Notes
Was a little worried about this one, but it went pretty smoothly. Really had to keep the brakes on for the first 2-3 segments and even then was comfortable until about the 6th one. That one wasn't too bad until I stopped paying attention to my watch and then had to make up some ground.
Training Plan Entry
Tempo
7 mi
~2 miles easy
21 Minute Progression
Shifting gears each 3:00 for a total of 7 shifts. This would be ridiculously easy on a treadmill but also work great outdoors if you just run off perceived effort and crank the pace just a bit each 3 minutes. Don't worry about exact splits.
7:10
7:00
6:50
6:40
6:30
6:20
6:00 (or faster)
Easy afterwards to get you to 6 miles or even 7 if you really want to.