Abstract
Over the last decade, the quantity and quality of scientific literature examining the relationship between physical activity (PA) and cardiovascular diseases (CVD) have significantly increased. Data from the literature now unequivocally show that physical inactivity is one of the major risk factors for CVD. It is believed that obesity, the prevalence of which has tripled over the last three decades, and physical inactivity among children are the main factors that will increase the prevalence of CVD in this century. The cardiovascular benefits of exercise are multifactorial and include important systemic effects on skeletal muscle, the peripheral vasculature, metabolism, and neurohumoral systems, as well as beneficial alterations within the myocardium itself. Thus, exercise does much more than change traditional risk factors, such as blood pressure, blood lipids, glucose tolerance and insulin resistance, metabolic syndrome, and overweight and obesity. Evidence from epidemiologic studies suggests that the preventive effects of PA may be achieved by 150 minutes of moderate PA a week, while increases in the intensity and volume of exercise lead to further health benefits. This dose–response gradient is curvilinear, with the largest gains from the first hour of weekly exercise. However, although much progress has been made in this field, existing studies performed on human subjects do not clearly show what type, intensity, and duration of exercise is most beneficial to cardiovascular fitness and metabolic optimization. Animal-based exercise studies may provide more information and help to elucidate the abilities of different training regimens to reduce the risk of CVD.