Resetting your watch when you travel is easy. Resetting your brain is a lot more difficult, which is why Jet Lag challenges even the savviest of travelers. When you travel by plane, you change the time of day without resetting your body's clock. Suddenly, it's 5pm outside but your body insists it's 11pm and time to go to bed. The dissonance between external events and your internal clock can make you dizzy, weak and ill: that's jet lag.

"It's not because you've been on a plane for that long," said Dr. Russell Rosenberg, CEO of NeuroTrials Research and the Atlanta School of Sleep Medicine. "It's because you're trying to sync up with environmental time when your own internal core time can't move that fast."

Jet lag will pass after a few days, once you fall into sync with your destination. Fortunately, there are strategies that can speed up your acclimation to a new time zone, and a few have been scientifically studied and proven to be effective.

If you're taking a very short trip -- just for a meeting, or for a weekend vacation break -- you may not want to deal with the hassle of jet lag at all. Just schedule your activities for the times you'd normally be awake, and stay on "home time."

Jet Lag Symptoms

Jet lag affects your whole body; it's a physical syndrome. Symptoms include stomach upset, deep fatigue, fuzzy-headedness, absentmindedness, slow-wittedness, poor concentration, weakness, disrupted bowel movements, and changes in the frequency of urination.

Let's say you fly out of New York just after lunch at 3pm. When it would have been time for your dinner at 7 o'clock, your stomach is going to release enzymes and stomach acids in anticipation of food, but when you touch down in San Francisco, it's only going to be 4pm -- too late for lunch, too early for supper. Three hours later, when you would have been curling up with a book for the evening and your bodily functions would have started shutting down in anticipation of sleep, you`ll be nodding off in your gazpacho as your California business associates are plying their wits and picking at their martini olives.

Jet lag usually takes three to four days to overcome naturally, Rosenberg said. It's worst if you're flying east because the human body cycle is actually slightly longer than 24 hours, which makes it hard to shift your body clock earlier. When you travel west, you're required to stay up late, which is more acceptable to your body than going to bed early. If you're traveling from east to west, your recovery will usually take 30% to 50% less time.

Most night-owl types tend to adapt faster to the new time zone on a trip out west. When traveling east, on the other hand, night owls tend to adjust far more slowly, and it's the early birds who get the worm. Likewise, "morning people" are more readily able to rise and shine at any hour, even if it means cutting short the sleep period for a few hours each day.

Age is also a factor in your ability to cope with jet lag. While even infants experience jet lag, they recover very quickly. "Kids in general, with circadian rhythms, do tend to have a more flexible clock," Rosenberg said. It becomes harder to adjust to rapid time zone shifts as you grow older, he said.

As you might guess, healthy people cope better with jet lag than people in poor health, whose body rhythms have already been disrupted. Jet lag will make you feel even worse if you travel while ill. If you must take prescription drugs during your trip, be aware that jet lag may impair their effectiveness.

Several other personality factors figure into your capacity to cope with east-west travel. Gregarious types, who love to meet new people, mix among various social groups, and travel in a pack, tend to cope better with jet lag than people who reach a destination and retreat to their rooms with a book or remote control. This is because the more you expose yourself to external stimuli in your new environment, the faster the necessary chemical changes will take place in your brain to help you adapt to your new surroundings.

How to Prepare for Jet Lag

Sleep doctors have two major approaches for speeding up adaptation to jet lag. You can mitigate the symptoms with drugs, and you can actually change your body clock with light therapy.

Also, for years, Argonne National Laboratories in Illinois has been offering a special diet which has plenty of anecdotal, although little scientific, backing for success.

For brief trips, you can curtail the symptoms of jet lag without having to take any drugs or follow any complicated diet regimens. Try the following tricks the next time you fly.

