Help me make sense of my recent VO2 & Lactate results

Recently (Feb 15th) visited a lab to get some VO2 & Lactate data. After the test, any questions I had were answered and I received some direction on what to do with this data. I’m looking for a second or third or tenth opinion on the results but also some guidance on how to adjust my training to maximize on my potential, if any.

VO2 Max (L/min) = 4.71
VO2 Max (ml/Kg/min) = 69.3
Lactate Max (mmol/L) = 12.9
HeartRate Max = 185
VO2 Aerobic Threshold = 3.5L/min @ 250W @ HR AT 147bpm
VO2 Anaerobic Threshold = 3.75L/min @ 280W @ HR VT 157bpm
Lactate Threshold = 4.1 mmol @ 280W @ HR LT 150bpm

If there’s any other data points I need to include, please let me know.

From my riding experience, I know that I can sit in the high 160bpm for a long while, flirt with 10-20 minute efforts in the 170’s, but if I let it rise into the 180’s, it’s hard to know how long I can last but I only ever really get into the 180s on climbs or in a race. Historically, I would call anything north of 175 my red zone and once I get into that red zone, it’s not something I easily recover from. Stopping and resting for 30 minutes usually helps the feeling of being sick subside. In 2017, I bought a smart trainer but didn’t really pay much attention to my numbers. In 2018, I got power pedals and this is when I started to watch the power data a bit better and trying to match my power output to HR for a complete picture. This has helped me pace things better so much so that I did a 20-min FTP test yesterday instead of a ramp test and nailed the pacing.

I have a 3-day event coming up and I would really like to perform at my best. What would you say my aerobic limit is and any suggestions for someone who can’t clear the build-up easily?

The lab gave me the following advice:

  • 1st aerobic threshold would be 140-147bpm which they called my all day pace
  • 2nd aerobic threshold which I want to avoid going over for extended periods is 157-160bpm

Would you agree with the advice given?

Hi veloriderkm,

well, assuming the lab has set your thresholds correctly, the short answer is yes. But there is a lot more to it than just the two-line advice for being successful at a race.

According to the lab results, your aerobic threshold (AeT, VT1, LT1) is at 79% of your HRmax or 89%FTP. Staying below AeT (<79%HRmax or <89%FTP) means you can go for many hours, maybe the whole day without fatigeing. On the other hand, riding near your anaerobic threshold (AnT, VT2, LT2) means you will be able to hold that pace for only 45min, maybe up to 75min depending on how well developed your fatigue resistance (lactate tolerance) is.

The value of a lab test is that you DETERMINE what your thresholds are, whereas an FTP-Test (20min, 8min, TR-Ramptest) only gives you an estimate of your AnT. And there are no reliable tests for AeT besides the lab test. In fact, the AeT (VT1, LT1) is the more important threshold for endurance athletes.

The lab test just tells you what your thresholds are, but not what your weakness and limiters are. You need to know these, in order to address them with appropriate training.

If the VO2 & Lactate test were done in one session, then it is strange that you have two different heart rates (150 and 157 bpm) at AnT (both 280W).

You seem to have a well developed aerobic base, your AeT is (relative to your AnT) quite high, only 30W below your AnT. You are saying, you can ride in the high 160bpm for a long while. If that „long while“ is near 75min, than you may also have a well developed fatigue resistance.

„but if I let it rise into the 180’s, it’s hard to know how long I can last “ At 180bpm you are near your HRmax, or VO2max, so you should not be able to hold this pace for longer than 8-10min. If you are using Golden Cheetah or WKO4, look at your PDC (power duration curve), there you can see how long you can hold a certain power.

I am curious, but what FTP value did you get from that 20-min test ?

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I haven’t previously tried Golden Cheetah or WKO4, thanks for the reason. I’ll check it out. My FTP from the 20-min test was 285W.

Hi veloriderkm,
great, your FTP from the 20min test is pretty accurate, it is almost spot on in respect to the lab test

How’s your power profile look? Are you more of a short power or long sustained kind of rider? Keeping in mind you can’t do both, would you prefer to shift the power profile to be more of one than the other?

Assuming your VO2max stays constant, if you train to lower VLamax, you should expect FTP to rise, while your anaerobic power decreases. If you wanted to raise both, you’d need to increase VO2max, but yours is already fairly high. And while you may very well still get it higher, it might not be the easiest get.

My (very rough) estimate of your VLamax based on the numbers you provided is 0.75. A TT specialist might get theirs down to 0.3 or so. If you keep the same VO2max, but lowered VLamax by that much, you could see FTP rise to (very approximately) 345. That FTP gain comes directly at the expense of your anaerobic power.

