I thought it was interesting that these artists saw their routines as liberating, preparation for the real art they were about to create. Often I look at preliminary drawings and warm up exercises as the crap I have to wade through before I can get to really creating and expressing, where I feel free. On the flipside though, I often look at my academic classes as liberating, where I can just think logically, a-b-c, and that's it, while in art I'm forced to pull something from inside me and throw it on a piece of paper. I don't know, things like this shift around for me a lot, I'm still figuring out how I like to work, but this article held an interesting perspective.