What Causes Jet Lag and How to Avoid It
Jet lag is a problem unique to the modern world. High speed jet aircraft make it possible to cross through a time zone in little more than an hour. But the more time zones you pass through, the worse you are likely to feel when you reach your destination.
So what is jet lag, and how can it be avoided?
The main symptoms of jet lag include difficulty sleeping, fatigue, irritability, loss of appetite, poor judgment, and lack of motivation. Researchers have tried a variety of drugs to treat jet lag, but few have been promising. In fact, the most useful drug found so far has been caffeine, although only if taken during the morning hours of your destination time-zone.
While studies have shown that the number of time zones crossed is the main factor, the direction of travel also affects jet lag. Travelling north or south does not cause jet lag at all. People generally have more difficulty adjusting to travel from west to east than from east to west.
This is because most creatures, including humans, have a natural cycle called a circadian rhythm which regulates many biological processes, such as sleep. The average human circadian rhythm is between 24 and 26 hours, making it slightly longer than the average day.
Eastward travel compresses days into shorter periods, moving people further from their natural cycle. Westward travel expands days into longer periods, sometimes within the natural 24 to 26 hour cycle, thus requiring less adjustment to the circadian rhythm. As a result, it is easier to recover from jet lag after westward travel compared to eastward travel.
A study conducted by John Moores University found that the best way to avoid jet lag is to adjust your behavior. First of all, arrive at your destination a few days early if you can, and until you have adjusted, don't take any long naps during the day. Exercising during the day in your new time zone will also help your circadian rhythm re-adjust.
Finally, be careful when you first spend time exposed to daylight. This is because exposure to light significantly affects how our circadian rhythm adjusts. When travelling eastward, the more time zones you cross, the more you should delay exposure to the sun on the first day.
If possible, arrive in the evening, to give your circadian rhythm a night to catch up. Sleep in a little the next day, but not past noon.
