[Maya Seckinger]

This is a great question!  Although it is curious your tests from earlier this year gave a different reading would say for at least an uphill effort this is your current anaerobic threshold. It is not uncommon to see slightly different results for an AnT test uphill versus on the flats. The fact that your resting HR is lower, and your AeT is lower makes me think having a lower AnT is not unusual. Especially compared to the test where you hadn’t trained in a month. You are probably carrying a little more training load even coming off a recovery week which will suppress your HR a little bit. All in all, this is GREAT news because this means you do not have ADS (aerobic deficiency syndrome) and as you said your aerobic days should be in zone 1 or low zone 2. You could re-test and you may see something slightly different, our heart rates do vary day to day as we are humans and not machines but I would not expect it to change very much at all. I am happy to hear the training is working, keep it up!