Exercise guide
Seated Open Knee Leg Raise On A Chair
- Beginner
- Compound
- Rep-based
- Waist
This beginner-friendly core exercise targets the lower abdominals and obliques by utilizing a seated position to isolate the midsection. The wide-knee positioning increases the challenge on the lower core and hip stabilizers compared to a standard leg raise.
Reviewed by the Crucible team · Updated June 2026
Muscles worked
Setup
- Sit on the edge of a sturdy chair or flat bench with your feet flat and knees wider than shoulder-width.
- Grip the edges of the seat behind your hips to stabilize your upper body.
- Lean back slightly (about 20-30 degrees) while keeping your chest open and spine neutral.
How to do it
- Exhale and pull your knees up toward your chest while maintaining the wide, 'open' knee position.
- Squeeze your abdominals at the top of the movement for a one-second pause to maximize peak contraction.
- Inhale as you slowly lower your legs back down toward the floor over a two-second count.
- Stop just before your feet touch the ground to maintain constant tension on the abdominal muscles.
Form checklist
- Keep your shoulders down and away from your ears to avoid neck tension.
- Maintain the wide knee angle throughout the entire range of motion.
- Avoid rounding your lower back excessively as you lift your legs.
- Ensure the movement is driven by your core, not by swinging your legs.
- Keep your core braced as if you are about to be poked in the stomach.
Pro tips
- Focus on the 'posterior pelvic tilt'—imagine pulling your belly button toward your spine to engage the deep transverse abdominis.
- Press your hands firmly into the chair to create 'radiating tension,' which helps stabilize your torso and allows for a stronger leg lift.
Make it harder
- Perform the movement with a slow 4-second eccentric (lowering) phase to increase time under tension.
- Hold a light dumbbell between your feet or wear ankle weights to increase the resistance.
Frequently asked
- What muscles does the seated open knee leg raise on a chair work?
- The seated open knee leg raise on a chair primarily targets the abs and obliques, and also works the hip flexors as secondary muscles.
- What equipment do you need for the seated open knee leg raise on a chair?
- The seated open knee leg raise on a chair requires no equipment — just your body weight.
- Is the seated open knee leg raise on a chair good for beginners?
- Yes. The seated open knee leg raise on a chair is a beginner-friendly movement and a strong foundation to build on.