A practical plan to beat jet lag

Jet lag happens when your body clock is still running on home time while the clocks around you have jumped forward or back. Your brain’s internal clock, a small group of cells in the hypothalamus, controls when you feel sleepy, hungry and alert. It can only shift gradually, and as a rough rule it adjusts by about one time zone per day without help. That’s why a seven-hour trip can leave you foggy for most of a week.

You can’t avoid jet lag completely on long trips, but you can shorten it a lot. The main tools are light, sleep timing and meal timing.

Why flying east feels worse

For most people the natural body clock runs slightly longer than 24 hours. That makes it easier to stay up later (as when flying west) than to go to bed and wake earlier (as when flying east). Expect eastward trips to take longer to adjust to.

Before you fly

• Shift your schedule early. For 3–4 days before an eastward trip, go to bed and get up about an hour earlier each day. For westward trips, move an hour later.
• Don’t start tired. A late night of packing before an early flight adds sleep debt to jet lag.
• Choose flight times wisely. When possible, pick flights that arrive in the late afternoon or early evening, so you only need to stay awake a few hours before a normal bedtime.

On the plane

• Set your watch and phone to destination time as soon as you board, and follow it.
• If it’s night at your destination, sleep: use an eye mask, earplugs and a neck pillow. If it’s daytime there, try to stay awake.
• Drink water regularly. Cabin air is very dry.
• Go easy on alcohol and caffeine; both disturb sleep quality.

After you land: light is the main lever

Daylight is the strongest signal your body clock responds to. Timing matters: light at the right moment shifts your clock in the direction you want, and light at the wrong moment can push it the other way.

Trip	Seek light	Avoid bright light
Flew east (e.g. Europe → Asia)	Morning, local time	Late evening
Flew west (e.g. Europe → Americas)	Late afternoon and evening	Early morning

On very large shifts of eight hours or more, the advice changes slightly for the first day or two, because early-morning light can land at the “wrong” time on your old clock. Planning tools from airlines and sleep researchers can calculate exact windows. For most trips, the simple table above works well.

Sleep, naps and meals

• Stay up until a reasonable local bedtime, even if it’s a struggle on the first night.
• If you must nap, keep it to 20–30 minutes and before mid-afternoon.
• Eat meals at local times. Meal timing also nudges the body clock.
• Move. A walk outside combines daylight and gentle exercise, two things that help you adjust.
• Keep caffeine to the morning. It helps you stay alert early but can wreck the next night’s sleep if taken late.

Short trips: sometimes, don’t adjust at all

For a two- or three-day work trip across several time zones, it can be easier to stay close to home time: schedule important meetings for when you would naturally be alert, and keep your usual sleep window as much as possible. You’ll bounce back faster when you get home.

What about melatonin?

Melatonin is a hormone that signals “night” to the body. Some studies suggest small doses taken at the target bedtime can reduce jet lag, especially on eastward flights. Rules on buying it differ by country, it can interact with other medicines, and it isn’t suitable for everyone, so talk to a pharmacist or doctor before using it.

Long-haul comfort also starts with a light bag; see packing carry-on only for two weeks.

General information only, not medical advice.