Whether you're a "Road Warrior" who has piled up thousands of Frequent Flier Miles, or someone who is planning a vacation to a distant location, you are likely to experience the phenomenon of "jet lag," which can have a profound effect on your sleep and alertness. Every day, millions of travelers struggle against one of the most common sleep disorders — jet lag. For years, jet lag was considered merely a state of mind. Now, studies have shown that the condition actually results from an imbalance in our body's natural "biological clock" caused by traveling to different time zones. Basically, our bodies work on a 24-hour cycle called "circadian rhythms." These rhythms are measured by the distinct rise and fall of body temperature, plasma levels of certain hormones and other biological conditions. All of these are influenced by our exposure to sunlight and help determine when we sleep and when we wake.
When traveling to a new time zone, our circadian rhythms are slow to adjust and remain on their original biological schedule for several days. This results in our bodies telling us it is time to sleep, when it's actually the middle of the afternoon, or it makes us want to stay awake when it is late at night. This experience is known as jet lag.
The National Sleep Foundation