I realized that I will be traveling on Friday from 3:30am until ~6:00pm. So I moved Friday's jog to today since I had to go in to the big city anyway. I ran flat mile repeats at a few different HR's to try to get a sense of how to run on Saturday.
2 mile warm-up. Felt incredibly rested and good.
1 mile at HR 125-130 in 7:46
1 mile at HR 130-135 in 7:31
1 mile at HR 135-140 in 7:20 (1 breath every 5 steps)
I've had many people caution me to start easy on Saturday. Once I hit mile 30 I will have a much better understanding of what 'starting easy' is, right now though... no clue. All of the above miles were very easy. Anyone with 50 mile racing experience, feel free to give some advice.
My strategy so far for Saturday: Respect the distance but don't fear it.