am i not spending enough time with my HR up? It's probably a 3-400m climb with a sharp uphill in the middle where I have to stand and really get on it. If it were a race, i'd run it.
I am about toast when i get to the top if i hammer my way up it, then take it easy down the back side of the 'ridge'. I do the repeat 10-20x depending on how far i ride for warmup