Stand tall
When you're walking, stand tall and picture a cape flowing off your shoulders, Superman-style, to ensure your best posture. A taller posture will give you the appearance of being slimmer, while also training your abs to stay taut and firm. Another good trick is to think of your back as a wall and your gut as a piece of furniture pushed up against the wall to keep it from buckling.

Watch your back
Contrary to popular belief, your abs aren't found just around your navel. They're an intricate system of muscles, connecting to your rib cage, your hips, and even your backbone. To have strong abs, you need not only belly exercises but also lower-back strength and exercises for your obliques (the abdominal muscles that run down the sides of your torso).

Avoid the four-letter word
When you lose weight on a "diet," muscle is the first thing to go. It's more expensive for your body to retain than fat is, so when you run low on calories, your body dumps muscle mass and turns it into energy. When you go off the diet, you begin to gain back the pounds - but because you now have less calorie-burning muscle, the weight you gain is fat. By dieting, you've effectively turned muscle into fat.

Tune in to muscle
Maybe you've heard of "muscle memory": the way your body learns to do a physical activity (like riding a bike) and never forgets. Well, your abs have a memory, too. If you consciously keep your abs firm throughout the day, they'll tend to stay firm even when you're relaxed.

Put exercise first
Research suggests that the best way to eat less at a meal is to work out right before it. This works in several ways:

First, you're less hungry when your metabolism is revving, such as right after a workout.
Second, you're thirstier, so you drink more water, which uses up space in your belly and relieves hunger.
Third, with your metabolism revved, the calories you do eat get burned for energy pronto - not stored as fat.

The harder your abs work, the better they make you look, and vice versa.

This is because you use your abs in virtually every movement that matters. Lifting. Running. Jumping. Reproducing. (It takes a lot of midsection stability to stand over that copy machine. Especially when it's printing on both sides of the page.) So the stronger they are, the harder and longer you'll be able to play. Here's a quick course in the anatomy of your abs.

Rectus Abdominis
This is the six-pack muscle that helps your upper body bend (like in a crunch) and also helps keep good posture. It's what people think of when they think of abs.

External Obliques
These muscles start on the ribs and extend diagonally down the sides of your waist. If a movement happens at your waist, the external obliques are involved. The torso rotation that's key to golf, tennis, and hockey is mostly a function of the external obliques. Even the basic crunching motion, attributed to the rectus abdominis (the six-pack muscle), wouldn't be possible without a strong contraction of the external obliques to stabilize the torso.

Internal Obliques
These lie between the rib cage and the external obliques, and also extend diagonally down the sides of your waist. Similar to the externals, the internal obliques are involved in torso rotation. You use these muscles when you breathe deeply.

Transverse Abdominis
It's a thin muscle that runs horizontally, surrounding your abdomen. It's also known as "the girdle" because it functions as a compressor for the abdomen, keeping everything in place.