Jet lag has a nasty habit of turning what should be a once-in-a-lifetime experience into something that you occasionally have to power through. For those taking long treks between vastly different timezones, adjusting your body clock can make all the difference when it comes to the overall enjoyability of your time away.

In this data-driven guide, we’re going to take a closer look at what you need to know about jet lag to better understand and, ultimately, beat it. If you’re wondering how to perfectly balance travel, having fun, and getting the optimum amount of sleep while you’re adventuring, be sure to read on.

What is jet lag?

First and foremost, let’s get a better grounding for what it means to actually be jet lagged. Those experiencing jet lag have had their internal clock – or "circadian rhythm” – disrupted as a result of hopping across one or multiple different timezones. (In fact, a less common name for jet lag is “time change syndrome”.) 

Think of it this way: you take off on a flight from Melbourne to Los Angeles at 12pm your local time. But, owing to the time difference (Los Angeles is 19 hours behind Melbourne), that means your flight is leaving at 5pm the day before in Los Angeles. You arrive at 7:25am local time, but, for you, your internal clock thinks it’s now 2:25am the following day. This shift between time zones could leave you groggy and extremely tired – especially if you weren’t able to sleep on the flight.

What causes us to become jet lagged?

As you can imagine, knocking your circadian rhythm out of whack like this can have a huge impact on how awake we feel. Your sleep-wake cycle will struggle to adjust for a short period after travel of this nature, and it can have a wider impact on things like the time of day when you’re hungry, or even when you might need to use the bathroom. 

The amount of sunlight we receive also plays a large role in our body’s ability to function properly. Light can regulate a number of hormones inside of us, but arguably the most important of these is a sleep-supporting one known as melatonin. 

Melatonin manages your circadian rhythm. The amount of melatonin we produce increases at night to get our bodies ready for sleep. But being exposed to light at night reduces this, which can make it more difficult to fall asleep.

While less common of a cause, the air pressure inside a plane's cabin can also trigger jet lag. Dry air conditions inside the plane will lead to you feeling more dehydrated, which can impact how your body functions.

What are the symptoms of being jet lagged? 

Most of us know that jet lag will make us feel a lot more tired when we arrive at our destination. But this is far from the only adverse effect that you might feel. Aside from a feeling of extreme tiredness, other symptoms that have commonly been associated with jet lag are: 

• An upset stomach

• Difficulty making judgments and decisions

• Memory lapses

• Irritability

• Apathy

The type of jet lag you experience is going to differ depending on whether you travel east (where you gain hours) or west (where you lose them). 

Losing hours might mean that you find it tough to fall asleep, as you try to adjust to a new schedule. Gaining hours might make it harder to stay awake during the day, as this could be a time when your body would normally be asleep.

28 Important facts about the impact of jet lag and its relationship with sleep 

Now that we have a better understanding of what jet lag is and how it might impact someone on their travels, it’s time to take action. The best way to do that is by understanding the nuances of this pesky flying phenomenon. Let’s dive into these 28 eye-opening facts to make getting your head around jet lag a breeze.

1. Jet lag can start before you fly 

Kicking things off with something less fun, research from the NUS Yong Loo Lin School of Medicine shows that jet lag symptoms can actually begin to surface before you step on a plane. Oura summarised the findings of the school, highlighting that waking up earlier than normal for morning flights meant that some travellers already found themselves at anywhere from a 30-to-50-minute disadvantage when it came to staving off the condition.

2. It takes about a day to adapt for every timezone you’re in 

Remember how we mentioned the importance of your circadian rhythm when dealing with jet lag? Better Health Victoria notes that it can take your body anywhere between a few days and a few weeks to adjust to a new timezone, suggesting one day per hour of timezone changes. This isn’t a hard-and-fast rule, with the length of time it takes to fall back into your normal routine differing person to person.

3. More than 70% of people experience jet lag when they fly long haul 

If you do find yourself experiencing the unpleasant side effects of jet lag, at least take some solace in knowing you’re not alone. Research has shown that 71% of Australian travellers will experience a few days of jet lag when they return from an international holiday. That means for every 10 people travelling long haul, just over seven of them will struggle with symptoms at some point after they get home.

4. Over 100 million people get jet lag every year 

And if that wasn’t already an eye-opening amount, the total numbers for global annual jet lag reports are even more stark. A whopping 100 million people are believed to experience jet lag every year, with this number only set to rise as more business and personal trips are taken by travellers jetting off across the world for one reason or another.

5. Eastwards is harder to acclimatise to than westbound travel

Those travelling to the east – who’ll be gaining hours – are found to have a harder time acclimatising to their new timezone than anyone headed in the opposite direction. This is thought to be because travelling westwards prolongs your body clock’s normal cycle, whereas travelling eastwards is more likely to confuse it.

