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.