Originally Posted by
jadocs
I don’t know. For me the auto calculated seems to be pretty close. I’m 52 (206lbs on a 19lb bike) and I have never seen above 168. I also use Training Peaks and it lets me know when I hit a new threshold which is currently 158 and the HR values auto calculate based on that. Here is a typical effort for myself.
Just because it's correct for some doesn't make it correct for all. The reason it's touted is because someone was able to figure out a formula that fit a large percentage of the people in the group they based it on.
Still what you don't tell us about the effort you posted is whether you were going all out and trying as hard as you possibly could.
I'm 61 and I can hit 180 briefly and stay in the low 170's for a short time.