World 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 - for adults 150 minutes of moderate aerobic exercise or 75 minutes of vigorous aerobic exercise per week, or an equivalent combination.

In 72 of the 159 countries for which data on physical inactivity were available in 2008 (i.e. 59%), 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.

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).  Currently, physical inactivity is estimated to account for an annual average of around 3.2 million deaths and more than 69 million DALYs. 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.

Rates of physical inactivity throughout the world suggest that we are failing to promote regular physical activity effectively. The reason does not lie in a lack of social recognition of the importance of physical activity or in a failure to address the issue on the part of policy-makers and public health agencies. Indeed, how best to promote regular physical activity has been hotly discussed for decades, and public health authorities and WHO have long waged a battle against physical inactivity through public health campaigns and various interventions that have focused on the benefits of physical activity for the prevention of noncommunicable diseases.

Health professionals have endeavoured to keep people physically active by highlighting the many ways in which engaging in physical activity at the recommended levels promotes health. Despite all these efforts, however, physical inactivity remains an important contributor to poor health throughout the world. But why? Are messages that underscore the health benefits of physical activity not the most effective way to motivate people to exercise regularly?

Download or read the full editorial from Philipe de Souto Barreto online (World Health Organisation).