Jet lag, or desynchronosis to give it its proper medical name, is a physiological condition resulting from a disturbance to the body clock when travelling rapidly from one time zone to another. Passengers travelling by ship are less likely to be affected as their body clocks have longer to adjust, but for travellers flying across different time zones it can be a real problem and the further you go the worse the effects are.
It varies from person to person but jet lag usually lasts several days and as a rough guide you can expect the disruption to last one day per time zone crossed. This means that if you are spending a fortnight in New Zealand, you could well spend the majority of your holiday feeling lethargic and not quite with it.
The body’s circadian rhythm (or body clock) is set to our local time so that we feel tired at night, alert in the morning and ready to eat at set times of the day. Travelling east to west or vice versa means that we cross various time zones resulting in us either having difficulty sleeping when we have travelled west to east, or wanting to sleep early in the evening when we have travelled east to west. It is easier to delay our bedtime than make ourselves sleep when we are not tired so, in general, flying east to west is easier to cope with.
Who does it affect?
People who have a very rigid routine for going to bed and getting up in the morning will find it harder to adjust to a different time zone. Conversely babies and young children who are used to falling asleep during the day will find it easier. Jet lag seems to hit the over 60s hard, although the reason for this is not known.
What are the symptoms?
The most common symptom of jet lag is sleep disturbance resulting in feeling generally unwell and lacking in energy, but that is just the tip of the iceberg. The body’s circadian rhythm does not only affect our sleep patterns but many other things too:
– Hunger – you may suffer from loss of appetite
– Temperature – you may sweat or feel cold
– Urine production – you might need to get up during the night to go to the bathroom
– Bowel habits – this can cause constipation or diarrhoea
– Digestion – you may suffer bouts of indigestion or nausea
Jet lag not only causes physical problems but cognitive ones too. These can include:
– Difficulty concentrating
– Feelings of disorientation
– Poor memory
What can be done about it?
One of the best ways to reset the body clock involves light. Depending on which time zone you have travelled to there are certain times when you should avoid light and other times when you should try to expose yourself to light (natural if possible but artificial light will do). BA has a handy tool on its website that will advise you what these times are.
Jet lag is not a curable condition, but there are various things that may help you cope with it:
– Don’t have a nap – no matter how tired you are after a long flight it is best to resist the temptation of having a nap when you arrive at your destination.
– Get used to your new routine quickly – your body may be telling you it’s dinner time when you arrive, but establish your new routine for eating and sleeping from the outset.
– Melatonin tablets – melatonin is a hormone produced by our bodies in the evening, preparing our bodies for sleep. Some travellers swear by melatonin supplements as a jet lag remedy. It is licensed in America but not in the UK for this purpose and is not suitable for everyone e.g. those taking the blood-thinning drug Warfarin or those with epilepsy.
There are also steps you can take before landing at your destination that may combat jet lag:
– For a few days before you travel, tweak your bed time to fit in with your destination i.e. go to bed later if you are travelling west and earlier if you are travelling east
– Keep calm because stress can exacerbate jet lag
– Drink plenty of fluids on the flight (limit alcohol and caffeine)
– Finally, if your trip is a short one of just a few days, try to stick as closely as possible to home time and don’t try to adjust to local time.