Sitting
I wish there was another way around it, but there isn't. Writers write. Start small when you first begin to write, because you are also learning to sit. I began with a thirty minute session. Then I added to that time each day until I could sit and write for a few hours (with a few breaks to the fridge or coffee pot). There are days the minutes drag and there are days the hours pass by like seconds. That's the way most jobs are.