Anecdotally, I intentionally never worked more than 4 hours any given day when writing my masters thesis. I ended up finishing many months ahead of my peers, wh

Anecdotally, I intentionally never worked more than 4 hours any given day when writing my masters thesis. I ended up finishing many months ahead of my peers, which I feel like was because of, not in spite of, limiting the hours I worked. I was always refreshed and motivated, and it was trivially easy to be productive and effective during the 4 hours I was working. After starting a regular 9-5, I've never felt the same kind of productivity, because I am never as rested and refreshed.