Day 51: 5mi, 42:45

I got back on the treadmill Sunday, after a longish layoff of three days. My splits:

mile 1: 8:23
mile 2: 8:11
mile 3: 8:20
mile 4: 8:43
mile 5: 9:04
HR t+1: 123
HR t+5: 92

So my pace seems to be steadier than when I first started the low HR training. I also noticed that I did not have to adjust my pace at all during the entire last mile. In previous runs, I had to keep slowing down pretty regularly - every quarter mile or so. It's only one data point, but it seems like my body is getting used to operating at this HR, and can maintain this level of exertion for longer now.