Lie on the floor while your legs are over your hips at 90 degrees and your arms are overhead. Take a deep breath, and when you exhale, lift your head and shoulders off the floor, and as you crunch up, open your legs so your arms chop through your legs. Repeat this movement for 1 minute.
When you want to work your obliques, chop each hand through the opposite leg, for example, when you lift your head and shoulders off the floor, chop with right hand through your left leg and alternate between the sides.