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Health

Understanding & Conquering Jet Lag

Tara Youngblood

18.01.22

Understanding Jet Lag
Jet lag is also referred to as circadian desynchrony. [1] Our body has its own internal clock (or circadian rhythms) that tells us when it’s time to awaken and go to sleep. [2] It’s essentially a mismatch between this internal clock with external environmental cues (daytime and nighttime in particular). [3]


Table of Contents:

In this article we'll discuss the following:

For example, when we step off the plane, our body may think it’s early evening when, after a long flight from Los Angeles to Boston, it’s actually after midnight.  This causes the mistaken need to stay wide awake and active because of two main problems:

  1. our visual system has not had enough time to grow accustomed to the darkness, and
  2. our core body temperature is too warm and has not reached the cooler temperature needed for a restful night’s sleep. [4]

In short, the normal clockwork and hormones (mainly melatonin) that regulate wake/sleep cycles tend to desynchronize due to travel through time zones. [5] [6]

Social Jet Lag

Not to get confused with jet lag, the term "social jet lag" was coined by Till Roennenberg, a German researcher, in 2006. Social jet lag delivers similar effects without traveling. It usually occurs by the shift in your sleep schedule. For example, you feel tired when returning to work from the holidays or adjust your schedule to stay up later because you don't have to work the next day. This can result in social jet lag finding yourself struggling to get up in the morning, and feeling sluggish throughout the day.  

Jet Lag vs. Travel Fatigue

Jet lag is often confused with travel fatigue. Travel fatigue is caused by a hectic and demanding schedule, lack of sleep, or the stress of being away from familiar routines. Additionally, travel fatigue occurs with any mode of travel, such as trains or cars. 

Jet lag, in contrast, is related to the changes in time zones and how such changes affect the circadian rhythm. This intricate system is controlled by the suprachiasmatic nucleus (SCN), located deep within our brains in the hypothalamus. The SCN is situated near the visual system so that it can take cues from sunlight and darkness. This allows our bodies to respond by waking up or falling asleep.

Jet Lag Symptoms

So, what does jet lag feel like? Symptoms can include the following:

  • Disorders of disturbed sleep, such as insomnia
  • Difficulty concentrating
  • Stomach problems
  • Extreme tiredness during the day
  • Changes in mood

Fortunately, the above symptoms improve steadily as the body gets used to the new time zone.

What Causes of Jet Lag

Jet lag is quite common. It's estimated that 60% to 70% of frequent travelers have experienced symptoms. The elderly have a harder time adapting to destination time zones than younger people.

Researchers agree that west-to-east plane travel leads to more serious symptoms than going from east to west. The greater number of time zones traveled may lead to more intense bouts of jet lag.  When traveling from north to south or vice versa, jet lag is not an issue because there is no crossing of time zones. Therefore, people experiencing disturbed sleep or tiredness are more likely to have travel fatigue. 

Jet Lag Relief and Treatment

It’s possible to use light, temperature, meals, and exercise to get accustomed to the new environment. These are called zeitgebers, which means "time-givers" in German. They are particularly helpful when traveling from west to east when losing time. The Federal Aviation Administration (FAA) describes zeitgebers as any external cue that resets the body’s internal clock, essentially getting the sleep-wake circadian rhythm back on track. [7]

The following zeitgebers can be instrumental in resetting sleep signals: [8]

Daylight

Light is an extremely important time-giver. Once you get to your destination if you need to stay awake, get as much natural light as possible. This keeps the body from producing melatonin, a natural sleep hormone. If it’s dark outside, it’s OK to utilize artificial light from lamps and overhead lights. However, try to avoid the flashing lights of your laptop or cellphone.

Temperature

There’s extensive scientific evidence that when core body temperature (CBT) drops, transition to restful sleep is much easier. Sleep experts recommend adjusting the room temperature to between 65- and 72- degrees Fahrenheit.

Exercise

Any kind of exercise, including brisk walking, calisthenics, and stretching is an excellent way to reset your circadian rhythm. If exercise is part of your at-home routine (which we highly recommend), try to exercise at the same time of day and well before the destination bedtime.

