How to shift your circadian clock to beat your jet lag

In the first flush of our relationship, my husband began taking a series of photos of me during our travels. In every one, I am asleep: sat on a chair at the Musée d’Orsay in Paris. Head on my chest in the back seat of a car in Kiev, Ukraine. On a train in France, mouth open, drooling. He is lucky I still married him.

Jet lag certainly isn’t pretty. Other than leaving you feeling exhausted – or wide awake – at the wrong time of day, a long flight across time zones can also cause gastrointestinal distress, off-kilter body temperature, headaches, irritability and cognitive impairment, all of which are much more serious for people who fly all the time, such as airline pilots. What can we do?

Many of us approach jet lag by prioritising sleep whenever we can, in order to counter the exhaustion. Even the National Health Service website for England recommends that you “change your sleep schedule to the new time zone as quickly as possible”, and many of us try to just knock ourselves out on overnight flights (often with the help of over-the-counter medicines or in-flight refreshments).

While this approach isn’t always wrong, it can sometimes do more harm than good. Instead, we need to think about jet lag in a more nuanced way, says Steven Lockley, a neuroscientist who was at Harvard University Medical School. “Jet lag really is…