Notes
15 minute warm-up, then
5 cycles of (a) 5 minutes FAST (8.0 to 9.0 mph), then (b) 2 minutes EASY (6.0 mph);
then, jog at 6.5 - 7.0 mph to complete total of 8 miles.
NOTE: This is first Interval workout since Achilles injury 2 weeks ago. Really felt no issues with achilles today. Hamstrings felt more likely to cramp or strain than did the achilles. I started the cycles at 8.0 mph, and bumped it up to 8.3, then 8.5, then 8.7. In the last cycle, I went at 9.0 mph and 2% incline, and it did not feel terribly difficult.
The Heart Rate plot (at Garmin Connect) shows a nice series of 5 progressively higher plateaus (153, 157, 160, 162, 165) corresponding to the increase in speed for each round. During the 2 minute cool-downs, got down to 135, 132, 138, 140, 135. The actual Max HR should be 165 -- the 173 that is reported was during the warm-up and the HRM was not reading properly for awhile.