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  7. Opposite Crunch

Exercise guide

Opposite Crunch

  • Beginner
  • Compound
  • Rep-based
  • Waist

The opposite crunch targets the rectus abdominis and obliques by incorporating torso rotation, improving core stability and rotational strength. This movement effectively engages the entire midsection through a cross-body pattern that emphasizes the mind-muscle connection with the obliques.

Reviewed by the Crucible team · Updated June 2026

Watch the Opposite Crunch demonstrationGuided video and your full workout live in the Crucible app.

Muscles worked

Primary

  • Abs
  • Obliques

Secondary

  • Erector spinae

Equipment

  • Body weight

Setup

  1. Lie flat on your back on a mat with your knees bent and feet flat on the floor, hip-width apart.
  2. Place your fingertips lightly behind your ears, keeping your elbows flared out wide.
  3. Engage your core by pressing your lower back firmly into the floor to eliminate any arch.

How to do it

  1. Exhale as you lift your right shoulder off the mat, rotating your torso to bring your right elbow toward your left knee.
  2. Simultaneously lift your left knee toward your chest so the elbow and knee meet over your midline.
  3. Inhale as you slowly lower both your upper body and foot back to the starting position with control.
  4. Repeat the movement on the opposite side, alternating sides for each repetition.

Form checklist

  • Keep your lower back pressed into the floor throughout the entire movement.
  • Lead the rotation with your shoulder and ribcage, not just by pulling your elbow forward.
  • Avoid pulling on your neck; your hands should only provide light support.
  • Maintain a slow, controlled tempo rather than using momentum to swing your limbs.

Pro tips

  • Focus on the 'crunch and twist' sensation, imagining you are trying to touch your armpit to the opposite hip bone.
  • Pause and squeeze at the peak of the contraction to maximize oblique fiber recruitment.

Make it harder

  • Keep both feet hovering 2-3 inches off the floor throughout the entire set to maintain constant tension.
  • Extend the non-working leg straight out just above the floor as you crunch toward the opposite side.

Frequently asked

What muscles does the opposite crunch work?
The opposite crunch primarily targets the abs and obliques, and also works the erector spinae as secondary muscles.
What equipment do you need for the opposite crunch?
The opposite crunch requires no equipment — just your body weight.
Is the opposite crunch good for beginners?
Yes. The opposite crunch is a beginner-friendly movement and a strong foundation to build on.

Related exercises

  • 3/4 Sit-UpBeginner · abs and obliques
  • 45 Degree Bicycle Twisting CrunchIntermediate · abs and obliques
  • 45 Degree Lean Back Alternate Knee RaiseBeginner · abs and obliques
  • 45 Degrees Arms PlankIntermediate · abs, deltoids, obliques, and pectorals

Train this with a plan, not guesswork

Crucible builds the opposite crunch into a precise program around your body, equipment, location, and time.

Download on the App Store