Frog Sit-Up

Frog Sit-Up Exercise Description

The Frog Sit-up is a bodyweight trunk-flexion exercise performed with the soles of the feet together and knees open (frog or butterfly position). This lower-body setup decreases the leverage of the hip flexors compared with straight‑leg sit-ups, shifting the emphasis toward the abdominal wall. The primary mover is the rectus abdominis, with the external and internal obliques assisting in trunk flexion and stabilization. The movement focuses on drawing the ribcage toward the pelvis with a controlled spinal curl rather than lifting primarily through the hips. It’s a simple floor variation that builds technique awareness, teaches bracing, and encourages smooth, segmental flexion under control.

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: Other
Muscle Position: Anterior
Gender: Male

How To Do The Frog Sit-Up Exercise

‘- Lie supine on a mat. Bring the soles of your feet together near your hips and let the knees fall out comfortably to the sides.
– Set a light posterior pelvic tilt: gently draw your belly button toward your spine and bring your ribs down so the low back is lightly “imprinted” on the mat.
– Place fingertips lightly at your temples or cross your arms over your chest. Keep elbows wide and neck relaxed.
– Inhale to prepare. Exhale as you initiate a slow curl by sliding the ribs toward the pelvis, lifting your head and shoulders as one unit.
– Keep the chin slightly nodded (as if holding a peach under the chin) and avoid pulling on the head or collapsing the neck.
– Continue curling up until your shoulder blades clear the floor and you feel strong abdominal tension without losing the pelvic tilt.
– Pause briefly at the top while maintaining braced midline and relaxed hip flexors.
– Lower with control on an inhale, reversing the sequence from upper back to mid-back, returning the shoulder blades to the floor last.
– Keep soles touching and knees relaxed throughout; avoid driving the movement with the hips or rocking for momentum.
– Stop the range if the low back begins to arch or the neck takes over; reset your brace and continue with smooth, controlled reps.

Frog Sit-Up Tips

‘- Bring the soles of your feet together near your hips and let your knees fall out comfortably to the sides.
– Set a light posterior pelvic tilt by drawing your belly button toward your spine and bringing your ribs down so your low back is lightly imprinted on the mat.
– Keep your fingertips only lightly at your temples or cross your arms over your chest, with elbows wide and neck relaxed.
– Inhale to prepare, then exhale as you initiate the curl to lift.
– Start the movement by sliding your ribs toward your pelvis, lifting your head and shoulders together as one unit rather than driving through the hips.
– Keep your chin slightly nodded, as if holding a peach under it, and avoid pulling on your head or collapsing your neck.
– Curl up only until your shoulder blades clear the floor and you feel strong abdominal tension without losing the pelvic tilt.
– Pause briefly at the top while maintaining a braced midline and relaxed hip flexors.
– Lower on an inhale with control, reversing the sequence from upper back to mid-back so your shoulder blades return to the floor last.
– Keep the soles of your feet touching and your knees relaxed, avoiding hip-driven movement, rocking for momentum, or continuing if your low back arches or your neck takes over.

Frog Sit-Up Beginner Introduction

In the Frog Sit-up, the person lies on the floor with a relaxed, open-leg position similar to a butterfly stretch, so feet are together and knees drop outward. This arrangement reduces how much the hip flexors contribute compared with a straight-leg version, encouraging the abs and side abs to handle more of the effort. Because it uses only bodyweight and a simple setup, it fits easily into home or gym core routines.

The motion centers on smoothly curling the spine as the ribcage moves toward the pelvis, rather than hinging mainly at the hips. The head, neck, and shoulders rise as one piece while the lower back stays gently anchored, highlighting controlled trunk flexion and steady breathing. Emphasis is placed on tension through the mid-section, a calm neck, and relaxed legs, so the movement teaches core bracing and precise control. Over time, this variation can help improve awareness of how each segment of the spine contributes to a strong, deliberate sit-up.