Frog Crunch
Frog Crunch Exercise Description
The Frog Crunch is a bodyweight floor exercise that emphasizes controlled trunk flexion to target the rectus abdominis, with assistance from the internal and external obliques and support from the transverse abdominis. Performed in a “frog” or butterfly leg position (hips abducted and externally rotated, soles of the feet together), it focuses the work on the abdominal wall rather than hip movement. The goal is to curl the ribcage toward the pelvis, lifting the shoulder blades just off the floor while maintaining a stable pelvis and quiet lower body. Proper execution uses a gentle abdominal brace, a slight posterior pelvic tilt, and a neutral neck to limit strain and keep the motion in the thoracic spine. This variation is a clear, compact way to practice high-quality crunch mechanics with minimal equipment and a short range of motion.
- Muscle Groups: Abs, Core, Waist
- Target Muscles: Rectus Abdominis
- Assisting Muscles: External Obliques, Internal Obliques
- Stabilizing Muscles: Multifidus, Transversus Abdominis
- Body Area: Upper Body
- Body Parts: Core, Torso
- Body Surface: Front
- Body Symmetry: Other
- Equipment: Bodyweight
- Exercise Patterns: Other
- Exercise Type: Strength
- Functional Grouping: Trunk Flexors
- Joint Involvement: Single-joint
- Muscle Location: Stomach
- Movement Direction: Vertical
- Muscle Position: Anterior
- Gender: Male
How To Do The Frog Crunch Exercise
‘- Lie supine on a mat; bring the soles of your feet together and let knees fall open comfortably.
– Slide heels in toward your hips as mobility allows; keep feet on the floor.
– Extend arms forward between the thighs with relaxed shoulders; keep head and neck neutral.
– Lightly brace the abdominal wall; bring ribs down toward the pelvis.
– Set a slight posterior pelvic tilt so the low back gently contacts the mat.
– Exhale as you curl the upper trunk: lift head, then shoulder blades, by shortening the distance between ribs and pelvis.
– Keep gaze up (not at your knees); chin lightly tucked; avoid pulling on the neck.
– Reach hands forward without swinging; keep legs relaxed and still.
– Pause briefly with shoulder blades off the mat while maintaining the pelvic position.
– Inhale and lower the torso with control until shoulders touch down softly—do not arch the low back.
– Repeat with the same small, smooth range; stop before momentum takes over or the pelvis shifts.
Frog Crunch Tips
‘- Bring the soles of your feet together and let your knees fall open comfortably before you start.
– Slide your heels in toward your hips as mobility allows while keeping your feet on the floor.
– Extend your arms forward between your thighs with relaxed shoulders and a neutral head and neck.
– Lightly brace your abdominal wall and bring your ribs down toward your pelvis before you curl up.
– Set a slight posterior pelvic tilt so your low back gently contacts the mat and keep that tilt throughout.
– Exhale as you curl the upper trunk, lifting the head first and then the shoulder blades.
– Keep your gaze up (not at your knees) with a light chin tuck, and avoid pulling on your neck.
– Reach your hands forward without swinging them, and keep your legs relaxed and still.
– Pause briefly with your shoulder blades off the mat while maintaining your pelvic position.
– Inhale and lower your torso with control until your shoulders touch down softly, without arching your low back.
– Use the same small, smooth range on each rep and stop before momentum takes over or your pelvis shifts.
Frog Crunch Beginner Introduction
The Frog Crunch is a bodyweight core move performed on the floor that highlights precise, small curling of the upper body. With the legs placed in a relaxed, butterfly-style position and the feet touching, the hips stay largely out of the effort so the front of the mid-section takes center stage. The motion brings the ribcage toward the hips, lifting the head and shoulder blades just slightly away from the ground while the pelvis stays steady and the neck remains in a natural line.
This variation zeroes in on the abs, with help from the side abs and deeper stabilizing muscles around the waist. Because the range of motion is intentionally compact, the emphasis falls on control, smooth tension, and a gentle bracing feeling through the midsection rather than big, swinging movements. The result is a clear, simple way to practice refined crunch mechanics on a mat, using only body weight and a calm, quiet lower body to support the work.