Mealtimes

Your meals and eating schedule have a definite effect on jet lag. Remember that food and beverage choices affect insulin levels, which in turn can impair the sleep cycle.

How Long Does Jet Lag Last?

In general, a longer recovery period is needed when traveling from west to east. Some experts state that traveling over just one or two time zones is minimally problematic. A good rule of thumb is about one day per time zone. Other factors to consider are the utilization of treatments and pre-flight strategies.

How to Reduce and Prevent Jet Lag?

Good planning is definitely advantageous when managing jet lag. Sleep experts have weighed in on helpful strategies before and during travel. 

Before Travel

  • If feasible, adjust your sleep schedule by about an hour each night prior to travel. You might be on your sleep schedule as the plane lands.
  • Protect healthy sleep habits at all costs, particularly prior to jet travel. Check out this article on flipping your sleep switch.
  • Ask your doctor for recommendations on medications or melatonin supplements.

During Travel

  • Drink lots of water! The dry air of the cabin causes dehydration. This can be detrimental to the circadian system in addition to overall health.
  • If you have a wristwatch or a travel clock, change it to your destination upon take-off. This will help you mentally adjust to your destination sleep cycle.
  • Explore in-flight sleep aids such as noise-canceling headphones and weighted blankets.

When to Contact Your Doctor

  • If you are a frequent traveler, or in the aviation industry, we recommend contacting a physician for long-term advice on medications and sleep hygiene practices that suit your needs.
  • If jet lag symptoms last longer than about a week. It’s important to note that symptoms can sometimes mimic other illnesses.
  • If symptoms are so serious as to cause major disruption to your business or vacation plans.

Important Key Takeaways

  • Jet lag is a temporary condition in which the internal clock of the body, mainly the circadian system, becomes misaligned with the environmental cues of the destination.
  • Symptoms are more intense when traveling from west to east (for example, from California to New York), as opposed to east-west travel.
  • Time-givers, also known as zeitgebers, can be extremely beneficial in managing jet lag.
  • Preparations made prior to jet travel can have a positive impact on your ability to conquer jet lag.

Extensive research and the expert opinions of health professionals emphasize that although jet lag can be a troublesome feature of in-flight travel, it does not need to interfere with our plans for success, productivity, and most of all, enjoyment. There are many steps that you can take to avoid jet lag and its challenges.

References:

1 Choy, M., Salbu, R.L. (2011). Jet lag: Current and potential therapies. P&T, 36(4). 221-231. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3086113/pdf/ptj36_4p221.pdf.

2 Mayo Clinic. (n.d.). Jet lag disorder. Mayo Clinic. [Blog Post]. Retrieved from: https://www.mayoclinic.org/diseases-conditions/jet-lag/symptoms-causes/syc-20374027.

3 Choy, M., Salbu, R.L. (2011). Jet lag: Current and potential therapies. P&T, 36(4). 221-231. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3086113/pdf/ptj36_4p221.pdf.

Roach, G.D., Sargent, C. (2019). Interventions to minimize jet lag after westward and eastward flight. Front. Physiol. https://doi.org/10.3389/fphys.2019.00927. Retrieved from: https://www.frontiersin.org/articles/10.3389/fphys.2019.00927/full.

5.Choy, M., Salbu, R.L. (2011). Jet lag: Current and potential therapies. P&T, 36(4). 221-231. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3086113/pdf/ptj36_4p221.pdf.

Centers for Disease Control and Prevention. (2021, May 13). Jet lag. [Blog Post]. Retrieved from: https://wwwnc.cdc.gov/travel/page/jet-lag.

[7] Choy, M., Salbu, R.L. (2011). Jet lag: Current and potential therapies. P&T, 36(4). 221-231. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3086113/pdf/ptj36_4p221.pdf.

[8] Choy, M., Salbu, R.L. (2011). Jet lag: Current and potential therapies. P&T, 36(4). 221-231. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3086113/pdf/ptj36_4p221.pdf.

About Tara Youngblood

Tara Youngblood is ChiliSleep’s co-founder and CEO. An accomplished scientist, author, and speaker, Tara’s unique ideas are revolutionizing the future of sleep health by making sleep easy, approachable, and drug-free.
Learn more about Tara.