Cardio Abs is about a 16 minute ab routine from Insanity. In the Insanity schedule, you typically do this workout right after you do either Pure Cardio or MAX Cardio Conditioning. This is quite a different ab workout than Ab Ripper X. Cardio Abs Starts with a brief warm up for you core. Also, you never do any crunches or sit ups. Instead, you are in a “C-Sit” position which really engages your core. You also do a lot of plank exercises. In my opinion, Cardio Abs is more of an abdominal endurance workout and Ab Ripper X is more of an abdominal definition workout. Both a important in a fitness program! I typically do Ab Ripper X once a week, and Cardio Abs once a week. Email me at rushing@austin.rr.com if you have any questions!