Crunch (On Stability Ball, Arms Straight)

Lie down on a stability ball. Place your hands behind your head with your fingers lightly touching your ears. Keep your arms straight throughout the exercise. Engage your core muscles by drawing your belly button towards your spine. Raise your upper body by flexing your abs, keeping your neck and spine aligned. Lower your body back down to the starting position. Repeat for the desired number of repetitions.

How to perform the Crunch (On Stability Ball, Arms Straight)

  1. Set up. Set up in a stable, balanced starting position appropriate for the Crunch (On Stability Ball, Arms Straight) using your stability ball.
  2. Brace and execute. Brace your core, control the descent, and move through a full pain-free range of motion while emphasizing your abdominals.
  3. Reset. Reverse the movement under control and reset between repetitions, keeping your form crisp on every rep.

Coaching cues

  • Move with intent — every rep should feel deliberate, not rushed.
  • Drive force through your abdominals rather than momentum.
  • Keep your breathing steady: exhale on the hard part, inhale on the reset.

Common mistakes

  • Using too much weight and losing positional control.
  • Cutting the range of motion short and missing the target muscle.
  • Letting your spine round or hyperextend instead of staying neutral.

Detailed cues, common mistakes, and demonstration video are available in the Fitly app.

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