7. Russian Twist

Instructions: Sit on a decline bench, with your legs firmly under the pads. Lean back slightly, so that your thighs and torso form a 90-degree angle. Extend your arms in front of you, so that they also form a 90-degree angle with your torso, and, while keeping your back straight, cross your arms over your chest or clasp them together in front of you. With your abs flexed, move as far as you can from right to left and left to right, and do the motion as quickly as you can without jerking or sacrificing proper form. Work your way up to 60 seconds of continuous movement. Feel free to wince.