An app based on a complex mathematical model promises full recovery from jet lag in just a few days, even for extreme time zone shifts.
Feeling groggy after that long-distance flight? Hold the coffee and reach for your mobile phone. A mathematical tool promises a full recovery in just a few days, even for extreme time zone shifts. While the model has not yet been proven in the real world, a recently released app will let people try it out for themselves.
Your daily activity is usually aligned with your circadian rhythm, a roughly 24-hour cycle controlled by exposure to light and darkness. But a sudden change in schedule caused by travelling to a different time zone can throw off this internal clock.
Timed exposure to bright lights can trigger biological markers associated with sleep patterns, such as levels of the sleep-related hormone melatonin and body temperature. That can help get the body in sync with a new schedule. Previous work on adjusting to jet lag showed that people who experience a 12-hour time shift but forgo light therapy will still be off-schedule after 12 days.
Mathematical models that recommend exposure patterns already exist, and the best current versions require more than a week of carefully adjusting your light exposure to get you over a 12-hour shift.
With help from Kirill Serkh at Yale University, Daniel Forger at the University of Michigan in Ann Arbor used techniques from a branch of maths called optimal control theory to reengineer a model that Forger designed in 1999. "The equations are very hard to solve numerically, that's what has taken so long," he says.