According the the Harvard Business Blog:
U.S. workers’ leisure time shrank 20% last year, down from an average of 20 hours a week in 2007 to an average of 16 hours in 2008. During the same period, their average work week increased by 1 hour. Why the 3-hour discrepancy? Researchers at Harris Interactive speculate that stressed-out employees are spending more time at home checking their email and thinking about work – that’s not exactly work, but it certainly isn’t leisure, either.
SOURCE: Harris Interactive