MECHANISMS LINKING SEDENTARY BEHAVIOUR TO HEALTH OUTCOMES

A large and expanding body of literature demonstrates that excessive sedentary time is associated with multiple facets of health including all-cause and cardiovascular disease mortality. This chapter provides a detailed overview of the mechanisms that are the prime candidates driving such negative health outcomes. The extant literature suggests that such mechanisms can be divided into two broad categories including “direct mechanisms” and “indirect mechanisms”. The key direct mechanisms include metabolic dysfunction and inflammation. The key indirect mechanism is the displacement of physical activity with sedentary behaviour. This chapter also discusses the role of TV viewing (one prominent domain of sedentary behaviour), which is likely a proxy for multiple unhealthy behaviours, for example, the consumption of high energy-dense foods. There are multiple other mechanisms not discussed in this chapter that may be implicated, likely to a lesser extant, in the association between sedentary behaviour and health outcomes such as reduced cerebral blood flow. For the eager reader we provided references for relevant literature for further exploration at the end of the chapter.