6. Older travellers may be more susceptible 

While travellers of any age can experience jet lag, seniors may feel its impact more. This is thought to be because your body clock gets used to your routine, making changes like flying across time zones more difficult to manage. 

7. Over a quarter of Australians take more than a week to recover from jet lag

28% of Australians said it takes them a week or more to recover from jet lag after travelling internationally. This isn’t surprising when you take into account just how far away Australia is from most destinations – you have to travel long haul if you want to visit other countries.

8. Jet lag means people often need a holiday from their holiday 

We’ve all been there. Sometimes the excitement and energy expended on a trip away means we come back mentally recharged, but physically wiped out. One survey found that 66% of Australians need extra time to recover when they come back. Younger travellers appear to feel the impact more: 34% of Gen Z travellers said they felt exhausted after a trip, compared to 21% of Millennials, 14% of Gen X and 8% of Baby Boomers. Jet lag can play a huge role in this, with the adverse feelings leaving many feeling like they need extra time to get their circadian rhythm back in check before they face the perils of a working day. 

9. Despite its impact, jet lag is not the only contributor to tiredness on holiday

As we’ve seen, jet lag can have a monumental impact on how well we sleep when we travel. But it’s not the only contributor to a poor night’s rest when we’re off on our adventures. Stepping away from our everyday lives can make us realise how tired we are, leading to that groggy feeling. Other common elements of holidays, like rich food, alcohol, afternoon naps and busy days exploring can also cause fatigue.

10. Business travellers lose close to an hour of sleep a night 

Travelling for business already comes with its own struggles. Being away from home and having to work at the same time isn’t something many people actively enjoy. Those issues can sometimes be compounded by the startling numbers regarding how much sleep these kinds of travellers tend to get. 

Reports show they average just 5 hours and 17 minutes of sleep a night, with the typical loss per person sitting at around 58 minutes. While this isn’t solely down to jet lag, the jump between timezones will unquestionably have a huge impact on those figures. Australians may be affected more than most – research shows that Australian business travellers spend 6 nights away on work trips, which is nearly double the global average of 3.5 nights.

11. A fifth of those are concerned about jet lag even after they get home 

Jet lag isn’t just something that goes away the moment you arrive home. And for business travellers, the reality of feeling groggy both during and after the trip is a real concern. One in five report this as a stressor for any work trip, with as many as 36% going as far as to say jet lag was a major concern in general for any business meeting overseas.

12. The immune system can get weaker after just a few days of poor sleep 

Have you ever noticed that you tend to catch a cold slightly more often after getting back from a long trip? Research shows that travellers experiencing sleep disruption for just 2–3 nights can have a 30% reduction in natural killer (NK) cell activity, a key component of the immune system. 

This makes them more susceptible to infections such as colds or travel-related illnesses. Couple that with the number of people you’ll be sharing a cabin with, and the chances of picking up a cold thanks to your jet lag go up.

13. Fatigue is the most common symptom of jet lag 

We’ve already briefly touched on the different kinds of symptoms that people will experience when they’re jet lagged. Perhaps to no great surprise, a feeling of immense fatigue and tiredness was the most commonly experienced. 50% of respondents in an In Tech Open survey said that this was the factor that had the biggest impact on them when battling jet lag.

14. Disruption to normal rhythms was the next biggest factor 

28% would say that it was the long-term impact of jet lag on their circadian rhythm, which was the hardest to deal with. This disruption to normal patterns of sleep might not have an immediately noticeable impact, but it can be something that takes longer to recover from after you get back from a holiday. 

15. Some people even struggle to eat when jet lagged 

The shift in timezones, as well as the queasy feeling that some of us get after our sleep falls out of its normal rhythm, also meant that a small handful of people found eating to be the biggest jet lag-related issue. 5% said that they struggled to comfortably keep food down after returning home or arriving in a new location. 

16. Sleep duration tends to recover quickly 

In encouraging news, the amount of time we sleep has been found to bounce back relatively fast. Oura found that the amount of sleep someone gets every night was able to rebound to within 12 minutes of their normal baseline within just two days of returning back to normal life at home. For savvy holidaymakers, that means building in a weekend after your trip to recover will see you in good shape by the time you head back to work on Monday. 

17. Sleep routine takes a lot longer to bounce back 

In less good news, your circadian rhythm and bedtime routine might take a bit longer to go back to normal. The same source said that those wanting to get back into their usual routine after a trip might have to wait anywhere up to 15 days before things began to gel properly again. This was especially true after longer trips to the east.

