Exercise guide
Alternate Oblique Crunch
- Beginner
- Isolation
- Rep-based
- Waist
The Alternate Oblique Crunch targets the internal and external obliques through a combination of spinal flexion and rotation, helping to define the waistline and improve rotational core stability.
Reviewed by the Crucible team · Updated June 2026
Muscles worked
Setup
- Lie flat on your back on a mat with your knees bent and feet flat on the floor, hip-width apart.
- Place your fingertips lightly behind your ears or head, keeping your elbows flared out wide to the sides.
- Engage your core by pressing your lower back firmly into the floor to eliminate any arch.
How to do it
- Exhale as you lift your head and shoulder blades off the floor, rotating your torso to bring your right elbow toward your left knee.
- Focus on squeezing the side of your waist (obliques) at the top of the movement.
- Inhale as you lower back down to the starting position with a controlled tempo.
- Repeat the movement on the opposite side, alternating sides for each repetition.
Form checklist
- Keep your elbows wide and avoid pulling on your neck with your hands.
- Ensure your lower back stays in contact with the floor throughout the entire set.
- Lead the movement with your shoulder rather than just your elbow to ensure full torso rotation.
- Maintain a space between your chin and chest to keep the airway open.
Pro tips
- Think about bringing your armpit toward the opposite knee rather than your elbow to maximize the oblique contraction.
- Pause for one second at the peak of the crunch to emphasize the mind-muscle connection in the lateral abs.
Make it harder
- Lift your feet off the floor into a 'tabletop' position (knees at 90 degrees) to increase the demand on the lower abs.
- Slow down the eccentric (lowering) phase to three seconds to increase time under tension.
Frequently asked
- What muscles does the alternate oblique crunch work?
- The alternate oblique crunch primarily targets the abs and obliques, and also works the erector spinae as secondary muscles.
- What equipment do you need for the alternate oblique crunch?
- The alternate oblique crunch requires no equipment — just your body weight.
- Is the alternate oblique crunch good for beginners?
- Yes. The alternate oblique crunch is a beginner-friendly movement and a strong foundation to build on.