Barbell Good Mornings primarily target the spinal erectors (lower back muscles), hamstrings (back of thighs), and glutes (buttocks). Place a barbell across your upper back, hinge at the hips while keeping a slight bend in the knees, and lean forward until your torso is nearly parallel to the floor. Slowly return to the starting position. This exercise improves lower-back strength, hamstring flexibility, and overall posterior-chain development while emphasizing controlled form.