So I did the heart rate test again this morning: 4:11/km. That's a few seconds better than the rather unpleasant 4:15/km of last week. I was also having to work the legs a bit harder to get up to a HR of 149, and the average HR was the correct 149, not 150. So I guess I am some way back towards where I was four weeks ago. But at the same time, I am still certainly not there, at least as measured by this test.
I still have no idea what weight to put on this test, but suffice to say that my main challenge to myself for this marathon on Sunday is to NOT entertain thoughts of going sub 3:00, but rather to run a realistic pace in the first half that will feel fairly comfortable and allow me to enjoy the run, but still yield a respectable time if I can hold it throughout. At present, I think that is something around 4:25 to 4:30/km. If I can do that and get to 30k feeling good, there is always a remote chance that I may actually pick up a few minutes in the last 12 km. Probably not, but I really, really want to give myself a chance of negative splitting whilst still running a semi-decent time. Just not sub three!