Congratulations on your increases in speed and HR at AeT. That’s a great accomplishment and a testament to the work you’ve done.
From what I understand, 2 mM is a somewhat arbitrary value that is the general average for most people. In research that I’ve read, actual AeT can vary between 1.5 and 2.5 mM. If I understand correctly, what’s more important than the numeric value is the inflection point in the lactate curve where lactate starts to steadily rise.
Did the doctor graph out your results? In that graph, at what mM reading does the line break from roughly horizontal and start steadily climbing?
From what you’ve described with nasal breathing, it does sound like your AeT is higher than 145. It is possible to breathe through your nose higher than AeT (especially without a proper warm up), but if you gradually ramp up and can still breathe through your nose, then I think you’re on the right track.
Whenever I’ve done lactate tests, the first inflection point in my curve is typically around 2.3 mM, and the bpm at that marker is also the typical maximum of my ability to breathe through my nose. My unconfirmed suspicion is that the individual variation in lactate values has something to do with the mix of slow and fast muscle fibers which is also highly individual.
I hope that helps. In general, it sounds like you’re on the right track. I’m sure Scott or Steve may have more comments on this.