Right after Ryan was born I started doing ab exercises from a post-natal ab course I took a few years ago. Pregnancy destroys the core, and building it back up first is essential to all other things that followed. I did those exercises for a few weeks until I was ready to run again ... and then I stopped doing them altogether.
Recently, I've started seeing my personal trainer again. We are definitely moving in baby steps as its been about a year since I've done any strength-type exercises. I've found that I'm pretty weak, but its not that surprising. What was surprising is my inability to do almost any type of ab work. My trainer gave me a few exercises to do today and I couldn't do them. She had to simplify all of them. Whatever I built back is completely gone. So, I'm back to the basics on everything it seems. Seems like it will be a little bit before I'm back to doing these.
(Ha! Ha! I've never been able to do anything like that. In fact, I dont think I could even hold my own weight hanging from a pole, let alone wing my legs around like that. Are there real people out there that do this stuff?)