Stand with dumbbells grasped to sides. Extend one leg back on forefoot. Lower body on other leg by flexing knee and hip of front leg until knee of rear leg is almost in contact with floor. Return to original standing position by extending the hip and knee of the forward leg. Repeat by alternating lunge with opposite leg. Keep torso upright during lunge; flexible hip flexors are important. A long lunge emphasizes the Gluteus Maximus; a short lunge emphasizes Quadriceps. The forward lunge is done in the same manner by extending the leg forward instead of to the rear.