Few studies have attempted to describe patterns of sedentary behavior among children and examine how these relate to patterns of physical activity. A group of 2,494 youth aged 11–15 years from the USA and UK completed a physical activity checklist. Low intercorrelations between sedentary behaviors suggest youth sedentariness is multifaceted and cannot be represented accurately by any one behavior such as TV viewing. Cluster analysis identified three groups of young people, differentiated by the level and type of sedentary behavior and physical activity. Physical activity and sedentary behavior are not two sides of the same coin. Further study should examine the health-related outcomes associated with sedentary behavior and the modifiable determinants of these behaviors among young people.
S.J. Marshall is with the Department of Exercise & Nutritional Sciences, San Diego State University, San Diego, CA; S.J.H. Biddle is with the British Heart Foundation National Centre for Physical Activity and Health, The School of Sport and Exercise Sciences, Loughborough University, Loughborough, UK; J.F. Sallis is with the Department of Psychology, T.L. McKenzie is with the Department of Exercise and Nutritional Sciences, and T.L. Conway is with the Graduate School of Public Health, San Diego State University, San Diego, CA.