Shawn Achor, a psychologist highlights the fact that happiness towards what we do is a sign for better productivity.
Through his humour, he shows us that the happier that we are, along with the fact of changing the way we interpret the world, we can find happiness in what we do.
He specifically goes with this process of changing the formula of our happiness to make ourselves gain the essence of interest within the particular work/subject/job that we feel ready to slack off and procrastinate upon.
I did try this method today and I could not believe that I had achieved so much in one day. I studied two lessons of Biology and Chemistry as well as a lesson of Maths, accompanied with studying a few topics from Psychology, and these were things that I need to cover for my upcoming exams that start next week. Plus, I did get some schoolwork done as well, so I do think that I have been productive by having a happy mindset.
So, change your happiness formula and see the workflow in how much you get done for a day.