1. U.S. Department of Health and Human Services Physical Activity and Health: a report of the surgeon general. Atlanta GA: U.S. Department of Health and Human services, Center for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, 1996.
2. World Health Organisation. Diet, nutrition and the prevention of chronic diseases. Joint WHO/FAO expert consultation. WHO technical report series no. 916. Geneva: WHO, 2003.
3. Kriska AM, Caspersen CJ. Introduction to a collection of physical activity questionnaires. Med Sci Sports Exerc 1997;29:S5–9.
4. Sjöström M, Ekelund U, Yngve A. Assessment of physical activity. In: Gibney MJ, Arab L, Margetts B, editors. Public health nutrition. United Kingdom: Nutrition Society, Blackwell Publishing; 2004. p. 83–105.
5. Sallis JF, Saelens BE. Assessment of physical activity by self-report: status, limitations, and future directions. Res Q Exerc Sport 2000;71:S1–14.