I subscribed to UA 16 wk. Big Mountain Plan last yr. for a climb in Alaska and used TP for my statistics. Both worked great and I felt I was in the best shape of my life considering my age (68yrs.). AeT test last yr. yielded 138 top of Zone 2 with 124/Zone 1. I repeated AeT test @ 3 months later and Zone 2 was 142 & Zone 1 was 128. I continued to train at these numbers. I just did another AeT test to begin another training cycle but I now know I set the speed of the treadmill too fast (NordicTrac, 10% grade, speed 4.0). HR at 30 min. was 157 & same at 45 min. when I stopped the test due to knowing I was way outside Zone 2 for too long and I felt effort was too great. Although I didn’t finish the test properly, it appears I don’t have any appreciable Heart Rate Drift. Would you recommend to retake test and reduce treadmill speed to get exact results?