Since in a small shop most people have to handle multiple roles, its sometimes hard to evaluate what your real work load is as far as any given set of tasks. The effort to effectively track each task is another task, and most people aren't really willing to give up 10-20% of their employees time to administrative tasks involving time tracking, so the end result is a sort of vague count "I spent about 5 hours programming, and about 2 hours production support and 1 hour administrative"
However, any computer programmer who is exhausted by heads down coding should probably find something better to do. When I was in my twenties I often would code for 10-12 hours a day for stretches lasting as long as a month. I think I once did 20 hour days for 4 weeks with really no break on weekends. Not that it was healthy, but as far as just pounding out code, testing it, packaging it for UAT and then moving on, I was pretty non-stop. Now that I am 40 I prefer not to do that however I had a project in which I lost my coder to another project and suddenly had to fill in for 8 weeks that wasn't on my schedule. I did a few all nighters, and certainly was averaging 14 hours per day for about 2 weeks, mostly coding.
Obviously that doesn't just mean writing a line of code a minute. It does involve testing things, finding answers to problems, designing algorithms, refactoring, but if you think programming is purely a function of typing out commands then I suspect you are writing trivial code.
In any case, I don't want to judge, and I don't think people are being fair talking about you being lazy. It is VERY difficult to really code productively when you have to break every hour. I find that I like to set myself up for 4 hour slots for programming, so that I can really warm up, get into the right head and have time to really complete a few significant things.
Still I think about programming when I am showering, or eating, or walking. Thinking is a big part of my job. Its really a challenge to just program at work and then stop thinking about it afterwards.
The real question always has to be, are you delivering what you promise to deliver on time. If you are having trouble getting things done on time then you have to worry about how you are organizing yourself. If you are feeling like you just can't program more than a certain number of hours a week without your head hurting then get a better monitor.