30-Second Summary
Long-haul flying can disrupt your body in more ways than jet lag. Hours of sitting, dry cabin air, altered meals, less movement and inadequate fluid intake can contribute to dehydration, bloating, constipation and cramping.
Start your journey well hydrated, keep drinking throughout the flight, move regularly and go easy on alcohol. Packing an electrolyte can also be a useful addition to your carry-on ā just check what else is in it, particularly added sugar.
A little preparation before you board can make those first precious hours of your holiday considerably more enjoyable.
Quick Answer
How can I feel better after a long-haul flight?
Don't wait until you're thirsty at 35,000 feet to start thinking about hydration.
Board well hydrated, drink water regularly, move whenever you can and keep alcohol to a minimum.
Consider packing an electrolyte too. Sodium, potassium and magnesium are involved in fluid balance, nerve signalling and normal muscle function ā all useful things to support during a long travel day.
And don't forget your gut. Long-haul travel can contribute to bloating, constipation and cramping, so what you do before and during the flight can affect how you feel when you arrive.
Why This Matters
A long-haul flight is an unusual day for your body.
You may leave home before breakfast, spend hours in airports, eat dinner when your body thinks it's lunchtime and then sit relatively still for 10, 15 or even 20 hours.
It's hardly surprising that you can arrive feeling a little... off.
Dry mouth. Puffy. Bloated. Constipated. Crampy. Tired.
Some of it is unavoidable.
But some of it isn't.
1. Start Hydrating Before You Get on the Plane
One of the easiest mistakes is treating hydration as something that begins once you're onboard.
It doesn't.
Think about hydration before you leave for the airport.
Aim to board already well hydrated rather than spending the flight trying to catch up.
Aircraft cabins are extremely dry, commonly with relative humidity around 10ā20%, so keep drinking regularly throughout the flight.
You don't need to obsessively drink litres of water. Just don't ignore it.
2. Don't Forget About Electrolytes
Hydration isn't only about water.
Your body also relies on electrolytes, including sodium, potassium and magnesium, which are involved in fluid balance, nerve signalling and normal muscle function.
They're particularly important when you're losing both fluid and electrolytes ā through heavy sweating, vomiting or diarrhoea, for example.
Even when you're well, putting an electrolyte product in your carry-on can be a useful part of your long-haul travel routine. It's easy to pack and means you have it available during the journey or when you arrive somewhere hot.
Just turn the packet over and see what's actually in it.
Some electrolyte products contain surprisingly high amounts of added sugar.
When developing The Belly Solution's Probiotic + Prebiotic + Electrolyte Rehydration Formula, we chose to formulate it with no added sugar.
š” Did You Know?
Sometimes travellers deliberately drink less because they don't want repeated trips to the bathroom.
But restricting your fluids isn't a great long-haul strategy.
Choose the aisle seat instead.
Your hydration ā and your legs ā may thank you.
3. What About That Glass of Wine?
We're not going to tell you that you can never enjoy a glass of wine on a flight.
But alcohol isn't a substitute for water.
A simple rule?
If you have a glass of wine, match it with a glass of water.
The same principle applies to multiple coffees. Enjoy them, but keep your water intake going too.
4. Your Gut Knows You're Travelling Too
It's not just your sleep cycle that gets confused.
Long periods of sitting, different foods, altered meal times, inadequate fluid intake and changes to your normal bathroom routine can all affect digestion.
That's one reason bloating and constipation are so commonly reported during travel.
Cramping may also be influenced by prolonged inactivity, muscle fatigue and changes in fluid and electrolyte balance.
Your entire routine has changed ā and your gut knows it.
5. Keep Moving
Your body wasn't designed to sit in an aircraft seat for 14 hours.
When it's safe:
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Get up and walk periodically.
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Flex and rotate your ankles.
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Stretch your calves.
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Change position regularly.
Movement can help with stiffness and comfort. Importantly, prolonged immobility during long-distance travel is also associated with an increased risk of deep vein thrombosis (DVT).
If you have individual risk factors for blood clots, speak with your healthcare professional before travelling.
6. Don't Stop When You Land
Your body doesn't reset the moment the seatbelt sign goes off.
If you've flown somewhere hot, you may immediately start losing more fluid through perspiration.
Keep drinking, get moving and give your sleep and digestive system a little time to adjust.
And perhaps don't plan your biggest night out for three hours after landing.
Your holiday has only just started.
Frequently Asked Questions
How much water should I drink on a long-haul flight?
There's no single amount that's right for everybody.
A practical approach is to board well hydrated and drink regularly throughout the journey rather than waiting until you're very thirsty.
Do I need electrolytes on every long-haul flight?
Not necessarily ā but there's certainly a case for putting an electrolyte product in your carry-on.
Electrolytes support normal fluid balance, nerve signalling and muscle function. Having them with you also means you're prepared if fluid losses increase during your journey or after you arrive, particularly somewhere hot.
And should vomiting or travellers' diarrhoea strike, replacing lost fluid and electrolytes becomes considerably more important.
Think of electrolytes as a useful addition to a well-prepared travel health kit.
Why do some electrolyte products contain sugar?
There are different reasons.
Glucose has a genuine role in oral rehydration solutions used for significant dehydration, helping the intestine absorb sodium and water.
But sugar can also make electrolyte drinks sweeter and more palatable ā particularly for children ā and, naturally, sweeter flavours can make products more commercially appealing.
That doesn't automatically make a higher-sugar product the best electrolyte choice for you.
For everyday travel hydration, look beyond the flavour and front-of-pack claims. Check the added sugar content and understand what you're actually drinking.
There are electrolyte formulations with no added sugar, including The Belly Solution's Probiotic + Prebiotic + Electrolyte Rehydration Formula.
Why do I get bloated or constipated when I fly?
Reduced movement, altered meals, inadequate fluid intake and disruption to your normal bathroom routine can all contribute.
Evidence Snapshot
Last reviewed: September 2026
Prepared using:
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Peer-reviewed scientific literature
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International travel health guidance
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Research relating to air travel, hydration and cabin environments
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Evidence relating to prolonged immobility and travel
This article is intended for educational purposes and will be reviewed periodically as new research becomes available.
The Bottom Line
You can't eliminate everything that makes a long-haul flight tiring.
But you can make the journey easier on your body.
Board well hydrated. Keep drinking. Move regularly. Go easy on alcohol. And consider putting an electrolyte in your carry-on.
When choosing one, don't assume they're all the same. Turn the packet over and check what's actually in it.
And remember, your digestive system is making the journey with you too. A little preparation can help you arrive ready to enjoy the trip rather than spending your first day recovering from the flight.
Continue Your Travel Health Journey
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