title: Environmental and policy interventions to promote physical activity.
abstract: BACKGROUND
  Because most adults in industrialized countries do not meet physical activity guidelines, population-wide interventions are needed. Environmental and policy interventions are based on ecological models of behavior and have the potential to influence entire populations. Ecological models are particularly applicable to physical activity because the behavior must be done in specific physical settings. Cross-sectional data indicate that environmental and policy variables are associated with physical activity behaviors of young people and adults.
  
  
  METHODS
  Seven published evaluations of environmental and policy interventions to increase physical activity were reviewed.
  
  
  RESULTS
  Two studies showed that placing signs encouraging stair use can be effective. Quasi-experimental evaluations provided limited evidence that broad environmental changes can be effective. Large-scale policy interventions are currently being conducted in several countries. PROPOSED MODEL: A model describing the development of policy and environmental interventions is proposed, in the hope of stimulating more research in this area. Advocacy or planning groups identify and work with agencies that control policies and environments that can be altered to increase physical activity. Educational and policy/environmental interventions are seen as complementary.
  
  
  CONCLUSIONS
  Lack of conceptual models and the inherent difficulties of evaluation have hampered research on environmental and policy interventions. Further research is needed, and practitioners and researchers should work together to evaluate programs.
authors.affiliation: Department of Psychology, San Diego State University, California 92120, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Sallis
authors.forename: A
authors.initials: A
authors.lastname: Bauman
authors.forename: M
authors.initials: M
authors.lastname: Pratt
mesh_terms: D000328:Adult; D004463:Ecology; D015444:Exercise; D005260:Female; D005500:Follow-Up Studies; D015438:Health Behavior; D006266:Health Education; D006293:Health Promotion; D006801:Humans; D007899:Leisure Activities; D008962:Models, Theoretical; D009517:New South Wales; D011634:Public Health; D011640:Public Policy; D016032:Randomized Controlled Trials as Topic; D012931:Social Environment; D013690:Television; D013997:Time Factors; D014481:United States; D016138:Walking; D017132:Workplace