This Partner Butt Challenge Will Give You the Best Ass of 2018

Want to reach your fitness goals with no ifs, ands, or *~bUtTs*~? Recruit a friend, and boost your booties together with this no-equipment fitness challenge for partners: It's designed to lift and strengthen both your backsides in just four weeks. (Pro tip: The safest way to perform these moves is with a partner who's about your same height and fitness level, and L-O-T-S of communication. GL!)

No fitness partner? Try this solo butt challenge instead.

~THE PLAN~

For each of the four workouts below, perform the moves with a partner as outlined below in the designated order. If a single round doesn't kick both your butts, repeat the entire circuit up to three times in a row, taking one- to two-minute breaks to recoup between rounds.

Perform the same workout with your partner two to three times per week, then progress to the next week's workout. Each week's workout gets progressively more difficult — NBD, since you'll both be getting stronger.

~WEEK 1~

Certified group exercise instructor Liz Chestang (above left) is wearing a Mesh Sports Bra, AERIE, $20; Banded Leggings, BELFORTE, $154; and Black Sneakers, UNDER ARMOUR, $37 at Amazon.com.

Certified fitness trainer Jen Rufo (above right) is wearing a Blush Sports Bra, BELFORTE, $54; Color Block Leggings, OUTDOOR VOICES, $95; and Grey Sneakers, APL, $160.

THE MOVES:

1. Back-to-Back Squat (30 seconds)

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How to do it: Stand back to back, and lean against each other as you walk forward until only your upper backs are touching. From this position, keeping weight in your heels and knees behind your toes, simultaneously bend your knees until your thighs are parallel to the ground. Push through the heels and evenly against each other as you extend your legs to complete one rep.

2. Double-Trouble Glute Bridge (30 seconds)

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How to do it: Lie on your backs with your feet facing each other, and inch forward until you're close enough to each other to press the entire soles of your feet to your partner's with your knees bent at a 90-degree angle. From this position, with arms outstretched on the floor along your sides, press evenly against each others' feet, and engage your butt and hamstrings simultaneously to lift your hips off the ground. When your body forms a straight line between your shoulders and knees, pause, then return to starting position with control to complete one rep.

3. Kneeling Toe Touch (30 seconds per side)

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How to do it: Face your partner on your hands and knees with your wrists about one foot away from your partners'. Raise one knee to the side as high as you can. (Your partner mirrors you.) Without dropping the knee, extend your leg and reach your toes to meet your partners'. Return to starting position to complete one rep. After 30 seconds, you both switch legs and continue for another 30 seconds.

4. High-Five Pass-Under (60 seconds)

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How to do it: Stand back-to-back with your partner about one foot apart from each other. Keeping your weight in your heels, your knees soft, and your back flat, your partner hinges forward from the waist and extends both arms through her legs as you extend your arms straight up overhead. Next, you hinge forward from the waist and reach your hands through your legs the legs to high-five your partner. Then, she extends her arms overhead and returns to her starting position to high-five you. That's one rep. Continue to alternate.

5. Traveling Tango Lunge (30 seconds per side)

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How to do it: Stand facing your partner with about two feet between you and your palms touching at chest height. Keeping your front knees behind your front toes and your shoulders over your hips, lunge forward with your left leg as your partner lunges backward with her right leg. Bend both knees 90 degrees, then extend your legs. Next, you lunge backward with your left leg as your partner lunges forward with her right leg. Continue to alternate between forward and backward lunges for 30 seconds, then you both switch legs and continue for another 30 seconds.

~WEEK 2~

Jen is wearing Pink Cutout Sports Bra, LORNA JANE, $67; Red Stripe Leggings, LULULEMON, $69; and Grey Sneakers, APL, $160. Liz is wearing a Red Sports Bra, LULULEMON, $58; Dark Pink Leggings, LORNA JANE, $95; and Black Sneakers, UNDER ARMOUR, $37 at Amazon.com.

THE MOVES:

1. Hip Bump + Jump (45 seconds)

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How to do it: Stand side-by-side next to your partner, facing opposite directions. With your feet about shoulders'-width apart, keeping your knees behind your toes, bend your knees into a squat, then extend your legs gently to bump hips with your partner. Next, take a second squat. Extend your legs with momentum to jump up, turn toward your partner, and land facing opposite directions in a squat position with feet about shoulders'-width apart. That's one rep.

2. Glute Bridge Bicycle (60 seconds)

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How to do it: Lie on your back facing your partner. Press the soles of your feet together, then scoot forward until both of your knees are bent 90 degrees. Extend your arms along your sides on the ground, and simultaneously press against each others' feet to lift your hips off the ground. From this starting position, without dropping your hips, extend your right leg and bend your left knee as your partner simultaneously bends her left knee and extends her left leg. Reverse legs to complete one rep, and continue without dropping your hips.

3. Donkey Kick Reach (60 seconds)

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How to do it: Get on all fours facing your partner with your heads at least several inches apart for safety. Keeping your hips square to the ground and your left knee bent, raise your left heel straight up to the sky as you slap right palms. Return to starting position, then raise your right heels as you slap left palms. Continue to alternate sides.

4. Roundhouse Kick (30 seconds per side)

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How to do it: Face your partner, and stand with your feet about shoulders'-width apart and toes turned slightly outward. Keeping your knees behind your toes, bend your knees about 90 degrees to lower into a squat while your partner kicks her left leg out, up, and over you. She lands in squat position, and you perform the same kick. Continue alternating positions, kicking with the left leg until it's time to switch legs.

