This is what we’ve learned about how to beat jet lag after 2 years of research and 200,000 air miles flown by our sleep scientists .

Let’s Start at the Beginning…

So what is jet lag – and what can we do about it? Let’s see what our sleep scientists have found after years of research and thousands of hours testing various ways to beat jet lag.

Jet lag, also called flight fatigue or desynchronosis, is a temporary circadian disorder that causes fatigue, insomnia, and other similar symptoms when one’s body is quickly transported, usually by jet airplane, to a new location and sunlight and darkness are out of sync with the body’s previous location.

Wow, that’s a mouthful, but anyone who has been ‘jet lagged’ knows how debilitating this condition is. Not many, however, know the full story behind it.

Understanding jet lag is the best way to begin to beat it, so let’s get started…

How Does Jet Lag Disrupt Our Body?

The term “jet lag”, sometimes written as “jetlag” began to appear around the middle of the 20th Century about a decade after commercial jet airplanes began flying passengers quickly to distant locations. Early research came to the conclusion that simply flying large distances caused jet lag, but eventually the actual cause was found to be the upsetting of the body’s circadian rhythm by newly introduced cycles of daylight, darkness, eating and other functions that were out of sync with what the body was accustomed to. Another obvious sign of this was the fact that people on long flights while traveling north to south or south to north were considerably less likely to suffer jet lag than those who took shorter flights but went from west to east or east to west.

West to east travel is considered to cause the more severe cases of jet lag because it pushes the cycle forward instead of backward, which appears easier for our bodies to adjust to. Jet lag can also be further induced by travelling to areas that have extreme sunlight or darkness or sunlight that contrasts with our natural environment, such as flying to the most extreme northern or southern regions of the earth.

The effects of jet lag are more pronounced as the distance of travel increases. When people fly across only one or two time zones in the U.S., they may be able to adjust to the difference without any noticeable effects of the time change. However, those who fly across three or more time zones will most likely develop noticeable symptoms of jet lag.

Symptoms of Jet Lag

In humans, the effects and symptoms of jet lag can occur to anyone, regardless of their sex or age, and it can lead to uncomfortable feelings of fatigue and disorientation. Additional jet lag symptoms include weakness, insomnia, mild depression, headaches, nausea, sleep disturbances, irritability and loss of appetite. A few individuals have reported other symptoms such as an increased susceptibility to illness, and heartbeat irregularities.

Jet lag is most commonly experienced during international travel, but they can also occur at almost any time whenever we fly east to west or west to east and our body’s natural day/night rhythm gets out of sync with the location that our mind and body experiences when we arrive at our new destination.

Most jet lag symptoms will usually disappear after a few days when the body eventually adjusts to the new cycle, but they can last longer depending on the amount of the disturbance to the body and the steps that are taken to combat them.

Things that Worsen Jet Lag

• Age: Elderly adults may have a slower recovery time from jet lag.

• Frequent travel: Pilots, airline flight attendants, and frequent travelers who are continually flying to different time zones can have more difficulty adjusting.

• Preexisting conditions: Poor sleep habits, preexisting sleep deprivation, and stress before travel can frequently exacerbate the symptoms of jet lag.

• Flight conditions: The monotony of traveling on an airplane in a cramped seat, immobile, cabin pressure and airline food can have an impact on the symptoms of jet lag.

• Alcohol: The effects of jet lag can be worsened by the consumption of alcoholic beverages

Medical Complications of Jet Lag

Any medical complications of jet lag are rare. If someone has a preexisting heart condition, the stress coming from the disruption of the circadian rhythm, combined with high altitude, the stress of travel and the immobility involved during flight can result in a heart attack. In cases where jet lag results in chronic sleep deprivation, then it’s possible that certain individuals who are predisposed could experience a stroke.

Who Experiences Jet Lag?

