I find that HR drift tends to cause my actual HR on long runs to drift upwards by about 10%points (WHR basis) whenever I do a long run.
Most guides incl Sean Fishpool's (in)famous article quote a range (eg 60-70%) for a long run. I find that in practice what I end up doing is starting towards the upper end of these ranges and holding my speed. This means that my HR drifts out of the range (and I can't bear to slow down).
For my last long run (2 hrs) my HR averaged (WHR basis) 79% with probbaly the first 20 mins <70%.
Am I doing this wrong? Should I be slowing and holding the HR.
What should this mean for my HR strategy for RACING a 1/2M or 10 miler?
For 10k's I seem to have evolved to start easy (first 4-5mins) then settling at 80-85% over the next 10 mins and then holding speed and letting HR rise to 90% before the "sprint" finish, averaging about 88% overall.
my guess would be to run the longer races at 5% points lower. ie not much harder than my "training runs". Views?