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10 ways to stay healthy on a long flight, from hydration to jet lag

Learn how to stay healthy on a long flight with 10 practical habits covering hydration, circulation, sleep, jet lag, germs and dry cabin air on long-haul trips

A long-haul flight asks the body to do something it rarely does on the ground. It has to sit almost still for many hours in dry air, at close quarters with many other people, while drifting away from its usual sleep schedule. Each part of that setup creates its own small strain. Together, they explain why travelers often step off a plane feeling stiff, parched and out of sync with the local clock.

The cabin itself is the first factor. Air on commercial jets carries very little moisture. Skin, eyes, nose and throat can dry out over the course of a trip. Stillness is the second. Sitting for long stretches slows blood flow in the legs. For some travelers, that raises the risk of deep vein thrombosis, a clot that forms in a deep vein.

Sleep and timing add another layer. An upright seat, cabin noise and light make rest hard to come by. Crossing several time zones leaves the body clock out of step with local time at the destination, which is the root of jet lag. A shared cabin also means shared surfaces, from tray tables to armrests, handled by many passengers.

None of these pressures requires elaborate preparation. Knowing how to stay healthy on a long flight comes down to small, repeatable habits that each address one problem. Steady water intake offsets dry cabin air, and lighter meals sit more comfortably during hours in a seat. Movement, seated exercises and, for some travelers, compression socks support circulation. Planning sleep around the destination's time zone eases the shift. Basic hygiene limits contact with germs. Moisturizer, saline spray and eye drops ease dry skin, eyes and nasal passages.

The 10 habits below are a practical selection rather than a complete program. Each one stands on its own. Readers can pick the ones that fit a particular trip, seat or schedule. Most cost little and need nothing beyond what fits in a carry-on bag. Rules on liquids, food and medicines vary by airport, airline and country. Checking them before departure avoids surprises at security or customs.

Travelers $TRV with medical conditions should get personal advice first. Anyone with a history of blood clots, recent surgery, pregnancy or another health concern should talk to a doctor before a long flight. That conversation can cover whether compression stockings make sense and how to time regular medications across time zones.

Drink water steadily through a long-haul flight

Sip water at regular intervals from boarding to landing to stay comfortable on a long-haul flight. Cabin air on commercial jets is very dry, and steady intake keeps the body ahead of that dryness instead of playing catch-up.

The dryness has a physical cause. Much of the air supplied to the cabin is drawn in from outside the aircraft at cruising altitude. Air at that height is extremely cold and holds very little moisture. As a result, cabin humidity stays low for the whole journey.

Low humidity increases the moisture the body loses through ordinary breathing. Over many hours, that loss can show up as a dry mouth, a headache or fatigue. Those are common signs of mild dehydration. They are easy to mistake for ordinary travel tiredness.

Small, frequent drinks suit a flight better than one large one. Drinking a big volume at once can mean several lavatory trips in quick succession. Regular sips spread intake evenly across the journey. One workable rhythm is a few mouthfuls whenever a meal or drink service passes, with more in the long gaps between services.

Thirst alone is not always a reliable guide, particularly when a traveler is distracted or asleep for long stretches. Urine color offers a simple check. Pale yellow generally indicates good hydration, while darker urine suggests a need to drink more.

Access to water is the main practical hurdle. A common approach is to carry an empty reusable bottle through the security checkpoint. Travelers $TRV then fill it at a fountain or bottle-filling station on the other side. Not every airport has filling stations, and container rules differ from one airport to the next. A quick look at the departure airport's guidance settles both questions.

On board, cabin crew can usually refill a bottle or bring extra cups between meal services. On long-haul routes, water is often available from the galley throughout the flight. Asking a crew member directly can be quicker than waiting for the next drink cart.

Where the bottle sits matters too. One stowed in the overhead bin tends to go untouched for hours. Keeping it in the seat-back pocket puts it within reach whenever thirst or habit prompts a sip.

Walk the aisle every hour or two on a long flight

Getting up to walk the aisle whenever the seatbelt sign is off keeps blood moving through the legs during a long-haul flight. Hours of sitting slow circulation in the lower legs, and a short walk restarts it.

The calf muscles do much of the work of returning blood from the feet to the heart. Each time they contract, they squeeze the veins and push blood upward. When a passenger sits still for hours, those muscles barely move. A bent knee and hip in a cramped seat can also press on the veins behind them.

For some travelers, that slowdown raises the risk of deep vein thrombosis, or DVT. This is a blood clot in a deep vein, usually in the lower leg or thigh. The main danger is that part of a clot can break loose and travel to the lungs. That condition, a pulmonary embolism, is a medical emergency.

Warning signs of DVT include swelling, pain, tenderness or warmth in one leg. These symptoms do not always appear during the flight. They can show up in the days after landing. Anyone who notices them should seek medical care. Sudden shortness of breath or chest pain calls for emergency help.

A common rhythm is to stand up and walk every hour or two while awake. A trip to the lavatory counts, and so does a slow lap to the back of the cabin and back. Booking an aisle seat makes this easier. It removes the need to wake or climb over neighbors each time.

Timing matters........

© Quartz