A.M. Ran with Derek. We did a 2.62 warmup. Then I did a modified Lindgren tempo. This time I warmed up for 0.5 miles at a slower pace before trying to run 5:00. Derek joined me for the last 2 miles.
Splits: 84, 83, 79 (jumped over a tree), 78 - 5:24 mile, 81, 85, 88, 87 (5:43), 86, 87 (14:01 at the turnaround), 89, 86 (5:47), 86, 84, 85, 86 (5:42), 82, 83, 84 (tree jump), 81 (5:30) - 28:06.2.
HR: climbed to 162 during the attempt at a 5:00 mile, then dropped miserably. Sat around 155 between 1.5 and 3.7. Then with Derek's help got up to 158. In the last mile got up to 160, and hit 166 in the last quarter.
Other observations: When running 5:44-5:48 pace HR was stuck at 155 but the breathing felt very labored. Once Derek joined me and I started running behind him, HR was higher, I was running faster, but the breathing felt a lot less labored. Possible explanation - breathing rate correlates with turnover. Earlier, the ground push-off power (which determines stride length) was reduced for some odd reason, so I had to turn over quicker to run a slower pace. Running behind Derek rebooted the push-off power computer, now I did not have to turn over as quickly.
Jogged with Derek to 10.25, dropped him off, drank a large cup of Powerade, then jogged to 13.62 and ran another 5 mile tempo on the exact same course except this time I did not have to jump over the tree twice.
Felt sluggish and unmotivated during that part, like I was ready to be done with the workout already. Very similar to mile 20 of the marathon. Was not sure what to expect of the tempo.
Splits in the second tempo: 5:48, 5:46, 14:27 at the turnaround, 5:49, 5:49, 5:42 - total time 28:54.7.
HR: Could not bring it over 150 in the first 2 miles. Then it hovered at 152-153 for the next two and a half. Then all of a sudden it shot up to 157 with no change in pace but there was a slight increase in the perception of effort. Was able to push it to 164 in the last quarter which I ran in 82.
Subjective observations: felt sluggish at the start. Had to focus on high turnover to keep the pace. Was able to keep the pace but it required a lot of concentration. When HR increased at 3.5 miles did not feel a significant increase in effort. At 3.25 felt that my ability to concentrate has decreased, and it coincided with a slight let-up on the pace. However, focusing on high turnover allowed me to regain the momentum. Breathing felt controlled, it was rhythmic but not exhaustingly bothersome like in the first tempo after the surge.
Analysis: the increased HR at 3.5 was probably the result of dehydration and rising temperatures - I was over 17 miles into the run, and it was already around 9:00 am. I was actually surprised earlier when I saw that I could maintain sub-5:50 pace with HR below 150 for so long that late into the run.
Ran a cool down of 1.38 miles which gave me 20 miles for the whole run.
I think I've got my marathon second half slow down figured out. Fuel shortage is nothing more that a conspiring catalyst. It is primarily caused by a weak nervous system. I've heard a cop tell me on several occasions that he got tired watching me run. This form of fatigue is somewhat similar to what that cop experiences. When the fuel is low the neural drive goes down. When the nervous system is naturally it may still be enough to maintain the pace. When it is weaker, this causes a problem.
This explains why it is so common for me to let a competitor go between 13 and 16, and even as late as 18 feeling like I could not run even one more mile at that pace, have him gap me enough to be out of sight, but then pass him after 20 miles even though I have slowed down myself. I have plenty of fuel, he has plenty of neural drive. He is running lower than me on fuel, but he can keep the pace because his neural drive is strong. After 13 I have two issues - the neural drive goes down just from the stress on the nervous system itself, plus the fuel runs a bit low which acts as a drive reducing catalyst. No big deal yet for the competitor because his nervous system is strong, he feels good, and knows nothing of his impending doom. I used to be like that when I was running 2:40s. Now, I sense the trouble to the point that I am forced to slow down, I do not have a choice. Then the competitor with his strong nervous system but a less deep gas tank just slams into a wall and cannot break 7:00 while I am still plodding along at 6:00-6:20 pace. This works only for competitors that have not yet built up their gas tank. The moment their gas tank starts working the scenario changes. At 13 all of a sudden I cannot keep their pace. I slow down, they do not. They never run out of fuel and finish ahead.
Now running the second half of TOU with a better than before realization of why I am running slow (and likely why I am getting beat as well) would be quite frustrating. Is there anything I can do about it? That remains to be seen.
T4 Racer - 487.93 miles
P.M. 1 with Julia in 9:55, 2 with Benjamin in 16:26, Jenny ran the first 1.5 with us in 12:52.
Five Fingers - 1227.27 miles