95 Adapted Physical Activity Quarterly, 2008, 25, 95-117 © 2008 Human Kinetics, Inc. Georgia C. Frey is with the Department of Kinesiology at Indiana University in Bloomington. E-mail: gfrey@indiana.edu. Heidi I. Stanish is with the Department of Exercise and Health Sciences at the University of Massachusetts in Boston. Viviene A. Temple is with the School of Exercise Sciences, Physical and Health Education at the University of Victoria, BC Canada. Physical Activity of Youth With Intellectual Disability: Review and Research Agenda Georgia C. Frey Indiana University Heidi I. Stanish Viviene A. Temple University of Massachusetts University of Victoria This review characterizes physical activity behavior in youth with intellectual dis- ability (ID) and identifies limitations in the published research. Keyword searches were used to identify articles from MEDLINE, EBSCOhost Research Databases, Psych Articles, Health Source, and SPORT Discus, and ProQuest Dissertations and Theses up to June 2007. Data were extracted from each study using a template of key items that included participant population, study design, data source, and outcome measure. Nineteen manuscripts met the inclusion criteria. Findings were mixed, with various studies indicating that youth with ID have lower, similar, and higher physical activity levels than peers without disabilities. Only two studies provided enough information to determine that some youth with ID were meet- ing minimum physical activity standards. Significant methodological limitations prohibit clear conclusions regarding physical activity in youth with ID. It is recommended that all children accumulate at least 30–60 min of physi- cal activity on all or most days of the week, including 10–15 min of continuous, moderate to vigorous activity. Adolescents should also be active daily or almost daily and engage in ≥ 20 min of continuous, moderate to vigorous activity at least three times per week (U.S. Department of Health and Human Services, USDHHS, 2000a). The data suggest that youth are generally not meeting these basic physical activity guidelines, and this is a likely contributor to the precipitous rise in childhood obesity over the last 20 years (USDHHS, 2000a). While there is extensive research on the physical activity behaviors, patterns, and determinants in youth without dis- abilities, similar data on those with intellectual disability (ID) are lacking. Fernhall and Unnithan (2002) conducted a review of physical activity research in youth with ID and concluded that the majority of work in this area addresses physical work capacity (i.e., fitness) and there is scant information on physical activity. The presence of health disparities in adults with ID is well documented (Sutherland, RESEARCH