What is Jet Lag and How to Manage it?

Key summary:

• Jet lag is simply a mismatch between our internal clock and the local time
• When informed about jet lag you’re likely to cope better
• Great news is that jet lag is short-term- and there are things we can do to minimise it!

What is Jet Lag?

Jet lag occurs when our 24-hour internal clock, known as our circadian rhythm, does not match the local day-night cycle. That is, your internal clock is out of synch with the local time. Jet lag can negatively impact your trip whether it’s work travel or a holiday.

Symptoms of Jet Lag

Not everyone experiences inconvenient and unpleasant symptoms with jet lag. Others can find their symptoms are very debilitating. Whether they are mild or quite challenging the most common symptoms of jet lag are:

• Sleeping difficulties: The main symptom is that the timing of sleep gets disrupted. It can be hard to get to sleep at the times that you want to sleep. You might also find that you wake up earlier than planned. Jet lag can also cause sleep to be light and disrupted and not feeling like it’s of good quality.
• Feeling sleepy during the day: Jet lag frequently causes you to feel drowsy or tired during the day.
• Feeling foggy: You may experience problems with attention or memory or simply feel like your thinking is slowed.
• Feeling physically tired: Your body may feel fatigued, heavy and tired whilst experiencing jet lag and can result in low energy..
• Feeling more emotional than usual: Jet lag can contribute to feelings of irritability and it can also exacerbate existing mental health problems.
• Stomach problems: Jet lag can cause a reduction in appetite, can cause nausea, or even constipation and irritable bowel syndrome. It can be difficult to feel hungry at the appropriate times.

What can cause Jet Lag?

As already stated, Jet Lag is caused by a mismatch between our internal body clock and the local time. It is more likely to occur when stress precedes or accompanies flying and if there’s difficulty sleeping on planes or other modes of transport. 

For example, if you fly from Perth to Melbourne and arrive at 8 p.m., your body might still operate as if it’s at 5 or 6 p.m. The timing mismatch, until there has been synchronisation to the local time, means that the processes and hormones regulating sleep are disrupted meaning sleep is disturbed.

How long can Jet Lag last?

Jet lag normally lasts for a few days but can persist for up to a few weeks. It’s also important to note that some symptoms can begin immediately but for some people they may sleep well the first night and the sleep problems don’t set in until the following days. There is a general rule of thumb that jet lag lasts for approximately 1-1.5 days per each time zone traveled. The severity and the duration of jet lag will vary depending on individual factors such as one’s age, their general physical and mental health, how much sleep they are able to get during the travel and their various  travel schedules.

Is Jet Lag worse when traveling east?

People often report that jet lag is worse when traveling east. This is because your internal clock is ahead of the local time and it is easier to delay your internal clock than to advance it. For instance if you had the time and the money it would be easier to travel back from Europe to Australia via the USA in terms of less susceptibility to jet lag. It might sound obvious but it’s worth pointing out that jet lag does not occur on flights that travel north-south and therefore do not cross multiple time zones.

How to manage Jet Lag?

Pleasingly, when we are  informed about jet lag and have a proactive plan to combat it then we’re likely to cope better. The following tips will help you to minimise the impacts of jet lag.

• For very short trips, it makes sense to try to keep your internal body clock aligned with your home time zone. That is, try to eat, sleep and work aligned with your home time zone and don’t try to adapt to the new destination (if it’s just a few days).
• When the trip will last more than a few days you should try to adapt to the new time zone as quickly as possible. This can be done via light exposure, and ensuring dark conditions prior to bedtime. Timing of light needs to be strategic, rather than just choosing a random time.  It’s best to be out in natural sunlight when you need to remain alert and stay awake, however, be mindful of staying out of light when you need to prepare for sleep.
• There are a number of practical strategies you can use to minimise and manage jet lag

Before Traveling: 

• As soon as you’re on the plane (usually a plane!) try to set your watch and your routines to the time of your final destination. 
  • For example, If you’re leaving Sydney around midnight and are flying to London where it is closer to midday, wait until it’s night time in the UK to sleep, and continue at least mentally adapting to London time in terms of timing of meals and naps.
• Wherever possible, try to build buffers into your schedule and try to arrive days in advance of an important meeting or event so that you have time to adapt your internal clock to the local time zone.
• Being in a rush, having a lot of stress, and worry surrounding the trip can heighten stress and make your travels more difficult so try to minimise stress via relaxation techniques and relaxing activities, including mindfulness.
• Focus on getting quality rest for at least a few nights before your trip so that you’re not already sleep-deprived at the beginning of the trip. This can be difficult as it’s busy in the lead up to going away but try to prioritise your sleep in the days before you commence your travel.

During the flight

• Take a water bottle to sip on throughout the flight to counter the dehydration that can occur in-flight.
• Reduce your alcohol and caffeine intake on-board. If possible, try to avoid them entirely.
• Keep meals light, opting for healthy food options such as fruit, vegetables and lean protein over heavy, , fatty meals and snacks and try to eat at the meal times of your destination..
• Try to get as much sleep as possible on the flight. Minimising sleep deprivation will help reduce jet lag.
• Practice mindfulness meditation during the flight and once at your destination to help clear your mind and improve your alertness.

After arrival at the destination

• Exercise outside particularly if it’s bright daylight. Exercising outside to receive appropriately timed daylight exposure will help to synchronise your internal clock to the new local time zone
• Avoid, or at least limit, excessive caffeine, alcohol, or heavy and calorie-rich meals.
• Avoid the temptation to sleep if it’s not the appropriate sleeping time. If you can’t stay away then keep naps to less than 20-30 minutes and only nap eight or more hours before your planned bedtime
• Melatonin might be helpful to help you adapt to the new time zone, but like all sleeping medication only use this short term and ensure you have medical advice about its risks and benefits.

In summary

Jet lag is common and mostly short term. It is related to the changes in time of day in the new destination, compared with where the travel originated. This can be best managed by using light to help with synchronising internal body clock to the new local time. It’s also important to try to adapt eating and sleeping times to the new time zone. Day time sleeping should be avoided except for brief naps of less than 30 minutes. Don’t worry too much about jet lag when/if you’re experiencing it as it is short term and whether it’s days or a few weeks it will pass. If you travel for work every week and you feel that it is becoming a problem for you then you should seek support from a sleep specialist.

References

1. https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=d2ca570b8746a1ecfbd155da14c8291f85545db2 
2. http://www.jvsmedicscorner.com/Medicine_files/Jet%20lag%20Review.pdf 
3. https://www.sciencedirect.com/science/article/abs/pii/S0140673607605297?via%3Dihub 
4. https://cet.org/wp-content/uploads/2017/10/Arendt-2009-SMR.pdf 
5. https://www.frontiersin.org/articles/10.3389/fphys.2019.00927/full