HI!
It has been my experience that pilates works the anterior core more, and yogs concentrates on the posterior core. I think with AS, where our tendency is to become kyphotic (hunching forward) that it is imperative to concentrate on our posterior chain and do more "pulling" work than "pushing" work.
Sooooo, with that said, perhaps a combination of the two would be great! I love them both, but nothing makes me feel better than lap swimming.
Regards!
Ellyn
