Two years after leaving compulsory education young people are more likely to be involved in physical activity if they live in an environment where it is the norm

Cardiovascular diseases, including coronary heart disease (CHD), are together the leading cause of death in the UK (Department of Health 1992; Smith and Jacobson 1987). Contributory risk factors include dietary factors, hypertension, obesity, smoking and physical inactivity. The American College of Sports Medicine (1986) has issued standard guidelines to adults concerning the level of physical activity necessary to minimise the risk of CHD. The advice was to follow a 20-minute session of aerobic activity for a minimum of three times a week at a sufficient intensity to produce an increase in heart rate, respiration and perspiration. Alternatively, short bursts of high intensity activity several times a day (such as brisk walking or stair climbing) has been recommended (Pert 1997).