Exercise guide
Sitting Floor Diagonal Knee Raise
- Intermediate
- Compound
- Rep-based
- Lower legs
- Upper legs
- Waist
This exercise targets the rectus abdominis and obliques by combining trunk flexion with rotation, enhancing core stability and rotational power. It is highly effective for defining the waistline and improving functional midsection strength.
Reviewed by the Crucible Fit team · Updated June 2026
Muscles worked
Setup
- Sit on the floor or the edge of a flat bench with your knees bent and feet flat.
- Lean your torso back at a 45-degree angle to engage your core, placing your hands on the floor behind your hips for support.
- Lift your feet 2-3 inches off the ground, balancing on your sit bones with your spine neutral.
How to do it
- Exhale and pull your right knee toward your left shoulder while slightly rotating your torso toward the rising knee.
- Inhale and lower the leg back to the starting position in a controlled manner without letting your foot touch the floor.
- Immediately repeat the movement on the opposite side, pulling the left knee toward the right shoulder.
- Maintain a steady, rhythmic tempo, focusing on the 'crunch' at the peak of each rotation.
Form checklist
- Keep your chest lifted and avoid rounding your shoulders forward.
- Ensure the rotation comes from your waist, not just moving your legs.
- Maintain the backward lean throughout the entire set to keep the abs under constant tension.
- Keep your neck neutral and gaze forward to avoid strain.
Pro tips
- Focus on the mind-muscle connection by imagining you are trying to touch your rib cage to the opposite hip bone.
- Pause for a split second at the peak of the contraction to maximize oblique engagement.
Make it harder
- Perform the movement with your hands behind your head (prisoner style) to remove the arm support and increase the balance challenge.
- Extend your legs fully between repetitions to increase the lever length and tension on the lower abs.
Frequently asked
- What muscles does the sitting floor diagonal knee raise work?
- The sitting floor diagonal knee raise primarily targets the abs and obliques, and also works the erector spinae, hip flexors, and quadriceps as secondary muscles.
- What equipment do you need for the sitting floor diagonal knee raise?
- The sitting floor diagonal knee raise requires no equipment — just your body weight.
- Is the sitting floor diagonal knee raise good for beginners?
- The sitting floor diagonal knee raise is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.