Jet lag is no fun. In fact, it’s one of the few drawbacks of jetting off to some far-off time zone for what should be some quality R&R.
While it’s common knowledge that our sleep and wake cycles — governed by biological circadian rhythms — can’t immediately adjust to a new time on the clock after rapidly skipping one or more time zones, we’re only just learning why.
Not all jet lag is created equal
While seasoned travellers know that flying eastward (say, from LA to New York) is much harder to recover from than the same flight in the opposite direction, we now know a little more about why this is the case.
Our natural cycles are actually 24.5 hours, not 24 hours
A new study just published in the scientific journal “Chaos” explains this phenomenon.
Using complex mathematical models, University of Maryland researchers found that if left to their own devices (no sunlight, alarm clocks, or time zones), the brain cells responsible for our circadian rhythms complete a full “cycle” in just over 24 hours. The difference in our natural cycle (about 24.5 hours) and a 24-hour day is slight, but when rapidly changing time zones the effects can add up.
Jet lag is less terrible when flying west because that direction adds hours to our days, giving our bodies more time to adjust
Because flying west adds hours to the day, we give our bodies the extra time they naturally need to sync up with a circadian cycle, making the adjustment period smoother.
Flying east, on the other hand, eats up hours, and forces our circadian rhythms to be cut even further.
The researchers came to the conclusion that when travelling west, our bodies need a little bit less than one day per time zone change to readjust, while when flying east, we crave about one and a half days per time zone. So, flying from New York to Paris — a difference of six hours — would take about eight full days to fully adjust, while the reverse would take less than six days.
There’s still no cure for jet lag
While the study is significant and pinpoints the cell behaviour responsible for a well-known response to travel, the fact remain that jet lag sucks, and there’s no magic cure to adjusting to your new alarm clock. Travel experts recommend exposing your body to natural light, staying hydrated, and flying during the daytime, which can all combat the effects of jet lag.
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