Swiss Ball Jackknife

Abs, obliques, hip flexorsSwiss Ball

Builds core and hip flexor strength while challenging balance on an unstable surface. Heavily loads the rectus abdominis, obliques, and shoulder stabilizers.

How to do it

1Get into a push-up position with your shins resting on a Swiss ball and hands stacked under your shoulders.

2Brace your core so your body forms a straight line from head to feet without sagging at the hips.

3Contract your abs and pull your knees toward your chest, rolling the ball forward with your feet and driving your hips up slightly.

4Pause for a second at full contraction while maintaining your balance.

5Slowly extend your legs back out to return to the high plank position.

Common mistakes

Letting your hips sag at the start or during the extension, straining your lower back.

Relying on momentum and jerking the ball, which disengages your abs and increases the risk of slipping off.

Excessively rounding your upper back, shifting tension away from your core into your neck and shoulders.

Breathing

Exhale as you pull your knees to your chest and contract your abs; inhale as you push back out.

Make it harder or easier

To regress, position the ball under your thighs instead of your shins or feet.

To progress, perform the exercise with only your toes resting on the ball or slow down the tempo.

This is general guidance, not a medical opinion. Listen to your body: if it hurts, stop. If you have an injury or a chronic condition, talk to a doctor first.