At just 20-25 (pain-free) miles a week, which is kind of baseline so I'm signed up for a local 5K this weekend. On Tuesday I did some tempo/threshold reps (3 to 5.5 minutes, 16 minutes total). Didn't feel that great, and maybe ran the first two too fast. Figuring on 6:20 mile pace or so on Saturday with progression from 6:30 to 6:10s but we'll see.