How many adults and children bicycle regularly in the U.S.?
According to the Statistical Abstract of the United States, in 2008 (the latest data available), 44,707,000 people said they participated in bike riding at least six times during the year. Of those, 18,052,000 were children (ages 7-17) and 26,6550,000 were adults (18+).
According to the Abstract, bike riding was the sixth most popular recreational activity for Americans, trailing only exercise walking, swimming, working out with weights, bowling, and camping.
—The Fact Monster