Exercise guide
Sitting Frog Crunch On A Padded Stool
- Intermediate
- Compound
- Rep-based
- Waist
The Sitting Frog Crunch targets the entire abdominal wall and hip flexors by utilizing a wide-knee position to increase lower-ab engagement. Performing this on a stool allows for a greater range of motion and challenges your core stability more than floor variations.
Reviewed by the Crucible team · Updated June 2026
Muscles worked
Setup
- Sit on the edge of a padded stool or bench, gripping the sides just behind your hips for support.
- Lean your torso back to a 45-degree angle while maintaining a flat back and neutral spine.
- Lift your feet off the ground, bringing your heels together and pointing your knees outward in a 'frog' position.
How to do it
- Inhale and extend your legs straight out in front of you, keeping your heels together and knees turned out.
- Exhale as you pull your knees back toward your chest, simultaneously crunching your upper body slightly forward to meet them.
- Maintain a controlled 2-1-2 tempo, focusing on the deep contraction in the lower abdominals.
- Keep your core braced throughout the entire range of motion to protect your lower back.
Form checklist
- Keep your heels glued together throughout the entire movement.
- Ensure your lower back does not arch excessively as you extend your legs.
- Keep your chest open and shoulders pulled back and down.
- Avoid using momentum or swinging the legs; use the abs to drive the movement.
Pro tips
- At the peak of the contraction, squeeze your heels together hard to further activate the lower abdominals and pelvic floor.
- Maintain a slight 'hollow body' position even at full extension to keep constant tension on the core muscles.
Make it harder
- Release your hands from the stool and hold them out to your sides to remove the stability assist and force the core to balance the body.
- Slow down the eccentric phase (leg extension) to four seconds to increase time under tension.
Frequently asked
- What muscles does the sitting frog crunch on a padded stool work?
- The sitting frog crunch on a padded stool primarily targets the abs and obliques, and also works the hip flexors as secondary muscles.
- What equipment do you need for the sitting frog crunch on a padded stool?
- The sitting frog crunch on a padded stool requires no equipment — just your body weight.
- Is the sitting frog crunch on a padded stool good for beginners?
- The sitting frog crunch on a padded stool is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.