This Crunch Variation Will Light Up Your Core and Stretch Your Inner Thighs

The butterfly crunch targets hard-to-reach oblique muscles as well as stretches the inner thighs and hips.
Image Credit: Maridav/iStock/GettyImages

There are only so many crunches you can crank out before becoming bored or hitting a plateau. But if you want to amplify your ab routine, you don't have to abandon crunches altogether. Instead, trying a challenging variation like the butterfly crunch can make a big difference.


The butterfly crunch — which involves placing the soles of your feet together, so your legs form a diamond shape like a butterfly's wings — is an outstanding way to work your obliques, which are often omitted in traditional crunches that largely lean on the rectus abdominis (the front superficial ab muscles), Ben Lauder-Dykes, trainer for Fhitting Room and certified kettlebell instructor, tells

Video of the Day


Plus, butterfly crunches also feel pretty great as they gently stretch your inner thighs (and open your hips).

How to Do a Butterfly Crunch

Skill Level Intermediate
Body Part Abs
  1. Lie on your back with your hands behind your head and the soles of your feet touching, so your legs form a diamond.
  2. Tuck your chin toward your chest, and then on an exhale, pull your sternum/ribs down toward the bellybutton as you curl your chest off the floor a few inches.
  3. Keeping your back flat and your abs tight, slowly lower back to the floor.


Exhale all of your breath on every rep to really hit the obliques, and press your feet into the floor to help keep your hips stable, Lauder-Dykes says.

4 Reasons to Do Butterfly Crunches

Butterfly crunches can help you crush your core-related fitness goals, but here are a few more reasons you should add them to your routine.

1. They Target Your Core, Not Your Hip Flexors

"In most crunches, the motion is normally dominated by the powerful hip flexors," Lauder-Dykes says. That's because your body often relies on flexion at the hip (rather than your ab muscles) to pull your torso up, he explains.


Conversely, in the butterfly crunch, the unique positioning of the legs limits the hip flexors. In other words, your core must do all the work to lift the load of your body.

2. They Light Up Your Obliques

While traditional crunches primarily work the rectus abdominis, they don't do much for your obliques. Butterfly crunches hit these hard-to-reach muscles.


Again, "opening the hips reduces the use of hip flexors to perform the crunch and allows both internal and external obliques to be engaged more throughout the motion," Lauder-Dykes says.

3. They Stretch Your Inner Thighs

While not the main focus of the exercise, you'll also get a nice inner thigh stretch during butterfly crunches, thanks to the open leg placement. It's always a smart idea to improve flexibility in your adductors because these muscles help with stability and balance.


4. They Help Open Your Hips

Stiff hips due to excessive sitting is a struggle for most of us. Butterfly crunches — in conjunction with additional stretches and exercises — may help offset the tightness and open the hips.

Again, placing the soles of your feet together compels your hips to spread and stretch wider.


Once You’ve Mastered the Butterfly Crunch, Try the Butterfly Sit-Up

This progression is more challenging than the crunch because it requires pulling the whole upper body off the floor, which significantly increases the resistance and range of motion of the movement, Lauder-Dykes says.

How to Do a Butterfly Sit-Up

Skill Level Advanced
Body Part Abs
  1. Lie on your back with your arms overhead and the soles of your feet touching, so your legs form a diamond.
  2. Tuck your chin toward the chest, and then on an exhale, pull the sternum/ribs down toward your bellybutton.
  3. Keep your core tight and slowly rise, curling your body up off the floor vertebra by vertebra (this helps to keep the ribcage down and the abs active instead of the hip flexors).
  4. Continue to crunch up until you come into a sitting position and reach forward with both hands to touch your feet.
  5. Reverse the movement, slowly lowering back down vertebra by vertebra.
  6. Remember to press your feet into the floor to help keep your hips stable throughout the movement.

Related Reading