From a New York Times online article:
At the moment, about two-thirds of Americans do not meet the standard exercise guidelines of about 30 minutes a day of moderate exercise, such as walking.
These findings might suggest that, if we adjusted our schedules and turned off the TV, phone or computer, most of us would have plenty of time to work out.
Almost all of the respondents — whatever their income, age, gender or ethnicity — reported about five hours a day of leisure time. Men tended to have more free time than women, older people more than the young, and African-American women the least of all. But no group reported less than about four and a half hours a day of free time.