime sleep.”