MUSCLES ENGAGED Abdominals The abdominal muscles (abs) provide movement and support to your core area. The deeper and closer to the spine the particular abdominal muscle is, the more effect over body posture it will have, and this often contributes significantly to a healthy back. Equipment Used Weighted Bar The weighted fitness bar is a simple, one piece solid steel bar encased in high quality easy grip rubber for a secure and comfortable grip. The weighted bar can be used for a variety of exercises and is used in personal training, physical therapy, and home workouts. Exercise Instructions Step 1 Start on your back with the weighted bar in your hands held over your head and both legs straight. Step 2 Lift both legs off of the floor and crunch up towards your ankles. Fully contract your abs at the top of the crunch. Step 3 Lower the weighted bar back down to the floor. Keep your core engaged and make sure your back doesn't arc off of the mat.