Most people do not exercise as much as they should. Every adult should accumulate 30 minutes or more of moderate-intensity physical activity on most, preferably all, days of the week.

The health benefits gained from increased physical activity depend on the initial physical fitness level. Beginners are expected to benefit most from increasing their activity to the recommended level.

If adults who lead inactive lives would adopt a more active lifestyle, there would be enormous benefit to the public's health and to individual well-being.

An active lifestyle does not require a regimented, vigorous exercise program. Instead, small changes that increase daily physical activity will enable individuals to reduce their risk of chronic disease and may contribute to enhanced quality of life.

In general, to enhance long-term participation in regular physical activity, several factors should be considered:

• The person, including gender, age, occupational status, health status, education, prior exercise experience

• The exercise programme, especially the intensity and type of activity.

• The environment, including the weather, community facilities, home-based programs, travel distances, time barriers, family and spousal support, employer and co-worker support, government, economic and public-policy support.