Does it take you several days to adjust to a new time zone after a long flight?
Do you wake up ridiculously early, or struggle to sleep when it still feels like the afternoon to you?
Fortunately, there are things you can do to reduce how long you suffer from jet lag, and perhaps even avoid it entirely.
In this article, you’ll discover what to do before you travel, during your flight, and on arrival to help you get into the swing of the new time zone quickly.
- What causes jet lag?
- Researchers show how to prevent jet lag
- Different approaches to beating jet lag
- Comparison of jet lag calculators
- Light boxes and glasses
- How to minimize travel fatigue
- Can melatonin help?
Disruption to your body clock
Jet lag occurs when you cross two or more time zones. When you cross time zones, the new timing of night and day won’t be aligned with your own body clock.
This has a direct impact on your daytime alertness and ability to sleep.
Your sleep is largely controlled by your internal body clock, and follows a 24 hour pattern, known as a circadian rhythm.
Your internal biology influences your body clock. But external factors, such as light, also play a role.
Your internal body clock is remarkably stable and doesn’t like change. Research shows that most people can only change their internal clock by 1 to 1.5 hours per day.
So a five hour time zone change can take three to five days before you adjust.
The role of sunlight
One of the most important external factors controlling your internal body clock is the daily cycle of light and dark. So controlling your exposure to sunlight can help adjust your sleep and wake timings.
Most people’s daily body clocks tend to run a bit slow. If left alone it would drift later by a few minutes every day.
But your daily sleep routine and exposure to light keeps it in check at 24 hours.
This natural drift helps explain why it’s generally quicker to shift your body clock when traveling west rather than east.
The rule of thumb is that you can expect to make a 60 minute change per day after an eastbound flight. And 90 minutes change per day after a westbound flight.
The most common symptoms of jet lag are:
- Difficulty falling asleep at night in the new time zone
- Waking up too early in the morning
- Feeling tired during the day
- Sudden desire to sleep during the day
- Loss of concentration
- Dizziness or disorientation
- Appetite changes
- Constipation or diarrhea
It’s helpful to recognize the difference between travel fatigue and jet lag, especially as the overall symptoms may feel the same.
Travel fatigue can be overcome relatively quickly, maybe after a rest and a good night’s sleep. Jet lag tiredness can stay with you until you adjust to the new time zone.
Later in the article, I’ll suggest some ways to reduce the initial travel fatigue from your journey.
In 2009, researchers from Rush University Medical Center in Chicago published an interesting report – How To Travel The World Without Jet Lag.
They showed that shifting your body clock, with controlled exposure to strong light, is the best way to deal with jet lag. They also suggest that taking melatonin can help.
The video below demonstrates how their technique works when flying east from Chicago to Paris.
Based on the Rush University research, there are three different approaches to dealing with the time zone changes:
A) Don’t worry about adjusting to the new time zone on short trips
If the time change is less than three hours and it’s a short trip, you may be better off not trying to adjust to the new time zone at all.
Instead, just keep close to your normal sleep schedule. Or if the time difference is more than three hours, perhaps only change your sleep times slightly.
B) Adjust to the new time zone after arrival
In reality, this is probably what most people have to do. But it can take up to a day for every hour of time difference before you finally get over the jet lag.
And it might take even longer if you aren’t aware of the factors which influence your internal clock, such as exposure to strong light.
C) Make calculated adjustments before leaving
By adjusting your sleep times and exposure to light, it’s possible to adjust your internal body clock towards the new time zone before you leave.
This will reduce the length of time you suffer from jet lag on arrival at your destination. Of course, changing your sleep routine in advance could be difficult for personal, social or work reasons.
But the attraction of this approach is that it might allow you to arrive at your destination virtually jet lag free.
The technique seems to be gaining more supporters, especially among business people and elite athletes. They need to be on the best form possible on arrival, regardless of the new time zone.
