Yes I so agree !! It does not make since to inject at 85% if they can go beyond that very easily.
Unfortunately most tests are run by RNs just following a protocol and do not individualize target rates.
I happen to be both a CEP and a RN. My vo2 max is 43 and my RHR 60 bpm, and I am 59 yo. They injected me at 85% so I really consider my test useless. Test was normal.
Although I also know the correlation between ischemic heart disease and an excellent level of fitness is very low...but in my clinic, I have seen ischemic changes (ST straightening and downsloping) at a very high level of exercise.
Thank you for posting.