1. World Health Organization Physical activity, Fact sheet. Updated February 2017. http://www.who.int/mediacentre/factsheets/fs385/en/ (accessed 10 Jul 2017).
2. Department of Health (2011) Start active, stay active: a report on physical activity from the four home countries’ Chief Medical Officers (DH, London) https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/216370/dh_128210.pdf (accessed 10 Jul 2017).
3. Scholes S Mindell J (2013) Physical activity in adults (Health and Social Care Information Centre), Health Survey for England 2012. Volume 1: Chapter 2. http://content.digital.nhs.uk/catalogue/PUB13218/HSE2012-Ch2-Phys-act-adults.pdf (accessed 21 Jul 2017).
4. Craig R Fuller E Mindell J Health and Social Care Information Centre , eds (2015) Health Survey for England, 2014 (NS) (HSCIC, London) http://content.digital.nhs.uk/catalogue/PUB19295 (accessed 10 Jul 2017).
5. Effect of physical inactivity on major non-communicable diseases worldwide: an analysis of burden of disease and life expectancy