Gloria Mark and Stephen Voida of the University of California, Irvine, and U.S. Army senior research scientist Armand Cardello said the research involved civilian employees who must use computers at the Army's Natick Soldier Systems Center outside Boston, who wore heart monitors for the study.
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 said.
People with e-mail switched windows an average of 37 times per hour, while those without e-mail changed screens half as often -- about 18 times in an hour, the researchers said.
"Other research has shown that people with steady 'high alert' heart rates have more cortisol, a hormone linked to stress. Stress on the job, in turn, has been linked to a variety of health problems," Mark said in a statement.
In addition, "participants loved being without e-mail, especially if their manager said it was OK. In general, they were much happier to interact in person."
The team presented the findings at the Association for Computing Machinery's Computer-Human Interaction Conference in Austin, Texas.