I had a great 4.2 mile run tonight! My wakeup HR was 51 this morning. I left early for work and ran when I got home, about dusk. I felt great and ran a faster pace than I usually do. I do my LSD at a "comfortable" pace. I don't try to run at any particular pace, and I let my body determine how fast I run.
When I first start running, my breathing pattern is 4-4, 4 steps (LRLR) as I breath in and 4 steps as I breath out. After the first mile, my breathing pattern goes to a 2-2 pattern. As with my pace, I don't force this pattern; my body just goes to it. Once in a while, if I need more oxygen when going up a hill or something, I'll do a 1-1 pattern, but I don't do it more than just a few times. Tonight, I caught myself doing a 1-2 pattern, one step as I breath in and two steps as I breath out. That's a strange pattern since it isn't symmetrical.