The next video shows another example of how to plan ahead, this time when traveling west from San Francisco to Beijing:
How changing your meal times can help
In 2016, researchers at Surrey University in the U.K. conducted an interesting jet lag study with 60 long-haul cabin crew.
They found that sticking to regular meal times based on the new time zone helped alleviate their jet lag. The study author reported:
We found that many crew tend to rely on sleep rather than eating strategies to alleviate symptoms of jet-lag, but this study has shown the crucial role meal times can indeed play in resetting the body clock.
So another useful tip could be to eat your meals based on the new time zone as soon as possible, even if it feels strange at first.
Jet lag planners and calculators provide guidance on light exposure to help you adjust your body clock.
Most of the advice from these online calculators is based on the average person. But there are a couple of important points to consider:
- If the time zone change is greater than about 8 hours, your body clock could either advance or delay to get you back to the new time. This is more likely to happen if flying east.
- People whose natural sleep cycle is much later, or much earlier, than average might find it easier to start adjusting their body clocks in different directions.
If these apply to you, the standard advice provided by jet lag calculators might be even less reliable. In either case, I personally wouldn’t rely entirely on an online planner.
If you have the time, I’d suggest watching the videos above and making your own calculations based on that advice.
Comparison of programs
I compared five different online calculators with the advice for two of the trips described by the Rush University researchers.
Their advice for these two trips is based on very accurate calculations, so they are good points to compare the calculators with.
The table below shows their advice for a flight leaving Chicago at 4.30 p.m. (Chicago time) and arriving in Paris at 8.30 a.m. (Paris time) the next morning.
Paris is 7 hours ahead of Chicago, so it feels as if you’re arriving at 1.30 a.m. in the morning.
|Day||Avoid light (Paris local time)||Seek light (Paris local time)|
|Arrival day||8.30 a.m. to 12 p.m.||12 p.m. to 4 p.m.|
|Day 2||8 a.m. to 11 a.m.||11 a.m. to 3 p.m.|
|Day 3||8 a.m. to 10 a.m.||10 a.m. to 2 p.m.|
|Day 4||8 a.m. to 9 a.m.||9 a.m. to 1 p.m.|
The second trip was between San Francisco and Beijing. In this case, I looked at adjusting your sleep times in San Francisco in the three days before the flight.
Here are the best three of the five calculators I tested:
Rating: 5 out of 5
I found Jetlag Rooster to be the most accurate overall. It’s easy to use, and it allows you to select when you want to start the adjustment – before, during the flight, or on arrival.
The advice given was very close to the Rush University calculations. For the Chicago to Paris flight, the recommended times to avoid and seek light were almost the same. For the San Francisco to Beijing flight, there were a couple of small differences in timings.
But overall, the calculations for the best times to seek and avoid light were very close, and the differences didn’t seem to be major.
2) Lumie jet lag optimizer
Rating: 4 out of 5
The Lumie jet lag optimizer is also easy to use, with clear and reasonably accurate advice.
However, it only gives advice for the three days on arrival, regardless of the number of time zone changes. Like other calculators, it assumes you can change your body clock faster than researchers say is normal.
It does offer some general advice for adjusting your body clock before you leave, but not based on your specific flight. Overall, it’s a pretty good calculator for when you arrive, but not quite as helpful as Rooster.
3) British Airways Jet Lag Advisor
Rating: 3 out of 5
The British Airways jet lag adviser only gives you two days worth of advice, regardless of the number of time zones crossed.
The recommendation for day one is okay, but day two seems to assume that you’ve adjusted your body clock by much more than what’s really possible.
The advice for the San Francisco to Beijing flight wasn’t much better, and again only covered 2 days. So I’m not convinced this advice will make enough of a difference to how much you experience jet lag.
Research suggests that exposure to strong light at the right time is the key to shifting your body clock.
Sports people regularly use this knowledge. for example, the Los Angeles Dodgers used light to avoid jet lag when playing in Australia.
