I read up a little bit about supplementation of BCAA's and it makes sense why they could be useful to use before, during, and after their workouts. But I also read up a little bit about proteins and their amino acid profiles and it shows that most proteins already have the BCAA's in them and enough of it. So for that reason I don't understand why one would need to further supplement with BCAA's if there are already consuming enough protein around their workout times. The best example I can think of is for me for example, I like to have protein shakes before and after my workouts.
Is there any reason why one would need to have more BCAA's during those times if they were already getting enough from the protein? Or does the idea of supplementing with BCAA's already assume that you aren't getting enough around those times?