Nothing puts a damper on a vacation like spending the first few days a groggy, jet-lagged mess. Crossing time zones to come home can be a slog, too.
You probably know what jet lag feels like: fatigue, a weird sleep schedule, and general unwellness. But why does it happen? Jet lag occurs when there’s a mismatch between your circadian rhythms—which influence the activity of cells and organs throughout your body—and time of day at your destination. Our biological clocks make us creatures of habit, used to sleeping, waking, and eating at roughly the same times every day. So when you abruptly cross time zones, your body gets confused by its new schedule and environment. As it adjusts, everything from your sleep cycle to your digestion may feel out of whack.
[time-brightcove not-tgx=”true”]To some degree, jet lag is an inevitable part of long-distance air travel. But, experts say, it is possible to minimize its effects to make the most of your trip—and cushion the blow of returning home. Here’s how.
If you’re facing a time change of only a few hours—say, the three-hour difference between Los Angeles and New York City—you can prepare in advance, says Dr. Sairam Parthasarathy, director of the Center for Sleep, Circadian and Neuroscience Research at the University of Arizona Health Sciences.
Starting about three days before traveling east, move up your bedtime by 30 minutes each night, Parthasarathy recommends. Going to bed progressively earlier will prime your body to start getting tired at a normal bedtime in New York, even though it’s early back in California. If necessary, you can also take a small dose of melatonin shortly before your desired bedtime. And, on the day you arrive in New York, try to avoid bright light exposure in the evening, which can keep you up longer, Parthasarathy says.
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Before flying west, reverse these instructions. Go to bed progressively later over the days before your flight, and once you land, try to get some light exposure in the afternoon and evening to delay sleep. Traveling west tends to be an easier adjustment, Parthasarathy says, because most people find it easier to willfully stay up than to force themselves to sleep when they’re not tired.
If you’re crossing lots of time zones—such as when flying from Los Angeles to London—you may step off the plane feeling like a zombie, ready for bed before lunchtime. There’s only so much you can do to prepare in advance for such a dramatic time difference, but what you do when you arrive matters, says Dr. Alon Avidan, director of the University of California, Los Angeles Sleep Disorders Center.
Light exposure is the single strongest factor regulating circadian rhythms. So if you land in London in the morning, try to avoid seeing direct sunlight until early afternoon. (That means wearing sunglasses if you’re going to be outside.) After crossing so many time zones, your “circadian clock might incorrectly mistake early-morning light in London for evening sunset,” only adding to your physiological confusion, Avidan explains. With each day of your trip, you can start seeing morning sun progressively earlier.
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And, even if you’re exhausted, resist the temptation to go to your hotel and fall into a deep sleep in the middle of the day. That’s “the last thing we want people to do,” Avidan says, because it only prolongs the mismatch between your internal time and the external time. If you absolutely need some shut-eye to get through the day, take a “strategic” power nap of no longer than 20 minutes, ideally no later than 2 p.m., Avidan suggests. Any longer or later and you’ll risk ruining your overnight sleep.
Caffeine can be used in a similar manner, he says. A coffee or two can help you power through the day, but don’t drink it so late that you can’t sleep at night.
While sunlight exposure is key, everything from food intake to physical activity to social interaction also plays a part in regulating circadian rhythms, Parthasarathy says. So think twice before you wolf down an airplane dinner that’s being served at 3 a.m. in the time zone you’re traveling toward. Your brain is saying, “‘Wait a second, what meal is that?’” Parthasarathy explains.
If you can hold out, he says, it’s often better to wait to eat until a regular mealtime at your destination. (Within reason, of course—if you’re on a long-haul flight, don’t feel like you have to starve yourself for hours on end, Avidan says.)
You may want to skip that in-flight cocktail, too, especially if you’re trying to get a full night’s sleep on the plane. Booze disrupts sleep, often causing you to wake prematurely when your blood alcohol levels drop, Avidan explains. If you really want to toast to your vacation, try to end the celebrations after one drink.
As much as you may want to spend your first day of vacation lounging in your cozy hotel bed, it’s better to get up and move, says Emily Schmitt, who runs the Circadian Rhythm and Exercise Research Lab at the University of Wyoming.
On your first morning in a new time zone, do 20 minutes of activity, she suggests. “It doesn’t have to be an all-out sprint or a hard CrossFit workout,” she says. “It could simply be wandering down to your local coffee shop.” Anything that gets you up and out of bed in the morning will help your body perk up and adjust to its new surroundings, she says. It may also help your digestion get back to normal.
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Light physical activity, such as walking, can also be a useful tool if you find yourself crashing early in the evening due to jet lag, Schmitt says. Movement boosts alertness, so it can be a helpful way to delay sleep until bedtime.
Parthasarathy says his patients sometimes try to use sleeping pills to ensure they get as much rest as possible on their long-haul flights. But that strategy can backfire, he warns. Medication mixed with jet lag-induced fatigue can lead to serious drowsiness, confusion, and disorientation upon waking. Tread very carefully if you choose to take medication while traveling, especially if it’s not one you use regularly, Parthasarathy says.
If all of this sounds complicated, turn to your phone. There are plenty of jet-lag calculators—like those from British Airways and Timeshifter—that tell you exactly how to prepare for jet lag based on your flight details.
