In recent decades, due to changes in transportation, diet, lifestyle, technology and workplace practices, there has been a decline in physical activity and an increase in sedentary behaviours, typically commencing in teenagehood.
A. Keys Facts and Figures - In Australia 
The Australian Health Survey: Physical Activity 2011-2012, conducted by the Australian Bureau of Statistics found that:
Young People (5-17 years)
- Only one in ten young people undertake the recommended 60 minutes of physical activity per day;
- More than two-thirds of teenagers spend over two hours a day engaged in screen-based entertainment;
- Physical activity decreases and screen-based activity increases with increasing age through adolescence;
- For 15-17 year olds, 75% have some kind of screen-based media in their bedroom, and this is associated with them spending an extra 2 hours per week watching or playing screen-based media compared with teenagers who do not have such an item in their bedroom;
- On a pedometer study, only 7% of teenagers walk an average of 12,000 steps per day, compared with 22% of young children aged 5 to 8 years.
The Australian Health Survey: Physical Activity 2011-2012 also found that:
- 60% of Australian adults do less than the recommended 30 minutes of moderate intensity physical activity per day;
- Nearly 70% of Australian adults (i.e. almost 12 million adults) are either sedentary or have low levels of physical activity;
- Physical activity levels were related to a number of environmental and socio-economic conditions:
B. Economic Costs
Recent economic studies in Australia estimate that the direct healthcare costs due to physical inactivity exceed $1.5 billion annually .
C. Morbidity and Mortality
Worldwide, physical inactivity is the fourth leading risk factor for global mortality, contributing to 6% of deaths annually . It is the second leading modifiable health risk factor contributing to the burden of disease and injury in Australia (coming second to cigarette smoking) .
In Australia, physical inactivity is the fifth leading risk factor for mortality in men and the third leading risk factor for women . In 2003, physical inactivity accounted for approximately 6.6% of the disease burden in the Australian population .
Physical Inactivity is estimated to be the main cause for approximately 21-25% of breast and colon cancers, 27% of diabetes and approximately 30% of ischaemic heart disease burden .
 Department of Health. Physical Activity and Sedentary Behaviour:
Research and Statistics. Available from
 Econtech 2007. Economic modelling of the net costs associated with non-participation in sport and physical activity. Canberra: Econtech.
 WHO 2010. Global Recommendations on Physical Activity for Health. Geneva, WHO. Available from http:/whqlibdoc.who.int/publications/2010/9789241599979_eng.pdf
 Begg S, Vos T, Barker B, Stevenson C, Stanley L, Lopez AD, 2007. The burden of disease and injury in Australia 2003. PHE 82. Canberra: AIHW (Australian Institute of Health and Welfare).
 Australian Institute of Health and Welfare (AIHW); Physical Inactivity. Available from http://www.aihw.gov.au/risk-factors-physical-inactivity/
 Global Health Risks: mortality and burden of disease attributable to selected major risks. World Health Organisation 2009.