Moderate or vigorous exercise? Which best helps prolong life?

Abstract

Introduction The vigorous reversal of major cardiovascular risk factors has led to much improvement in cardiovascular morbidity in the last few decades. This is owed to the powerful pharmacological agents with which we can obtain correction of atherogenic plasma lipid patterns, adequate control of raised blood pressure and improvement in coagulation abnormalities. However, in spite of the strong epidemiological evidence, little attention has been addressed to sympathetic overactivity as a risk factor for cardiovascular events either in normal or hypertensive individuals. Subjects with sympathetic predominance often exhibit several other risk factors for atherosclerosis such as overweight, metabolic disturbances, and high haematocrit [1], a condition that is related to an increased risk of myocardial infarction, stroke, and cardiovascular mortality [2]. Indeed, available evidence indicates that, in spite of efforts provided by institutions and health services to implement effective strategies for improving the cardiovascular risk profile in both the primary and secondary prevention settings, the prevalence of major risk factors remains high in industrialised countries [3,4]. This calls for improvement of unhealthy lifestyle, a condition that has frequently been observed in hypertensive patients with heightened sympathetic tone. Besides reducing the consumption of tobacco, alcohol and caffeinated beverages, effort should be put in promoting a programme of regular physical activity. Regular endurance exercise causes a reduction in sympathetic tone with beneficial effects on heart rate, blood pressure and the other components of the metabolic syndrome [2,5,6]. Adoption of an exercise programme could revert to normal mild elevations of blood pressure and improve the metabolic profile. The value of regular physical activity in preventing the development of coronary artery disease and other chronic diseases has been demonstrated in many studies [7,8] and the importance of exercise for health has been stressed in the documents of several Scientific Societies [9,10]. Although this approach