Low FTP during lab-tested VO2 max + VLamax

Maybe some of you data nerds can help me. I had the opportunity to do VO2max and VLamax tests in a sports lab today because they had some kind of half price deal. The lab results showed no great surprises regarding my overall profile which is much more geared towards endurance at the moment (VO2 max of 49 and VLamax of 0.44 mmol/s), but the associated FTP ramp test that I did with the respiratory mask on was really quite rubbish. It came out as 209, even though I did TR ramp tests 3 and 4 weeks ago that were 233 and 228 respectively. I can think of a few possible reasons: 1. I do my tests with my power meter, but this test was on the lab turbo. I know there are differences there, but 24 w seems like a lot. 2. Ten days ago I did a 650 km Audax and possibly I’m not yet fully recovered, though I really feel fine. Anyway, now I’m really not sure what the takeway value of the lab tests for me is. They are a snapshot of something but were they a representative snapshot of my fitness?

Most likely it is just that they have provided you a much more accurate Lactate Threshold Power. FTP is a proxy for that based on roughly what you could hold for an extended period.

You’d probably find that if you set your FTP to the 209 you’d be able to/have to complete longer FTP intervals etc, and perhaps some of your Supra-Threshold work wouldn’t feel as tough.

Mostly FTP in TR is just ahead of what our actual FTP is, that helps stimulate the gains by always increasing the intensity load.

I think it’s pretty indicative of what a lot of athletes would find unless they’d been doing long FTP intervals already.


I’m curious, do you have the data from the test? Do you know how they identified threshold?

What’s your weight? I’d like to use your VO2max and VLamax to estimate your threshold.

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But the FTP test protocol from today was from a ramp test just like the one in TR (with a slightly steeper ramp and respiratory mask on), so I don’t think there should have been a big difference.

But did they take your threshold as 75% of last minute or from blood lactate, or from the gas?

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Thanks. It was just a normal ramp test, starting at 80 W and going up 25 every minute. I topped out at 270 after ca. 10 mins. I weigh 66 kg.

Hmm, I think from the power? They only did a VLamax sprint test, not the continuous lactate measurement during exercise.

Yeah… so I would go back to them and ask about protocol for the ramp test. Specifically the percentage of final minute they use to work out threshold.

All threshold measurement is pretty protocol dependent, and the key is to use the same protocols. Starting wattage, step size etc is all affecting your outcomes.


Ramp tests have been show to reliably estimate your maximum aerobic power (“MAP”). However everyone has a different fractional utilization (FTP / MAP), and therefore it is strongly recommend to only use MAP based FTP estimate as a target for a longer 20+ minute test.

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Yes, but I’m making the assumption here that they either used the change in gas exchange values, or hopefully blood lactate measurement to define your lactate threshold.

It’s unlikely your Lactate Threshold is the same as your FTP from the TR ramp test.

There’s terrific value in the Ramp Test so long as you understand the limitations. Think of it as a fitness score that is very useful for setting training levels within the TR ecosystem.


Except if you listen to or read what Coach Chad had to say, which is that estimating FTP correctly is very important. Because your Coggan classic zones are based on it. And because TR created workouts using Coggan classic zones.

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That makes sense, considering a workload of 270 watts is an O2 consumption of about 3,250 ml/min. I estimate your MLSS at about 195 watts, which may be low, but in the ballpark.

Something tells me you’re carrying residual fatigue and should have performed better on the ramp test. However, if you aren’t used to ramps while wearing a mask and being in a clinical setting, it can impact your max.

Your threshold was likely calculated from RER>1, so as long as the metabolic cart and ergometer were calibrated properly, it’s going to be closer to your threshold than using some arbitrary percentage of MAP. Do you remember what metabolic cart was used?

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It wouldn’t surprise me if there were 20W difference between a ramp-test-derived FTP and one of the various lab methods of measuring ‘ftp’. Throw on top of that the difference between two different types of power meter…no surprise there is some difference.


I would trust the lab test, tho it’s nicer to assume you have a higher ftp.

However, unless you plan to regularly lab test to reassess, the TR number is better to base your TR training on since you can consistently retest it be yourself.


Thanks, yes I will do that. This was a half-price deal because the company have just expanded into testing and I wasn’t totally convinced by their general approach to things re asking the right questions of me and providing the right info.

Yes I agree with both of what you say. I do trust the test, but I also know that the power zones it gave me will be too low for TR. This is like the reverse problem of using an outdoor FTP number on the turbo and finding that all the power zones are now too high for indoor training. I guess ultimately it’s about consistency within the system that you’re using.


Sorry, what is a ‘metabolic cart’? And you’re also right that other factors maybe came into play (not that I want to make excuses!). I have asthma and wearing the mask was definitely mentally hard in the last minute of the test. Also the German fear of draughts and air conditioning (‘makes you sick’) meant there was no fan, so it was pretty hot.

Yes, this! FTP is not an absolute number. It’s a relative number that you can use for training. So your FTP was 209 in that lab on that day. 209 doesn’t help you train on your equipment.

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The bit of kit you’re hooked up to to assess VO2

The metabolic cart is the device that you were breathing into :slight_smile: I was wondering if you knew what device it was, since not all metabolic carts are created equal.

It sounds like you were not in the ideal environment. Having no fan would certainly impact your test.

I wouldn’t think too much of the test. I offer them (in a very non-clinical setting) and unless you’re looking for insight to your physiology, you can save money by testing with a high-quality power meter, a deliberate testing protocol, and a stopwatch.

How much was your test at half-off?