3National Institutes of Health. Consensus Development Panel on Physical Activity and Cardiovascular Health. Journal of the American Medical Association 1996; 276: 241–6.
7 A Steptoe , J Wardle , R Fuller , A Holte , J Justo , R Sanderman , Leisure-time physical exercise: prevalence, attitudinal correlates, and behavioral correlates among young Europeans from 21 countries. Preventive Medicine 1997; 26: 845–54.
8 T Baranowski , C Anderson , C Carmack . Mediating variable framework in physical activity interventions. How are we doing? How might we do better? American Journal of Preventive Medicine 1998; 15: 266–97.
9 SG Trost , N Owen , AE Bauman , JF Sallis , W Brown . Correlates of adults' participation in physical activity: review and update. Medicine and Science in Sports and Exercise 2002; 34: 1996–2001.
10 N Humpel , N Owen , E Leslie . Environmental factors associated with adults' participation in physical activity: a review. American Journal of Preventive Medicine 2002; 22: 188–99.
11 BE Saelens , JF Sallis , LD Frank . Environmental correlates of walking and cycling: findings from the transportation, urban design, and planning literatures. Annals of Behavioral Medicine 2003; 25: 80–91.
12 N Owen , N Humpel , E Leslie , A Bauman , J Sallis . Understanding environmental influences on walking: review and research agenda. American Journal of Preventive Medicine 2004; 27: 67–76.
14 B Gilles-Corti , R Donovan . The relative influence of individual, social and physical environment determinants of physical activity. Social Science & Medicine 2002; 54: 1793–812.
15 J Sallis , M Johnson , K Calfas , S Caparosa , J Nichols . Assessing perceived physical environmental variables that may influence physical activity. Research Quarterly for Exercise and Sport 1997; 68: 345–51.
16 I De Bourdeaudhuij , J Sallis , B Saelens . Environmental correlates of physical activity in a sample of Belgian adults. American Journal of Health Promotion 2003; 18: 83–92.
17 D Stead . Relationships between land use, socioeconomic factors, and travel patterns in Britain. Environmental Planning B 2001; 28: 499–528.
18 I De Bourdeaudhuij , J Sallis . Relative contribution of psychological determinants to the prediction of physical activity in three population based samples. Preventive Medicine 2002; 34: 279–88.
22 BE Saelens , JF Sallis , JB Black , D Chen . Neighborhood-based differences in physical activity: an environment scale evaluation. American Journal of Public Health 2003; 93: 1552–8.
25 CL Craig , AL Marshall , M Sjostrom , AE Bauman , ML Booth , BE Ainsworth . International physical activity questionnaire: 12-country reliability and validity. Medicine and Science in Sports and Exercise 2003; 35: 1381–95.
26 I De Bourdeaudhuij , P Van Oost . A cluster-analytic approach toward physical activity and other health related behaviors. Medicine and Science in Sports and Exercise 1999; 31: 605–12.
27 G De Backer , M Kornitzer , J Sobolski , M Dramaix , S Degré , M de Marneffe , Physical activity and physical fitness levels of Belgian males aged 40–55 years. Cardiology 1981; 67 :110–28.
28 AR Folsom , TC Cook , JM Sprafka , GL Burke , SW Norsted , DR Jacobs . Differences in leisure-time physical activity levels between blacks and whites in population-based samples: the Minnesota Heart Survey. Journal of Behavioral Medicine 1991; 14: 1–9.
29 JM Jakicic , RR Wing , BA Butler , RW Jeffery . The relationship between presence of exercise equipment in the home and physical activity level. American Journal of Health Promotion 1997; 11: 363–5.
30 RC Brownson , EA Baker , RA Housemann , LK Brennan , SJ Bacak . Environmental and policy determinants of physical activity in the United States. American Journal of Public Health 2001; 91: 1995–2003.
31 EL Deci , RM Ryan . Intrinsic Motivation and Self-determination in Human Behaviour. New York: Plenum Press, 1985.
33 D Ingledew , D Markland , A Medley . Exercise motives and stages of change. Journal of Health Psychology 1998; 3: 477–89.
35 PF Coogan , MA Coogan . When worlds collide: observations on the integration of epidemiology and transportation behavioral analysis in the study of walking. American Journal of Health Promotion 2004; 19: 39–44.