18. A lack of sleep can have a huge impact on wider mental health 

The crux of the issue is that a lack of sleep brought on by jet lag can have a big effect on your overall mental health and well-being. A survey by the Mental Health Commission of New South Wales found that 55% of people who struggle to sleep often or always have high levels of psychological distress. This can have a huge impact beyond returning to normal sleep patterns, with it dragging into your day-to-day life.  

19. Losing sleep can leave you more than twice as stressed 

If jet lag does strike on your travels, it can leave you feeling a little more on edge during your time away. Research shows that a lack of sleep can leave you feeling as much as 2.5 times more stressed than you would on a regular day. This kind of level was commonly experienced by those who got less than 6 hours of sleep on a given night. 

20. Sleep issues commonly precede periods of feeling low

What’s more, falling out of our circadian rhythm puts us in a position where we’re slightly more susceptible to other mental health and well-being issues. The Mental Health Commission of New South Wales survey found that respondents who reported sleep difficulties were more likely to give themselves a lower mental health score:

• Often or almost always had sleep difficulties: 4.9

• Sometimes had sleep difficulties: 6.4

• Never or rarely had sleep difficulties: 7.5

21. For some, travel actually means more chances to sleep 

Interestingly though, jet lag isn’t always a factor for those who travel. In fact, in some cases, the hop between timezones seems to have the opposite impact. A study has shown that those who might usually be classified as “underslept individuals” actually got more sleep while they were on their travels, whereas those who regularly got more than 7.5 hours a night tended to see their total hours of sleep dip. 

22. The jet lag therapy market is now worth billions

A variety of techniques and preventative measures used to combat jet lag are often grouped together under the banner of “jet lag therapy”. This includes supplements, as well as light therapy. This market reached a whopping US $441.1 million (AU $653.26 million) in 2024, having been rapidly driven forward by the evolving use of technology and tools within the sleep management sector. 

23. The market is expected to grow further in the future 

And this looks like it’s only the beginning for the wider market. Forecasted figures show just how much of a factor the need to battle jet lag has become, with predictions from the folks who crunch the numbers suggesting that from 2025 through to 2033, the value of these transformative treatments and preventative measures is expected to grow at a rate of 3.73% per year. That would see the total value jump from US $441.1 million (AU $653.26 million) to US $619.3 million (AU $917.17 million) in that time.

24. Sleep tourism is an alternative that one in five people are now trying out 

As if that wasn’t already enough, a lot of holidaymakers are now also taking the power of sleep back into their own hands. Sleep tourism is a new phenomenon where people are actively seeking out places to go and get the rest and relaxation they need as an intrinsic part of their time away. It’s thought that as many as 20% of all travellers are expected to go on this kind of trip at some point on an annual basis, while 60% of Australians say sleeping is the main activity for their next break.

25. A lot of people will pay more for a sleep enhanced room 

Such is the weight being placed on a good night’s rest, that travellers are willing to go as far as to pay more for a room which has been designed with enhancing the sleep experience in mind. The same survey found that 43% of respondents were willing to hand over more money to make sure that they weren’t going to see their overall sleep quality levels suffer. In total, it’s thought that those on a sleep tourism getaway were willing to spend an average of US $1,752 (AU $2,596.57). 

26. Italy, Japan, Greece and the Maldives lead the way for sleep tourism

The best spots to try this revolutionary new form of tourism? Well, you’ll find them dotted all over the globe. From Asia to Africa, Europe to North America, there is a wide array of serene destinations that tourists looking for tranquil travel are trying out. 

Kyoto in Japan ranks first, with 19% of respondents saying they’d give this historic cultural hub a try. The islands of Santorini in Greece (14%, the Amalfi Coast in Italy (13%), and the Maldives (11%) were the next most popular. When it came to North America, Big Sur in California led the way with 8% of responses, followed by its neighbour the Napa Valley (8%) and Arizona’s desert town of Sedona (7%). 

27. But nearly two-thirds of sleep tourism is domestic

Despite the clear desire for travellers to get out and see more of the world at a slower pace, the bulk of sleep tourism is still more of a domestic pursuit. Market research shows that close to two-thirds of sleep tourism happens in the form of staycations, with 63% of people going on this kind of holiday choosing to stick within their own borders. If you’re keen to do the same, an analysis of hotel reviews that mentioned good sleep found that four Australian cities ranked in the global top 20: Brisbane, Sydney, Perth and Melbourne.  

28. The sleep tourism market is another that is expected to see major growth 

Just like with the growing popularity of jet lag therapy, the market for sleep tourism looks ready to steamroll on. Many estimate as much as 12.4% of compound annual growth in the sector between now and 2030, with its total value rising to US $148.98 billion (AU $220.87 billion) in that time if those figures turn out to be correct.  

