Society today is faced with increasing incidences of poor physical and mental health,related to modern lifestyles that cannot be addressed by medicine alone.Contributing factors have been identified as an increasingly sedentary population,increasing levels of mental stress related to urban living and contemporary work practices,and hazardous city environments such as.noise and air-pollution.They contribute to public health problems,increased expenditures of the public health system,may lower productivity at work and increase work leave.