Gas exchange test - with or without blood lactate

Hi all,

I’d like to take gas exchange test. Where I live I can do it, but they also offer higher priced version of this test with blood lactate measurement.

I’ve never done test like that. My question is whether it’s fine to go without blood lactate? What will I miss if I won’t do blood lactate measurements?


Assuming they will be determining your FTP using the blood lactate data you would miss out on knowing what % of vo2 max your threshold will be.
It’s good data to know if you are limited with a low % or high %. Think of it as the lowest hanging fruit to work on.
ftp < 75% of vo2 max then you should really work on training more time at or just below ftp
ftp > 80% would mean your should focus on improving vo2 max as 82% is about the ceiling for FTP

Data like fat max number I think only needs the gas test.

As with all tests, it’s just a test. If you do not plan on adapting your training behind it then its just a number. I actually would love to know my vo2 max simply for ego purposes

Usually vo2max determination and spiroergometry (e.g. gas exchange test) use different test protocols. You will get a vo2max from a spiro but this is just an estimate, not the real value measured as in a dedicated vo2max test.

If money is not an issue I would do the additional La testing. To confirm the spiro test and to put one’s physiologgy into context (e.g. how does my La curve look like).

HOwever, I guess they only use 3min steps. Furthermore, I would have little faith in spiros conducted outside of universities or Olympic training centers.

This is private lab and they use spiroergometry devices called Cosmed Quark and K4b2.
They increase load every 3 minutes. So, this will be VO2Max determination test, right?

As far as I understand they will be able to mark my Ventilatory threshold 1 and VT2. Is it true that VT2 is just about the same as LT? Or at least 2-3 bpm off than LT.

My concern is that if I’ll go with blood lactate measurement this will be too intrusive and will affect entire results. I’m little scared about taking blood from finger. Maybe my question should be if there is a point to do this test without measuring blood lactate?

a dedicated vo2max test has shorter steps, more around 1min steps (of course, this depends on watt increase per step as well)

no, vt1 and lt1, and vt2 and lt2 can differ quite a lot. most often vt1 is higher than lt1. with LT2 you have the problem that there are 1000 different ways to calculate it.

believe me, wearing a mask during these tests is the most unpleasant experience. and they don’t do the lactate with the ear lobes?

Your first lab step test will suck anyway.