If you suffer from severe jet leg, it may be because your body overshoots as it attempts to adjust to large leaps forward in time, new research shows.

In order to help the body more easily adjust to time changes, travelers shouldn't advance more than four hours at a time, says a team from the University of Massachusetts in Amherst.

Based on their study of the circadian rhythms of rats, they say this approach enables the body's clock to advance smoothly and nudges the entire system in the right time direction.

"Jet lag isn't a horrible thing that we have to conquer -- and our clock is a very important regulator at a basic level," researcher Hava Siegelmann said in a prepared statement. "Medications to target the clock may be counter-productive if they affect future oscillatory behavior," she said.

"Instead, take a stopover if you are traveling for more than six hours -- relax for a day and then continue. Understand and go with your body's natural oscillations," Siegelmann advised.

The research also has implications for rotational shift workers, such as airline attendants and nurses, because the body has more difficulty adjusting to some shifts than others.

The study was published in the current issue of the Journal of Biological Rhythms.

• More articles on Jet Lag