Notes
The 8 miles 4 through 11 at Marathon HR, that is: zone 4. Felt OK but had to back off a little at the end of mile 7 and the last couple were like a zombie death march.
Still, definite progress with what would have been PBs for the 10-mile distance (by six minutes) and possible even half-marathon as well although that's a closer call.
Training Plan Entry
Tempo
13 mi
Marathon pace for 8 miles