Lactate Testing - Data and Results

Training
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First am jealous because the Accutrend system is really nice and you can measure other stuff with it just by getting different strips… That said, it’s not really meant for sweaty athletes as a DIY device.

The blood gets pulled onto the strip “pad” by capillary action. Have you tried getting a good bubble and bringing the strip down to the blood bubble rather than the finger down to the pad? The latter is how most videos show testing. But the videos are for cholesterol, blood glucose, etc. e.g. not sweaty bike riders.

Most test protocols you’ll be sweating from working hard on the trainer. I always try to get my test finger as dry as possible before pricking. I use paper towels then a wipe with alcohol soaked pad (standard stuff). Then obviously wipe off and discard the first bubble and test the second bubble.

Any chance of getting an assistant to help run a test or two to help get good data?

You could do something like a vLaMax test to drive a high value of lactate. That stimulus plus a helper to do the finger stick and sampling would give you confidence that the meter is functioning properly.

The test protocol is a warm up, then an all out 30 second sprint. Full gas. Take a sample asap and then another every 2-3 min until you reach baseline. For purpose here of just getting a decent data set and testing the meter, you could do the 30 seconds, then take a sample every 3 min for 9-12 min. That would give you a curve. Note most vLAmax protocols will test every 60 seconds after the sprint. But you won’t be able to test that quickly to start so make it easy and do the sprint then test every 2-3 min. We’re not after a perfect curve at this time, we want you to get some good measurements with your meter.

You could also guess-estimate your 2-3mMol point and do a ride at that pace. Something around 80% FTP ought to do it. Perform a 15-30 min effort and take a sample every 5 min or so. Just to get you in the accurate range of the meter.

All ideas. Perhaps someone else has the Accutrend and can me more specific.

Stick with it and you’ll come up with a routine to obtain good data!!

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I don’t use that device but have found getting off the bike, sitting at a table and resting both my target finger and the wrist of the hand holding the meter on the table to stop them shaking seems to help. Likewise, dry, alcohol wipe, dry again prick, wipe of blood with paper then use the second bubble. Mark Burnley on Twitter also said don’t squeeze your finger too hard to get the bubble. Also make sure you don’t inadvertently touch your skin with the strip either.

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Thanks for the reply,

  1. I could ask my wife but, she is not going to do it every time so need to figure it out.
  2. The accutrend requires you to load the strip then either drop the blood onto the pad or remove the strip, get he sample onto the pad and then reinsert. However if you take too long machine switches off so requirea quite a slick execution all while making sure not to touch the pad.
  3. The pad itself aeems to require a fair bit of blood - that seems to be a fair portion of my issue.
  4. So far i am battling to even get readings consistently at rest (either out of range as “too low” or an error (most likely contaminated)

I am wiping hand, wiping first drop away etc.

Il keep at it and hopefully improve.

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187

I hate to say it but the Accutrend does not seem an ideal device for the home-tester. First of all you need quite some blood volume for each probe. At least 15 µL. My Lactate Pro 2 requires only 0.3 µL. This is quite a drop.

Secondly, looking at the manual I can see why it is quite easy to get a contamination:

grafik

in combination with requiring quite an amount of blood

grafik

I can only compare it to my experiences with the Lactate Pro 2. There was a learning curve but the Accutrend appears to be more fussy. Not sure how this would work with self-testing at higher intensities.

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I hate to say it but i think you are right :(, blood volume seems to be the issue.

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189

I sometimes have this problem early on in a workout or if taking a resting sample. Poking the side of a finger, rather than the thicker pad part, helps.

Once I’m warmed up and working hard, the blood starts to flow.

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Darth you seem to be a bit of an expert do you or anyone else know if the aerobic/anaerobic curve intersection on WKO more or less correlate to LT2?

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No. LT2 would be a bit lower than FTP, which is predominantly aerobic (as is LT2)

So roughly 40-60mins in the WKO curve that you posted. So to the right of the “inflection point” (mFTP)

A good rule of thumb for “is it anaerobic?”, think 800m track race (running). Lasts about 2 minutes. In the old days we would say 800m run (so 2 min max effort) is 50/50 aerobic/anaerobic. Not all that precise but you get the idea. Not predominantly anaerobic but a significant anaerobic contribution.

Anything longer than running an 800m in high school is overwhelmingly aerobic.

So look at where the anaerobic contribution plot and the aerobic contribution plot cross. What is the duration (in mins) at that point?

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192

apologies, not the power curve but the aerobic component therein. so, in this example around 268 watts for a 281 watt ftp.

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I’m referring to the vertical solid line at 1:17. That’s 50% aerobic and 50% anaerobic. That’s just a little bit faster than it takes to run an 800m race, so that modeling seems about right.

Your question is about LT2. That’s not LT2

In WKO, if you click to the right of mFTP (maybe at 45mins), you’ll get a value and percentage contribution for roughly LT2. It’s going to be overwhelmingly aerobic and other than initial familiarity not much use.

