Regular physical activity yields benefits to men and women of all ages. The risk of premature death is reduced, as is that of incurring or dying of ischaemic heart disease. These benefits are attainable with only moderate physical activity, such as a 30-minute daily walk, though a "dose-dependent" relationship exists between physical activity and health benefits: "Some exercise is better than none, and more is better than less". Both the World Health Organisation, and the National Institutes of Health in the USA, for example, recommend that clinicians should counsel all patients to enroll in some programme of regular physical activity tailored to suit their health status and personal life-style.