Researchers have reached conflicting opinions as to whether younger or older people are more affected by jet lag. Some studies have shown that younger people have the ability to more easily handle the circadian rhythm changes because they are less ingrained in their bodies. However, other studies have shown the complete opposite; that since the circadian rhythms of younger people are less ingrained, they’re more likely to suffer from the fluctuations. Nearly all studies, however, point out that women appear to be at higher risk to encounter the effects of jet lag, probably because women’s estrogen levels have a large impact on their circadian rhythms.

Statistics say that nearly 93% of all travelers will someday experience jet lag. It’s generally accepted that the body takes about one day for each time zone crossed to be able to fully recover from jet lag and adjust to the new location. This can vary between individuals quite drastically, as some people may suffer severe, debilitating jet lag, while others may not be affected at all.

The effects of jet lag can also be aggravated by other factors. Many people tend to experience feelings of nervousness or anxiety or nervousness when they travel by airplanes, and this can sometimes make jet lag worse than normal. Also, the dry air that is circulated inside airplanes can also be hard on people who are accustomed to humid environments, causing sore throats or headaches.

When flying, and to help ease the effects of jet lag, it’s important to maintain proper hydration, so drinking water is always advised. Alcohol, when taken either just before or during a flight is not considered a good idea as alcohol can have a much stronger effect on people when they fly, and has a dehydrating effect that’s counterproductive to maintaining proper hydration.

Excerpts from the Report:

“The quality of sleep can be as critical as the quantity of sleep in restoring an individual. If an individual obtains 8 hours of sleep but the sleep is disrupted tens or hundreds of times, then upon awakening, the individual may feel as if only a few hours of sleep were obtained.

“There are many diverse reasons for disrupted sleep, from environmental causes (e.g., noise, light) to physical sleep disorders. For example, there is a sleep disorder called “periodic leg movements during sleep” that involves one or both legs twitching throughout sleep (see appendix A for further information). With each leg twitch, the sleeper is awakened briefly. Hundreds of these brief awakenings can occur during one sleep period. The sleeper can be completely unaware of the twitches or awakenings but feel sleepy and tired even after the sleep.

“Circadian adaptation in flight crews after trans-meridian flights has been examined in only a few studies. Klein and colleagues at the DLR (the German Aerospace Establishment) found that flying skills of 12 German fighter pilots tested in an F-104 simulator were less impaired after a westward flight (as passengers) crossing eight time zones than after the return eastward flight.”

“Adaptation of sleep and the temperature rhythm to local time was faster after westward flights. In an international study coordinated by NASA, sleep of long-haul flight crews during the first layover of scheduled international trips was less disturbed after westward flights crossing eight to nine time zones than after eastward flights crossing eight time zones. In the same study, crewmembers who scored as more evening-type showed lower levels of daytime sleepiness after an eastward flight crossing eight time zones (Tokyo-San Francisco) than did more morning-types.

“A NASA study of the effects of aging found that as flight crews get older, they become more morning-type and the amplitude of their circadian temperature rhythm declines. Daily percentage sleep loss during trips was 3.5 times greater among long-haul crews aged 50-60 than among long-haul crews aged 20-30.”

Common Misconceptions

The next part of the module identified widely held misconceptions at the time and explained why they were false.

“Scheduled rest period allows for required sleep

“NASA short-haul field study – The average layover was 12.5 hours long – Pilots slept about 1 hour less per night on trips than at home – However, pilots had to wake up for duty more than 1 hr earlier than normal – They could not fall asleep earlier to compensate for the early wake-up. Sleep laboratory finding – It is very difficult to fall asleep earlier than usual, except when cumulative sleep debt overcomes circadian factors.

“The information on this slide is based on a NASA long-haul study that also demonstrates the misconception that the entire rest period is available for sleep. The study examined 29 pilots in B-747s (each series except 400) during four trip patterns that lasted 5-9 days. The average duty period was 10.3 hours, followed by an average layover of 24.8 hours, resulting in an average rest/duty cycle of 35.1 hours. There were usually two sleep episodes (total 11.5 hr of sleep) per layover.

