12/13/13 NOTE: I am republishing this as I found out that I accidentally published this as ‘private’ back in September. My apologies.
UGH! This one is so tough for me! Lay on your back with your arms out to your sides and flat on the floor. Lift your legs at a 90 degree angle and move them side to side.
Easy option: Bend your knees
Hard option: Keep legs straight
Work your way up to a total of 40 full rotations.
So What? I run. 
Holy cow that looks fun! lol
Fun, but man…I must have sucky obliques! You can totally feel the work afterwards.
LOL there may or may not have been a hint of sarcasm in my comment 😉
Doh! Bahahahahah!