How Much Water You Should Drink When You Fly, According to Science
Staying hydrated while you fly is no easy feat. It seems that everything is working to get in between you and hydration while you're up in the air—the no-liquids TSA rule, dry cabin air, and a refreshments cart that comes around every once in a blue moon. These factors make air travel dehydration all too common. Nevertheless, staying hydrated is paramount to your health, especially when you're flying. The next time you find yourself on a plane, here's exactly how much water your body needs.
A recent article by Condé Nast Traveler sought to find the magic equation for keeping your body hydrated in-flight. They asked Clayton T. Cowl, MD, chair of the Division of Preventive, Occupational, and Aerospace Medicine at the Mayo Clinic, to weigh in on the issue. It turns out "there's no specific catch-all for how much water you need to drink while flying," says Cowl. However, doctors and travel health organisations do have some recommendations when it comes to how much water you should be drinking while you're at 30,000 feet. The Aerospace Medical Association suggests taking in 30 mL of water for every hour that you're in the air. As the flight time increases, your attention to hydration should increase as well.
There are a number of factors at work when it comes to your increased risk for dehydration while flying. Cabin humidity can be anywhere from 25% (or newer planes like the Dreamliner 787 or the Airbus A350) down to just 10%, so it's important to continue loading up on water in these dehydrating environment. High altitudes mean you lose fluids faster. If you're drinking alcohol during the flight, this will continue to dehydrate your body "on the cellular level," says Cowl, which he notes you should combat with an eight-ounce glass of water per glass of wine.