That's it. Summer vacation is finally here. You've worked hard all year, counting down the weeks and checking off the days on the calendar. Your bags are packed and have been sitting by the door since yesterday. And now, here you are on the plane, headed to the other side of the world—Thailand, California, Japan. It's the trip you've been dreaming of for so long.
Then you arrive. The scenery is magnificent, the air smells fresh, and everything feels like a change of scenery. But your body hasn’t adjusted yet. It’s still on your home time. By 3:00 p.m. local time, you’re already dozing off, ready for bed. At 3:00 a.m., you’re wide awake, eyes wide open, staring at the ceiling of a hotel room. Welcome to jet lag.
Every traveler is familiar with this phenomenon. It can turn the first few days of a long-awaited trip into a foggy, exhausting time. But don’t worry: understanding what’s happening in your body and adopting a few simple habits will help you recover much faster and enjoy your vacation to the fullest.
What is jet lag?
Jet lag is the temporary misalignment between your internal clock and the local time at your destination. When you travel across several time zones in a matter of hours, your body becomes desynchronized. It continues to operate on the time of your departure, while the sun, meals, and social life follow a completely different rhythm. You’re out of sync.
Imagine that your body has a precisely calibrated internal clock. This clock is called the circadian rhythm. It regulates your sleep, wakefulness, body temperature, digestion, and hormone secretion. It is set to a cycle of approximately 24 hours, governed by the alternation of day and night.
When you travel east or west across multiple time zones, this internal clock cannot readjust instantly. It takes time. This adjustment period is precisely what we call jet lag. Your body must literally reset its internal clock, setting it back or forward depending on the direction of travel.
Why does jet lag occur?
The Role of the Biological Clock
At the center of your brain is a small structure that acts as a conductor: it synchronizes all of your body’s rhythms. This biological clock is primarily regulated by light. When your eyes detect daylight, your brain understands that it’s time to be awake. When darkness falls, it triggers the production of melatonin, the hormone that prepares you for sleep.
The problem with long-haul travel is that you experience an abrupt change in lighting conditions. Your internal clock shows one time, but the light outside indicates another. This time lag throws your entire body off balance.
The direction of the trip matters
Not all trips are the same when it comes to jet lag. Traveling east—for example, from Paris to Tokyo—is generally more difficult. You have to set your clock forward, shorten your day, go to bed earlier than usual, and wake up early the next day. However, our bodies naturally have a harder time falling asleep early than they do staying up late.
Traveling westward—from Paris to New York, for example—is often easier to handle. You extend your day and go to bed later. This is closer to the natural rhythm of our body clock, which runs slightly beyond 24 hours. Crossing several time zones in either direction, however, remains taxing.
The number of time zones crossed
The more time zones you cross, the longer it takes to adjust. A one- or two-hour time difference is overcome almost without thinking about it. A seven-, eight-, or ten-hour time difference, on the other hand, requires several days to adjust. As a general rule, it’s estimated that it takes about one day to recover for each time zone crossed.
What are the symptoms of jet lag?
Jet lag causes different symptoms depending on the person. The most common symptoms primarily affect sleep, but they aren't limited to that.
Fatigue is often the first sign. A drowsiness that hits you in the middle of the day, just when your body thought it was nighttime at home. You start dozing off around local lunchtime. Conversely, nighttime insomnia keeps you awake when the city is asleep, because your internal clock thinks it’s daytime. You wake up in the middle of the night, unable to fall back asleep.
Added to this are often difficulty concentrating, a feeling of mental fog, and trouble thinking clearly. Some people also experience digestive issues, since your digestive system has its own internal rhythm, which is disrupted by changes in mealtimes. Headaches, irritability, and mood swings sometimes round out the picture.
These symptoms are unpleasant but temporary. They gradually subside as your body adjusts to the local time. The good news is that there are many tips to help speed up this adjustment.
How can you prepare your body before a trip?
Managing jet lag doesn't start when you arrive. It starts even before you pack your bags and board the plane. A few days of preparation can make a real difference.
Gradually adjust your schedule
In the days leading up to your departure, you can start adjusting your schedule to match that of your destination. If you’re traveling east, try going to bed and waking up a little earlier each day. If you’re traveling west, do the opposite: gradually go to bed later. Even shifting your schedule by an hour or two before departure helps your body get a head start on adjusting. Write down these new times somewhere so you can stick to them.
