Smart Workout Diary

Frog Sit-Up

The frog sit-up is a bodyweight abdominal exercise performed lying on your back with the soles of the feet together and knees opened outward. It primarily trains the rectus abdominis through trunk flexion while reducing the contribution of the hip flexors for many people. It can support core strength and abdominal endurance.

Demonstration

Frog Sit-Up — demonstration 1
Frog Sit-Up — demonstration 2

Instructions

  1. Set up: Lie on your back on a comfortable, firm surface. Bring the soles of your feet together close to your body and let your knees fall outward.
  2. Position your arms: Extend your arms overhead or reach them toward your feet; keep the position consistent throughout the set.
  3. Brace: Gently tighten your abdominal muscles, keep your neck long, and exhale as you begin to curl your upper body upward.
  4. Sit up: Lift your shoulders and torso smoothly toward your feet, using your abdominals rather than pulling with the neck or swinging your arms.
  5. Return with control: Inhale and lower your torso slowly until your upper back reaches the floor. Repeat without bouncing or forcefully arching your lower back.
Muscle Group
Abs
Type
Calisthenics
Mechanics
Compound
Equipment
Body Only
Difficulty
Beginner

Technique tips

  1. Move deliberately: Use a smooth curl up and a slow descent; momentum makes the exercise less effective and harder to control.
  2. Protect the neck: Keep your chin lightly tucked and your gaze generally upward. Do not pull your head forward with your hands.
  3. Choose a manageable range: Lift only as far as you can while keeping the movement controlled and comfortable through the hips and lower back.
  4. Match breathing to the movement: Exhale as you rise and inhale as you lower to help maintain abdominal tension.
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