Exposure to strong sunlight is the best option. But it’s not always possible to go out into the sun whenever you need to. And in that case, a good alternative is to use a lightbox or light glasses while indoors.
Some of these devices can be quite expensive, and not so practical for travel. But there are some more affordable, and more portable options too.
Lumie produces a number of light boxes and wake-up lights, and supply them to the UK National Health Service. Their website suggests that a Zest portable light box could be used to overcome jet lag.
Biobrite also manufactures a number of different light boxes, ranging from subtle desk lamps to larger panels of light.
They even say they have a light visor which is used by NASA astronauts to minimize jet lag!
This UK based company focuses on sleep disorders and has some competitively priced portable light boxes, specifically created to help overcome jet lag.
They state that because their lightbox uses LEDs, it greatly decreases the amount of time you actually need to spend in front of it.
These glasses, and the claims by the manufacturer, have received quite a lot of publicity in the press.
They are designed to be worn when you should be seeking strong light. They use 100% UV-free green light, which helps your body to adjust its body clock.
The Luminette visor light glasses are designed to help with the winter blues, but can also be used to help you get strong light when traveling.
The manufacturer claims that the more targeted effect of the light on the eyes helps reduce the time you actually need to use them when compared to a lightbox.
When flying long distance it’s common to suffer from travel fatigue, even if there’s no significant time zone change. A typical example is flying from the USA to South America.
There are things you can do before you travel to help with travel fatigue. These steps probably won’t help you change your body clock, but they can help you feel more rested.
Steps to take before you travel
- Try to ensure you’re well rested in the days leading up to your journey. If you work yourself into the ground and travel when exhausted, you may find it takes longer to recover and/or overcome the jet lag.
- Do some exercise the day before traveling, or in the morning if traveling later in the day. But avoid strenuous exercise close to the flight time if you plan to sleep on the plane.
- Limit the amount of alcohol you drink before flying. Alcohol might help you fall asleep, but then disrupts your quality of sleep.
Things that help while on the journey
- Drink plenty of liquids, such as water and juices, and avoid alcohol or caffeine. Buy a large bottle of water to take with you once you go through security.
- Bring accessories to help you sleep better. A good sleep mask, some earplugs, a good travel pillow and a cozy warm jumper can all help.
- If you have a long stopover, take the opportunity to walk around and get the blood moving in your body. If there are facilities like a shower, freshening up might help you sleep on the next leg of the journey.
- If you decide to use sleeping pills, remember that they can leave you feeling groggy when you wake up. If you can sleep naturally, it will benefit you when you arrive.
Melatonin receives a lot of attention because it’s sometimes seen as more ‘natural’ than many other sleeping pills.
In a previous article, I discussed how melatonin might not help with insomnia but can help you avoid jet lag.
The researchers in Rush University explain how melatonin might help with jet lag in two ways:
- Taking a dose of 3 mg before bedtime for the first few nights following an eastbound flight. In this case, it’s really helping you to go to sleep when you body is saying it’s time to be awake.
- Taking a smaller dose of 0.5 mg two to three hours before you’re due to go to sleep in the new time zone. This is about the time your body would normally start producing melatonin.
Although there’s no cure for jet lag, there are things you can do to reduce how long you suffer from it.
The key to beating jet lag is to change your body clock to match the new time zone. This requires a good understanding of how exposure to light at different times can affect your body clock.
There are a number of online calculators which can help you design an effective jet lag plan. I recommended the Rooster calculator as a good option.
On arrival at an exciting new destination, it’s difficult to resist the temptation to start exploring. But, armed with your plan, you can take some measures to help your body clock without spoiling your trip.
Perhaps the most exciting idea is that by making some adjustments to your body clock before departure, it may be possible to arrive virtually jet lag free.
How does jet lag affect you when you travel? Do you have any tips for dealing with it? Feel free to share your experience and any tips in the comments below.