The transtheoretical model and physical activity adherence
The World Health Organization defi nes health as ‘a state of complete physical, mental and social well-being, and not merely the absence of disease’ (World Health Organization, 2006). Substantial evidence demonstrates that regular physical activity is an essential component of physical and psychological health (Physical Activity Guidelines Advisory Committee, 2008). Despite the obvious importance of physical activity, however, 60 per cent of the world’s population does not accumulate enough physical activity to attain the health benefi ts (World Health Organization, 2002). To achieve maximum individual and public health impact, however, recommended levels of physical activity must be attained early in life and maintained across the entire lifespan.