Core training targets the muscles deep within the abdomen which connect to the spine, pelvis and shoulders, which assist in the maintenance of good posture. Some core exercises include Crunches, Oblique Crunches, and The Plank. Oblique Plank, Static Leg and Back, Dynamic Leg and Back, Hamstring Raises, 'Superman', Held Straight Legs, Controlled Lowering and Raising of Legs, and Leg Extensions. Equipment such as barbells and stability balls can be used to help you achieve those gains.