10 Ways you can prevent jet lag from becoming a factor on your trip 

Now that you’ve got a better grasp of how and why jet lag can have such an impact on a trip away, it’s time to take the power back. While there’s no guaranteed way to make sure jet lag doesn’t impact you in some capacity, there are plenty of tricks to help reduce that unwanted feeling of lethargy or grogginess. Here are 10 actionable tips to try when you’re next travelling on a long haul flight.

1. You can prevent jet lag by sleeping earlier before travel 

Our first snippet of advice is to gradually adjust your sleep schedule prior to the date of your trip. This doesn’t have to be anything dramatic. Something as simple as going to bed 15 minutes earlier (if you’re headed east) or later (if you’re going west) every night for around two weeks prior to your trip will have a big impact. Also, think about doing the same thing when it comes to when you eat. Getting your circadian rhythm in line with your new timezone can mitigate several potential hours of lost sleep. 

2. Consider arriving a few days early, or building in rest days 

If you’re going away with a specific purpose in mind, such as a business meeting or to attend an event, planning to arrive a little before the time you need to is another smart idea. Most of the more extreme symptoms of jet lag will slowly wear off after a few days in a new timezone, which gives you a window to turn up, get to grips with them, then start to feel more like yourself again in time for the main purpose of your trip. If there isn’t a specific event you’ve travelled for, these extra days will still give you a chance to guarantee you’re experiencing your holiday to its fullest. 

3. Manage your bright light exposure 

We’ve already discussed how getting too much exposure to light can keep you awake when you might want to sleep. But, naturally, the opposite can also be true. Even just getting outside for 10-to-30 minutes can help provide enough vitamin D and melatonin suppression to make sure you’re feeling awake enough to take on the day. The exact length of time depends on the time of year, amount of skin exposure, and skin colour – people with darker skin need to spend more time in the sun before they convert pre-vitamin D to vitamin D. It’s also important to think about sun protection. As Better Health Victoria points out, UV light is the main cause of skin cancer as well as the best source of vitamin D.

4. Staying hydrated can reduce the impact of jet lag

Keeping up your hydration levels is another way to make sure you’re doing what you can to stave off some of the more challenging symptoms. The exact amount of water you should drink daily varies for each person. As a general guide, men need around 2.6 litres per day to keep their body functioning at top capacity, while women need around 2.1 litres per day. Make more of a concerted effort than you usually would to drink during travel, as well as the days before and after. If it helps, you can set reminders to drink every hour or so.

5. Change your watch before you travel 

While it won’t have the same impact from a physical perspective, changing your watch to the timezone you’re travelling to can help to make the transition between them a little easier. Starting this a few days before you travel will also give you a rough idea of what your body feels like during times when you might need to eat or sleep in your travel destination. You can find the timezone you’ll be visiting online.

6. Consider an app that helps to prevent jet lag 

More awareness than ever exists around how and why we need to battle jet lag. As a result, there are now plenty of apps that exist to make drifting off to the land of nod faster than ever before. And there’s a clear keenness from travellers – particularly those flying for business – to adopt their usage. A recent report found that 69% of people travelling for this reason were either already using these kinds of apps, or intended to start using them in the future. 

7. Try not to nap for too long when you arrive (particularly eastwards) 

It might be tempting to catch a little shut eye when you travel (especially if you’re moving eastwards, where your body will feel like you’ve lost sleep). But doing this can actually keep your internal clock out of rhythm for longer. The Sleep Health Foundation recommends napping for no more than 30 minutes and staying awake for at least four hours before you go to bed.

8. Melatonin has emerged as one remedy for those unable to sleep on their travels

We’ve already discussed how melatonin plays a big role in the ease with which we fall asleep. If you find that you’re struggling to drift off, it’s now possible to take melatonin supplements, which can make falling asleep faster. 78.4% of respondents in a recent study said that using the hormone supplement helped them, with it having a peak impact on them after roughly one hour after usage. It requires a prescription in Australia, so be sure to talk to your healthcare provider if you think melatonin may help you.

9. Tasimelteon is another alternative 

An alternative to melatonin is the supplement tasimelteon. This was found to increase total sleep time in participants of a study by as much as 85 minutes per night. It was also found to improve next-day alertness (the time it took to wake up and feel ready to face the day) by as much as 15 minutes. 

10. Light therapy can also battle jet lag

Light therapy is another option for those wanting to improve sleep time. While this is more useful after returning from a trip, it still plays an important role in making sure sleep patterns return to healthy levels. The process sees the use of special light boxes, or dawn simulators, which can help to trigger the body’s ability to manage its own circadian rhythms.