Smart Workout Diary

Stability Ball Single-Leg Crunch

The stability ball single-leg crunch is an abdominal exercise performed with the upper back supported on a stability ball while one leg is lifted. It primarily trains the rectus abdominis while challenging trunk control and balance. It can support core strength and body awareness.

Demonstration

Stability Ball Single-Leg Crunch — demonstration 1
Stability Ball Single-Leg Crunch — demonstration 2

Instructions

  1. Set up securely: Place the stability ball on a non-slip surface and sit on it. Walk your feet forward until the ball supports your mid to upper back.
  2. Find your position: Keep one foot flat on the floor with the knee bent, then lift the other foot so that leg stays off the floor. Lightly support your head with your hands without pulling on your neck.
  3. Brace: Keep your hips level, ribs down, and gently tighten your abdominal muscles before moving.
  4. Crunch up: Exhale as you curl your shoulders and upper back forward, lifting only as far as you can without losing ball control or straining your neck.
  5. Return with control: Inhale and slowly lower until your upper back is supported by the ball. Complete repetitions, then switch the lifted leg.
Muscle Group
Abs
Type
Strength
Mechanics
Isolation
Equipment
Exercise Ball, Body Only
Difficulty
Intermediate

Technique tips

  1. Keep the ball still: If it rolls excessively, reduce the range of motion or place your supporting foot closer to your body.
  2. Lead with the ribs: Think about bringing your ribs toward your pelvis rather than pulling your head forward.
  3. Use a controlled tempo: Avoid bouncing on the ball, and lower slowly on every repetition.
  4. Choose a manageable setup: Keep the lifted leg position comfortable and stop if you cannot maintain a level pelvis.
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