The 5 Rules of Flat Abs

Most of us don't stress about a bit of belly fat hanging over our waistbands during the winter—after all, damage control is just a body-shaping undergarment away, right? But what if you're headed to a place where not even Spanx can save you: the beach or the pool?

The frustrating reality is that the midsection is one of the trickiest areas to tone. That's why even women dedicated to regular exercise often can't iron out their abs. Fortunately, I've come up with some tips and tricks for the ultimate tummy—flattening plan. Not only is it super effective, but it's likely loads easier than the agonizing ab workouts you've been putting yourself through (that are probably getting you no results!).

RULE #1: Attack your hidden core muscles.

Crunches target only superficial muscles, so they aren't the most efficient way to work your abs. Fact: To burn one pound of fat, you have to do 250,000 crunches. That's 100 crunches a day for seven years. Uh, no thanks. Instead, you should target the muscles that lie beneath the superficial ones: your transverse abdominis, multifidis, and internal obliques. Strengthening them pulls in your middle like a corset, keeping the area looking flat and toned. Core moves like planks or mountain climbers (see below) target these "hidden" muscles. To practice engaging them, try this drill: Lie on your back and place your palms just below your navel. Exhale and allow your tummy to expand as far as you can, then focus on pulling your belly button toward your spine, drawing your abdomen toward the floor. Hold for 5 seconds. Repeat 8 to 10 times.

RULE #2: Move your butt.

Your booty and your belly are unlikely partners in crime. Here's why: Over time, sitting around too much renders your glutes practically useless and causes your hip flexors—the muscles that connect your hipbones to your legs—to become stiff. This couch-potato combo tilts your pelvis forward, which increases the arch in your back and puts stress on your spine. From a cosmetic standpoint, it pushes your abdomen out, making even a relatively flat stomach bulge. That means that to lose your gut, you've got to work your butt. Exercises like the single-leg deadlift and hip-glute raise (see below) will help you get a stronger behind. Combat tight hip flexors with this stretch: In a lunge position, lower yourself so your back knee is resting on the floor. Push your hips forward, keeping your back upright, until you feel a stretch in the front of the hip. Hold for 10 seconds, relax, and repeat. Switch legs. You can increase the stretch by reaching your arms over your head.

RULE #3: Eat flat-belly foods.

You can't see ab muscles if they're buried under a layer of fat. Excavate them by following these easy dietary guidelines.

*Pump up your protein intake. Substituting meat, fish, dairy, and nuts for carbs can reduce the amount of fat around your middle. Researchers have discovered that when people exchange carbohydrates in favor of an equal amount of protein, they reduced overall belly fat.

*Eliminate added sugar. The average American eats about 20 teaspoons of sugar daily in the form of processed foods like soda, baked goods, breakfast cereals, fruit drinks, and even flavored yogurt. That's about 325 empty calories every day. All that sugar increases insulin production, which slows your metabolism.

*Don't fear fat. Research shows that diets containing more than 50 percent fat are just as effective for weight loss as those that are low in fat. Fat is filling and adds flavor to your meals—both of which help you avoid feeling deprived, so you can stick to your diet. Eat foods rich in monounsaturated fats, such as olives, nuts, and avocados; research has even found that it's OK to enjoy whole foods that contain saturated fat (including milk, cheese, and butter) in moderation.

*Beat the bloat. No matter how much ab fat you lose or muscle you tone, if you're bloated, you won't look (or feel!) your best in a swimsuit. Carbonated beverages, and even good-for-you foods such as beans and broccoli, can make your stomach swell. And keep your sodium intake in check: Nutritionists suggest you stay under 2,000 milligrams to avoid retaining excess water. (Most of us get closer to 5,000 a day.)

RULE #4: Stop stressing.

Your kids. Your in-laws. Your never-ending to-do list. I get it—life is hard. But anxiety can produce extra cortisol, a hormone that encourages the body to store fat, particularly in your belly. According to researchers, your midsection is four times as likely as the rest of your body to store stress-induced fat. Help keep anxiety in check by taking little breaks from work every 90 minutes. Another way stress sabotages your abs: When tension runs high, we reach for fattening foods. To keep your hand out of the office candy jar, keep it out of reach. In one study, participants who had to walk six feet to reach the candy ate up to seven fewer chocolates per day than when the jar was conveniently located at their desk.

RULE #5: Work your abs less often.

Ditch your daily ab workouts. You need only three sessions a week to see maximum results. Training every day with endless crunches won't flatten your belly faster. You'll see benefits quicker if you give your muscles a day to fully recover between workouts. That's because stressing your muscles during a workout breaks down the tissues, and they need rest days to rebuild and get stronger. What's more, you should stick to only 15 to 20 reps of each move. If you can easily do that many, it's time to for harder moves. And if flat abs are important to you, promote them to the top of your fitness to-do list. A lot of people exercise their abdominal muscles at the end of their workout, and that's when you get sloppy or run out of time. You should do them first, and then move on to your cardio. To get them looking great, you need to make them a priority. You'll be glad you did.