Originally Posted by
Hermes
I am not sure I would use the word "normal". I suspect that if OP had no warmup and started up the hill AND it was a real 7 to 8%, he overcooked the start (HR dramatically lagged power and he flooded his system with lactate he could not process). Once this happens, it is impossible to recover on a steep climb because you cannot go slow enough and spin out the lactate. He has enough fitness to keep going but when he got to the top, his legs were fried.
I agree 100%. Based on the OP's post he knew that he should have warmed up. I was suggesting that during training for the specific task there would be some pains that are not common to riding while seated, which may not be limiters to the interval.