HR Zones from VO2Max Test

Hi Coaches,

I did a VO2Max Test in a Lab (Ramp Protocol + Lactate Measurement) 3 years ago. I wonder whether one becomes fitter, does HR Zones change in terms of LT1 and LT2 or HR zones remains fairly constant but what changes are the power produced at each of these zones?

Thanks in advance,

Not a coach; but, I’ll throw my hat in the ring…

My understanding is that HR associated with LT1 and LT2 is pretty consistent and slow to change. Even though the test data is 3 years old, I imagine the heart rates are within 1-2 beats of the test results.

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Hi @AlexM370, great question. Yes, in all of the tests I’ve done over the years I normally see fairly small changes in HR response as a whole. The power, pace, and lactate responses can usually change more drastically. You may see, depending on the specific protocol, more variability in HR response (e.g., 1 min ramp protocol vs. 4-5 min step protocol) and your lactate curve can look different. There may be lower peak numbers as the length of the protocol and stage durations get longer, or as your fatigue during testing changes. So you have to be aware of how the protocol can affect results and the curve generated. Practically, I would just suggest that you maintain a similar protocol in order to compare results.
Coach Ryan

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So, using my LT1 HR from my previous VO2Max Test today, would I be “able” to fairly round up my new LT1 power, give it or take it?

For LT2, would probably be best to do an hour of power, I guess

Thanks again for your responses

Hi @AlexM370,
That’s a reasonable start, yes. You might consider some of the other methods to estimate LT1 as a way to verify. There is a good discussion on a new method proposed in another part of the forum. But honestly, you can use some base rides to dial this in, especially if you already have some HR ranges from previous testing.

For LT2, an hour of power would be great. There are some methods out there that can give insight into another threshold point, called respiratory compensation point, by looking at HR deflection points. None of these are perfect, but it’s al about selecting your method and understanding the pros and cons with each one. But again, if you have ranges from the past, the hour of power would certainly be an easy way to determine how your HR aligns with previous data.

Coach Ryan


Hi @ryan,

Thanks again for your response. Yes, I’ve been following this thread on the forum. Will also give it a try using the HRV logger App.