“A provocative finding here is that the average temperature rhythm for these long-haul pilots was extended to 25.7 hours. This is longer than the usual 24-hour circadian cycle and longer than the usual free-running rhythm of 24.9 hours. It suggests that after a period of time, the circadian clock could no longer follow the many time-zone changes and irregular hours of work and rest. This NASA field study confirms that the circadian clock cannot keep up with the time zone changes and non-24-hour duty/rest cycles experienced by long-haul flight crews. In addition, a 24-hour sleep/wake cycle is impossible with the average duty/rest pattern of 10 hours of duty followed by a 25-hour layover.

“An extensive scientific literature clearly demonstrates the effectiveness of naps in improving subsequent alertness and performance. One important consideration when napping close to a duty period is to minimize the chances of going into deep NREM sleep (stages 3 and 4). If awakened out of deep sleep, an individual may continue to feel groggy, sleepy, or disoriented for 10-15 minutes. This phenomenon is called sleep inertia. Therefore, if taking a nap before a duty period, limiting its duration to 45 minutes or less will decrease the chances of having significant amounts of deep sleep.

“A brief nap can be an important way to decrease the length of continuous wakefulness. It is usually much better to get some sleep than none at all. When you nap at times other than immediately before a duty period, then the nap can be longer. In this case, a nap longer than 2 hours is likely to get an individual through at least one NREM/REM cycle. Strategic napping can be an extremely effective countermeasure in improving subsequent alertness and performance. Some individuals call these “power” naps. In flight operations, “NASA naps” have been demonstrated to be an effective acute fatigue countermeasure.

In the third part of the module, recommendations were provided for flight operation alertness management strategies.

“The fact that sleep during trips was reported not only as shorter but also as more disturbed, suggests that the effects of this sleep restriction on subsequent daytime sleepiness, performance, and mood may be greater than those reported in laboratory studies with similar levels of sleep restriction. The effects of duty demands on subjective fatigue and mood are most clearly seen in the comparisons of ratings made pre-trip, during flight segments, during layovers, and post-trip. During layovers, fatigue and negative affect were rated as highest and positive affect and activation as lowest.

“Positive affect was rated as highest during flight segments, even though fatigue ratings were higher than for either pre-trip or post-trip. Post-trip recovery was indicated by return of fatigue levels to baseline, the lowest negative affect ratings, and the highest levels of activation. Significant time-of-day variations were found in fatigue, negative affect, and activation. Fatigue and negative affect were low in the first three ratings after awakening, and rose thereafter to reach their highest daily values in the final rating before sleep. As expected, activation showed the opposite time-of-day variation.

“No significant relationships were found between the timing, duration, or flight hours in a duty period and the fatigue and mood during layovers. Subjects think they are managing their fatigue when, in fact, they are not. However, potential countermeasures are currently being evaluated, and in the future may provide additional strategies for overall alertness management in flight operations.”

The Education and Training Module was intended to be used by trained individuals as a live presentation to provide a forum to discuss how the information and recommended strategies could be applied in flight operations.

Tips for Fighting Jet Lag

If possible, plan to arrive early at your destination so that you will have time for your body to adjust to the new location.

Get plenty of sleep before leaving. Sleep-deprivation will usually worsen the effects of jet lag.

Adjust your schedule gradually before leaving. If you’re planning to travel eastward, try going to bed an hour earlier each night a few days before departing. If you’re traveling westward, try going to bed an hour later each night and also eat meals correspondingly later than usual.

Remember also to regulate your exposure to bright light. Since light is a primary influence on your circadian rhythm, regulating light exposure to correspond with your schedule will help you adjust to your new location. If you’re traveling eastward, exposure to light earlier in the evening will help you adjust to your new destination while exposure to morning light an hour later each day will help if you’re traveling westward.

