Writing all day

I have been writing all day at work. I am working on updating our project's design document. Prior to development we had written this document with what we planned to do. Now that we're done we have to update it to the reality of what we actually did. Since yesterday I've broken the current document into a master document and many subdocuments each of which is a chapter (something I've only just learned how to do with MicroSoft Word and its outline format). Yesterday and today I've worked on the Introduction and the Portal, the web application, chapters. Another member of my group is working on his chapter for the work he did. I sat all day typing and reading and writing. My butt was sore from sitting so long. Now there are still several more chapters to do, and I don't relish sitting there all day tomorrow and the next. But I will persist.