Exercise guide
Crunchy Frog On Floor
- Intermediate
- Compound
- Rep-based
- Waist
The Crunchy Frog is a dynamic core exercise that combines a V-sit with a knee tuck to target the entire abdominal wall, hip flexors, and stabilizers. It improves balance and coordination while building significant tension in the midsection through a wide range of motion.
Reviewed by the Crucible Fit team · Updated June 2026
Muscles worked
Setup
- Sit on the floor with your knees bent and feet flat, then lean back slightly to balance on your sit bones.
- Lift your feet off the floor and extend your legs straight out at a 45-degree angle.
- Extend your arms out wide to your sides, parallel to the floor, creating a 'T' shape.
How to do it
- Exhale and pull your knees toward your chest while simultaneously sweeping your arms forward to 'hug' your shins.
- Inhale and reverse the movement by extending your legs back out and opening your arms wide to the sides.
- Maintain a controlled, rhythmic tempo, keeping your feet and shoulder blades off the floor throughout the set.
Form checklist
- Keep your chest lifted and avoid excessive rounding of the lower back.
- Maintain balance on your sit bones without letting your feet touch the ground.
- Synchronize the arm sweep with the leg tuck for maximum stability.
- Keep your core braced tightly during the extension phase to protect the spine.
Pro tips
- Focus on the peak contraction at the top by squeezing your abs as your knees meet your chest.
- Slow down the extension phase to increase time under tension for the lower abdominals.
- Keep your toes pointed and quads engaged to maintain a rigid lower body during extension.
Make it harder
- Hold a light medicine ball or dumbbell to increase resistance on the core and chest.
- Add a two-second pause at the point of full extension to challenge your stability.
Frequently asked
- What muscles does the crunchy frog on floor work?
- The crunchy frog on floor primarily targets the abs, obliques, and pectorals, and also works the erector spinae and serratus anterior as secondary muscles.
- What equipment do you need for the crunchy frog on floor?
- The crunchy frog on floor requires no equipment — just your body weight.
- Is the crunchy frog on floor good for beginners?
- The crunchy frog on floor is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.
Related exercises
- 45 Degrees Arms PlankIntermediate · abs, deltoids, obliques, and pectorals
- Alternate Leg Lift Tap Arms CircleIntermediate · abs, deltoids, obliques, and pectorals
- Barbell Leg Twist PressAdvanced · abs, obliques, and pectorals
- Battling Ropes Half KneelingIntermediate · abs, biceps, deltoids, obliques, and pectorals