Build Muscle and Lose Fat
If your main goal is losing of fat while putting on muscle, try the following. Strength training should be done to get a better muscle to fat ratio and therefore improve metabolism. Use moderate weights at a fast training pace (very little rest between sets and exercises). You should lower your calorie intake (but not try to starve yourself) and should eat frequent but small high protein meals. Sugars, sweets and junk food should be eliminated from your diet. Engage daily in some activity like brisk walking, biking, etc., and try to increase the amount of time you spend each week.