Jack - welcome back, great to hear from you! Hope the reunion went well!
Glenn - absolutely! That data is only the steady state (SS), or if you prefer steady distance (SD) pieces, and my heart rate is getting much higher during the sprint intervals, endurance intervals and hard distance pieces. I've actually not always been wearing my HRM for those rows, but have done for all 9 of hard distance pieces - including today ...
PP 4.1.5 - Hard Distance - 7,500m - 29:24.7 (1:57.6 pace) 27.5 spm.
I started out intending to have this be a 'not ridiculously' hard piece with an average 1:59 by doing the first 1,500m at 2:01 and stepping down 0:01 each 1,500m, but as I went on there was more flicking or settling on the slightly quicker side of the target, and it felt better to run with that than try to slow down at all, and then did speed up a bit more at the end, so the 2nd and 3rd last 500m splits were under 1:55 and the final was at 1:49.5:
In terms of heart rate, perhaps because of the negative split it my HR was at the lower end of the 'hard distance range' for the first 15 minutes or so, but did continue to climb, and peaked at 192. In the chart below today's row is the orange line, my 5k PB the red line and my 10k PB the blue line.
Across these 9 rows (which have a combined duration of 3:45:40) my heart rate has been at or above 75% of HRR (for me >=160) 86% of the time, and at or above above 90% of HRR (for me >= 181) 37.5% of the time - so comfortable I am giving it a bit of a nudge on these days.