1. Department of Health. Start Active, Stay Active: A report on physical activity for health from the four home countries' Chief Medical Officers. 2011.
2. Effect of physical inactivity on major non-communicable diseases worldwide: an analysis of burden of disease and life expectancy;IM Lee;Lancet,2012
3. Inadequate physical activity and health care expenditures in the United States;SA Carlson;Prog Cardiovasc Dis,2015
4. World Health Organisation. Global Recommendations on Physical Activity for Health. 2010 2010.
5. U.S. Department of Health & Human Services 2008 physical activity guidelines for Americans. Washington D.C. United States.