TY - JOUR T1 - Physical inactivity remains the greatest public health problem of the 21st century: evidence, improved methods and solutions using the ‘7 investments that work’ as a framework JF - British Journal of Sports Medicine JO - Br J Sports Med SP - 169 LP - 170 DO - 10.1136/bjsports-2013-093372 VL - 48 IS - 3 AU - Stewart G Trost AU - Steven N Blair AU - Karim M Khan Y1 - 2014/02/01 UR - http://bjsm.bmj.com/content/48/3/169.abstract N2 - In 2009, BJSM's first editorial argued that ‘Physical inactivity is the greatest public health problem of the 21st century’.1 The data supporting that claim have not yet been challenged. Now, 5 years after BJSM published its first dedicated ‘Physical Activity is Medicine’ theme issue (http://bjsm.bmj.com/content/43/1.toc) we are pleased to highlight 23 new contributions from six countries. This issue contains an analysis of the cost of physical inactivity from the US Centre for Diseases Control.2 We also report the cost-effectiveness of one particular physical activity intervention for adults.3 The essential framing document for this BJSM issue is ‘the 7 investments for Physical Activity’ from the International Society for Physical Activity and Health (ISPAH).4 The articles in this issue elaborate on these 7 evidence-based investments. We recommend anyone advocating for the public health benefits of physical activity to consider framing their argument in the multisector, multisystem approach concisely captured in the ‘7 investments that work’ document. There is no ‘magic bullet’ to alleviate physical inactivity so do not try to suggest one. There are seven proven, relatively easy to implement steps. Many jurisdictions are already implementing elements of the ‘7 investments’; the document was approved by the WHO5 and cited by … ER -