If you have ever flown across a few time zones, you are undoubtedly familiar with the struggles of adjusting your sleep to the new hours - jet lag. Why is jet lag so hard to tolerate? Is there anything that can be done about it?
First, it should be recognized that your body wishes to keep a regular sleep schedule, as is reflected in sleep hygiene guidelines. Certainly we are creatures of habit, and our bodies like when we go to bed and get up at the same time every day. Our biological clock, which is controlled by part of the brain called the suprachiasmatic nucleus, helps us to keep a regular schedule by releasing hormones on a regular pattern. This pattern is called a circadian - or near-day - rhythm. Our sleep follows this same regular pattern.
When we disrupt the regularity of these cycles, our body treats us unkindly by making us sleepy or alert when we don’t wish to be. We may also have difficulty thinking, an upset stomach, a headache, or even mild mood changes. It is no wonder that we have trouble sleeping when we travel. For example, if you were to go to bed three hours early tonight, you would have great difficulty falling asleep. However, if you fly from California to New York and crawl into bed at your normal bedtime, you are effectively attempting the same thing (considering the time zone change).
How can we counter our circadian rhythm when we travel? One solution would be to keep the same sleep/wake hours as our original time zone, going to bed and getting up based on the times at home. This may not be the best way to enjoy our travels, especially if we fly great distances. An alternative would be to slowly adapt to the new time zone prior to leaving.
We can conquer jet lag by adjusting our sleep by an hour for a week at a time. If we are crossing two time zones, the change can occur over two weeks. If traveling west, we would go to bed and get up an hour later for one full week. During the second week we would repeat the same, going to bed and getting up another hour later. If traveling east, we would go to bed and get up an hour earlier each week. If we can slowly adapt to the change, we will tolerate it better. Unfortunately, unless the trip is quite lengthy, we wouldn’t be able to adjust the other way for our return home.
Another alternative is the use of melatonin. Melatonin is a naturally occurring hormone in our body that follows a circadian pattern. It is often called a "sleep hormone" because it peaks during the night, but it only induces sleep at higher doses. It can, however, cue our body to adjust our naturally occurring circadian rhythm. By taking a melatonin pill a few hours before our desired bedtime, we will more likely be able to sleep. If we find ourselves waking too early, melatonin in the early morning hours will help us sleep in.
The use of a light box can also shift our circadian rhythms when we travel. Imagine it pushing back your desire to sleep. If you are sleepy too early, use the light box at night to put off bedtime. If you are sleeping too late into the morning, use it when you get up to alert your body and mind.
Any of these solutions will help you to adjust your sleep schedule to a new time zone, and make your travels from home the joy that they should be.
Gooley, J.J. "Treatment of circadian rhythm sleep disorders with light." Annals of the Academy of Medicine, Singapore. 37(8):669-76, 2008 Aug.
Sack, R.L. "The pathophysiology of jet lag." Travel Medicine & Infectious Disease. 2009 Mar;7(2):102-10.
Sack, R.L. et al. "Circadian rhythm sleep disorders: part I, basic principles, shift work and jet lag disorders.: Sleep. 30(11):1460-83, 2007 Nov 1.
Srinivasan, V. et al. "Jet lag: therapeutic use of melatonin and possible application of melatonin analogs." Travel Medicine & Infectious Disease. 6(1-2):17-28, 2008 Jan-Mar.