Physical inactivity is one of the most common and persistent contributors to poor health in the world. It is defined as the failure to achieve the minimum recommended physical activity, which is, for adults, 150 minutes of moderate aerobic exercise or 75 minutes of vigorous aerobic exercise per week, or an equivalent combination. ¹ In 72 of the 159 countries for which data on physical inactivity were available in 2008 (i.e. 59%), ² its population prevalence that year exceeded 30%, and in two of the regions of the World Health Organization (WHO) – the Americas and the Eastern Mediterranean – prevalence exceeded 40%. According to WHO estimates, physical inactivity is the world’s fourth leading risk factor for death. ¹ In 2002, physical inactivity was estimated to have led to 1.9 million deaths globally and to have accounted for 19 million disability-adjusted life years (DALYs). ³ Currently, physical inactivity is estimated to account for an annual average of around 3.2 million deaths and more than 69 million DALYs. ⁴ This represents an increase of 68.4% in the number of deaths and a 3.6-fold increase in the number of DALYs in just over one decade.