Do it: With your feet shoulder-width apart, lift a barbell off the rig, centering it evenly across your shoulders. (This version of the squat targets the core, not the legs, and so you should be using far less weight than you would for a traditional back squat.) Send your glutes back like you’re lowering into a chair, bending at the knees as deeply as possible. Press through your heels to return to the starting position for one rep. Do 12 reps for one set.
To do it:Get into pushup position with both hands on the stability ball directly below your shoulders (your feet can be slightly wider than shoulder-width apart to give you extra stability). Contract your abdominals and try to bring your body into a straight line from your neck all the way to you toes (your butt should not be sticking out, so contract your glutes and keep your hips down). Once you are stable, lift your right leg a few inches off the ground and hold for 10 seconds. Repeat on the other side. Try to do three sets of a 10-second hold, and then advance to a 30-second hold.
“Unless you’re naturally gifted or a child, six-pack abs are always going to be a challenge. But remember, muscles have memory, so once you achieve a six pack once, if you lose it, it’ll be easier to get it back later. These days, I can get six-pack abs pretty quickly because I have such deeply ingrained muscle memory from my teenage years as a gymnast, when I was practicing in the gym five hours a day, six days a week.

To do it: Lie on your back with your knees bent, feet flat on the ground. Bring both arms overhead and hold onto the bottom of couch or a heavy medicine ball (as shown). Cross your right ankle on top of your left knee. Exhale and lift your legs in (in the same cross-legged position) as close to your chest as possible, lifting your hips and lower back off the floor. Inhale and slowly return to the starting position. That’s one rep. Try for up to 15 reps with the right leg, then repeat on the left.
You may think of power bars as protein-loaded snacks that are perfect pre- or post-workout. And while you’re not entirely wrong, you’re not entirely wrong, either. In addition to high protein levels, many power bars are surreptitiously loaded with sugar, which will bring any ab-seeking efforts of yours screeching to a halt. So, if you’re going to reach for a bar, be sure to check the nutrition facts first. Many bars—like the offerings from ONE or thinkThin—only have 1 gram of sugar for 20 grams of protein (and still taste delicious, to boot).
Common knowledge will tell you that, to get six-pack abs, carbs are verboten. Common knowledge is right—kind of. The key is to avoid the wrong carbs, like French fries, and eat the right carbs, like sweet potatoes. These orange goodies are full of carotenoids, which prevent calories from turning into fat; fiber, which helps you stay sated, and ultimately eat less; and Vitamin C, which’ll give you energy (for working out). And for more ab-shredding foods, check out the 10 Healthy Carbs That Won’t Derail Your Six-Pack.

To do it: Start with feet in a wide stance, knees bent, arms up on guard. Keeping your lower body still, quickly lean your upper body to the right, then come back through the center and lean to the left. Repeat lean back to the right. Next, lower your upper body, from the right around to the left side, making a half circle with your torso. Return to start position. That’s one rep. (Tip: it helps to keep a steady rhythm with this move, think—or say aloud—1, 2, 3, weave to help you keep your tempo). Repeat 10 times total, alternating starting on the right and left sides.
"My goals six years ago was to 'get abs' and I used to think cardio and crunches would get me there. But it wasn’t until I started lifting weights and varying my abdominal exercises that I started to see a major change. You don’t realize how much you use your core muscles in order to perform powerful rapid movements like deadlifts!" — Shante Franca, @shantefranca