A great deal of long-haul advice is about feeling prepared rather than arriving better. Three things genuinely change how you feel on landing: hydration, movement, and light timing. Almost everything else is optional comfort.
1. The cabin is drier than a desert
Aircraft cabin humidity runs around 10 to 20 percent. The Sahara averages higher. That is the reason for the dry throat, the sinus headache, and much of what people call jet lag but is actually dehydration.
Roughly 250ml an hour is a sensible target. The practical problem is that cabin service comes round every few hours with a small cup, so the reliable method is to take an empty bottle through security and fill it airside, then top it up from the galley.
Alcohol works against this on two fronts: it is a diuretic, and it fragments sleep quality even where it speeds sleep onset. The pre-flight drink is a genuine cost on an overnight flight.
2. Movement, and why it matters more than posture
Sitting still for many hours with mild dehydration is the mechanism behind deep vein thrombosis. The risk for a healthy traveller on one flight is low but not zero, and it rises with flight length, age, and existing risk factors.
What helps:
Walk the aisle every two to three hours. Not a stretch routine — just standing and moving.
Ankle rotations and calf contractions in the seat, a few times an hour. The calf muscle is the pump that returns blood from the legs.
Compression socks on anything over about six hours. Cheap, mildly uncomfortable to put on, and the one piece of long-haul kit with real evidence behind it.
An aisle seat makes all of this more likely to actually happen, which is a better argument for it than any comfort claim.
3. Light, which is how you fix jet lag
Light is the dominant signal for the body clock, far stronger than meal timing or sleep effort.
Flying east — you need to advance your clock. Seek bright light in the destination's morning; avoid it in the local evening. This is the harder direction and typically takes a day per time zone.
Flying west — you need to delay. Get evening light at the destination, avoid early morning brightness. Usually easier and quicker to adjust.
Set your watch to destination time when you board and start behaving as if you are there — that is not superstition, it is the scheduling decision that makes the light timing work.
Melatonin has modest evidence as a supplementary timing cue, taken at destination bedtime, in small doses. It is an adjunct to light, not a replacement.
The seat, briefly
| Seat | Best for |
|---|---|
| Aisle | Moving, drinking water, restlessness |
| Window | Sleeping, wall to lean on, light control |
| Bulkhead | Legroom, no recline in front |
| Exit row | Legroom, colder, seats may not recline |
| Behind galley/toilet | Avoid — noise and traffic all night |
Seats over the wing are marginally smoother in turbulence; the very back of the aircraft moves most.
What is mostly folklore
Elaborate onboard skincare routines. Pleasant, no effect on how you feel next day.
Avoiding all food to "reset" the clock. Fasting protocols have thin evidence and make a long flight miserable.
Sleeping pills. They produce unconsciousness rather than restorative sleep, and combining immobility with sedation is exactly the DVT scenario you want to avoid.
Neck pillows, which are a genuine personal preference rather than a universal aid — most people find inflatable ones worse than a rolled jumper.
Water, movement, light. Everything else is preference.