Physical activity interventions

Introduction Sedentary lifestyles are a global public health problem (World Health Organization (WHO), 2004). Those who are physically inactive have an increased risk of premature death and of developing major chronic diseases; including coronary heart disease, cancers and diabetes (Baumann, 2004). Physical activity (PA) refers to any bodily movement resulting in energy expenditure (Caspersen, 1989) and includes routine activities such as walking and housework, as well as structured exercise, sport and occupational activity. For general health benefits, it is recommended that adults accumulate a total of at least 30 minutes a day of at least moderate intensity PA on five or more days a week (Department of Health (DOH), 2004). Children are advised to accumulate at least 60 minutes of at least moderate intensity activity every day (DOH, 2004). Over the last 20 to 30 years PA levels have declined, largely due to a reduction in PA at work, in the home and as a means of transport (DOH, 2004). It is estimated that 60% to 85% of adults are insufficiently active to benefit their health and promoting PA is a priority for health policy in most developed nations (WHO, 2004). This chapter provides an overview of the application of psychological theory in PA interventions. Discussion is mostly restricted to adult populations as very few studies have examined the effect of psychologically-based interventions on PA levels in children (Lewis et al., 2002).