Jet lag arises when you are traveling and you internal body clock’s time is out of sync with the local time at your destination. For example, if you depart from London at 9 pm and fly to Bangkok you will land some 13 hours later when the time in London is now 10 am the following morning. But, because you have flown across a number of time zones, the local time at Bangkok international airport is now 4 pm that same afternoon.

After you have traveled to your hotel, checked in and taken a shower your body will now tell you that it is time to have something to eat. Now, your body clock thinks that it is lunchtime and, although everyone else will be having dinner, it doesn’t matter to your body clock what you call the meal, it is only interested in the fact that it is time to eat. At this stage everything is fine, however, a couple of hours later when everybody starts going to bed your problems will start as your body clock believes it is now only late afternoon.

A time difference of 6 hours, like that shown in this illustration, is significant and most people would feel jet lag. In fact, although a couple of hours will hardly be noticeable, anything over about 4 hours will produce the symptoms of jet lag in most of us.

There are of course several things which you can do before your journey, during your flight and at your destination to help to reduce jet lag but one difficulty which researchers have found recently is that when your body clock experiences a large shift in time it usually overcompensates when adjusting itself and therefore leaves you suffering from a double dose of jet lag for a while before it finally settles down. Against this background, how do you compensate for this?

To a certain extent you can take this into account and lower any symptoms of jet lag by starting to adjust your body clock before you travel, but circumstances may make this hard. An alternative course of action therefore is simply to break your journey if you are going to be traveling across more than 4 or 5 time zones.

In the case of our illustrative trip to Thailand this might for example involve breaking your journey half way and relaxing for a day before flying on. Today’s air travel might have made the world smaller but I’m afraid that it is going to take the human body a little bit longer to catch up to modern technology.