Prevalence of physical inactivity and its relation to social class in US adults: results from the Third National Health and Nutrition Examination Survey, 1988-1994

Purpose: This study examines the prevalence of physical inactivity during l eisure time in a national representative sample of U.S. adults. Methods: Da ta were obtained from the Third National Health and Nutrition Examination S urvey, conducted between 1988 and 1994. A total of 18,825 adults aged 20 yr and older participated in a home interview where information about physica l activity, education, income, occupation, employment, and labor force part icipation was obtained. Results: The prevalence of physical inactivity amon g U.S. adults was 23%, with more women (28%) than men (17%) reporting being inactive during their leisure time. Additionally, inactivity is more commo n among in social class such as persons who are less educated, living below the poverty line, living in households with income below 20,000 dollars, a nd who are retired. In every category of social class, women experienced a higher prevalence of physical inactivity than men. Conclusions: We conclude that social class is associated with physical inactivity and that more res earch is needed to better understand the effect that other social and envir onmental factors have on sedentary behaviors in our society.