The Flat-Belly Workouts Celebrities Swear By for Sexy, Sculpted Abs

Try the workout: J.Lo's Ab Workout

You can always count on J.Lo to show up on the red carpet wearing a dress with sky-high slits, a plunging neckline, or body-bearing cutouts.The actress and singer often trains with Health's contributing fitness editor Tracy Anderson to sculpt her incredible physique.To work out like J.Lo, try this plank variation circuit from Anderson six times a week, plus 30 to 60 minutes of cardio every day for a full-body burn.Not sure where to start? Try a J.Lo favorite: boxing. Throwing five rounds of jabs, uppercuts, and punches will have you feeling the burn.

Try it: Britney Spears' Ab Workout

The pop star isn't shy about sharing her favorite workouts on social media. Thanks to Instagram, we know Britney Spears sculpts her enviable abs using a mix of yoga, dance, and targeted core exercises. A few of her go-to moves: modified crunches in boat pose for a killer lower abdominal burn, knee-to-chest leg lifts with a lunge, and handstands with a wall assists. To add cardio into the mix, Spears hits the trails for a good old-fashioned hike.

Try it: Kendall Jenner's Ab Workout

Kendall Jenner maintains her long, lean physique with the help of personal trainer Gunnar Peterson. But while one-on-one sweat sessions certainly help the model get her sculpted midsection,she has a few techniques anyone can do. Jenner swears by the app Instant Abs Trainer (free; iTunes) for on-the-go core workouts, and she uses her downtime to squeeze in quick ab exercises.

"Sometimes when I'm watching TV I think to myself, 'I should be doing crunches and sit-ups right now'," she wrote on her app. "Then I get off the couch and do it."

Try it: Kim Kardashian's Ab Workout

Kim Kardashian ramped up her fitness routine after giving birth, and luckily for us, the Keeping Up With the Kardashians star has been documenting many of her workouts on social media. When she isn't doing interval sprints up steep hills, Kardashian is focusing on her core, and some of her favorite ab-burning moves include pike-ups and bear crawls.

Try it: Khloe Kardashian's Ab Workout

Clearly, a dedication to fitness runs in the family.Earlier this year, Khloe Kardashian told Health that she credits some of her weight loss with cutting out dairy from her diet, but anyone who follows the reality star on Instagram knows that she's also a gym fanatic.

For a full-body burn, Kardashian starts with cardio: "I love jumping rope," she told usin a previous interview. She's also been spotted hitting up SoulCycle for spin class. And to specifically target her core, she'll do exercises like one-legged weighted dead lifts on a upside down Bosu ball or sit-ups with a medicine ball. At the top of each sit-up, she adds an overhead press to work her arms too. Trainer Gunnar Peterson also taught her ab-torching moves like pull-ups, ab roll-ups, sled pushes, and weighted pull-overs.

Try it: Megan Fox's Ab Workout

The Transformers actress says hip-thrusts are the ab move that helped her tone her midsection after giving birth. Her trainer Harley Pasternak previously told Health that this move helped lengthen her abs and hip flexors while simultaneously strengthening her hip extensors, back, glutes, and hamstrings.

To steal Fox's ab exercise, lie face up on the floor with your knees bent and place your heels on top of a bench. Keep your arms extended out to the side, then engage your abs and squeeze your glutes while slowly pressing your hips up toward the ceiling.Your body should form a diagonal line from knees to shoulders. Hold this position for a few moments, then lower back to your starting position. Do three sets of 20 reps.

Try it: Maria Menounos' Ab Workout

Maria Menounos says she rarely hits the gym. Instead, she fits in core-blasters throughout her busy day. "I have this one little routine that anyone can get through," she explained to Health in a previous interview. "Fifty sit-ups: 20 straight up and down, 10 to the side, 10 to the other side, another 10 straight up and down. If you do that every night, you'll see results."

Try it: Julianne Hough's Ab Workout

Dancing queen Julianne Hough is serious about her fitness. The Dancing with the Stars judge has said that she loves to mix mind-body activities into her routine, such as hiking and yoga, and that switching up her workouts is key to her success.

For her role in Grease: Live!, Hough worked with Tracy Anderson to get in shape. To tone her legs, butt, and abs all at once, Hough did an exercise Anderson calls the Jazz Split Plank Lift. To do this move, get in a side plank position and lift your hips off the ground, followed by your leg. Return to resting position to complete one rep, then switch sides. Feel the burn?

Try it: Halle Berry's Ab Workout

The actress may be in her 50s, but you'd never guess judging by her rock-hard core.To sculpt her abs, Berry relies on one ultra-effective move called The Rocky."It targets all of your abs—mid, low, and obliques—to lengthen your core, with beautiful definition," her trainer Nat Bardonnet told Health in a previous interview.

To do this move, start by lying face up on a bench, hands gripping it, with legs together and raised to 90 degrees so feet are up towards the ceiling.(No bench? Stretch out on the floor, anchoring yourself by holding on to a solid piece of furniture.)Use core strength to lift your butt off the bench. Slowly lower your butt down, followed by legs, bringing them to about a 30-degree angle.Be sure to keep your lower back pressed firmly into the bench. Raise legs up, returning to start, to complete one rep.

Try it: Carrie Underwood's Ab Workout

The country singer's toned-all-over physique is total #fitspo. To get abs like Carrie Underwood's, try a bird-dog plank. Her trainer Erin Oprea says you'll feel this exercise diagonally through your core.

Here's how to do this move: Get into the top part of a pushup with feet wider than normal. With a flat back and engaged core, extend your right arm and left leg straight out so they're parallel with the floor. Bring your right elbow and left leg in to meet, and then extend both back out. Do eight to 12 reps, and then switch sides. Do three sets, three days a week to get your core in Underwood-level shape.

Try it: Lady Gaga's Ab Workout

After seeing a snap of Lady Gaga's abs on her trainer Harley Pasternak's Instagram, we had to find out how she got her core in such great shape. Pasternak recommends three core-targeting exercises: pike plank, dolphin extension, and Russian trunk twist.

"The key to getting great abs is not overdoing the front of the midsection, but rather focusing on the back of the midsection and the corset muscle that pulls the abs in,” he explained to Health in a previous interview.

Try it: Gwyneth Paltrow's Ab Workout

We may not always agree with Gwyneth Paltrow's health advice (hello, jade eggs and psychic vampire spray), but there's no denying that her abs are on fire. The mother of two trains with none other than Tracy Anderson, who created a Paltrow-inspired circuit to activate your core muscles.

Try it: Janet Jackson's Ab Workout

Janet Jackson is an onstage icon, and she's got the killer abs to match. Her trainer Tony Martinez says the singer uses a few tried-and-true exercises to keep her core in such great shape. To target her lower abs in particular, Jackson does cross-legged reverse crunches. To do this crunch variation, lie face up with your knees bent, feet flat on the floor, and palms facing down underneath you. Cross your right ankle over your left knee then lift your legs up and in towards your chest. Do 15 reps, then switch sides.