Mathematicians battle jet lag

Looking for a jet-lag cure? A new mathematical model may help you overcome jet lag faster than anyone thought possible.

And scientists need your help to test it out.

A research team from the University of Michigan and Yale University has released a free iPhone app that loads a complex, jet-lag conquering model right into your smartphone. You type in your current location and destination as well as what kind of light you will have access to, and the (free) app gives you a schedule of light exposure that should reset your internal clock in the most efficient way.

“These are the fastest schedules that have ever been proposed,” said Olivia Walch, a doctoral student at the University of Michigan who designed the app, called Entrain. “Our schedule takes what could be 12 days of adjusting down to four.”

Entrainment is the scientific term for fully adjusting to a new time zone — hence the app’s name.

The mathematical model was created by Daniel Forger, a biological mathematician who has been studying circadian clocks since the 1990s. A paper describing his research was published Thursday in the journal PLOS Computational Biology. The Entrain app was released the same day.

Forger acknowledges that the schedules his model spits out may sometimes seem counterintuitive, but intuition, he says, is not the point.

“We’re trying to move the science beyond your grandmother’s advice of ‘wake up late’ or ‘avoid carbohydrates’ to something that can be rigorously tested,” he said. “All I know is these schedules are optimal according to the mathematics.”

Forger spent 10 years building his model based on data collected from sleep studies done at Harvard and the University of Michigan. He had no idea what type of schedules the model would come up with when he first started, so he was pleasantly surprised that according to the math, the best way to beat jet lag is to adjust the time of your dawn and dusk each day.

“At first I thought the schedules would be a mess,” he said, “that they would tell people they need 500 watts at 5 o’clock and 1,000 watts at 5:10. But in fact, they just divide the day into a time when you get light and time when you should avoid light.”

For example, if you are traveling from New York to London, the app will tell you that upon arrival you should begin light at 7:58 a.m., and begin dark at 8:14 p.m. The following day, you expose yourself to light at 6:18 a.m. and avoid light at 7:53 p.m. On the third day, the app tells you to begin light at 6:01 a.m.

If you stick to the schedule, your circadian clock should be fully entrained 10 minutes later on the last day.

Even if you can’t stick to the proposed schedule, you can still use the app. You tell it what you did wrong, and the app recalculates the best way to get you over your jet lag.

If you’d like to help the researchers improve the model, you can choose to send your data back to the scientists at the University of Michigan at the end of the app’s suggested entrainment process.

“I’m confident that our model can reproduce data from published experiments, but what real people are doing outside of a sleep lab environment could be very different,” said Forger.

He added that while he has used the app successfully to decrease his jet-lagged time, he doesn’t think anyone should take that as an endorsement of it.

“Anecdotally I can say it helped me, but I’m biased,” he said. “Rather than saying this helped me or didn’t, let’s see what people are actually doing.”