Jet Lag - “time zone change syndrome”

Jet Lag is classified as a seconday circadian dysrhythmia.

Jet lag occurs with rapid travel across time zones, resulting in a misalignment between the timing of body's circadian rhythms with those of the external physical environment. Symptoms include general malaise, daytime sleepiness, difficulties in initiating or maintaining sleep, impaired performance, and decrements in subjective daytime alertness and performance. These symptoms usually last for several days until the traveler adapts to the new time zone. Some people also notice digestive and bowel movement problems.

Senior citizens generally need longer to recover from jet lag. Their circadian cycles are slower to adjust to the new time zone.

Eastward travel (requiring advancing circadian rhythms and sleep-wake hours) is usually more difficult to adjust than westward travel. Eastward travel generally results in difficulty falling asleep and westward travel in difficulty maintaining sleep. Jet lag can also be made worse by poor air quality (in the plane and after the flight) and being forced to sit still for a long flight.

Jet Lag Factors

• Travelling East is worse
• Age (worse over 50)
• 25-30% of people minimally affected
• 25-30% of people highly susceptible
• Morning people more affected than night owls
  

Jet lag is a negative consequence of our circadian cycle which afflicts travelers who rapidly cross multiple time zones. The condition produces a number of unwanted effects including excessive sleepiness, poor sleep, loss of concentration, poor motor control, slowed reflexes, nausea, and irritability. Jet lag results from the inability of our circadian clock to make an immediate adjustment to the changes in light cues that an individual experiences when rapidly crossing time zones. After such travel, the body is in conflict. The biological clock carries the rhythm entrained by the original time zone, even though the clock is out of step with the cues in the new time zone. This conflict between external and internal clocks and signals is called desynchronization, and it affects more than just the sleep/wake cycle. All the rhythms are out of sync, and they take a number of days to re-entrain to the new time zone. Eastward travel generally causes more severe jet lag than westward travel, because traveling east requires that we shorten our day and adjust to time cues occurring earlier than our clock is used to.

British Airways' website has a page on recovering lost sleep due to jet lag. Its very simple advice just suggests an honest assessment of how many hours you need compared to how many you've slept recently. The flaw in this method is that people rarely truely know how much sleep they really need.

How hotels can help

A 2003 article in the Cornell Hotel and Restaurant Administration Quarterly recommends hotels serving international travelers take measures to help their guests recover from jet lag. These include measures to get the traveler’s circadian rhythm adjusted to local time and a good sleep during nighttime at the hotel. Measures include commonsense things like a comfortable mattress and temperature control, as well as the ability to produce total darkness in the room. The hotel should also provide opportunities to easily experience bright sunshine as this is an effective way to reset the circadian clock.

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How To Avoid Jet Lag

“Jet lag” is a common term for the condition that follows after your circadian rhythm, or body clock, somehow gets altered. Jet lag is marked by a feeling of being generally unwell, with fatigue, irritability, gastrointestinal discomfort, disorientation and, sometimes, depression. The condition is most commonly suffered by air travelers who cross more than three time zones in a single flight – hence the “jet” part.

But jet lag isn't exclusive to air travelers – even workers who work on shifting schedules tend to experience its symptoms. Whatever the cause, being jet lagged is a troublesome condition that may take weeks to recover from.

While getting rid of jet lag will take some time, there are some general tips that can help you avoid much of its troublesome symptoms.

Before flying

What you do before flying can help prevent jet lag from being all that bad. Before flying, make sure that everything in your life is in order – in other words, make sure you don't spend the travel time worrying about anything. Try not to fly tired, hung over, or sick.

While flying

Make sure you dress comfortably for the flight, and bring soft slippers with you so you can take off your shoes. Also bring blindfolds, neckrests, or earplugs – anything to help you sleep. Try not to sit still for too long – periodically walk the aisles, and do some stretching exercises in your seat to avoid blood clots.

When your plane stops over somewhere and there's an opportunity to get off the plane, then do so. If there's an opportunity to get a shower at the stopover point, then by all means do so. It'll be good to stretch your legs before another grueling flight, and a shower will make you feel even better.

After flying

Many people make the mistake of getting a full eight hours of sleep immediately upon arriving at their destination. This will only make it harder to adjust your body clock to the current time zone. If you really have to sleep, take only two hours to get rid of the fatigue. After waking up, take an hour's walk in the sun to help your body get used to the change.

There's an unwritten rule of thumb that the best way to get rid of jet lag is gradually over a few days. The number of days should be according to the number of time zones crossed. In other words, you'll need to adjust your body clock by one or two hours every day.

Certain medications can help you sleep earlier, but remember to only use these as a last resort – they may make jet lag worse.

Getting out of jet lag

Honestly, you pretty much have to plow through it. Exposure to daylight at your new location can help reset your circadian clock, and it is a good idea to take a walk right after you wake up.

Remember to follow the normal rules for getting good sleep: no long naps at the wrong time, good hygiene, watch the caffeine and alcohol.

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