Recovery 5 miles

Yesterday's training: Rest
Today's training: 4.89 miles, 50:14 (10:17 min/mi), avg 144 bpm/max 155 bpm/5:20 above 150bpm

I was a minute slower and heart rate 2 bpm higher than my last five mile recovery run. Looking more closely I was at the same time at 3 miles, so the 1 minute difference is all in the last two miles.

Probably not worth reading anything into it, but I did wonder if my fitness is slipping from the taper plus recovery. I've been debating what pace to do mid-week medium long runs at. Last go around, I did them at <160 bpm, but I was considering lowering that to <150 to make sure I got up to 60-65 peak mpw without injury since I'm assuming volume is more important than intensity since I'm short on endurance. I'm also uncertain of the long-run pace. Following Daniels/Pfitz would I base it on my 10K time or my marathon time. I believe Daniels would say the 10K time, but does that make sense?

I'll try under 150 again tomorrow for my ~10 mile run. I have a 10-mile race a week from tomorrow, so that will be a nice 10 mile tempo run.