Most jet lag hacks fix the wrong problem. A few actually work.

Every long-haul trip comes with free advice. Stay up until bedtime. Drink three litres of water. Skip the plane food. Have a glass of wine and sleep through it.

Some of it works. Some of it works for a different reason than people think. And some of it quietly makes jet lag worse. Here’s each popular hack, checked against the published research, with the verdict first.

Why do so many jet lag hacks miss?

Because most of them treat jet lag as tiredness. It isn’t, mainly. It’s a clock problem.

Your body runs on an internal clock, and after a long flight that clock is still set to home. The sleep you lose on the flight comes back fast. In a study of 64,847 trips logged by 57,240 Oura ring users, sleep duration was back to within about 12 minutes of normal after roughly two days. Sleep timing and sleep architecture were a different story: after long eastward trips, they can still be off two weeks later S2.

So a hack that helps you catch up on sleep is solving the easy half. The hard half is moving the clock. And the strongest lever for that is light, timed to your body clock rather than to the wall clock S1.

The verdicts at a glance

Hack	Verdict	Why	Source
Stay up until local bedtime	Half right	Good for sleep timing, but it says nothing about when to get light, which does the real work	S1, S3
Get sunlight as soon as you land	Depends on the time	Light before your body clock’s low point pushes you later; after it, earlier	S1
Drink lots of water	Worth doing, wrong reason	Cabin air is dry. Water keeps you hydrated. It doesn’t move your clock	S3
Fast before or during the flight	Promising, not proven in travelers	Meal timing evidence is mostly from mice; eating on local time is the supported part	S3, S4
Wine to sleep on the plane	No	Diuretic, and bad for sleep and recovery	S3
Coffee all day to push through	Timing matters	Fine in the morning and early afternoon; not near planned sleep	S3
Nap as soon as you arrive	Short ones, yes	Keep it short and avoid evening naps	S1, S3
Work out on arrival	Useful, if timed	Exercise nudges the clock at the same times light does	S1, S3
Melatonin at bedtime	Yes, at bedtime	The trials gave it close to bedtime at the destination; at other times it can push your clock the wrong way	S1, S3, S5
Shift your sleep before you go	Yes	Moving bedtime 30–60 minutes a day for a few days starts the shift early	S1, S3

Does staying up until local bedtime work?

Partly. It’s the most common piece of jet lag advice, and it isn’t wrong. A 2026 sports medicine review of athlete travel says to “immediately switch to local schedules for meals and sleep” on arrival S3.

The problem is what it leaves out. Forcing yourself awake until 11pm local time says nothing about light, and light is what shifts the clock. Light in the roughly 12 hours before your body clock’s low point pushes your clock later. Light in the 12 hours after it pushes your clock earlier. The biggest shifts happen within 3 to 6 hours either side of that low point S1.

That’s why “stay up and get outside” can backfire. Take a morning landing in Tokyo after a flight from Zurich. For someone who sleeps 23:00 to 07:00 at home, the body’s low point is still somewhere around 4am Zurich time. That’s late morning or midday in Tokyo, depending on the season. Morning sun on the walk from the train is landing on the wrong side of that point. It pushes the clock later, when an eastward trip needs it earlier. (That timing is our worked example from the figures in S1, not a number from a study of that route.)

So stay up if you can. But the light matters more than the bedtime. If you want to see where the light windows fall for your own flight, the jet lag calculator works them out day by day.

Should you get sunlight the moment you land?

Only if it’s the right side of your body clock’s low point. The research is clear that light before that point delays you and light after it advances you S1. The athlete travel review puts it the same way: after an eastward flight, get bright light in your biological morning and avoid it in your biological afternoon and night. After a westward flight, flip it. Seek late-afternoon light and avoid morning light S3.

When avoiding light is the job, the Frontiers review suggests being inside with the lights off or as dim as possible S1. Sunglasses and an eye mask count. The review of athlete travel suggests eye masks, dim lighting or blue-blocking glasses, and 30 to 180 minutes in natural light when light is the job S3.

