Fitness and Muscle Work

The long arm crunch is ranked the 6th most effective ab exercise, changing the traditional floor crunch by straightening the arms behind you. This adds a longer lever to the move, adding a bit more challenge and difficulty. This move also emphasizes the upper part of the abs, although it's important to remember that your rectus abdominis is actually one long muscle that travels from your lower chest to your pelvis. While you can emphasize one part, any exercise you do will work the entire muscle. Directions Lie on a mat and extend the arms straight out behind the head with hands clasped, keeping the arms next to the ears. Contract the abs and lift the shoulder blades off the floor. Keep the arms straight and avoid straining the neck. If you feel neck pain, take one hand behind the head while keeping the other arm extended. Lower and repeat for 1-3 sets of 12-16 reps.  source: about.com

The Torso Track comes out as number 5 for effective ab exercises, but this is one of my least favorite exercises because it can cause lower-back pain, particularly if you roll out too far. In fact, in the ACE study, researchers found that a significant number of subjects reported lower-back pain, so you may want to skip the expense, and discomfort, of this one and choose other exercises that can target the abs with equal effectiveness. Directions Grip the handles of the Torso Track and pull the abs in without holding your breath (as though bracing them). Exhale and glide forward as far as you comfortably can. If you collapse in the middle and feel it in your back, you've gone too far. Contract the abs to pull your body back. Add tension by using more tension chords.

The vertical leg crunch is another effective move for the rectus abdominis and the obliques. Directions Lie on the floor and extend the legs straight up with knees crossed. You can place your hands on the floor for support. Contract the abs to lift the shoulder blades off the floor, as though reaching your chest towards your feet. Keep the legs in a fixed position and imagine bringing your belly button towards your spine at the top of the movement. Lower and repeat for 1-3 sets of 12-16 reps.  source : about.com

The exercise ball is an excellent tool to strengthen the abs and is the third most effective move for targeting the rectus abdominis. What makes this move a bit more effective than crunches on the floor is that the legs are often involved in floor crunches. On the ball, the abs do more work. Directions Lie on the ball, positioning it under the lower back. Cross your arms over the chest or place them behind your head. Contract your abs to lift your torso off the ball, pulling the bottom of your ribcage down toward your hips. As you curl up, keep the ball stable (i.e., the ball shouldn't roll). Lower back down, getting a stretch in the abs, and repeat for 1-3 sets of 12-16 reps. source: about.com

The captain's chair leg raise is the second most effective move for the rectus abdominis as well as the obliques. You can do a variety of exercises on the captain's chair, which is a rack with padded arms that allows your legs to hang free and can be found in most health clubs and gyms. The key to keeping this move safe and effective is, first, to avoid swinging the legs or using momentum to bring the legs up. Second, keeping the knees bent will help you focus more on the abdominals and less on the hip flexors. Directions: Stand on the chair and grip handholds to stabilize your upper body. Press your back against the pad and contract the abs to raise the legs and lift knees towards your chest. Don't arch the back or swing the legs up. Slowly lower back down and repeat for 1-3 sets of 12-16 reps. source: about.com

The most effective ab exercises start with the bicycle, which is the best move for targeting the rectus abdominis (the 'six pack') and the obliques (the waist), according to the study. Direction Lie flat on the floor with your lower back pressed to the ground. Put your hands beside your head. Bring knees up to about 45- degree angle and slowly go through a bicycle pedal motion. Touch your left elbow to your right knee, then your right elbow to your left knee. Keep even, relaxed breathing throughout. Lie on the floor and lace your fingers behind your head. Bring the knees in towards the chest and lift the shoulder blades off the floor without pulling on the neck. Straighten the left leg out while simultaneously turning the upper body to the right, taking the left elbow towards the right knee. Switch sides, bringing the right elbow towards the left knee. Continue alternating sides in a 'pedaling' motion for 1-3 sets of 12-16 reps.  Related post Plank

Direction Lie face down on mat resting on the forearms, palms flat on the floor. Push off the floor, raising up onto toes and resting on the elbows. Keep your back flat, in a straight line from head to heels. Tilt your pelvis and contract your abdominals to prevent your rear end from sticking up in the air or sagging in the middle. Hold for 20 to 60 seconds, lower and repeat for 3-5 reps. The plank exercise ranked number 10 in the ACE study and is a great way to build endurance in both the abs and back, as well as the stabilizer muscles.