Notes
This was meant to be 4 x 6:00 miles.
I learned three things from this partially-failed workout:
(1) Don't try and make a big jump like going from 4 x 6:11 miles to 4 x 6:00 miles. Too much.
(2) Don't run the first interval too fast (5:55).
(3) Don't push a big final lap (i.e. a 1:26.6) and then expect to recover OK for the next interval.