Notes
I wanted to go for 22, but at 19 the 2 I ran this morning made it too easy to turn back when I had to stop to cross a street. I was feeling great through about 16. At 17 as I was starting to hurt a car turned left in front of me and almost ran me over, making me slam on the breaks. I started back up but after than my legs were hurting a lot and you can see it in my mile times.
Anyway, I did this on the 4.25 mile loop around my house which has some decent hills, so I think it was good specific prep for Boston.