The abs are key to a great physique. You may have nice arms, but can you show off your stomach? They are also instrumental to several sports because they are an important factor in running, jumping, and throwing. The exercises below (along with a reduced calorie diet) are great for developing a killer six-pack.
Lie on your back; bring your legs up until they form a 90-degree angle with the floor. Keep your legs as straight as possible to really make the lower abs burn.
Don't allow your legs to touch the floor to keep constant tension on your abs. Stop when you are about 1-2 inches off the ground, and start the next rep.
Lying Leg Thrusts:
Lie on your back. Perform a lying leg raise. Thrust your heels to the ceiling, breathe out; keep contracting the lower abs so that you are raising your torso.
Lower out of the thrust back to your initial position, leaving your feet straight up. Lower your legs back to the starting position.
Hanging Leg Raises:
Hang from a chin-up bar, or use a dip stand, or another devise so that your feet do not touch the ground when they are directly below you. Bring your knees up to your chest, in a slow, controlled motion. To maximize the exercise, keep your legs straight, and bring them up slowly to form a "L" with your torso.
Lying on your back, put your knees up in the air so that your thighs are at a right angle to the ground, with your knees bent. Put your hands either behind your head or on the sides of your head. Slowly raise your shoulders off the ground and focus on keeping your abs tight.
Do not let your shoulder blades touch the ground during the exercise if you can help it. Do not focus on going all the way up, as much as having a slow, consistent pace, and really flexing the abdominal muscles throughout.
These are like ab crunches; lay on your back, in the bent-knee position, but crunch diagonally so that you touch each elbow to the opposite hip alternately. At the top position, one shoulder and one hip should be off the ground.
Lie on your side and cradle your head in your hands. Bend your knees, place one elbow, and arm on the ground just under your head. Keep your hands linked, and point the other elbow up. Twist your body and lift the lower elbow up off the ground and across your torso.
Do this in a slow manner, and hold it at the top for a second before lowering and repeating. Try not to go all the way down, stop just short of the bottom so you get more of a work. Be sure to do this for both sides.