Physical activity has been defined by the World Health Organisation as "all movements in everyday life, including work, recreation, exercise and sporting activities". For an average sedentary adult, at least 30 minutes of cumulative moderate physical activity everyday or on most days of the week is sufficient to obtain health benefits.

Physical activity has major benefits to health. It reduces the risk of:
   Obesity
   Type 2 Diabetes
   Coronary Heart Disease
   Colon Cancer
   Osteoporosis
   Stroke
   Falls and Fractures
   Anxiety and Stress, and improves Mental Well-being

There are also indirect benefits of physical activity.  Active travel such as cycling and walking reduces traffic congestion and pollution and physically active children and young people are less inclined to become involved in crime and risk taking behaviour such as drugs, alcohol and smoking.

The likelihood of sedentary behaviour increases with age, being most common in those aged over 45.  There are no significant differences in sedentary levels for male or females, however more males than females tend to take above the recommended levels of physical activity.