Why are we failing to promote physical activity globally?

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.

Physical inactivity is a complex and multifactorial behaviour whose determinants vary across countries.^5,6 These determinants encompass individual factors, such as age and sex,⁷ as well as environmental,⁸ geopolitical and economic factors. Health-related and psychosocial factors, such as the presence of a chronic disease or poor self-efficacy, affect people’s ability to engage in regular physical activity.^9,10 A high crime rate, dense traffic and the absence of parks or sidewalks, to give some examples, can discourage people from exercising outdoors. On the other hand, most countries with a low prevalence of physical inactivity (i.e. < 20%)² are African and Asian countries whose economies are largely dependent on physically demanding labour (e.g. agriculture and mining).

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 WHO² 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?

Our persistent failure to promote physical activity throughout the world suggests that public campaigns and social recognition of the health benefits of a physically active lifestyle are not enough to change people’s behaviour. Nonetheless, public health campaigns for improving physical activity have centred almost exclusively around the message that physical inactivity and a sedentary lifestyle are harmful to health and that, conversely, adhering to the recommended levels of physical activity brings multiple health benefits. But health is only one among the many factors that can encourage participation in physical activity, and it does not appear to be the most important one.

Since health-based models have failed to promote physical activity to the extent necessary, we must shift the argument from the finality or utility of physical activity (i.e. promoting health) to what a person experiences when physically active. Preliminary data suggests that the association between physical activity and psychological well-being, for example, is not dependent on the level of the physical activity but on what the person experiences during exercise and afterwards.¹¹ Under this new approach, regular exercise would be presented as a challenging and potentially interesting activity with the flexibility of being adaptable to a person’s circumstances (rather than vice versa). Information on the health benefits of physical activity should be part of this new model, but not the central part. Physical activity guidelines would still provide a goal to be pursued by as many people as possible but would no longer constitute a mandatory goal for everyone, given many people’s inability to engage in moderate or vigorous physical activity for the recommended minimum of 150 minutes per week.

To be effective, this new proposed approach to the promotion of physical activity must be endorsed and disseminated by national and international health authorities, especially WHO. Since a dose–response relationship has been shown to exist between physical activity levels and several health outcomes, the best guideline for some – maybe most – people to follow might be that some activity, no matter how little, is better than none. Moreover, the health benefits of physical activity are maintained only with regular practice. Thus, to improve adherence to physical activity, health professionals should strengthen the health message with the more compelling argument that “physical activity makes life worth living”.