  • Start resetting your body clock before you fly. Shift your bedtime by an hour or two in the right direction starting three days before your trip.
  • Drink lots of water before, during, and after your flight. Experts recommend that you drink at least two 8-ounce glasses just before departure and 1 liter for every hour you spend in the air -- in addition to beverages you drink with meals. Even if you don't feel thirsty, drink up. Thirst doesn't necessarily precede the symptoms of dehydration, which can set in without warning.
  • The minute you step into the airplane cabin, adopt the hour of the time zone you're traveling to. Reset your watch and start to think according to the new time zone.
  • Avoid drinking alcohol or ingesting other depressants, such as Dramamine or other motion-sickness drugs, before, and during your flight.
  • Eat more lightly than you are accustomed to before your flight and while you're in the air.
  • Daytime naps are OK to take after you arrive, but keep them to 30 minutes or less so they don't interfere with your nighttime sleep.

Light Therapy to Treat Jet Lag

Timing exposure to light is the best way to resynchronize your circadian rhythms, according to a February 4 article in the New England Journal of Medicine by Dr. Robert Sack of Oregon's Health and Science University.

Unfortunately, it's not just about going outside in daylight and keeping things dark at night. Dr. Rosenberg points out that if you're traveling from the East Coast to Europe, it actually helps to avoid light in the early morning for the first few days and seek it once your body clock thinks it's about 4:30am -- that's 10:30am, western European time.

A British maker of light-therapy devices, Lumie (, has a quick-and-dirty light-timing tool that can help you figure out when to seek and when to avoid bright light. If you need to find light when it's dark outside, you can use special light boxes, light visors or just blast indoor lights (hotel lighting may not be enough). If you need to make things darker and you can't stay in a darkened room, low-transmittance sunglasses may help, according to Dr. Sack's article.

Jet Lag Pills

The hormone melatonin and the prescription medications Ambien and Nuvigil all do different, potentially useful things to help with jet lag. Melatonin helps alter your circadian rhythms. Ambien and Nuvigil knock you out and keep you awake respectively. The two prescription drugs don't actually fix jet lag, Rosenberg said, but they help moderate the symptoms to make you less miserable and more functional while your body adapts.

In a June 2010 study published in the Mayo Clinic Proceedings, Rosenberg found that 150 mg of Nuvigil issued to people taking an eastbound trip over six time zones helped them feel more awake on the first two days after their trip, reducing that horrible sinking, sleepy feeling you get with eastbound jet lag. Nuvigil hasn't been approved by the FDA to treat jet lag, Dr. Rosenberg notes, but he says it offers travelers an excellent option for promoting wakefulness when they have to hit the ground running. Sack's article says that a strong hit of caffeine can also make you more alert, but with caffeine, you risk making jet-lag-related insomnia worse.

Ambien, otherwise known as zolpidem, helps you sleep. According to Dr. Sack's article, a study showed that 10 mg of generic Ambien significantly improved sleep quality for eastbound travelers, but fliers should be very cautious about taking sleep aids on their flights. Because there's less time to sleep during a flight, his article recommends a short-duration sleeping pill like Sonata if you aim to knock out while in the air.

Melatonin is a hormone that occurs naturally in the body, secreted by the pineal gland in the forebrain, and induces sleep. Daylight curbs the natural production melatonin, but when night falls the pineal gland releases the hormone into the bloodstream and triggers the sleep cycle.

Melatonin not only induces sleep but improves sleep quality as well. Taken 2 hours before bedtime on an eastbound trip, a dose of melatonin will trick your body into thinking that night has fallen earlier. In the conclusion of his article, Dr. Sack suggests taking a 3-mg dose of melatonin in the evening if heading east, and taking an 0.5-mg dose if you wake up too early when heading west. He also suggests not taking both melatonin and Ambien; the combination is associated with higher amounts of sleepiness and confusion.

Be careful not to go overboard and take too much melatonin, or you may suffer a hangover and feel addled the following day. But taken in small quantities, clinical tests have shown melatonin to be nonaddictive, nontoxic, and safe, and it causes very few side effects.

Make sure to get melatonin from a trusted pharmacist—although sold over the counter, the quality of melatonin is completely unregulated, so there's no guarantee that what you buy at the health food store is actually melatonin.

Sascha Segan collected Lowell Thomas awards from the Society of American Travel Writers Foundation for his columns. He lives in New York City with his family.

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