Jet lag can ruin the first few days of a holiday or act as a serious obstacle to the frequent business flyer.
What is jet lag?
Jet lag or desynchronosis is the temporary disruption of your ‘body clock’ when you fly across several time zones. This causes the traveller’s internal clock to be out of sync with the external environment. This internal body clock is actually a portion of the brain which controls the timing of you biological functions, which includes when you sleep and eat. These are known as the circadian rhythms, and are responsible for helping you wake up in the morning and sleep at night.
Causes of Jet Lag
When you travel across a number of time zones, the body clock goes out of sync with the destination time, and so it experiences daylight and darkness contrary to the rhythms it has grown accustomed to.
The body’s natural pattern therefore becomes upset as the rhythms which dictate when you should eat and sleep no longer correspond to the environment of your destination.
Jet lag occurs, because the body cannot automatically realign these rhythms. The speed at which you body readjusts itself to new daylight and darkness hours and eating and sleeping patterns is entirely dependent upon the individual. So while it may take a few days for certain people to readjust to a new time zone, others seem to experience little disruption to their body’s natural sleeping pattern.
The symptoms of jet lag can be quite varied, though on the whole, an individual may experience fatigue, exhaustion, inability to sleep, disorientation, lost desire to eat, head aches, stomach aches and a general feeling of fuzziness.
Many cases of air rage often result from jet lag, as an overall feeling of disorientation can result in frustration and anger.
Preventing Jet lag
Jet lag is entirely dependent upon the number of time zones crossed, and not, as is often believed, the actual length of the flight. People tend to find that travelling east has the greatest effect upon the body. Jet lag is unlike all other sleep disorders, in that it is not caused by abnormal sleep patterns such as insomnia. In fact, those who live quite a rigid lifestyle, tend to suffer worst, especially if you sleep and awake at roughly the same time every day and eat your main meals at approximately the same time.
Travellers with less of a daily routine are effected far less by jet lag. Babies, for example, tend not to suffer from jet lag.
Studies carried out by NASA show that for every time zone a traveller passes, one day is required to fully regain your natural rhythm and energy levels.
Any of the following can also contribute to jet lag:
- Alcohol: The effect of alcohol on the body is multiplied at altitude, so drinking even relatively small amounts of alcohol can compound tiredness and intensify hangovers upon arrival.
- Solution: Avoid drinking alcohol the night before flying. Above all do not drink at all during the day of flying or while flying.
- Dehydration: Air cabins tend to rely on recycled air via air conditioning units. This inevitably dries both the skin and can lead to dry nasal and throat membranes.
- Solution: Drink plenty of water prior to flying and ensure that you carry a bottle of water with you the flight to regularly take small drinks from. An intensive moisturizer is also useful to prevent the skin from becoming too dehydrated and dry.
- Headaches and a sore throat may become accentuated in such a dry atmosphere.
- Solution: Again, it is essential to drink plenty of water before and during the flight to combat such conditions.
- Pre-flight condition: If you start your flight stressed and tired, then it is unlikely that you will emerge much fresher.
- Solution: A good night’s sleep prior to flying and some light exercising (maybe a brisk walk in the morning) will put your body in a far better ‘flight-condition’, ready to face the potential effects of jet lag.
- Immobility: Prolonged period of immobility will naturally tire the body and invoke lethargy.
- Solution: Keep moving, walk around the cabin at regular interval to keep the blood pumping around your body.
Update (2015): Here’s a great video on Jet Lag (suggested by one user):
Using Time Zones to prevent Jet Lag
By understanding how time zones are split up around the world, it is possible to create a strategy to prevent jet lag. It is best to arrive in daylight hours, as sunlight naturally alerts the body, consequently there is a greater likelihood that you will readjust to local time faster, and not sleep through the day.
Thus if you leave London at midday and travel for six hours west towards New York, upon arrival the local time will be 13:00 hours, though your body will still be set on London time, which is actually 18:00 hours, thus your body will start to anticipate darkness, an evening meal and sleep.
To counter jetlag, you need to now try and stay awake until the early evening, when you can enjoy a good nights sleep. By planning to arrive during daylight hours, this should be easier, than arriving during darkness.
If you arrive during the night, you will need to try and get some immediate sleep to be ready to start the following day in line with local time. Naturally, this can be difficult if the time your body is still adjusted to is daylight hours as you will probably not feel tired until the following day at your destination, when really you should be staying active.
By planning ahead your flight departure and arrival times, so that you arrive at your destination during daylight hours, it can be possible to significantly curb jetlag.
Flying across time zones is the main cause of jet lag. Our regular circadian sleep-wake patterns are upset when we fly, because different regions of the world experience daylight and night time at different times due to the curvature of the earth.
The earth is divided into 24 time zones each approximately 15 degrees wide, these constitute one hour in time difference. So, say we started in London (Greenwich Mean Time), and travelled across three 15 degree time zones, depending upon the direction we would arrive either three hours before (west) or three hours after (east) the time in London.
The meridian (middle line) for all these time zones is found running through Greenwich, London.
Directly opposite meridian line is the International Date Line. Here, both time zones meet and so we encounter the point where there is a difference in days, so that when it is light on one side of the earth it is dark on the other.
The international date line is not straight, to avoid creating different time zones with a single country, thus it zigzags its way across the globe.