In a few years, direct flights lasting 20 hours will possibly be a reality. On such occasions, we wonder how we could keep ourselves as healthy and fit as possible on a very long air journey.

The announcement by various airlines that from 2025 they will be able to offer direct flights from Australia to the US and Europe has opened a new debate about how much the human body can withstand in the air – mentally and physically.

In particular, the non-stop flights will last 20 hours and will concern the trips from Sydney to New York and London. The Sydney-London route will be the longest direct passenger flight in the world.

Even if we never have to make such a trip, it is very likely that we will have to make a trip of fewer hours, but still a long one. And the feeling of being on a plane for 13 or 15 hours might not be much different.

How long-haul flights can increase stress levels

If someone has a fear of flying, the so-called aerophobia, then being on a plane (especially if it is for many hours) can be a painful experience. First, let’s say that there are two categories of people who are afraid of flying:

• The first category is those who suffer from panic disorders or agoraphobia, i.e. fear of being with a lot of people in one place.
• The second category concerns people who are afraid that the plane will crash.

As a Harvard University psychology professor explains, those who belong to the first group usually have a history of panicking in places where escape is uncomfortable or difficult, such as on the subway, on airplanes or in crowded stores. And those in the second group have a lot of misconceptions about how common crashes are.

Whatever anxiety people who are afraid of flying may have, it will probably be reduced, as the events they fear will not materialize. Even panic attacks themselves are not dangerous and resolve on their own.

Our body on a long-haul flight

An important and well-known side effect of flying, either in long or very long flights, is jet lag .

Jet lag occurs when the normal sleep pattern is disrupted after a long flight as a person crosses two or more time zones. Usually, it improves within a few days as the body adjusts to the new time zone. Jet lag can throw off our internal or biological clock, scientifically called the circadian rhythm, and cause difficulty sleeping and problems with memory and concentration. The worst is when a person crosses several time zones in a short period of time, as happens for example on a round trip.

What to do

To reduce the effects of jet lag, the UK’s National Health Service (NHS) recommends:

• Drink plenty of water during the flight.
• Walk around the cabin often.
• Try to sleep if it is night at your destination.
• After you arrive, try to change the sleep schedule to the new time zone as soon as possible.
• Go outside during the day because natural light will help your body clock adjust.

What happens to our oxygen inside the plane

Another issue that can affect the body and consequently our mental health is the oxygen on the plane. The amount of oxygen in an airplane is the same as on the ground. The difference is that when we fly at high altitude, the air pressure in the cabin affects the way oxygen is absorbed by the blood .

That is, while the oxygen level in the blood should be between 95-100%, when we are in the air this can decrease. For most healthy people it is not a problem. But if someone has a medical condition, such as asthma or chronic obstructive pulmonary disease (COPD), then they may start the flight with a lower level of oxygen in their blood and during the flight it may drop even further. So, symptoms such as headaches, shortness of breath, cough or fast heartbeats can be caused.

How to feel well on board

The solution to managing to keep your well-being at high levels during a long-haul flight is movement. Physical activity on the plane, i.e. walking at regular intervals along the aisles, helps maintain blood flow and therefore reduces the chance of blood clots (which increases especially in older ages).

Some experts even recommend stretches or exercises to keep your posture straight in the seat, or even seated yoga.