Ok. It could possibly be 195 as I had it up there a few times at the end of some brutal races, but then lost a bit of confidence with my HR monitor and whether that was accurate.
My peak rate recently was 5mins into the start of that 1:48 half where it rose extremely quickly to 197 then settled around 170-175 but I don't remember feeling particularly bad at that point in the race. The run averaged 172.
Probably time to reassess. It's amazing how quickly you forget about all these basic things getting drawn into theoretical paces and intervals etc.
I double checked those figured. I think my max is 185 and my 8:50 HR is 155 so that is around 83%. Although my max may be a bit light there. I can't believe I was running all my easy runs as threshold runs. My threshold pace is 8:00/mi.
10k hilly trail (supposedly a +2min course) 50:10
No real proper time for Marathon as I was shot by halfway running 30-40secs slower than HM pace. Bad race. Although I managed a 4:35 two years ago on a hilly trail marathon in torrential rain.