Real talk: It takes more than a couple o' crunches to sculpt a rock-solid stomach. But you can give your belly some sexy definition without quitting your day job. All it takes is five minutes a day and this efficient fitness plan.

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Getty Images/ Ruben Chamorro/ Krystalina Tom/ Lauren Ahn

In this plan, you'll perform one five-minute workout five days a week for four weeks, taking two rest days per week whenever you want them. At the end of each week, you'll progress to a more difficult workout, which will be added below every Monday in May. (Miss the May 2 kickoff? No sweat, you can begin any time.)

Each workout is made up of five exercises designed by New York City-based fitness trainer Chelsea Dornan. For each move, do as many reps as you can in 60 seconds. Then move on to the next exercise. That's it!

Use the calendar above to stay on track. Then post your before and after pictures using the hashtag #CosmoAbsChallenge and tag @Cosmopolitan for a chance to be retweeted, regrammed, or featured on Cosmopolitan.com. 

WEEK ONE

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Getty Images/ Ruben Chamorro/ Krystalina Tom/ Lauren Ahn

Chelsea is wearing a Red Crop Top, ALALA, $75; Crop Tight, ALALA, $105; and Black Sneakers, APL, $140.

[youtube ]https://www.youtube.com/watch?v=KEwCqqHC2zM&featur... [/youtube]

The Moves

1. Forearm Plank With Knee Dip

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Ruben Chamorro

How to do it: Get into a forearm plank position with your shoulders stacked over your elbows, ears away from your shoulders, and palms pressed together. Your body should form a straight line between your head and your heels. Keeping your hips square to the ground, bend your left knee to gently tap the ground. Return to starting position, then repeat on the opposite knee. Continue to alternate knees without letting your hips pike or sag. 

2. Basic Crunches

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Ruben Chamorro

Lie on your back with your knees bent and the soles of your feet on the floor. Place your hands behind your head and open your elbows to the sides. Keeping your lower back pressed against the floor, exhale as you engage your core to lift your head and shoulders up off the ground. On the inhale, release with control to complete one rep. 

3. Heel Touches

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Ruben Chamorro

How to do it: Lie on your back with your knees bent and the soles of your feet on the floor. Extend your arms along your sides a few inches off the floor with palms facing in, and engage your core to lift your head and shoulders up off the floor. Keeping your shoulders equidistant from the floor, reach your left hand toward your left heel. Repeat on the opposite side to complete one rep, then continue to alternate sides. 

4. Reverse Crunch With Bent Legs

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Ruben Chamorro

How to do it: Lie on your back and wedge a hand underneath each hip, palms pressing into the floor. From this position, bend your knees about 90 degrees and press them together as you engage your core to lift both feet off the floor. When your knees are over your hips, exhale and lift your hips a few inches up off the ground. With control, release your legs and lower your feet back toward the floor without touching to complete one rep. 

5. High Knees

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Ruben Chamorro

How to do it: Stand with your elbows bent 90 degrees and forearms extended forward, palms facing down. Raise your left knee to meet your left hand, then hop onto the left foot as you raise your right knee to meet your right hand. Continue to alternate in quick succession. 

WEEK TWO

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GETTY IMAGES/ RUBEN CHAMORRO/ KRYSTALINA TOM/ LAUREN AHN
youtubeView full post on Youtube

The Moves

1. Forearm Planks With Alternating Leg Raises

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Ruben Chamorro

How to do it: Get into a forearm plank position with elbows underneath your shoulders and your body in a straight line from the top of your head to your heels. Keeping your hips square to the ground, raise one heel at a time. Continue to alternate for 60 seconds.

2. Cross-Body Crunch With Toe Touches

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Ruben Chamorro

How to do it: Lie on your back with your legs extend straight up, ankles stacked above your hips. Bring both hands behind you head with elbows out to the sides and engage your core to lift your head and shoulders off the ground. From this position, twist from the waist to the right as reach your left hand toward the right toes. Release to starting position and repeat on the opposite side. Continue to alternate side for 60 seconds.

3. Russian Twists

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Ruben Chamorro

How to do it: Sit on the ground with your legs together, knees bent, and feet raised. Bring your palms together at chest level. Keeping your lower body as stable as possible, twist from the waist to turn your upper body all the way to the left. Repeat on the opposite side and continue to alternate for 60 seconds.

4. Scissor Legs 

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Ruben Chamorro

How to do it: Lie on your back with your palms underneath your hips and engage your core to raise your legs 45 degrees off the ground (lower is harder), keeping them as straight as possible. Cross your left leg over your right leg, then cross your right leg over your left leg. Continue to alternate in quick succession for 60 seconds without dropping your legs.

