First Contact With Jet Lag

Jet lag gets a bad reputation because most people don't do the two things that would help them most. They don't prepare in advance, and they don't force sunlight and food at the right times when they arrive.

Everyone talks about jet lag like it's mysterious. It isn't. Your body is running on a chemical clock, roughly 24-hour, that's controlled by light hitting a specific part of your brain. Move your body across a lot of time zones quickly and the clock is telling you it's 4am when it's noon outside. That mismatch is jet lag. Fix the mismatch faster and the jet lag lifts.

Direction matters

Flying west is easier than flying east. This is not a myth, it's how the circadian system works. Your natural clock runs slightly longer than 24 hours, so extending your day by flying west is easier than compressing it by flying east.

New York to London is harder than London to New York, even though the distance is the same. Los Angeles to Tokyo is brutal both ways but especially going west. If you can pick, direct flights that arrive in the early evening at your destination give your body the easiest landing.

The two-day rule

For trips under two or three days, don't bother adjusting. It's actually easier to stay on your home time zone and just power through meetings. Business travelers who cross the Atlantic for two nights often keep breakfast at what would be breakfast at home, even if it's 1pm locally.

For anything longer, commit to the new time zone from the moment you board.

Preparing before the flight

The most useful preparation happens in the days before you fly, not on the plane. Start shifting your bedtime and meal times an hour or two toward the destination for two or three nights before you leave.

If you're flying east, go to bed earlier. If west, later. This won't fully adjust you, but it takes the edge off.

Book your flight with the arrival in mind. A red-eye that lands at 7am local time gives you a full day of sunlight to work with. A flight that lands at 10pm makes it easier to go straight to bed.

What to do on the plane

Set your watch to destination time when you board and start living on it. If it's daytime at your destination, stay awake. If it's night, try to sleep.

Skip the alcohol. Skip the second coffee. Drink water constantly. Eat when the destination would be eating, not when the cabin crew brings food, unless the two happen to line up.

If you need to sleep and can't, melatonin in a low dose, 0.5 to 1 milligram, taken at what would be bedtime at your destination, is well studied and helps most people. Sleeping pills work but leave you groggy on landing.

The first day at destination

This is the day that decides whether jet lag lifts in two days or drags on for a week.

If you land in the morning, do not nap. Not even for 20 minutes. You will not wake up after 20 minutes. You will wake up at 3am and be up until 6am wondering what went wrong. Get outside. Sunlight on your face for at least 20 minutes early in the day is the single strongest signal you can give your circadian clock.

If you land in the evening, eat a small dinner and go to bed at a normal local hour, even if you're not sleepy. Take a low dose of melatonin about an hour before.

Coffee is fine in the morning, avoid it after 2pm local time for the first few days.

Meals as anchors

Meal times are a stronger circadian signal than most people realize. Eating breakfast at 8am and dinner at 7pm at your destination, even if you're not particularly hungry, helps your body decide it's actually in that time zone.

Skip the mini-bar snack at 3am, even if you're wide awake. Eating at the wrong time confuses your metabolism and drags out the adjustment.

Sunlight, actually

The advice to get sunlight is repeated so often it becomes background noise. Do it anyway. And do it deliberately.

Morning sunlight advances your clock. Evening sunlight delays it. Which one you need depends on which direction you flew.

Flying east, you need to advance your clock, so get bright morning light and avoid bright evening light. Flying west, you need to delay it, so seek evening light and shade the mornings a little.

Overcast days are still bright enough to work. If you're at a rainy destination or working indoors, a good bright-light lamp for 20 to 30 minutes can help.

The middle of the night wake-up

At some point in your first few nights, you will wake up at 3am and be completely alert. This is normal.

Do not turn on bright lights. Do not check your phone in a way that turns it into a scroll session. Do not eat a real meal, though a small snack is fine.

The best thing to do is read something calming, or listen to a slow podcast, or just lie in the dark with your eyes closed. Sleep often returns after an hour or two. If it doesn't, the next day is harder but the following night is usually the fix.

What actually doesn't work

A few pieces of common jet lag advice do more harm than good.

Sleeping most of the flight and then trying to power through the first day. This works only if you actually slept. Most people don't.

Fasting for 16 hours before landing. There's some old research behind this, but the evidence is weak and it makes you miserable.

Multiple over-the-counter sleep aids. They stack up and leave you foggy for days.

When it gets long

For anything more than about six time zones, plan for two to three days of real adjustment. Some people take a full week to feel normal after a Sydney to London kind of flight. Build a buffer into your first day or two, especially if you're arriving for a meeting or event.

The reward for treating jet lag as something you actively manage rather than something that happens to you is a real one. You get more of your trip. You feel like yourself sooner. And you stop losing the first three days of every long-haul journey to the same avoidable fog.