1. NICE. Four Commonly used methods to increase physical activity. National Institute for Health and Clinical Excellence. 2006. http://www.nice.org.uk/nicemedia/pdf/PHYSICAL-ALS2_FINAL.pdf (accessed 8 Jul 2012).
2. Physical inactivity: the biggest public health problem of the 21st century;Blair;Br J Sports Med,2009
3. As different as Venus from Mars: time to distinguish efficacy (can it work?) from effectiveness (does it work?);Khan;Br J Sports Med,2011
4. Chief Medical Officers of England, Scotland, Wales and Northern Ireland. Start active, stay active 2011. http://www.dh.gov.uk/en/Publicationsandstatistics/Publications/PublicationsPolicyAndGuidance (accessed 6 Jul 2012).