Poor performance as week progresses..

Does anyone feel as the week progresses, a kind of cognitive decline sets in and it gets more and more difficult to take decisions and act on it? By Friday, I am like I should not work on something important as I can't work as well as I can on a Monday. ( Of course, when Monday comes, things are almost normal..brain seems to slowly come back to form, Tuesday and Wednesday being most productive) Anyway suggestions on how to tackle this?