Jet Lag Explained: What Causes It and How to Recover Faster

Whether you’re jetting off on a long-haul holiday, travelling for work or visiting family overseas, jet lag can quickly take the shine off your trip. From poor sleep and daytime fatigue to brain fog and disrupted digestion, crossing time zones can leave both your body and mind struggling to keep up.

But while jet lag is common, there’s no universal fix. The way we respond to disrupted sleep and travel fatigue can vary hugely from person to person. And understanding that is one of the most important parts of managing it well.

In this guide, we’ll explain what jet lag actually is. We’ll also cover what causes jet lag, how long it can last and some practical ways to help your body adjust more comfortably when travelling across time zones.

What is Jet Lag?

Jet lag is a temporary sleep disruption that happens when your internal body clock (also known as your circadian rhythm) becomes out of sync with a new local time zone.

Your circadian rhythm helps regulate important functions like:

• sleep and wake cycles
• energy levels
• hormone production
• digestion
• body temperature

When you travel quickly across multiple time zones, your body clock is still operating on your original schedule while the environment around you has changed. This mismatch can lead to symptoms such as:

• difficulty falling asleep
• waking too early
• daytime tiredness
• poor concentration
• irritability
• headaches
• digestive discomfort
• reduced physical performance

Jet lag is usually more noticeable after long-haul travel, particularly when crossing several time zones eastbound.

Why Does Jet Lag Affect Everyone Differently?

One of the biggest misconceptions about jet lag is that recovery follows the same pattern for everyone. In reality, there is no one-size-fits-all timeline or solution.

Our sleep expert explains that factors such as your chronotype (whether you naturally prefer early mornings or later nights), your usual sleep quality, your sleep need and how well you cope with sleep disruption can all influence how severely jet lag affects you.

For some people, travelling across multiple time zones may cause only mild tiredness for a day or two. Others may feel more disrupted for longer.

That’s why it’s important not to become too focused on generic rules or recovery formulas. You may have heard advice suggesting it takes “one day per time zone crossed” or “two hours per time zone” to recover from jet lag, but these estimates can often feel discouraging and aren’t always helpful in real-world situations.

For example, someone travelling across 10 time zones for a two-week holiday doesn’t necessarily need to expect to feel jet lagged for the entire trip. Recovery is far more individual than that.

The most effective jet lag approach is usually to:

• listen to your body
• experiment with routines
• notice what helps you feel more rested
• avoid putting pressure on yourself to “recover perfectly”

Common Symptoms of Jet Lag

Jet lag symptoms can range from mild to more disruptive depending on the individual and the journey. Common signs include:

• Sleep Disruption: Difficulty falling asleep at the correct local time or waking during the night is one of the most common symptoms of jet lag.
• Daytime Fatigue: You may feel unusually sleepy, low in energy or mentally sluggish throughout the day.
• Difficulty Concentrating: Many people experience brain fog, slower reaction times or reduced focus after long-haul travel.
• Digestive Changes: Changes to meal timings, hydration and sleep can affect digestion, appetite and regularity.
• Mood Changes: Irritability, low mood or feeling emotionally “off balance” can also happen when sleep and body rhythms are disrupted.

 

What Causes Jet Lag?

Jet lag happens because your body clock responds primarily to environmental cues including:

• daylight exposure
• meal timing
• activity levels
• sleep routines

When these cues suddenly change after international travel, your internal rhythm takes time to adapt.

Generally, crossing more time zones increases the likelihood of suffering jet lag symptoms, though personal sleep habits and travel routines also play a big role.

Other travel-related factors can make fatigue worse too. Some examples are:

• dehydration
• poor sleep during flights
• alcohol consumption
• cabin pressure
• stress and overstimulation
• long travel schedules

How to Reduce Jet Lag and Travel Fatigue

While you may not be able to avoid jet lag entirely, there are several ways to help your body adjust more comfortably. Without further ado, here are our top tips for travellers hoping to reduce travel tiredness:

1. Gradually adjust your sleep schedule before travelling: If possible, begin shifting your bedtime slightly closer to your destination time zone a few days before departure.
2. Prioritising sleep before you travel: Starting a trip already sleep-deprived can make jet lag feel much worse. Try to maintain a consistent sleep routine ahead of jetting off.
3. Stay hydrated: Flying can contribute to dehydration, which may worsen tiredness and headaches. Drink water regularly before, during and after your flight.
4. Get daylight exposure: Natural light is one of the strongest signals for resetting your body clock. Spending time outdoors during daylight hours can help your circadian rhythm adapt more quickly.
5. Move your body: Gentle movement such as walking or stretching can help reduce stiffness, improve circulation and support energy levels after travel.
6. Be mindful with caffeine and alcohol: Caffeine and alcohol can both interfere with sleep quality and hydration, particularly during flights or close to bedtime.
7. Try to adapt to local time: Eating meals and sleeping according to the local schedule can help your body begin adjusting to the new time zone more naturally.
8. Don’t force sleep: If you can’t get to sleep immediately, avoid creating stress around it. Resting quietly is still beneficial, and putting pressure on yourself to sleep can sometimes make it harder.

 

Tips for Sleeping Better on a Plane

Although sleeping during flights isn’t always easy, a few simple adjustments can help improve comfort and reduce travel fatigue:

• use a supportive travel pillow
• wear comfortable clothing
• limit screen time before trying to sleep
• use an eye mask and earplugs
• stay hydrated
• avoid heavy meals before sleeping
• try relaxation techniques or calming audio

Even short periods of quality rest during travel can make a difference when you arrive. For more advice on sleeping on a plane, check out our dedicated blog post.

How Long Does Jet Lag Last?

There’s no exact timeline for jet lag recovery because sleep needs and circadian rhythms differ from person to person.

Some travellers may feel adjusted within a day or two, while others may take longer depending on:

• the number of time zones crossed
• direction of travel
• age
• stress levels
• overall sleep health
• sleep quality during travel

Rather than focusing on a fixed recovery timeframe, it’s usually more helpful to pay attention to how your body feels and support it with good sleep habits, hydration and daylight exposure.

Can You Prevent Jet Lag Completely?

Not entirely – especially after long-haul travel – but you can reduce its impact.

Good sleep habits before travel, maintaining hydration, getting daylight exposure and allowing yourself time to adjust can all help to minimise jet lag symptoms and speed up recovery.

Most importantly, try not to panic if your sleep feels temporarily disrupted. Your body is adapting to a major schedule change, and a little flexibility and patience often go a long way.

Jet Lag: Final Thoughts

Jet lag affects everyone differently, which is why there’s no perfect recovery formula. Your sleep habits, chronotype, overall sleep quality and travel experience all influence how your body responds to crossing time zones.

Instead of relying on rigid timelines or generic rules, focus on listening to your body. Prioritise rest where possible and experiment with routines that help you to feel at your best.

With a little forward planning (and action), as well as good sleep habits and a bit of patience, most people can reduce travel fatigue and settle into their new time zone more comfortably faster, leaving more energy to actually enjoy the trip.