It shouldn't be so surprising that an ability to concentrate is a skill that can be improved, and that the best way to improve a skill is to directly practice it!
> The point of not being able to read a whole book seems like bunk to me, though, since I read for recreation, and it takes the amount of time it takes. I can't sit and read a whole book, just like I can't sit and watch a whole season of a television show.
I don't that's what the article refers to -- it's finishing the book at all, not just in one sitting.