This thesis examines the influence of moderate exercise, attainable by a large percentage of the population, on lipoprotein metabolism in the fasted and postprandial states in normolipidaemic subjects. A cross-sectional study in middle-aged men and women (endurance athletes, recreational exercisers and sedentary controls) revealed that the more favourable fasted blood lipid profiles found in athletes were also apparent in recreational exercisers, with higher high density lipoprotein (HDL) cholesterol concentrations in female (1.94 v 1.57 mmol.l-1, p < 0.05), but not male (1.50 v 1.34 mmol.l-1 NS), recreational exercisers than sedentary controls. HDLz cholesterol concentrations were higher in both male (26%, p < 0.05) and female (42%, p < 0.01) recreational exercisers than controls.