I am a healthy 20-year-old woman. All of my life I have had a lower abdominal storage of fat -- almost like a second section of my stomach: My stomach seems to end at my belly button, and a roll begins. I have tried to get rid of it to no avail. I do a cardiovascular workout (30 minutes on the Precor, 10 minutes rowing) at least three times a week and weight-train when I have the chance.

Do you have any suggestion for exercises that target this area? It affects the clothing I wear, and I am getting frustrated. I heard that the "reverse crunch" would help (lie on back, legs in the air, and lower the legs but don't let them touch the ground), or using the tall chair-like machine (minus a seat) at the gym (where you rest your arms on pads and can raise and lower your legs).

This is a good, tough question because there are so many different theories about the correct way to work the abdominals. Some experts will tell you to work them every day, while others will tell you to work them twice a week. Some will tell you to do crunches and crunches only, while some say crunches are a waste of time. Even research on this topic is inconclusive.

I can tell you this: You will not be able to spot-reduce your lower abs -- that is, magically zap fat off that area by exercising it. The body just doesn't work that way. You'll have to reduce overall body fat to reduce fat in that area, and even then I can't promise you'll lose enough there to make you happy. But don't despair. You can make that area look better by toning it up. So let's talk about how to do that.

First, a little anatomy: You have four major abdominal muscles. The one that runs the length of your torso from your sternum to your pelvis is called the rectus abdominis. Because it is one long wide flat sheet of muscle, some scientists think it's a waste of time to do exercises to focus on the upper half of that muscle and other exercises to focus on the lower half. Me, I think that regular crunches do tend to hit the upper rectus fibers and reverse crunches tend to hit the lower fibers, so it's probably worth your while to do some of each. I will describe good form for both types of exercises shortly.

As for the high-chair exercises you mention, I don't recommend them, because they tend to emphasize a front hip muscle group known collectively as the hip flexors. These muscles tend to be a little too strong to begin with, and if they get so strong they overpower the ab and lower-back muscles, you may begin to have chronic back problems. You're better off sticking to floor exercises such as crunches. Below, I describe basic "upper rectus" crunches and reverse "lower rectus" crunches. And since I'm in a good mood, I'm going to throw in a couple of bonus exercises: some twist crunches for the internal and external oblique muscles (the two muscle groups that interweave along the sides of your waist) and a lower-back strengthener (for the erector spinae muscles.) I believe you need to do at least one of each type of exercise for a complete "three-dimensional" middle body workout.

For beginners: Do one set of each exercise, 8-15 reps per set. Gradually increase to two sets of each. Remember to exhale as you exert effort, since the act of forceful breathing kicks in the fourth major abdominal muscle group, the transversus abdominis.

Basic Crunch

1. Lie on your back with your knees bent and feet flat on the floor, hip-width apart. Place your hands behind your head so that your thumbs are behind your ears. Don't lace your fingers together. Hold your elbows out to the sides but rounded slightly in. Tilt your chin slightly so that there's a few inches of space between your chin and your chest.
   
   
2. Gently pulling your abdominals inward, curl up and forward so that your head, neck, and shoulder blades lift off the floor. Hold for a moment at the top of the movement, and then lower slowly back down.

Reverse Crunch

1. Lie on your back with your legs off the floor, your knees bent and positioned directly over your hips; cross your ankles and drop your heels toward your butt. Rest your arms on the floor beside you. Rest your head on the floor, relax your shoulders, and pull your abdominals inward.
   
   
2. Lift your butt one or two inches off the floor so that your legs move directly up. Hold the position for a moment, and then lower slowly.

Crunch with a Twist

1. Lie on your back with your knees bent and your feet hip-width apart and flat on the floor. Place your hands behind your head so that your thumbs are behind your ears. Don't lace your fingers together. Bring your elbows out to the sides and round them slightly inward. Tilt your chin so that there is a few inches between your chin and your chest. Pull your abdominals inward.
   
   
2. As you curl your head, neck and shoulder blades off the floor, twist your torso to the right, bringing your left shoulder toward your right knee. Your shoulder doesn't need to actually touch your knee. Lower back down. On the next repetition, twist your torso to the left, bringing your right shoulder toward your left knee. Continue alternating sides.

Pelvic Tilt

1. Lie on your back with your knees bent and feet flat on the floor about hip-width apart. Rest your arms wherever they're most comfortable. Gently press your back down and pull your abdominals in toward your spine. Don't tilt your head up and back.
   
   
2. Keeping your entire back against the floor, gently squeeze your butt, and tilt your hips up until your rear end curls an inch or two off the floor. Hold this position for a moment and then slowly lower your hips back down.

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