Productivity has various shades and maximizing productivity of a corporate slave is difficult.
What I have observed is people sprint only under to two situations- first when a lion is behind them or when they are chasing a gold treasure. Expecting people to sprint all the time doing work as normal without any gains or losses doesn't get winners in any situations.
In my experience my work day is generally divided into three sets of tasks. Periods which I spend firefighting, providing support to some urgent issue, providing information, routine chores, fixing bugs, adding features. The most productive periods of my work involve doing new stuff. The most unproductive and boring stuff involves manual testing, writing test cases and documentation.
So if you see it- money, fear of getting fired and interesting work form the biggest motivating factors in my daily productivity efforts. I never understood CEO/VP/Manager BS talk of expecting people to remain ridiculously productive regardless of rewards and quality of work. Especially when they themselves don't follow that advice. No manager/CEO/VP I've every met wants to work in a non growth area of work. They never want to touch anything that is not rewarding to their very own careers. Yet they expect their reports to the very thing they would never do.
Other wise personal productivity wise, my day breaks up into three parts 8:00-12:00, 13:00-17:00, 20:00-00:00. I skip the last part sometimes. Another thing that I've learned about productivity is to know how to tackle inevitable distraction. How not to get overwhelmed by tasks at hand, How to use GTD efficiently and learn to work from one session to another.