So this week I have returned to my roots, low heart rate training. For me this means keeping my heart rate between 126 and 132. As a practice I keep at or below 130 at least 90% of the time. Everybody says if you train slow you will run slow, which is fine by me (not).
On Monday I ran 4.88 miles with the following splits: 14:27, 14:39, 15:09, 15:29 and 13:44 (15:34 pace)
This morning, same temperature, I started a half-hour earlier and ran 6.63 miles as follows: 13:39, 12:56, 13:11, 13:28, 13:42, 14:03 and 9:04 (14:25 pace).
Thus, my pace on my last lap was the same as the pace on my first lap on Monday, and my average pace dropped from 15:03/mile to 13:35/mile. By contrast, the best one I have run so far was on May 4 of this year, 20 degrees cooler than this morning, 6 miles at an average pace of 12:14. So for context, this morning I was closer to my best time than to Monday's time. Heat adjusted, I don't know what the difference would be, or even whether I was better or worse this morning than on May 4.
I don't quite know what to make of this. Possibly on Monday I was still tired from my 20-mile run on Saturday. Another possibility is that since I have been neglecting my aerobic training this summer, out of necessity dealing with injuries and trying to get ready for a couple of races, I am now starting to get back into "aerobic" shape, which they say is a different type of conditioning with a separate fitness level, or lack thereof. Other than that, it is all part of the wonderful mystery of running. Kind of like golf.
Y'all might not think much of my "fast" splits this morning, but to this old man they were music in the night. Just from the sheer excitement of it all I had a hard time keeping my heart rate down.