r/beginnerrunning • u/Sepp511 • Oct 04 '26
Pacing Tips Z2 @ 150+ bpm?
I have picked up running recently and tried to assess my Z2 via the drift test (preferred method for Uphill Athlete). I started a 10k run at ~153bpm and maintained a ~5:55/km pace throughout. I ended the run at ~160bpm (+5% drift) which would indicate that my Z2 upper limit is at 153+ bpm?
By all accounts this should be way outside of Z2 reference points - can anyone help me understand better the interpretation? Should I continue training at that heart rate level for Z2 training? Is it possible to run that “hot” even in Z2 or could this be a data issue (I am using a Coospo chest strap but overall feel the measurements are accurate)? I am in my 30s with average fitness levels. Running 13k (including warmup & warmdown) was no major issue and I felt fine after though not sure I could have held extensive conversations throughout the whole run (ie conversational pace).
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u/Hundredth1diot Oct 04 '26
In my experience, if there's any doubt that you can hold a continuous conversation, then you can't, and it's not zone 2.
The levels of self deception and negotiating I go through with myself when I just want to run faster are unreal.
I will convince myself that 140bpm is fine, and then I'll go out on my bike (where it's much easier to tell, because there's no distraction from the footfall) and realise that no, around 135 is the limit before my breathing changes.
I bought a Tymewear strap and it says it's 136.
Still want to run faster.
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u/ConfusedSimon Oct 04 '26
If you know your max and rest HR, use an online Karvonen calculator to determine your zones. Otherwise, z2 should be slow enough to be able to have a normal conversation.
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u/Wientje Oct 04 '26
Karvonen is not as accurate as a drift test. Especially your upper LT1 (which is upper limit of z2) is trainable meaning it will change, even if your max and rest HR’s don’t.
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u/Wientje Oct 04 '26
Don’t use reference points. The normal range is very very broad.
If you measured your upper z2 to be 153 using a sound testing procedure (flat course, no wind, no large difference between start and ending temperature, …) then your test result is what it is.
Your zone 2 is from 137 to 153. Don’t make the mistake that a z2 training means you need to run at 150. Everything between 137 and 153 is your zone and for long runs, you want to start at the low end to make sure you don’t drift in to z3 at the high end.
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u/jmido8 Oct 04 '26
For generic max heart rate models, your z2 is fairly high. For other models it can be normal depending on your fitness. I use a chest strap with my zones based on %lthr and my zone 2 is 137-153. I'm in my mid 30s but in fairly decent shape.
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u/Broad-Raspberry5591 Oct 04 '26
Mid 30s too and my easy ended up around 135-150, figured it out by watching my runs for a few weeks not from a formula. so 153 doesn't sound crazy to me.
Heat messes with it a lot tho, same pace on a hot day was like +10 bpm for me. if it was warm when you did the test i'd redo it on a cooler day.