If you have ever landed in London wide awake at 3am or nodded off during a lunch meeting in New York, you already know the problem. Knowing how to deal with jet lag comes down to helping your body clock catch up with the local time faster, using light, sleep timing, meals and hydration. This is general information to help you plan, not medical advice.
What jet lag actually is
Your body runs on an internal 24-hour clock, the circadian rhythm, that governs sleep, alertness, hunger, digestion and body temperature. It takes its main cue from light. When you cross several time zones quickly, your internal clock is still set to Singapore time while the sun outside says something else. The mismatch is what makes you groggy, foggy, bloated or restless.
Common symptoms include difficulty falling or staying asleep, daytime tiredness, poor concentration, headaches, low mood and an unsettled stomach. As a rough guide, the body shifts by only about one time zone per day on its own, so the more zones you cross, the longer full adjustment can take. The good news is that a bit of planning shortens the misery considerably.
Direction of travel matters
The direction you fly changes how hard jet lag hits.
- Flying east (for example Singapore to Australia, Japan or the west coast of North America across the Pacific) usually feels harder. You are asking your body to sleep earlier than it wants to, and advancing the clock is tougher.
- Flying west (for example Singapore to Europe or, in the other direction, towards the Americas) tends to be gentler, because staying up later and delaying sleep is easier for most people.
- North to south trips with little time change, such as flights within the region, cause little or no jet lag even when the journey is long.
Knowing this helps you plan: eastward trips deserve more preparation before you leave.
Before you fly
You can start adjusting a few days ahead so you land closer to local time.
- Shift your schedule gradually. For an eastward trip, go to bed and wake up 30 to 60 minutes earlier each day for two or three days. For a westward trip, do the opposite and stay up a little later.
- Manage light at home. Bright morning light helps you wake earlier; dimming lights in the evening helps you sleep earlier.
- Arrive rested, not wrecked. Do not fly out exhausted from last-minute packing. Sort your bags and documents early so the final night is calm.
- Set your watch to the destination time as you board. Start thinking in local time straight away.
Our pre-travel checklist for Singapore travellers is a handy way to get the admin out of the way early.
During the flight
The flight is where you set the tone for the first 48 hours.
Sleep on the plane strategically
Sleep only when it is night at your destination, not simply because you are tired. If it will be daytime when you land, try to stay awake for the last few hours of the flight. If it will be night, block out the cabin with an eye mask, earplugs or noise-cancelling headphones, recline, and rest even if you do not fully sleep.
Hydration and food
Cabin air is dry, so drink water steadily and go easy on alcohol and excess coffee, both of which disrupt sleep and worsen dehydration. Eat lighter meals and, where you can, try to eat roughly in line with meal times at your destination rather than your departure city.
Move and stretch
Get up every couple of hours, walk the aisle and stretch your calves. This keeps you comfortable and helps you feel more human on arrival. Our tips for surviving overnight and red-eye flights go into resting on board in more detail.
After you land
The first day sets the pace for the whole trip.
- Get outside into daylight at the right time. If you flew east and need to wake earlier, seek bright morning light. If you flew west and need to stay up later, get light in the late afternoon and early evening.
- Do not nap for hours. A short nap of 20 to 30 minutes can take the edge off, but long afternoon naps wreck the coming night.
- Eat on local time from the first meal. Meal timing is a strong signal to your body clock.
- Stay awake until a reasonable local bedtime, then keep the room dark and cool for a solid night.
Quick comparison: eastward vs westward strategies
| Factor | Flying east (harder) | Flying west (easier) |
|---|---|---|
| What your clock must do | Advance, sleep earlier | Delay, sleep later |
| Pre-trip shift | Sleep and wake earlier | Sleep and wake later |
| Best light timing | Bright morning light | Late afternoon and evening light |
| On arrival goal | Force an earlier bedtime | Push to a later bedtime |
| Typical recovery feel | Slower, plan more | Quicker for most people |
Children and older travellers
Children often adjust reasonably well but can be more sensitive to overtiredness. Keep meal and nap times moving towards local time gradually, get them into daylight and outdoor play, and expect a couple of unsettled nights. Keep the first day gentle rather than packed with activity.
Older travellers may find adjustment slower and sleep more easily disturbed. Build in a lighter first day, prioritise daytime light exposure, keep well hydrated and avoid stacking long flights with an immediate early start. Anyone managing a health condition or taking regular medication should speak to a doctor or pharmacist before relying on any sleep aids, and should also plan dosing across time zones carefully.
A simple plan that works
You do not need anything fancy. Shift your schedule slightly before an eastward trip, set your watch to destination time as you board, sleep on the plane only when it is night where you are going, drink water and go easy on alcohol, then chase daylight and local meal times the moment you land. Give yourself a lighter first day, resist the long afternoon nap, and most people feel close to normal within a few days.
Jet lag is temporary and manageable. With a little preparation you spend more of your trip enjoying the destination and less of it staring at the ceiling.
Explore more: Long-haul flight comfort tips · Surviving overnight and red-eye flights · Pre-travel checklist for Singapore