Inverted abs on the ball. Begin w/ the ball places slightly below your knees. Next draw the balk toward you by flexing you abs, and lifting your hips upward. Work to avoid bending your knees. As you draw the ball forward, rotate to one side or the other slightly to engage obliques and transverse abdominals. Return to plank and repeat 12x per side. To increase intensity throw a set of pushups in between each side! (Taken with instagram)
