“There are just two key points of focus: dawn and dusk,” says Daniel Forger, PhD, a professor of mathematics and research professor of computational medicine at the University of Michigan. Essentially, adjusting as fast as possible to a time change is simply a matter of knowing when to let in light and when to shut it all out (or off). While other factors like nutrition and activity still need to be explored, light exposure is the most important piece of the puzzle, since it’s the strongest signal to our internal circadian clock, he explains. “It takes longer to fully adjust than people realize, about a day per each hour’s shift,” Forger says. “If I were to fly to Asia from Michigan today, it would take about two weeks for my circadian clock to catch up, but if I really stuck to optimal light schedules, it should only take three to four days.” So how can you make light work for you on your next far-flung trip? The basic rule is to shorten the length of your day’s exposure to light when you’re traveling to a time zone behind your own, and lengthen it when you’re traveling forward in time. Luckily, you don’t have to do the math yourself to get all the jet-setting benefits. The team turned the data from their study in PLOS Computational Biology into a mathematical formula available on a free app, Entrain, which tailors an ideal light exposure plan to your travel plans. More from Prevention: The Healthiest Airport Is…