5. Mountain Climbers

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Ruben Chamorro

How to do it: Get into plank position with your palms beneath your shoulders, and body in a straight line between the top of your head and your heels. Drive your right knee in toward your chest, then return to starting position. Repeat on the opposite side, then continue to alternate sides in quick succession for 60 seconds.

WEEK 3

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Getty Images/ Ruben Chamorro / Krystalina Tom / Lauren Ahn

The Moves

1. Plank Hip Dips

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Ruben Chamorro

How to do it: Begin in plank position with your forearms on the floor. Draw your abs in toward your spine, keep your elbows beneath your shoulders and palms pressed together, and your body in a straight line between the top of your head and your heels. Twist from the waist to tilt your left hip toward the ground, then come back to center and repeat on the opposite side. Continue to alternate sides. 

2. Crunch and Hold With Arm Pulses

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Ruben Chamorro

How to do it: Lie face-up on your back with your legs extended and arms along your sides, palms facing down. Keeping your legs straight and lower back pressed against the floor, engage your core and lift your feet about 45 degrees off the floor. Lift your head, neck, and shoulders off the ground as you raise your arms until they're parallel to the floor. From this position, pulse your arms up and down.

3. Standing Heel Touches

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Ruben Chamorro

How to do it: Stand with your feet about hips-width apart with your toes facing forward, and bend your knees about 45 degrees, sitting back into your heels. From this position, engage your core as you reach your left hand to tap your left heel, then come back to center. Repeat on the opposite side, and continue to alternate sides. 

4. Reverse Crunch With Straight Legs

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Ruben Chamorro

How to do it: Lie on your back with your legs outstretched and feet together. Bring your arms along your sides or under your hips for support, and press your palms into the floor. Keeping your legs as straight as possible, engage your core as you lift your feet straight up over your hips. Next, raise your hips up off the ground to stretch your toes toward the ceiling. With control, slowly lower your hips to the floor, then lower your legs with control as low as you can go without arching your lower back or touching your feet to the ground. That's one rep. 

5. Cross-Body Mountain Climbers

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Ruben Chamorro

How to do it: Get into a hands plank position with your shoulders stacked above your wrists and your body in a straight line between your head and your heels. Engage your core as you bend the left knee and bring it in toward the outside of your right elbow. Return to starting position and repeat on the opposite side, this time bending the right knee and bringing it to the outside of your left elbow. That's one rep. Continue to alternate sides, increasing your speed for an extra challenge.

WEEK 4

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Getty Images/ Ruben Chamorro / Lauren Ahn

The Moves

1. Commandos

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Ruben Chamorro

How to do it: Get into hands plank position with your shoulders stacked over your wrists and your body in a straight line between the top of your head and your heels. Keeping your hips square to the ground and core engaged, lower down to your right forearm, then your left. Next, come back to a hands plank leading with your left hand. Alternate lead hand as you continue. 

2. Jackknives

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Ruben Chamorro

How to do it: Lie face-up on a mat with arms extended overhead and legs outstretched. Engage your core as you simultaneously raise your legs 45-degrees off the floor and lift your upper body, bringing your arms forward and parallel to the ground for momentum. Release to starting position with control and continue. 

3. Alternating Side Plank Extensions

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Ruben Chamorro

How to do it: Start in a forearm plank position with your shoulders stacked over your elbows and your body in a straight line between the top of your head and your heels. Shift your weight into your left forearm as you stack your right hip over your left and roll onto the outside of your left foot, stacking your right foot above it. Extend your top arm and leg toward the sky. Then bring both limbs back down and return to forearm plank position. Repeat on the opposite side and continue to alternate sides. 

4. Reverse Crunch to Hip Raise

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Getty Images

How to do it: Lie on your back with your legs outstretched and feet together. Bring your arms along your sides and press your palms into the floor. Keeping your legs as straight as possible, engage your core as you lift your feet straight up over your hips. Next, raise your hips up off the ground to stretch your toes toward the ceiling. With control, lower one vertebrae at a time until your hips are back on the floor. Keep your core tight as you lower your legs back to starting position to complete one rep. 

5. Single-Leg Froggers

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Getty Images

How to do it: Start in hands plank position with your wrists stacked beneath your shoulders and body in a straight line between the top of your head and your heels. Step your left foot to the outside of your left palm. In one dynamic motion, jump your left foot back to plank position and your right foot to the outside of your right palm. Then reverse feet and continue to alternate in quick succession.

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Headshot of Elizabeth Narins
Elizabeth Narins
Senior fitness and health editor

Elizabeth Narins is a Brooklyn, NY-based writer and a former senior editor at Cosmopolitan.com, where she wrote about fitness, health, and more. Follow her at @ejnarins.