To get an equivalent increase in FTP from VO2max with the same anaerobic power you have now would require VO2max to increase to (again, approximately) 85.4.

IMO, the later sounds like a much more impressive performance gain, but also MUCH harder to attain.

To get better and more accurate numbers, you’d probably want to get your VLamax tested also. That’s probably overkill though. I had put together a rough equation to calculate the numbers, but I’d need to get ahold of a nice dataset to fine tune the equation more accurately. As it is now, it’s probably good enough to get an idea of the magnitude of change you can achieve by targeting either a lower VLamax, or a higher VO2max.


Appreciate the detailed response. I’m going to try and attach a screenshot of my lifetime power profile (2013 - today) based on when I started cycling but I’ve only trained with power starting in 2017 on a smart trainer and 2018 with power pedals. There was a brief flirtation with a powertap wheelset in 2015 but I don’t think my pre-2017 data is relevant, didn’t really make any changes in how I train or ride until 2017.

If my future goals are to be more competitive in variable terrain, climbing events, road races, crits, would it make sense to increase my VLamax?

Hi @roflsocks - what’s the calculation for determining VLaMax (however rough - referenced in your post above)? I have some lab data (Vo2, MLSS etc) and am keen to derive VLaMax.

Any advice appreciated!

VLaMax is about the increase of lactacte per second. Here is the calculation using a Wingate test of 15 to 60 seconds:

VLaMax = (Lactacte_max - Lactate_rest)/(test_duration - alactic_duration)

Lactate_max is the highest measured value after the Wingate test. You test until it declines. The maximum appears normally 3 to 10 minutes after the test.

Lactate_rest is the measured value before the test.

test_duration is subject to your test period 15sec, 30sec or 60 sec.

alactic_duration is the period where you use ATP for energy production - around 2 to 3 seconds.

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(1 + 1 / VLamax / Vc) * VO2max * Pc = FTP

This uses two constants, one is a multiplier for VLamax, and one for overall power output.
Vc is the VLamax constant: approx 7.43
Pc is the power constant: approx 3.45

Please note, I put this together as basically a proof of concept using a TINY dataset. I’d really need to get ahold of a larger dataset to provide more accurate constants. Based on my brief testing so far, it seems most accurate at average FTP values, and varies some at either extreme.

I think at this point, it’s most useful as a tool to help understand the degree to which FTP can be impacted, based on the numbers that you do have. And less to focus on exactly what the numbers are. But I really liked being able to roughly say that you can have say, a 20% change in FTP. When previously, I simply had a “well this should affect FTP some, but no one really knows how much.”

And I’ll add because I just saw @abalakov responding, the formula he linked is preferable for calculating VLamax, if you have the lactate test data. Whereas the formula that I put together will let you solve for either VLamax, VO2max, or FTP, assuming that you have known values for any two.


Based on FTP=280W and VO2max = 69.3 ml/KG/min => 0,7864.

Take it with a grain of salt. It should be in a range of +/-10%.

Is this using relative VO2max (ie ml/min/kg)? I’d guess it is.

VLamax in mmol/l/min and FTP in W?

It seems to me that you would need absolute VO2max (l/min) in order to apply a constant, but that’s just a hunch.

Here are a couple of real values with relative VO2max and how it compares:

VLaMax VO2Max FTP Calc@roflsocks
0,3 50 250 250
0,3 60 310 300
0,9 63 250 250
0,5 63 310 276

Based on those values, the following formula seems to fit:

-32.48 + -136 * VLamax + 6.449 * VO2max = FTP

Gives a calculated value for each athlete of:

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I’m being dim and can’t plug my stats into @roflsocks equation (I’m a microbiologist…)…

My ftp is 330W and VO2 max is 70 mg/L/kg…so what’s my VLaMax (ish - ballpark of course). :slight_smile:

Based on -32.48 + -136 * VLamax + 6.449 * 70 = 330 => VLaMax = 0,654

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Awesome - thanks!!

One more point, if I lose weight and my relative VO2 Max goes up, but my FTP doesn’t change, to account for this in the above equation, my VLaMax would have to rise too…whereas, in reality this may not have happened.

There is a negative correlation between VO2Max and VLaMax. There is minus in front of the 136.

-32.48 - 136 * VLaMax + 6.449 * 70 = 330 => VLaMax = 0,654

If VO2max goes up then your FTP raises. You are able to bring the same O2 to less body mass as result of body weight loss, which improves performances. If you want to keep FTP stable (not a realistic assumption) then you would need bring VLaMax up.

See also

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I think you’re right, the constants only work if weight is also constant. The formula produces reasonable numbers if you assume a 70kg ish rider but if it’s a 50kg rider the FTP numbers don’t make sense.