Researchers from the University of California, Irvine, and the U.S. Army conducted a study in which heart rate monitors were attached to computer users in a suburban office setting, while software sensors detected how often they switched between on-screen windows.
People who read e-mail changed screens twice as often and were in a steady "high alert" state, with constant elevated heart rates, a UC Irvine release reported Friday.
Participants who were then removed from e-mail for five days experienced more natural, variable heart rates, the researchers said.
"We found that when you remove e-mail from workers' lives, they multitask less and experience less stress," UC Irvine informatics Professor Gloria Mark said.
The study was funded by the Army and the National Science Foundation and involved computer-dependent civilian employees at the Army's Natick Soldier Systems Center outside Boston.
People with e-mail switched windows an average of 37 times per hour, the study found, while those without changed screens half as often, about 18 times in an hour.
Those with no e-mail reported feeling better able to do their jobs and stay on task, with fewer stressful and time-wasting interruptions.
Mark suggested controlling e-mail login times, batching messages or other strategies might be helpful.
"E-mail vacations on the job may be a good idea," she said. "We need to experiment with that."