Workout D

Exercise Description

Lie flat on your back. Bring your knees to a 90° angle directly over your hips, and extend your arms straight up toward the ceiling.
Place the stability ball between your hands and your knees. Drive the stationary arm and knee into the ball to create active tension.
Ensure your lower back is completely flush against the floor. There should be absolutely no space or arching under your lower spine.
Simultaneously lower your right arm backward over your head and extend your left leg forward. Keep them hovering just above the floor without touching it.
Exhale, return the extended arm and leg back to the ball, and repeat on the opposite side (left arm and right leg).

Frequent Errors

If your lower back arches away from the floor during the extension, you lose core engagement and risk straining your spine.
Speed relies on momentum rather than muscle control. Perform the movement slowly and deliberately, focusing on the quality of your abdominal bracing.
The Swiss ball provides feedback. If you loosen your grip or stop pushing it between the working points, you lose the extra core activation.
Lowering your arms and legs too far toward the floor can over-tax your lower back. Only lower them as far as you can while maintaining a flat spine.
Breath-holding restricts deep core muscle activation. Inhale to prepare and exhale as you extend your limbs to help brace your core.

Coach Notes

Perform the exercise without the Swiss ball, pushing with the opposite hand and knee while extending your free limbs. Focus on the push/counter-push that creates abdominal tension.

Circuit