You are referring to 268 watts of a total of 530 watts. Again, 268 + 263 = 530. It is modeling the contribution at 1:17. So to answer your original question, the answer is no, it does not correlate to LT2. It might be close (because any power at roughly 85-95% mFTP could be LT2), but it would just be coincidental. Also, if LT2 went up, that power value at 85-95% mFTP would go up as well, so in that sense it meets one criteria of correlation (directionality), but the entire curve at that point would move with training/detraining. So any single value in that range “correlates” to LT2 because every value in that range “correlates” to LT2. But that crossover of contribution (50/50) is nothing special.

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194

Thanks for the compliment. But I’m no expert!! Am just an experimentalist with a lactate meter.

That said, in my data to date, have never seen a clear LT2 inflection. So inferring LT2 from a different plot I would find difficult!

No help but glad you asked and curious what the others will add.

-Darth

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195

thanks to both you and @tshortt …looks like I’m on the hunt for a lactate meter.

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196

I assume (based on your question), that you are interested in LT2. Whereas I think you can get most of the value of knowing that elusive number by doing a good long(ish) field test to determine FTP, if you look upthread, Darth has a few posts on why it might be valuable to go the extra mile and generate a lactate curve for yourself (mainly around MLSS, pacing, mental aspects…just showing fellow riders “yeah, this is threshold” type of input). Super helpful, and based on what he posted: fun.

Besides participating in an online coaching forum run by Steve Neal (where ppl posted lactate curves, etc), I found the most value getting LT1 (or some demarcation between lower intensity and mid-level intensity). Like Darth, many ppl posting could not clearly identify LT2 and Steve would just (seemingly) pick a number “higher up” on the curve. But for reasons not important here, we were not as interested in LT2 as we were LT1, balance point, and other aspects of the various protocols.

Also interested in how you get on.

(I have had success w/ my lactate meter from lactate dot com)

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Same here. I have the prior version of the lactate plus meter (yellow one). The Scout and the Lactate Plus both seem to work well for the types of things we cyclists do.

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The Scout is hard to find in N. America right now. There is a paper out there measuring the accuracy of a bunch of lactate meters and it seems as though some are good at low mmol concentrations some are good at high mmols…the scout tested well at both. but if we are being honest the 1-2mmol accuracy is really the most important.

@tshortt I’m actually way more interested in LT1, but the LT2 numbers on WKO just looked very close to where I would estimate my LT2 to be. thanks for the thoughtful responses!

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Have you tried doing 30 minutes at what you think is LT2 and comparing lactate from 10mins and 30 mins to see if it’s increased by more than 1mmol?

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No, but only because I could not get a good guess for LT2. I did a few MLSS tests (data above in the thread) and after a learning curve they were solid and consistent with training results and race results (as they should be). I might have been 5w under on my best MLSS test, but it was darn close to expectations and nice data set.

What happened is I got into this lactate stuff with interest in nailing my 40km TT pacing. e.g. MLSS. And to help some buddies do the same. We had guys who always went out too hard and others who we knew were underperforming. Having a chemical measure - quantified data - seemed useful. So I bought a meter and offered to run tests on pals just for cost of the strips and disposables. At the time that meant $20 per test.

We quickly realized that MLSS testing required a lot of time and effort and repeated tests. The guys mostly didn’t want to dedicate that much time to my basement… After doing some MLSS tests, and having some guys use the data to adjust training with success (which was nice outcome), Covid hit and our collective interest in 40 km TTs dropped and we were all afraid to keep testing because of Covid concerns. Plus, without races, a lot of the momentum to do this stuff fades away.

During that time (couple years!!!), I became enamored with LT1 and zone 2 (ISM, Steve Neal, Maffetone, et al) type training methods. So I started performing what I hope are robust lactate test protocols to nail down LT1. That seemed to work out well and added confidence in my training methods at the time. I grew stronger and happier on the bike and LT1 shifted rightward and MLSS moved up too.

Currently, must admit I don’t have any bike goals or training goals. Other than to ride a lot and not get dropped and not get too fat. So I’ve been very lax in both adding to the lactate data sets for this thread and in structured training methods for myself. Partly, am not in great shape, not fixated on bike training and do not want to know my present numbers in detail. Let alone know them and share them here - LOL :slight_smile:

Folks will argue if you have good power data you don’t need lactate. I find that to be mostly true but with exceptions. Its always the exceptions that are interesting!!

The reason I measure lactate is it uncouples RPE (sensations, mental) from the physiology. If your brain is screaming RPE 8-9-10, and your physiology is showing 4-5-6, then there is a disconnect and room for improvement. If your brain is maxed for RPE (or lower) but you are at MLSS for say a 40km TT, then you are doing a good job. Finally, LT1 (as discussed in depth on the forum) seems to be a useful piece of information. LT1 changes with fitness and is not simply a % of FTP.

None of this is essential, but I find it interesting and in some cases very useful too.

Didn’t mean to write a book chapter but hope its useful to someone doing lactate tests or thinking about it

-Darth

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201

Saw this on Twitter today:

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202

Isn’t hard to deal with blood samples from a bunch of people, in terms of risk of some infection?. I like the idea of sharing the cost of strips, but the risks seem high.

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you can’t use strips twice, these are one-time disposables.

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