Effects of an anaerobic exercise program on serum lipids and lipoproteins in sedentary male subjects were studied for 12 weeks. No dietary changes were made, and individuals were encouraged to maintain their body weight. Increase in lean body weight, decrease in percent body fat, and unchanged total body weight occurred in subjects participating in the resistive weight training program, while the men's serum cholesterol and low-density lipoprotein-cholesterol decreased and their high-density lipoprotein-cholesterol increased. Lipid profile improvements were attributed to exercise.