When I used Hal's training program, I didn't have a specific race pace, just a general idea of going a consistent speed. What speed that should be, I had no idea. Maybe flat 10s? I never trained them though.
When I switched to the Hansons program in August, every Wednesday run was to be done at race pace, so I definitely needed to know my target time. I somewhat arbitrarily picked 10:30. In Chicago, I maintained that for about 17 miles, then started getting slower. I trained 10:30s again for Cincinnati this spring, maintained it for about 18 miles, then slowed down for a few miles, before recovering my pace the last 4 miles.
Looking toward Chicago this fall, I wanted a faster race pace, but how much faster? If I trained 10:15s, would that be taking the easy route and not pushing myself? Would 10:00s be too fast? I had no idea.
I consulted the McMillan pace calculator, where a runner enters a recent finishing time, and it projects finishing times for everything from 1 mile to a full marathon. I entered my time from the Martian half, knowing that the longer my race, the more accurate the prediction.
What's interesting is that McMillan thinks I should be running faster for the 5k and 10k than I have managed at races. Granted, I could have pushed a little faster on my last 10k (55:28 PR), but I felt like I was dying and needed oxygen when I did the 3.14 Pi run in 26:08 haha