Just based on this workout I did today, what do you think I can do? IT was 4x400 with 90 seconds rest (59, 60, 60, 59) 5 minutes rest, then 3x300 with 90 seconds rest (42, 43, 43).
The 400s were smooth. The last 300 was some work, but I could've done another if I had to. My pr right now is 4:01 from a few months ago, and I haven't run it since. Tapering off of ~50mpw currently. What should I am for?