Baseball performance takes a hit from jet lag—study

Professional baseball players who lose sleep due to jet lag may make more mistakes in the game, according to a study Monday.

The biggest negative effects were seen when players skipped just two or three time zones moving eastward, disrupting their body clock, said the study in the Proceedings of the National Academy of Sciences, a peer-reviewed US journal.

“The negative effects of jet lag we found are subtle, but they are detectable and significant,” said lead author Ravi Allada, a researcher at Northwestern University.

“And they happen on both offense and defense and for both home and away teams, often in surprising ways.”

For instance, players returning home after traveling were significantly more impaired on offense than those playing on the away team, said the report, based on data spanning 20 years and including more than 40,000 games.

Fewer stolen bases, and more hits into double plays were among the negative effects seen on offense.

On defense, both home and away teams suffered, as tired pitchers tended to give up more home runs.

“The effects are sufficiently large to erase the home field advantage,” said Allada, associate director of Northwestern University’s Center for Sleep and Circadian Biology.

The study was based on data from Major League Baseball from 1992 to 2011.

Allada said if he were a baseball manager who wanted to avoid the impact of jet lag on player performance, “I would send my first starting pitcher a day or two ahead, so he could adjust his clock to the local environment.”