are continuously debating and fine-tuning their advice, they agree that exposure
to light is one of the most effective ways to combat jet lag.
rules for when you should seek out or avoid light are complicated and depend on
whether you travel east or west and how many time zones you are crossing,” said
Russell Foster, head of Oxford University’s Nuffield Laboratory of Ophthalmology and one of the world’s leading
experts on jet lag.
activates the pineal gland, which triggers a physical process that winds up and
sets your body’s internal clock, while darkness encourages your body to sleep by
lowering your temperature and sending melatonin, a natural sleep-inducing
hormone, into the bloodstream.
signals from sunlight and darkness – which are key to resetting the body’s
internal clock – can be difficult when you’re flying cross-country or halfway
across the world. Thankfully, two websites offer step-by-step, personalised
help for combating jet lag. Using your flight itinerary, each site provides a
suggested sleep schedule based on how many time zones you’ll cross and which
direction you’ll be travelling.
Jet Lag Rooster is
an online calculator that employs similar guidelines to those used at academic
institutions such as the Mayo Center for Sleep Medicine
in Minnesota and Rush University Medical Center in Chicago. Type in your itinerary and the site will give
you an hour-by-hour breakdown of when to sleep and when to go outside and seek
example, on an Atlanta to Moscow itinerary where a passenger lands at 10 am,
Jet Lag Rooster advises a schedule of doing the best you can that first day and
night (without specifying particular hours) and then, on the following day, avoid light after 11 am. The next
day, it recommends you begin to avoid light a little later – after 12:30 pm –
and on the day after that, it suggests you begin to avoid light after 2 pm.
The reasoning behind
this advice is that the average person can only adjust their internal clock by
an incremental amount of 60 to 90 minutes a day. Jet Lag Rooster encourages
travellers to pace themselves accordingly, which means it may take a person
travelling between Atlanta and Moscow about seven to 10 days to shift their
body clock the necessary 10 hours.
British Airways also created an online jet lag fighting calculator, where the advice is based on
research by Chris Idzikowski, director of the sleep assessment and advisory
service at Edinburgh Sleep Centre. The science behind the site’s
conclusions is the same as Jet Lag Rooster’s, but the tool condenses the advice
to a few sentences, rather than give an hour-by-hour breakdown.
to note that when scientists say you should seek out “light”, they mean ideally
being outdoors for up to half an hour. Outdoor light is always better than
indoor light. Even an overcast spring day in say, Reykjavik, will provide
enough light to reset a body clock, compared with sitting indoors, which won’t.
On the flip side, avoiding light can entail wearing sunglasses or staying
light boxes, or flat lamps that simulate natural white light with a blue tint,
are also effective, noted Foster, who has been consulting with Delta on the feasibility of introducing
such lights into airport lounges. However, there is no word yet from the
airline on whether it will put the concept into practice.
Sean O’Neill is
the travel tech columnist for BBC Travel