What is jet lag?
Jet lag is a fatigued, out-of-sync feeling you experience after flying across several time zones. The rapid travel disturbs your normal body rhythms.
How does it occur?
Each person has an internal body clock that determines when sleeping, waking, and hunger occur in a 24-hour period. When you travel across several time zones, your day is longer or shorter than 24 hours. Your normal body rhythms cannot adjust quickly to this shorter or longer day, which results in jet lag.
Not all jet lags are the same. Traveling eastward, which shortens your day, is more difficult than flying westward, which lengthens it.
What are the symptoms?
The symptoms of jet lag may include:
- drowsiness during the day
- difficulty in sleeping
- dulling of mental ability and memory
- gastrointestinal discomfort, diarrhea, or constipation
- minor coordination problems and reduced physical activity
How long will the effects of jet lag last?
West-to-east trips require on day of recovery for each time zone crossed; east-to-west journeys require one day for each one and a half time zones crossed.
The adjustment can be eased by breaking up a long journey with a stopover. If you have an important event or meeting to attend at your destination, try to get there two or three days early.
What can be done to help prevent jet lag?
Physical conditioning increases stamina and reduces travel-related stress and fatigue. Continue to exercise while traveling as well. Even if you don't regularly exercise, it helps to learn a few stretching and relaxation techniques to practice when needed. On the plane, take regular breaks to stretch, walk around the cabin, and exercise while sitting.
The air in planes is dry and it is common to become dehydrated before having any sensation of thirst. Drink plenty of water before, during, and after your flight to lessen problems of dizziness, fatigue, and constipation that can result from dehydration.
Large meals and excessive caffeine intake may cause problems with sleep and digestion. Eat lightly and avoid or reduce caffeine.
Don't smoke, drink large amounts of alcohol or take unnecessary medication while in flight. The high altitude and dehydration can increase the effects of any drug.
Keep any naps during travel days to less than 45 minutes. This will reduce the "drugged" feeling that results from deep sleep and allow you to sleep more easily at night.
Spend some time in daylight as soon as possible once you arrive at your destination. If you are traveling east expose yourself to morning light; if traveling west, expose yourself to afternoon light. This will help your body systems adjust.
Adapt your meal times and other daily activities to those of your destination as soon as possible after you arrive. If it is practical to do so, adjust your schedule gradually in the days leading up to your trip.
If possible, limit your activities the first day after your arrival. Relax, get to know your environment and pick up the pace after a good night's sleep. Focus your energies on becoming adjusted to your new schedule, not on maintaining the one you were following at home.
Although many people use melatonin to relieve insomnia and jet lag symptoms, its use is still under debate in the medical community. Melatonin is a hormone produced in the human body that plays a roll in regulating the sleep-wake cycle. Synthetic and animal-derived melatonin products are widely available in the United States but since the government does not regulate them, their purity and potency cannot be guaranteed.
Diets and pills that claim to decrease symptoms of jet lag have not been proven effective.
How do I adjust medications prescribed at a certain hour?
If you are diabetic and use long-acting insulin, you may have to change to regular insulin until you have adjusted to the time, food, and activity of your destination.
You may have to adjust other medication schedules according to the actual hours between doses rather than the local time at your destination.