Ever wonder why major league baseball players sometimes slump? Studies show the culprit might be simple jet lag. Time-zone trauma can wipe out home-field advantage, make pitchers give up runs, and silence a team’s bats.
Travelers have long known about the fatigue, poor sleep, and other effects of having their body clocks out of whack. Those symptoms make up the condition nicknamed “jet lag.” Professional athletes are no different. A new study released by the Proceedings of the National Academy of Sciences helps document the phenomenon.
Dr. Ravi Allada of Northwestern University says he and his colleagues analyzed the effects of body-clock disruptions on human performance. They studied baseball—a sport with hundreds of games per year. Because of tight schedules, ballplayers usually don’t get to settle in to new time zones when they travel.
Researchers looked at 20 years of Major League Baseball data. The large sample size helped make the study reliable. They found 4,919 instances of teams taking the field after crossing two or three time zones without enough time to adjust. (People need about a day of adjustment for each time zone crossed.)
Results generally showed that traveling eastward causes more problems than going west. That’s a known feature of jet lag, because the traveler “loses” hours by moving eastward. Surprisingly, teams were more bothered by jet lag at home than when they played away.
Studies showed that teams won about 54% of games played at home. That’s a 4% home advantage. But when east-traveling jet-lagged home teams played away teams without jet lag, that edge vanished.
Here are some other findings:
—After traveling east, jet-lagged home teams hit fewer doubles and triples, stole fewer bases, and grounded into more double plays than when they weren’t affected.
—Eastward traveling pitchers allowed more home runs, both at home and away: roughly one home run every 10 games.
Researchers can’t explain why jet lag hampers teams more at home than elsewhere. They suggest that the structured on-the-road schedule may actually benefit players.
Those researchers also suggest a way to help pitchers of distant away games: Send them a few days ahead of the team.
Ballplayers know jet lag is a problem. The Major League Baseball Players Association has made changes in scheduling rules starting next year. For example, each team’s 162-game regular season schedule will be played over 187 days—up from 183.
Athletes and fans have always believed in the home-field advantage. Now science shows why sometimes the home crowd just isn’t enough.