Get a Good Night's Sleep Before You Leave
Setting out on a trip when you’re already tired, with accumulated sleep debt, makes the effects of jet lag worse. In the week leading up to your trip, make sure to get plenty of sleep and get a full night’s rest every night. A well-rested body adapts more easily to change. Your bedding plays an important role here: getting a good night’s sleep in the days leading up to your departure builds up a valuable energy reserve. This gives you a real advantage in starting your trip with peace of mind.
Choose Your Flight Wisely
If possible, choose a flight that arrives at your destination in the evening. That way, you can go to bed shortly after arrival, at a reasonable local time, and let your body begin adjusting right from the first night. Also, be sure to pack your bags in advance, without any stress, so you can set off well-rested rather than exhausted from a last-minute sleepless night.
How can you recover quickly after crossing the finish line?
Once you arrive, there are a few simple tips that can help you adjust to the time zone more quickly and recover faster.
Exposing Yourself to Natural Light
Light is your best ally. It’s what resets your internal clock most effectively. As soon as you arrive, expose yourself to daylight. Go outside, take a walk, and enjoy the sun. This exposure sends a clear signal to your brain: now is the time to be alert. Conversely, when evening comes, dim the lights and minimize screen time to let melatonin do its job and help you fall asleep.
Set the local time immediately
As soon as you board the plane, set your watch to the time at your destination. This small, symbolic gesture helps you mentally adjust to the new time zone. Upon arrival, start living according to local time right away. Eat at local mealtimes, go to bed when night falls there, and wake up with the sunrise—even if your body resists a little at first.
Resisting the urge to take a long nap
When you arrive, it’s very tempting to collapse onto the bed. But a long nap in the middle of the day may make your jet lag worse. If you’re really exhausted, a short nap of twenty to thirty minutes can help you feel better without disrupting your sleep later that night. The goal is to hold out until the evening so you can go to bed at a normal local time, without delaying your bedtime too much.
Stay hydrated and eat light
Long flights can cause dehydration. The dry cabin air, inactivity, and sometimes the alcohol served on board—all of these take a toll on your body. Drink water regularly during the flight and upon arrival. Opt for light meals that are easier to digest and won’t put extra strain on your body, which is already working hard to adjust. Our article on hydration and sleep explains how to stay properly hydrated without disrupting your sleep.
Are there any natural remedies for jet lag?
There are several gentle approaches that can help you adjust, in addition to the good habits already mentioned.
Melatonin is undoubtedly the best known. This natural sleep hormone, available as a supplement, can help reset your sleep schedule when you’re dealing with significant jet lag. It should be taken at your local bedtime. However, it’s best to consult a healthcare professional before using it, particularly regarding dosage and timing.
Certain plants known for their calming properties, such as ravintsara or valerian, can promote relaxation and make it easier to fall asleep during the first few nights, when jet lag-related insomnia sets in. Evening herbal teas also help establish a comforting bedtime routine in a new environment.
Finally, don’t underestimate the power of a good sleep routine. Establishing soothing routines—even while traveling—helps your body fall asleep more easily. A cool, dark, and quiet room, a little reading, a few minutes of slow breathing: these simple steps are worth their weight in gold.
The Return: Don't Overlook It
We rarely think about it, but jet lag also affects us on the way back. After a vacation spent on the other side of the world, coming home means having to readjust all over again. The time difference then works in the opposite direction, and it can be just as tiring.
Plan ahead for your return. If possible, schedule a day of rest before going back to work. This will allow you to ease back into things, get back into your routine, and, most importantly, sleep in your own bed. After a long trip, nothing beats the familiar comfort of your own bedding to complete your recovery. Returning to a mattress that supports your body and breathable bedding helps your body readjust to its usual rhythm.
Key takeaway: Prepare your body before departure by gradually adjusting your schedule. Expose yourself to natural light as soon as you arrive, adjust to the local time right away, stay hydrated, and avoid long naps. Allow about one day of recovery for each time zone you cross, and keep in mind that the return trip also requires time to readjust.
Jet lag is part of the journey. It’s the price—which, in the end, is quite small—you pay for the chance to discover distant horizons. By understanding how your internal clock works and following these simple tips, you can turn this challenge into a minor, temporary inconvenience. Prepare your body before departure, expose yourself to light upon arrival, adjust to the local time right away, stay hydrated, and prioritize sleep throughout your trip. That way, you’ll enjoy your vacation to the fullest, with a clear mind and a well-rested body. And when you return, give yourself time to get back on track—your bed, your room, your rhythm. The trip will remain a wonderful memory, without the lingering fatigue.