5. Squatting Shuffle (60 seconds)

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How to do it: Stand with your feet together and face your partner with about two feet between you. Grasp each others' forearms. Keeping your knees behind your toes and your weight in your heels, simultaneously bend both knees into a squat, then — without standing up — step to your left (your partner's right). Staying low, return to starting position, and continue to shuffle back and forth.

~WEEK 3~

Jen is wearing a Blue Sequin Bralette, AERIE, $21; Light Blue Leggings, AERIE, $25; and Grey Sneakers, APL, $160. Liz is wearing a Navy Blue Sports Bra, PHAT BUDDHA, $64; Shimmer Leggings, PHAT BUDDHA, $79; and Black Sneakers, UNDER ARMOUR, $37 at Amazon.com.

THE MOVES:

1. High Knee + Squat Hold (30 seconds per position)

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How to do it: Face your partner. Keeping your chest high and knees behind your toes, bend your knees about 45 degrees (or more), and extend your arms straight forward. As you hold this position, your partner jogs in place, raising her knees to hip height. Switch roles after 30 seconds.

2. Sitting Hip Bump (30 seconds per side)

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How to do it: Sit side by side with your partner with your knees bent and heels several inches from your butt. Place your palms on the floor behind your hips, with your fingers facing your feet. From this position, press through your heels simultaneously to raise your hips and bump sides (your left, your partner's right) with your partner. Next, lower your hips to starting position with control, and raise your hips to the opposite side. Continue to alternate sides. After the allotted time, you both face the opposite direction and continue, bumping opposite sides (your right, your partner's left).

3. Kneeling Leg Circle (30 seconds per side)

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How to do it: Get on all fours facing away from your partner, gaze down (unless you're posing for a photo, like Liz and Jen above). Your toes should be several inches apart. Extend your left legs, and point your toes as you circle your legs clockwise around one another's legs. Continue for 30 seconds without dropping your leg, and then switch legs to continue.

4. Plank + Lift (30 seconds/position)

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How to do it: Perform a hands plank, with your body forming a straight line from the top of your head to your toes. Keeping your feet together, your partner stands behind you with her feet on either side of yours. With a flat back, she bends from her waist (keeping her knees soft, if desired) to grasp your ankles and lift your legs off the ground as she returns to standing position. With control, she lowers your legs back to her knee-height. You continue to hold the plank for 30 seconds, then switch roles.

5. Switch Jump (30 seconds)

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How to do it: Face your partner with your toes about six inches apart, and grasp each other's left hands. Keeping your shoulders above your hips and your knees behind your toes, you each take a large step backward and bend the knees to 90 degrees. From this position, extend both your legs, and release your hands as you jump up and land with your legs reversed — this time, with your left in front and your right behind you. Grasp right hands as you land. That's one rep. Continue to alternate.

~WEEK 4~

Liz is wearing a Silver Sequin Bralette, AERIE, $21; Silver Leggings, AERIE, $25; and Black Sneakers, UNDER ARMOUR, $37 at Amazon.com. Jen is wearing a Gray Star Bralette, AERIE, $15; Gunmetal Metallic Leggings, MIRA RAE, $62; and Grey Sneakers, APL, $160.

THE MOVES:

1. Squat Jump (45 seconds)

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How to do it: Stand facing your partner about one yard away from each other, with your feet about shoulders'-width apart. Keeping your knees behind your toes and your weight in your heels, simultaneously bend your knees and reach both hands to touch the floor just outside your feet. Next, extend your legs, and bring your arms overhead as you jump straight up and slap each others' palms overhead. Land with soft knees, and continue.

2. Marching Bridge (30 seconds per position)

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How to do it: Lie on your stomach with your arms bent and forearms on either side of your chest for support, palms facing down. Bend both knees with your soles of your feet facing the ceiling. Your partner lies face-up behind you, with her butt 1-2 feet away from your knees. With her arms extended along her sides on the ground, and her palms facing down, she places her left heel on the bottom of your left sneaker, and her right heel on the bottom of your right sneaker. She lifts her hips to form a straight line between her knees and shoulders, and holds. Meanwhile, you lift from your butt and hamstrings (rather than lower back) to lift one knee at a time several inches off the floor, pressing straight up. Alternate sides for 30 seconds, then swap positions with your partner.

3. Knee to Elbow (30 seconds per side)

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How to do it: On all fours, facing away from your partner with your toes touching, keep your knee bent as you raise your left leg out to hip height (or as high as you can). Keeping your knee, shin, and foot on the same plane, bring your knee to your elbow, then behind you to tap the bottom of your foot to your partner's foot. Continue for 30 seconds, then switch legs.

4. Seesaw Stand Up (60 seconds)

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How to do it: Stand facing your partner with your feet about hips'-width apart, your toes nearly touching hers. Keeping a soft bend in the knee, grasp each other's forearms. With control, bend your knees to bring your butt to the ground as your partner, who keeps her weight in her heels, bends from the waist to support you. Next, you engage your butt and thighs to stand as your partner engages the backs of her legs to assist you up with control (and without stepping backwards). Reverse roles and continue to alternate.

5. Lunge Twist (60 seconds)

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How to do it: Stand about two large steps away from your partner, and face each other. Bring your hands behind your head with your elbows bent out to the sides. Keeping your shoulders over your hips, you both simultaneously take a large step forward with the left foot. You both bend both knees 90 degrees, then twist from the waist until your right elbows meet. Twist back to center, then return to starting position. Next, repeat on the opposite side, stepping forward with the right leg and twisting until left elbows meet. That's one rep.

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