Mathematicians Create App To Beat Jet Lag

The solution is simpler than previously thought


Travis Rathbone

How can you get over jet lag? There are hundreds of suggestions, but few of them have been rigorously tested. So some mathematicians from the University of Michigan created an app that can help you, which relies on new mathematical models and the latest science.

Jet lag occurs when your body's circadian rhythms fall out of sync with your surroundings, such as when you quickly move to an area that is 12 hours behind where you were previously. One thing that certainly helps to adjust is exposure to sunlight--cells in your retina use this information to tell the brain that it is daylight, and that the body should be awake. But how much sunlight does the body need to adjust? And at what times?

Daniel Forger, a mathematical biologist at the University of Michigan who studies biological clocks and graduate student Olivia Walch created 1,000 possible trips, and combined them with studies on how light affects human circadian rhythms. They then used applied optimal control theory, a mathematical tool for finding ideal solutions. The results were published in PLOS Computational Biology, and the an app using the study's insights is called Entrain.

It turns out that to shift your clock, you really just need to adjust what your eyes and brain perceive as dawn and dusk, as explained in Scientific American:

Shifting your clock quickly just requires a new bedtime and long periods of bright light or complete darkness. These schedules significantly outperformed previous suggestions. Using this method, it takes only four days to fully sync after a 12-hour time zone shift. With other methods, it takes seven to 13 days or more. Even better, this method helps you “partially” sync in two days, which means you can sleep just fine. Olivia Walch, a graduate student at the University of Michigan, then developed an iPhone app with the model, called Entrain, which allows users to set tailored schedules. First, you enter your normal sleep schedule and then choose the area you’re traveling to and the type of light you’ll be encountering on your trip (Are you hiking outdoors? Or attending an indoor conference?). The app then provides a custom schedule, telling you when you should be in the light or in the dark as well as how many days it will take to fully adjust.

For more of the latest on high-tech snoozing, check out Popular Science's March 2014 issue on the science of sleep.