Why east is harder in the first place is its own story. We cover it in east vs west.

Does drinking lots of water help jet lag?

It helps you. It doesn’t help your body clock.

The case for drinking on the plane is solid. Aircraft cabins are pressurised to the equivalent of about 2,400 metres, which increases the water you lose through breathing. Cabin humidity is typically below 20% S3. Add hours of sitting still and a muted sense of thirst, and it’s easy to land dry. The athlete review recommends starting the flight well hydrated and drinking regularly throughout it S3.

What none of our sources claim is that water shifts the clock. The Frontiers review draws the line clearly. It separates travel fatigue, the headache and fog from the flight itself, from jet lag, the clock problem. Dehydration is on the travel fatigue list S1. Drink the water. It deals with the flight. Just don’t expect it to do the light’s job.

Does fasting before a flight reset your clock?

This is the most interesting hack on the list, and the least proven in actual travelers.

The idea is that your gut and liver keep their own clocks, and those follow food. The athlete review says timed feeding can help reset these peripheral clocks after travel, and that “emerging human studies support similar benefits” S3. Its practical advice is simple: eat meals on local time as soon as possible S3.

The newest evidence is from mice. In a 2026 study, male mice under a light cycle advanced by 6 hours every 6 days gained more weight and body fat than mice on a stable cycle, despite eating a similar amount. Restricting their food to a 12-hour window lined up with the shifting dark phase prevented that weight gain S4. That’s a meaningful result. It’s also a mouse study about metabolic health, not a trial of jet lag in people.

So: eating on the destination’s clock is supported. A strict pre-flight fast is a reasonable experiment, but none of the studies we cite test it in human travelers.

Does wine on the plane help you sleep?

No. The athlete review is blunt: avoid alcohol, because it’s a diuretic and it harms sleep and recovery S3. On a flight where the air is already drying you out, that’s two problems at once.

Can you just drink coffee and push through?

You can, if you’re careful about when. The athlete review suggests caffeine in the morning to early afternoon at your destination, around 100 to 200 mg, and minimising it in your biological evening or in the hours before you plan to sleep S3. Coffee at 4pm in Tokyo might feel like breakfast to your body, but if you’re trying to sleep at 11pm local time, it’s still in the way.

Should you nap when you arrive?

Short naps, yes. The Frontiers review suggests a nap during periods where you’re avoiding light, limited to one hour so it doesn’t cut into the night S1. The athlete review’s practical table is stricter: 20 to 30 minutes, and no evening naps S3. Set an alarm. A three-hour afternoon nap is the one that wrecks the first night.

Does exercise help with jet lag?

A little, and it’s easy to add. Exercise is a zeitgeber, meaning a signal your body clock responds to S3. Exercise in your early biological morning can advance the clock, and exercise in your early biological night can delay it S3. The Frontiers review notes that the right times to exercise for a phase shift line up with the right times for light S1. So a walk outside in the right window does both jobs at once.

What about melatonin?

Melatonin is the most studied hack here. A 2002 Cochrane review of the human randomised trials, still the benchmark, found that melatonin taken close to the target bedtime at the destination reduced jet lag in nine of ten trials S5. That’s the practical default. It isn’t a sleeping pill so much as a timing signal: depending on when you take it, it can push your clock earlier or later S1. Lab work finds bigger shifts from earlier doses, but those land in your body’s daytime and make you sleepy S1, which is why the advice stays at bedtime. Check with your doctor before you take it.

The full breakdown, with direction-by-direction timing, is in melatonin for jet lag.

Can you shift before you fly?

Yes, and it’s one of the most underused options. The Frontiers review describes moving bedtime and wake time 30 to 60 minutes a day for 3 to 4 days before the trip: earlier before an eastward flight, later before a westward one, with light timed to match S1. The athlete review suggests the same 30 to 60 minutes a day, starting 3 to 7 days out S3. It’s not always practical around work. Even a day or two means you land with less of the shift still to do.