Had a pretty tough workout last night. I was proposing another tempo run, this time 12 km, and was going to write an email to Joachim to invite him to join me. Before I could, he wrote to me and announced he was doing 3 x 4.4 km "intervals" at 3:47/km with a mile recovery between each. My first reaction was to gulp. My second was to think that, well, that structure would be similar to a good tempo run. Tempo intervals I think they call it. Having not done any intervals quite as long as that (I think the most I've done is 2 km), I decided what the heck, but I told him that my target pace would be more likely to be 3:50.
And 3:50 is what we set out to do. I developed a sore left fetlock (soleus) during the first interval, but decided to press on. Despite a bit of concern about more severe damage, I went on to complete the workout, though it did suppress my pace a bit on the third rep as you can see from the data:
Time Pace HRav
16:43 3:48 155
16:41 3:48 156
16:56 3:51 154
Again noteworthy is how stable and low my heart rate stayed for this pace. At any other time in my running history, 3:50/k pace would have seen me getting over 160, if not in the first or second km, at least by 3 and 4. But not at the moment.
Before anybody gets too excited about what this means, I can assure you that it does not mean I can run a 4:00/km marathon. It just means that lactate threshold is not the limiting factor. There is no doubt in my mind that my legs would give way at around 25 km if I went out at that pace. In fact they might give way at 4:10/km. So balancing the theoretical potential against the biomechanical realities is what makes the selection of a target pace really interesting for this marathon. In some ways it comes down to a simple question: how bad do ya want it? How much pain are you willing to withstand? I suppose a lot depends on how the rest of the taper goes. But it is indeed getting interesting, even for me.