Thirty-three sedentary individuals (males, n=24; females, n=9) were studied to see the effects of 15-20 weeks of endurance training by walking and jogging on high-density lipoprotein, serum total cholesterol, and serum triglyceride. The training group (also called the moderately trained group) was then compared to a sedentary group and a highly trained group (25+ miles/week) to see what affect, if any, the endurance training had on their lipoprotein profile.Even though maximal oxygen uptake increased and percent fat decreased in the moderately trained group, no favorable differences mere seen in HDL-cholesterol, HDL-cholesterol/total cholesterol, serum total cholesterol, or serum triglyceride when comparing this group with the sedentary group.Significant changes did exist between the moderately trained and the highly trained groups when comparing HDL-cholesterol, HDL-cholesterol/total cholesterol, and serum triglyceride values.It appears that 15-20 weeks of endurance training does in fact increase one Is fitness level, but more training at a higher intensity and/or longer duration is needed to produce favorable changes in the lipoprotein profile.