Physical activity is defined by the World Health Organisation as all movements in everyday life, including work, recreation, exercise and sporting activities. It can be structured or unstructured, planned or incidental. Research indicates that significant health benefits can be achieved by including a moderate amount of physical activity (30 minutes) 5 days a week. Physical activity is ranked second only to tobacco control in being the most important factor in health promotion and disease prevention in Australia. Data from the 2000 National Physical Activity Survey showed that over 7 million Australians aged 18-75 years (54%) did not undertake sufficient physical activity to obtain a health benefit. Over 2 million of these (15% of people aged 18-75 years) were sedentary, that is they did no physical activity in their leisure time. The health, social and economic costs of physical inactivity are incalculable. In light of the obesity and diabetes epidemics and an increasingly sedentary lifestyle, what can Australians do to maximise their physical activity and thereby minimise their exposure to ill health?