Rather than the full 2,400 m, I run five laps, or 2,000 m per rep (five laps of a 400 m track). This makes each rep last about the same time as Hadd's runner, "Joe". The conditions can play an important role. During the first test it was 24 degrees and humid. On Wednesday it was 28 degrees and not so humid. All in all, I don't think the difference in temperature had too great an influence. So, the idea of the test, if you didn't read Ewen's post, is to run a series of consecutively higher heart rates, starting around 70 to 75% of maximum and then 10 beats higher each time with the last one being around 90% of max. In so doing, you should be able to identify your lactic accumulation threshold, where your muscles tip over from being able to clear lactic acid as fast as it forms to a state of net lactic acid accumulation, in other words, unsustainable.
Here are my results given as average pace (minutes per km) for the entire 2000 m:
|Date||135 (73%)||145 (78%)||154 (83%)||165 (89%)||175 (94%)|
It is easy to run a little erratically in the first couple of laps as you bring heart rate up to target, so I thought it would also be helpful to look only at the average pace of the last two laps. If there is more fade in one test than another, the data of the last two laps should highlight that.
Results as average pace (minutes per km) for just the last 800 m
There are two main points to take out of these numbers:
1) I have shown a fairly dramatic improvement at the 145 (178% HRmax) level. This is logical because it is where I have been spending a lot of my time in training AND, I think I tended to neglect it in the past, running either harder or easier than the low 140s.
2) There has been no noticeable improvement at the 165 and 175 levels. I attribute this to a combination of a few things. i. It was warmer on Wednesday, so maybe I was starting to get some heat accumulation. ii. I just haven't run enough km or at high enough heart rates to move these limits yet. iii. My aerobic fitness for these heart rates was already pretty well trained on June 20.
By the time of the next test the weather will be starting to get milder and I will have been doing more distance at upper aerobic pace, exhausting though it is. So it will be interesting to see what will happen next.