In fact, for only about 16 to 20 times a season did teams have to travel three time zones and then promptly play a game, Winter said.
In a bit of a surprise, the researchers also found that teams traveling east to west suffered the most. Normally, people think west-to-east travel is most disruptive to their bodies.
Winter speculated that east-to-west travel may leave baseball players at less than their daily physical peak during games. "Their peak is not matching up to when they're being asked to perform," he said.
Dr. Robert Vorona, assistant professor of sleep medicine at Eastern Virginia Medical School, said jet lag disrupts the connection "between our internal rhythms and the external environment, because the body cannot shift that quickly."
However, an estimated one-third of people don't suffer from jet lag, so a team with more of these types of people could adapt more quickly to travel, he said.
Winter said it's not likely that baseball teams will ever get a week off between games, like professional football teams. But more recovery time after coast-to-coast trips would be helpful, he said.
As for the supposed advantage for West Coast teams, Winter said he wasn't sure why they haven't done better. "Why they're not winning more World Series, I don't know," he said. "Payroll, I guess."
Learn more about jet lag from the U.S. Centers for Disease Control and Prevention.
SOURCES: W. Christopher Winter, M.D., medical director, Sleep Medicine Center, Martha Jefferson Hospital, Charlottesville, Va.; Robert Vorona, M.D., assistant professor, sleep medicine, Eastern Virginia Medical School, Norfolk; June 10, 2008, Sleep 2008,
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