Was getting some separation between my HR and Pace on Z2 runs. My pace was the same, but when running with a new person I found my HR was elevated to Z3, while pace stayed in Z2. Should I count this as Z2 or Z3?
It’s probably unlikely to continue unless your fitness level is going DOWN rather than up. When fitness is increasing, athletes tend to find that they run faster at the same HR. Exhibiting a higher HR at the same pace is more likely just noise. If you have reason to believe that your fitness is in fact improving (e.g., lower RPE at any given pace), then retesting is in order.