That’s impossible to answer. Heart rates are like fingerprints; they’re unique to the person and irrelevant for everyone else.
One person’s AeT may be 110, and another’s may be 180. Someone who starts at 110 probably has a lower maximum and will never be able to get to 180. But absolute heart rates have nothing to do with fitness, so how high a heart rate is at a given intensity doesn’t mean much. An athlete’s changes in heart rate relative to their own history are what’s important.
However, based on your description of the effort relative to the pace and PA:HR, it does sound like you have ADS.
You could try another test at a lower heart rate (even if you have to walk). Or you could do a treadmill test at a constant speed and manually calculate the PA:HR. To do so:
* Pick a speed on the treadmill slower than your first two tests;
* Stay on the treadmill for at least 30′-60′ (the longer, the more reliable the test);
* Record the workout, pressing the lap button halfway through;
* When you’re done, divide the average heart rate of the second half by the average heart rate of the first;
* Lastly, subtract one and multiply by 100 to get the percentage HR drift.
For example, if (2nd_half_HR) / (1st_half_HR) = 1.091, then the drift was 9.1%.
With that info, start doing all of your aerobic training at whatever pace elicits a drift of less than 5%.