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Abs · Intermediate

Jack knife on Ball

Trunk-flexion drill that develops abdominal strength and control using a stability ball, with emphasis on the abdominals.

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Exercise overview

Training details

AbsHip Flexors

Equipment

Stability Ball

Sets × reps

3 × 12

Rest

1 min

How to perform it

Step-by-step instructions

  1. 01Start by lying on your back with your legs extended and arms overhead holding onto the stability ball.
  2. 02Simultaneously lift your legs and upper body while bringing the stability ball towards your legs.
  3. 03Squeeze at the top for a moment, and then slowly lower back to the starting position.
  4. 04Repeat for the prescribed repetitions.
  5. 05Complete the prescribed repetitions while maintaining the same alignment and control.

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Variations

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Closely related versions of this movement with a different grip, setup, equipment, stance, or difficulty.

Easier regressionJackknife Sit UpRelated variationJanda Sit Up

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Alternatives

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Substitute exercises that train similar muscles or serve a comparable purpose in a workout.

Comparable substituteCurl-UpComparable substituteReverse CrunchComparable substituteHanging Leg Raise

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