Exceptions to the Rule

The exceptions to this are if you plan to travel a great distance, such as eight or more time zones from your original location. In this case, your body may interpret exposure to light in the early morning as dusk and evening light could be interpreted as dawn. To help counteract this bodily confusion, in the morning wear sunglasses and avoid bright light as much as possible. Later, in the late afternoon, allow your body to perceive as much sunlight as possible during your first few days after arriving at your destination.

During your Trip

While traveling, move around as much as possible. Get up and walk around periodically, stretch and do some static exercises. But once you’ve landed at your destination, avoid heavy exercise if it’s getting close to bedtime as it can keep you awake when you’re trying to sleep.

Eating sensibly is also a good rule to follow when traveling distances that will create jet lag. Many frequent fliers swear by special jet lag diets, such as eating a heavy diet a few days prior to traveling and then fasting on flight day, but no studies have shown special dieting to be an effective preventative for jet lag.

Remember also to stay hydrated. Dehydration will worsen the effects of jet lag. Drinking plenty of water before, during and after your flight is very important as it will help to counteract the drier air of an airline cabin. Avoid caffeine and alcohol as both of these can dehydrate you and keep you awake when you’re trying to get some rest.

If it’s nighttime at your destination, try to sleep on the plane. Use an eye mask, earplugs or headphones to help block out light and noise. If it’s daytime at your destination, try to stay awake and resist the urge to sleep to help reduce the effects of jet lag.

Stay on your new schedule. Just prior to leaving, set your watch to the current time of your destination. Once there, even though you’ll be sleepy, do your best to go to bed at the local nighttime. before you leave. Once you reach your destination, try not to sleep until the local nighttime, no matter how tired you might be. Schedule your meals the same way, by having mealtime at the regular local times.

Remedies

There are also many natural remedies that can be used to combat jet lag. As with any medication, consulting your physician first is recommended as self-treating any condition by avoiding standard care can possibly have serious consequences.

Valerian

The herb valerian is commonly used as a natural sleep aid. When taken for jet lag, it’s reported to be useful in helping to adjust to new time zones by helping people go to sleep at a different time than when they are accustomed. Valerian is not considered addictive and is not likely to cause grogginess when waking up.

Melatonin

Melatonin is a unique hormone released by your body as you perceive the sun beginning to set and it helps your body to prepare for sleep. Your body’s circadian rhythm, or internal clock, is controlled by its perception of natural daylight and by amount of melatonin that’s released into your body. The next morning when your body perceives the sun rising, melatonin production is stopped and this helps you to wake up.

Studies show that taking melatonin is effective in resetting your circadian rhythm to an earlier time of day, such as when you’re a passenger in a plane flying eastward. In this case, it’s advised that you take melatonin at the bedtime of your destination each night until you have adapted to the time at the destination. If you fly westward, to reset your body clock to a later time, melatonin should be taken at the time of morning at your destination.

Some jet lag remedies also contain melatonin to help you sleep when your body finds it difficult to adjust to the time of your destination. Melatonin is usually most effective when it’s taken around two to three hours prior to when you want to fall asleep.

The NIH Report on Melatonin

Conclusions

Although there are numerous methods available today to combat the effects of jet lag, a central theme appears to be the recurring mention of the body’s own natural sleep-inducing hormone, melatonin.

Melatonin, best known by many as “the sleep hormone,” is essential to regulating the body’s 24-hour biological clock and sleep-wake cycle. Melatonin release is triggered by the absence of light. As night approaches, melatonin levels rise, preparing the body for sleep. Melatonin levels fall back as daytime arrives, and the body becomes alert and prepared for a waking day. Over years of scientific inquiry, our understanding of melatonin’s role in the body has broadened. We’re still learning about the range of melatonin’s influence. But the hormone is now recognized as having influence in several important biological functions, including the immune system and metabolic system.