Taylor Swift caused a stir after the Super Bowl this year by answering a question about her flight (on her private jet, no less) from Tokyo to Las Vegas. When her boyfriend Travis Kelce of the Kansas City Chiefs asked her "how do you not have jet lag right now?" she responded, perhaps jokingly, "jet lag is a choice."
But sleep experts like Jade Wu would like Swift and others to know that "jet lag is very real. It's biologically ingrained."
Jet lag is a form of circadian misalignment, an umbrella term for any time your body clock is out of sync with your current time zone or where the sun is in the sky, says Wu, a behavioral sleep medicine psychologist and researcher at Duke University.
It happens when you cross multiple time zones in a very short amount of time, she says. A direct flight from Tokyo to Las Vegas, for instance, takes about 10 hours and sets your internal clock forward by 17 hours (in Standard Time). So if you land in Las Vegas at 7 p.m., your body might still be on Tokyo time, which is noon the next day.
What happens to your body during jet lag
For many folks, jet lag can leave them feeling groggy and out of sync with their surroundings. "Our thinking is slower, our mood is worse, our metabolism is not as good. We can't sleep when we want to sleep but we can't feel awake when we want to be awake," says Wu.
That's because almost everything in our bodies — like our blood pressure, our organ systems and our cognitive function — runs on an internal clock, says Wu. "These clocks are synced up to each other. During jet lag, suddenly all these clocks are confused. They're saying: 'Wait a second, I thought it was daytime. Why is it night?' "
That includes the master clock in your brain called the suprachiasmatic nucleus (SCN). "Think of all the clocks in your body as a billion-person orchestra. The SCN is the maestro. And if the maestro can't keep time, then the entire orchestra falls apart," she says.
How to minimize jet lag symptoms
To mitigate the effects of jet lag, a little preparation goes a long way, says Wu. Here are some tips to help manage symptoms of grogginess.
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Rest up beforehand. Take supplemental naps ahead of your journey, but don't force it if you're not sleepy. The goal is to get as much rest as possible so that when you're in a period of less sleep, you'll feel a little more alert.
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Time shift your sleep. Gradually adjust your schedule toward your target time zone before you leave. Let's say you live in Chicago and your usual bedtime is at 11 p.m. and you're traveling to Lisbon, Portugal, in a week. Start heading to bed (and getting up) about 15 to 30 minutes earlier each day. By the time your trip rolls around, your bedtime should be about 8 p.m. How does that help with the time change? Rather than trying to fall asleep at 5 a.m. Lisbon time (11 p.m. Chicago time), you'll now be trying to fall asleep at 2 a.m. Lisbon time — a more reasonable hour to hit the hay. If you need help with this step, try using jet lag apps like Time Shifter to create a schedule.
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Book a flight that works with your nighttime sleep schedule, not against it. If you're flying to Taipei, Taiwan, from Los Angeles, for example, take a very late flight so you can get your eight hours of nighttime sleep on the 14-hour plane ride. When you arrive, it'll be morning local time, and you'll have enough rest to start your day.
- Be careful with alcohol and caffeine. Alcohol can block or interfere with deep sleep, making sleep more fragmented. And Wu discourages using caffeine to fight jet lag because it can lead to unpredictable outcomes. Sometimes it can make you exhausted or wired or both. However, if you're heading east, you could aim to have some caffeine to help stay up. Avoid it if you're going west.
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Consider the direction you're headed. If you're going west, say to Seoul, you'll have to stay up and wake up later. If you're going east, say to Madrid, you'll have to sleep and wake up earlier. "Going west is easier because your body [naturally] wants to go to bed later. Going east is hard because you have to fight [sleep]," says Wu.
If you're traveling west, take a short nap on the flight so you can go to bed at a reasonable hour once you reach your destination. By the time you land, hopefully you'll be sleepy enough to "sleep a nice, solid night and wake up in the morning local time," says Wu.
If you're traveling east, try to stay up during your flight. "When you land, you're not going to be sleepy yet by the local bedtime. So you may need to take a sleep aid to help you fall asleep that night," she says.
- Once you reach your destination, quickly try to adjust to the local time. "Get lots of light first thing in the morning," says Wu. Exposing yourself to daylight early in the day can help sync your circadian clock to your new time zone. "Go outside, exercise, walk, hike, go around town. The quicker you get actively engaged in the rhythm of the local schedule, the more quickly you'll adjust."
The digital story was written by Malaka Gharib and edited by Andee Tagle and Meghan Keane. The visual editor is Beck Harlan. We'd love to hear from you. Leave us a voicemail at 202-216-9823, or email us at LifeKit@npr.org.
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