Start: Get into a pushup position with the tops of your feet and your shins on the ball and your hands on the floor.

Finish: Pull your knees close t your chest, letting the ball roll slightly forward keep your arms straight, and squeeze your abs hard at the top.

Start: Lie on your nondominant  side. Support your weight with that forearm and the outside edge of that foot. Your body should form a straight line from head to ankles.

Finish: Pull your abs in as far as you can, and hold this position for 10 to 30 seconds, breathing steadily. Relax. If you can do the entire 30 seconds, 1 rep is enough, If not try for any combination of reps that gets you u to 30 seconds Then repeat on your other side.

Start: Get into a modified pushup position with your weight on your forearms and toes. Your body should form a straight line from head to heels .

Finish: Pull your abs in as far as you can, and hold this position for 20 to 60 seconds, breathing steadily. Relax, If you can do the entire 60 seconds, 1 rep is enough, If not, try for any combination of reps that gets you up to 60 seconds.

Start: Get down on your hands and knees. Keeping  your back flat.

Finish: Take a deep breath, allowing your belly to pooch out. Then forcibly exhale and round your back like an angry cat as you lift your navel up toward your spine. When you can exhale no more, keep your back rounded and your navel in as you purse your lips and take shallow breaths through your nose for several seconds. That's  1 repetition; it should take 20 to 30 seconds. Inhale as you flatten your back to the starting position.

Start: Lie with your knees bent at 90 degrees so your thighs point toward the ceiling. Hold your hand behind your ears.

Finish: Pump your legs back and forth, bicycle-style, as you simultaneously rotate your torso from side to side by moving an armpit up toward the opposite knee.

Attach a rope handle to a high cable pulley and grasp it at both ends as you raise your arms overhead. Stand with a slightly staggered stance as you use your core muscles to go from a slightly extended spine to a slightly rounded back position. To do this, use your abdominals to pull your chest toward your pelvis. Pause for a second, then return the weight to the starting position.

Stand aside an adjustable cable station with the pulley set at about chest height. Reach across your body and grab the handle with the hand furthest away from the weight stack and then wrap the other hand over it. Keeping your knees bent and arms straight but not locked, use your core muscles to work the weight around in a wide, arching motion. When your arms are in a perpendicular line to the weight stack and the cable is in contact with your shoulder, pause for a second, then return the weight t the starting position.

Attach a rope handle to a high cable pulley, grab it with both hands, and stand with your right side facing the cable station and your feet shoulder-width apart. Hold the rope over your inside shoulder, as if you were about to swing. Pull the rope down and across your torso by bending and twisting at your waist so that it ends up on the far side of your outside calf. Pause at the bottom, then slowly straighten back to the starting position. Finish the repetitions on this side, then switch sides to complete the set.

Lie down on the floor in front of a low pulley and loop the ankle straps around your ankles. Keeping your knees bent about 90 degrees, use your abs to roll your hips back towards your chest. At the top of the movement your thighs should be close to your chest with your tailbone off the ground. Pause there for a second, lower, and repeat.

Attach the rope handle to a high pulley a kneel down facing the machine with your buttocks near your heels abut not resting on them. Holding the ropes at the sides of your head, crunch your rib cage toward your pelvis without moving any other part of your body. Pause when your elbows touch your knees, ten slowly return the weight to the starting position. You can also crunch down bringing one elbow to the opposite knee to involve the obliques more.

Attach a rope handle to a high pulley and stand with your back to the pulley with your neck between the ropes. Holding the handle to your chest, bend forward at the waist, rounding your back, and aim your chest toward your pelvis. Hold the contracted position for a second, then raise the weight back up and repeat.

Grab a pair of dumbbells and position yourself as if to do a set of pushups with your feet slightly wider than shoulder-width apart. Keeping your lower back flat and abs braced tight, row one dumbbell up by drawing your elbow past your torso, as you support your body weight on the other side. Pause at the top for a second, then lower and repeat with the other side. Try to keep your hips as still as possible the entire time you're rowing.

A much more advanced version of the Barbell Rollout. This time start on your feet instead of your knees and follow the same instructions as above.

Kneel on the ground holding a barbell with two small plates on the end of it with a shoulder-width grip. Keeping your back flat, allow the bar to roll out in front of you as you extend your arms and torso to follow it. Go out as far as you can without arching your back, then use your abdominals to drag the bar back to the starting position.

Stand holding a pair of dumbbells over your head with your knees slightly bent and arms straight, Begin by leaning to one side as far as you can, making sure that you keep the same distance between the two dumbbells. Avoid twisting your body as you do this. When you reach your lowest point, pause for a second before returning back to the starting position and repeating to the other side.

This time you simply reverse the movement by starting in the down position and chopping the weight in a wide arc upward until the weight is above one shoulder.

Stand with your feet shoulder-width apart and knees slightly bent holding a light dumbbell with both hands, with your arms outstretched over one shoulder. Begin by using your core muscles to "chop" the weight down across the front of your body in an arcing motion, finishing when your hands are outside your opposite leg midway between your knee and ankle. Pause for a second, then raise back up and repeat.

Sit on the floor with your knees bent and your feet flat. Hold a light dumbbell at arm's length in front of your chest. Lean back so your torso is at a 45-degree angle to the floor Twist to the left as far as you can, pause, then reverse your movement and twist all the way back to the right as far as you can.

Lie on your back with your knees bent and feet flat n the floor. Holding a dumbbell against your upper chest, begin by lifting your shoulder blades up off the floor. When you've gone as high as you can without your feet moving, pause for a second and then lower back down to the starting position.

Lie with your legs straight out on the floor and your arms straight in the air, fingers pointing toward the ceiling.

While contracting your abs, fold your body u by lifting your legs off the floor and stretching your arms toward your toes. Keep your back straight. Pause at your full extension, then return to the starting position.