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VO2max estimation relies on age based formula for maximum HR. How can it be accurate at all?

silentvoyager
over 3 years ago

Reading the paper on Firstbeat VO2max algorithm I see the following quote:

"Because the Firstbeat method is sub-maximal by nature, it uses an age-based estimated maximum heart rate (HRmax) in the calculation. Therefore, the error in the HRmax estimation affects the accuracy of the VO2max estimate."

https://assets.firstbeat.com/firstbeat/uploads/2017/06/white_paper_VO2max_30.6.2017.pdf

Now that Garmin owns Firstbeat, I wonder if that is still the case? For example, if a person has completed a lactate threshold test, why not use that is a far more accurate estimate for HRmax. Or if someone entered their HRmax, why not use that?

Can someone from Garmin comment on this? Does VO2max estimation uses the user provided HRmax or the age based formula HRmax?

Personally, I've noticed that my VO2max seems a bit low, and it always gets punished when I run at a bit harder effort. It might look to the algorithm that I run closer to my HRmax than I actually do. I estimate that my HRmax is 8-10 beats above the the age formula, and that is supported by my LTHR test, which produces LTHR at about 90% of what I believe my HRmax is. 

  • 0 over 3 years ago

    From the very same paragraph that you quote from:

    "If the person's real HRmax is known, the VO2max assessment error falls to the 5% level."

    The age-based estimate is only the default. If you enter a different personal maximum, it will use that updated datapoint. If you have MaxHR autodetect on, it will use that as your new maximum (obviously only if it is higher than the existing entered/default maxHR).

    HRMax is pretty constant, regardless of fitness level, only declining gradually with age. The problem with LTHR is that it can change with fitness level - typical values are 86-92% of maxHR, but amongst athletes 89-92% is more common. And it will vary with fitness level - the same person may show 89% in base training, but 92% when peaking. So not only will maxHR estimates derived from LTHR be wrong, they will be inconsistently wrong.

    Estimating VO2Max from HRMax has its issues. But the alternatives are worse. Or involve being hooked up to a gas-exchange mask in a lab.