This study was designed to examine the ability an endurance exercise training program to alter blood levels of cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides in children. Thirty-one sixth grade students age 10-12 years (20 girls, 11 boys) who were healthy and active volunteered for participation. The training program consisted of 13 weeks of aerobic activities three days a week, 25 minutes per session, with training intensity assessed by heart rate monitors. Serum lipids and maximal oxygen uptake (VO2max) were measured at the beginning of a control period, 13 weeks later at the beginning of the training program, and at the termination of 13 weeks of training. VO2max values for the group improved 5.4%, but no significant changes were observed in any of the blood lipid levels between the control and training periods. These findings suggest that aerobic training of 13-weeks duration is not an effective means of altering blood lipids in healthy normolipemic children.