jet lag

We all know that feeling of disorientation and dislocation that comes with travelling through different time-zones; it takes time to re-set our body clocks to the rhythm of our new surroundings.   It’s not just about the obvious disturbance to our sleep-wake cycle, which is regulated by the brain’s master clock and gets re-set first.  It’s also about the effects on the individual clocks of our body’s main organs  –  our digestive processes, for instance  –  and these take longer to re-adjust.   On average, it takes one day for every time zone you travel to acclimatise fully.

This has a deep affect on our performance and wellbeing.  According to British Airways, jet-lag can downgrade decision-making ability by 50% and attention by an astonishing 75%.   But though we can’t escape the effects, we can certainly do a lot to minimise them and get our body back to its healthy equilibrium as fast as possible.

It’s a fact that we recover more quickly when travelling West (e.g. London to New York) than when going East (e.g. London to Hong Kong).  This is because our circadian rhythms can adjust themselves better when your day is stretched than when it’s condensed.   The key to setting and re-setting the master-clock is daylight.  And the best way to help this is to seek out daylight at particular times of day and avoid it at others.

Here’s some advice on how to help your body re-adjust quickly, depending on where you’re flying to:



Time zones Example Advice
Going West 2 – 8 London – New York On arrival, seek out late afternoon / evening light for a few days.
8 – 12 London – Honolulu On arrival, seek out late morning / afternoon light for several days.  Avoid light in late afternoon and early evening.
Going East 2 – 8 London – Mumbai On arrival, seek out morning / early afternoon light for several days. Avoid light in the very early morning.
8 – 12 London – Sydney On arrival, for the first 3-4 days, seek out mid-afternoon light and avoid morning light.  After about 5 days, seek out morning light.

You can also help the process by taking melatonin.  This is a natural hormone produced by the pineal gland during the night.  It’s easily obtained over the counter in the US, though only on prescription in the UK.  It’s not worth taking for time zones of less than 5 hours, however, and it can cause unwanted side-effects (sleepiness, lowered alertness etc.).

Here’s the most effective way to take melatonin (5mg tabs) for long-haul flights:

Going West:  don’t take anything before your flight.  On arriving at your destination, take a capsule at 11pm local time for 4 days.

Going East:  take one capsule on your departure day or on the flight at the destination bedtime.  On arrival, take one at the local bedtime for 4 days.

You can’t defy your body-clock and defeat jet-lag entirely, but you can diminish its effects and re-synchronise your body with your new time setting.  And in doing so, you can nurture your health and wellbeing, inside and out.