High density lipoprotein(HDL) contains at least two types of lipoprotein particles which might have different physiologic roles: lipoprotein (Lp) A-I and Lp A-I: A-II. The influence of exercise on the response of serum apo A-I containing lipoprotein particles was investigated in 30 healthy young males after 10 weeks of physical training at a milittary base. 30 sedentary males matched for age, body mass index (BMI), nutrient intake and lipid values comprised the control group. Total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), HDL2-C, HDL3-C, low density lipoprotein cholesterol (LDL-C), triglycerides (TG), apolipoprotein (apo) A-I, apo B, Lp A-I and Lp A-I: A-II were studied before and after the exercise program in both groups. The exercise group showed a significant increase in HDL-C, HDL2-C, Lp A-I (p