While long-haul flights are certainly exhausting across the board, jet lag is not caused by the number of hours clocked on a plane—but by changing time zones. “Rapid travel between time zones temporarily disrupts this biological clock," says Chris Colwell, a professor in psychiatry at the UCLA Medical School. “Our system does readjust, but this takes time. It can take a couple of weeks to adjust to the new time in Europe or Asia.” A traveler flying from New York to Madrid, for example, will change time zones six times along the way.
While jet lag is widely known to interfere with normal sleeping patterns, its symptoms extend well beyond a lousy night of sleep. Other symptoms of jet lag include irritability, a tendency to catch colds and flus, gastrointestinal problems, loss of motivation, and even mild depression. Colwell adds that “You may find cognitive processes like memory impacted.” Being aware of jet lag’s impact on your mind and body can help you adjust, both physically and psychologically, to a new time zone.
Heading east is more difficult than traveling west, according to Colwell. A 1999 article in the Journal of Sport Behavior explained that eastward travel is more difficult because it compresses days into shorter time periods, taking a person further from the body’s natural rhythms. Westward travel, by comparison, expands days to more closely correlate with the body’s internal cycle. “In essence, it is easier for us to delay our clock than to speed it up,” Colwell says.
Stretching during a long airplane flight helps reduce the physical stress of travel, of course, but don’t forget to keep it moving once you land. While the exercise has little direct effect on adjusting the body’s biological clock, research suggests that moderate physical training leads to an increase in sleep length and quality of rest (according to a paper documenting the incidence of jet lag on the cabin crew of a commercial airline, published in 2004 by the Indian Journal of Aerospace Medicine). Try to exercise a few hours before bedtime or get aerobic exercise after waking up for the best results.
It may be tempting to kick off a holiday by getting loaded on the plane. But when it comes to jet lag, staying hydrated is essential and alcohol dehydrates the body. Drinking too much on the flight is one of the most common mistakes travelers make when it comes to worsening jet lag, according to Andrew Criglington, the inventor of “No-Jet-Lag” homeopathic prevention and CEO of Miers Laboratories. Take it easy with the in-flight cocktails, and temper each alcoholic drink with plenty of water.
To nap or not to nap? That is the question when it comes to sleep disorders caused by jet lag. Most people think naps should be avoided at all costs once you arrive at your new destination But according to Colwell “it can be helpful to take a nap” as long as you limit it to 30 or 40 minutes. “A long nap can confuse your biological clock and make the re-adjustment to the new time zone worse.” Rest then, but only for a brief period.
Because the body’s sleep-wake cycle is tied to patterns of day and night/light and dark, and since regulating hormones such as melatonin likewise follow this cycle, exposing yourself to sunlight after taking a long-haul flight can help the body’s internal clock reset itself. Sleep with the window shades up your first few days of vacation and let the morning sunlight filter into your room. Or, better yet, park yourself on a sunny bench for a few minutes each morning and let nature do its magic. The more your body is exposed to natural patterns of light and dark, the faster it will return to its innate rhythm.
NASA helps its astronauts prepare for missions in space by adjusting their sleeping patterns before they launch. If you have enough time and your schedule allows for it, take a few days before you fly to adjust your sleep and wake patterns to more closely resemble those of your new destination. Even if you only manage to shift your normal patterns by a few hours, you’ll feel the difference once you’re on holiday.
Research shows that skipping the airplane meal and eating lightly at regular mealtimes once you arrive in the new time zone assists the body with getting back on track. “Recognize that your whole digestive system is tightly coupled to this biological clock and takes many days to re-adjust,” says Colwell. “Eat lightly and try not to push your system in the meantime.” Some research shows that a light period of fasting before you travel may also be beneficial in reducing jet lag’s gastrointestinal effects.
Some travelers combat jet lag renegade-style: with doctor-prescribed sleeping pills. While they're certainly common tools to induce sleep, they don't actually help the body’s adjusting process or restore the natural cycle of day and night. What’s more, while sleeping pills may knock you out, studies show that the quality of rest you get may not be premieum. If you can, opt for natural remedies.