Exercise guide
Lying Obliques Crunch
- Beginner
- Isolation
- Rep-based
- Waist
This exercise isolates the internal and external obliques through lateral spinal flexion, helping to define the waistline and improve core stability. By rotating the hips while keeping the shoulders square, you create a pre-stretch that enhances muscle recruitment.
Reviewed by the Crucible Fit team · Updated June 2026
Muscles worked
Setup
- Lie flat on your back with your knees bent and feet flat on the floor.
- Lower both knees to one side until they rest on the floor, keeping your upper back and shoulders flat against the mat.
- Place your fingertips lightly behind your ears or cross your arms over your chest.
How to do it
- Exhale and contract your obliques to lift your shoulder blades straight up off the floor toward the ceiling.
- Pause for a second at the top, focusing on the squeeze in the side of your abdomen.
- Inhale as you slowly lower your upper body back to the starting position with a controlled tempo.
- Complete the set on one side before rotating your legs to the opposite side and repeating.
Form checklist
- Keep your gaze toward the ceiling to maintain a neutral neck and spine.
- Avoid pulling on your head; your hands should only provide light support.
- Ensure your shoulders remain square to the ceiling rather than twisting your torso toward your knees.
- Maintain a slow, controlled pace to eliminate momentum.
Pro tips
- Imagine trying to shorten the distance between your bottom rib and your hip bone on every rep to maximize the contraction.
- Keep your elbows wide and out of your peripheral vision to prevent your arms from assisting the lift.
Make it harder
- Perform the crunch with your legs elevated and knees bent at 90 degrees to increase the load on the core.
- Extend your top arm straight past your hip to increase the lever length and resistance.
Frequently asked
- What muscles does the lying obliques crunch work?
- The lying obliques crunch primarily targets the abs and obliques, and also works the erector spinae as secondary muscles.
- What equipment do you need for the lying obliques crunch?
- The lying obliques crunch requires no equipment — just your body weight.
- Is the lying obliques crunch good for beginners?
- Yes. The lying obliques crunch is a beginner-friendly movement and a strong foundation to build on.