Journal of Behavioral Medicine, Vol. 30, No. 2, April 2007 ( C  2007) DOI: 10.1007/s10865-006-9091-2 The Relationship between Vigorous Physical Activity and Juvenile Delinquency: A Mediating Role for Self-Esteem? Guy E. J. Faulkner, 1,6 Edward M. Adlaf, 2,3 Hyacinth M. Irving, 2 Kenneth R. Allison, 2 John J. M. Dwyer, 4,5 and Jack Goodman 1 Accepted for publication: November 22, 2006 Published online: February 1, 2007 Many policy-related reviews of the potential social value of sport and physical activity list the prevention of juvenile delinquency. We examined the relationships among vigorous physical activity, self-esteem, and delinquent behavior among adolescents in a large cross-sectional survey of Ontario adolescents. Data are based on questionnaires from 3,796 students (range 11–20 years) derived from the 2005 Ontario Student Drug Use Survey. Negative binomi- nal regression methods were used to estimate both additive and interactive models predict- ing delinquent behavior. Vigorous physical activity was positively associated with delinquent behavior; however, this pattern of association was observed only among male adolescents. There was no evidence of a mediating role for self-esteem. Our findings suggest that physical activity is not the solution for reducing juvenile delinquency. KEY WORDS: delinquency; adolescence; physical activity; self-esteem. INTRODUCTION The psychological and physical benefits of phys- ical activity have been the primary focus of research efforts in the field of physical activity and health. The impact of physical activity on social outcomes, which by their nature may be difficult to delineate, has been less explored although social and moral development has traditionally been associated with physical educa- tion and sport. One way to explore this relationship in adolescents is to examine delinquent behavior (Mutrie and Parfitt, 1998). Many policy-related re- 1 Faculty of Physical Education and Health University of Toronto, Toronto, ON, Canada. 2 Department of Public Health Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada. 3 Centre for Addiction and Mental Health, Toronto, ON, Canada. 4 Department of Family Relations and Applied Nutrition, College of Social and Applied Human Sciences, University of Guelph, Guelph, ON, Canada. 5 Public Health Research, Education and Development Program, Public Health Services, Hamilton, ON, Canada. 6 To whom correspondence should be addressed at University of Toronto, Faculty of Physical Education and Health, University of Toronto, 55 Harbord Street, Toronto, Ontario, M5S 2W6, Canada; e-mail: guy.faulkner@utoronto.ca. views of the potential social value of sport and physi- cal activity list the prevention of juvenile delinquency as an issue to which these activities can make a con- tribution. For example, sport and physical activity are seen as vehicles of social policy aimed at reducing delinquency among young people in the UK (e.g., DCMS/Strategy Unit, 2002). Public Health Agency of Canada (2005) states that problems of juvenile delinquency can decrease when appropriate physical activity programs are available, and in Australia, sport and physical activities can facilitate personal and social development and may have crime pre- vention potential with careful planning (Australian Institute of Criminology, 2000, 2003). These claims could be interpreted as overly opti- mistic given that equivocal evidence exists to support them. For example, participation in sport has not been found to deter delinquency in one longitudinal cohort of 876 New Zealand adolescents (Begg et al., 1996). Another longitudinal study of 477 Norwegian boys aged 11 to 13 years found that participation in power sports (e.g., boxing, weightlifting, wrestling, and martial arts) led to an increase in antisocial behaviors in the form of elevated levels of violent and non-violent behaviors outside of the sport 155 0160-7715/07/0400-0155/0 C  2007 Springer Science+Business Media, LLC