I came along a new exercise for exercising the obliques.

Sit on a ball.
Using one arm first hold a dumbell aloft.
Keep the arm vertical with the plam facing front.
Using the side of the body (Obliques etc.) trun the body downward to bring the weight toward the knee.
Raise the weight vertical again.

This is best done over a time period (30 secs - 1 minute.)
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