Hi Mateo,

Congratulations on your increases in speed and HR at AeT. That’s a great accomplishment and a testament to the work you’ve done.

From what I understand, 2 mM is a somewhat arbitrary value that is the general average for most people. In research that I’ve read, actual AeT can vary between 1.5 and 2.5 mM. If I understand correctly, what’s more important than the numeric value is the inflection point in the lactate curve where lactate starts to steadily rise.

Did the doctor graph out your results? In that graph, at what mM reading does the line break from roughly horizontal and start steadily climbing?

From what you’ve described with nasal breathing, it does sound like your AeT is higher than 145. It is possible to breathe through your nose higher than AeT (especially without a proper warm up), but if you gradually ramp up and can still breathe through your nose, then I think you’re on the right track.

Whenever I’ve done lactate tests, the first inflection point in my curve is typically around 2.3 mM, and the bpm at that marker is also the typical maximum of my ability to breathe through my nose. My unconfirmed suspicion is that the individual variation in lactate values has something to do with the mix of slow and fast muscle fibers which is also highly individual.

I hope that helps. In general, it sounds like you’re on the right track. I’m sure Scott or Steve may have more comments on this.

Scott S.

With lactate testing trumping all, I would suggest you ditch the breathing scale of exertion, or whatever you want to call it. As you become more fit with slow twitch muscles efficiency gains, you can go on the aerobic system longer and harder, but your breathing can somewhat change. Your heart carries o2 to the muscles, but you need o2 in the lungs to feed the blood stream.

As far as the 2 mmol/L mark, that is the baseline for most people at rest. It is common to see a dip from that number at lower intensities. I don’t think using the “inflection point” to mark aet is the best, especially since it can move based on testing parameters. If one is truly interested in finding their aet with lactate testing, they should run a maxlass test which is time consuming, tiring and most likely expensive in a lab setting. I would guess that the 2mmol/l point is about as good as it gets in terms of aet in what is common testing protocol.

The 4 mmol/L being a marker for Anaerobic threshold, I am not so sure about. In fact, mader documented 4 to be an indicator of the aerobic system. That is different than saying anything above 4 is Anaerobic work, I haven’t studied that out, but for those with strong Anaerobic systems it is probably light. But most of those working solely on their aerobic system will have a weak Anaerobic system, so perhaps 4 is a good number?

Personally, I do a 2 point test to get my pace and hr at 4 mmol/L through linear interpretation. I then rest for 30 mins and run an Anaerobic test. I then use this to judge the efficacy of my training over the past period and to set goals for my next period. I set my aet based on how I feel. I inch it up slowly, monitor hr during sleep, active recovery and how I am feeling in relation to the work load. The testing 6 weeks or so later then verifies the adjustments I’ve made.

Finally, one should expect their Anaerobic capacity to decrease when mainly working their aerobic system. The opposite is also true.

I’m interested to hear Johnstons take on all this, as I asked many of these questions a week or 2 ago. It’s a complex subject, misunderstood by many, mastered by few….I’m far from a master and only a novice, but I drink from the Olbrecht cup when it comes to lactate testing and I am still learning…

Thanks, ConMan. Those are good points.

It’s actually Olbrecht who recommends using 2mM and 4mM as aerobic and anaerobic threshold proxies rather than a precise MaxLaSS test:

“The experimental determination of MaxLaSS is very work and time intensive; time and efforts that are lost for training.”

“The different methodologies to determine the metabolic thresholds based on multiple step tests are not only very time consuming but are also subject to intensive discussions on their validity and reproducibility. [In contrast], it is very easy to determine a fixed aerobic (at 2 mmol/l lactate) and a fixed anaerobic threshold (at 4 mmol/l lactate); the methodology to determine an individual anaerobic threshold (varying from 1 to 6 mmol/l), on the other hand, is much more complex and all the more controversial as far as the reliability and validity of the method are concerned.”

~ Jan Olbrecht, The Science of Winning, “What about the lactate thresholds?”, page 118

If I understand Olbrecht correctly, although 4mM is a very rough proxy for an anaerobic threshold it’s close enough in intensity to the real AnT that it won’t affect actual training prescriptions or short change the athlete in his or her development.

As an example, a cyclist friend of mine could hold 300W at 4mM. His actual MaxLaSS (at 6mM) was 320W. To reach his MaxLaSS, his lactate increased by 50%, but his power output only increased by ~7%. If he hadn’t known his actual MaxLaSS of 320W, and instead structured his training with 300W as his AnT (only 6% below), it wouldn’t have cost him very much in lost effectiveness. It may even have been more sustainable. More importantly, he could have done a lot more ongoing testing without the impact of cost and fatigue from the tests.

Olbrecht doesn’t say that 2mM and 4mM are the actual thresholds. His idea is that it’s easier to use a fixed lactate value and track the changes in speed or intensity at that value than it is to try and pin down a moving target like MaxLaSS. Since it’s easier to measure speed against fixed lactate values, testing is likely to be done more frequently, and the more frequent testing will better steer the athlete’s training.

@Scott Semple,

I think we’re saying the same thing. In other words, a lactate test in itself doesn’t give you a single deterministic point (or points), but rather is a measuring stick. A couple other considerations, however….

1) I believe it was Mader who uses V4 as a “marker” for aerobic fitness. I’ll try and dig up the paper, but it will take a few days.
2) Also don’t forget Olbrecht uses a 1 point test. He has enough data for swimmers where he can input age, height, weight etc and 1 test point within like 2.5 to 6 mmol/l and he can produce a V4 number for you with a small amount of error. He then uses that number to determine one’s overall fitness and can build a training plan around that. Pretty amazing actually!
3) frequency of testing, Olbrecht says no less than 6 weeks.

How all this works in my crazy head seems to at least make sense to me. But, what I do know, even many of the labs at universities seem to not offer up a lot other than a lactate curve. But, describing how to use that curve is their downfall, IMO. I’m basing this only on one person’s experience, and the fact that people are here asking similar questions. I do agree with the lactate.com testing protocol – test for V4 and then an anaerobic test – unfortunately, I haven’t seen a lab offer such testing.

Great conversation going on here. I don’t have anything substantially different to add but will make a couple of comments based on my experience.

2nMo/l is not set in stone as the AeT. An RER (Respiratory Exchange Ratio) of .85 is generally considered to indicate 50-50 fat vs carbs which shows the upper limit if the aerobic systems capacity before its being overwhelmed by the glycolytic contribution. We and many others call this the AeT. This usually corresponds to a rise of 1mMol/L above baseline lactate levels (not resting). This also usuallyfalls very close to 2mMol/L. Keep in mind that many factors come into play when taking these measurements as we are dealing with a highly complex multi-variable system. It doesn’t lend itself to 2 decimal place accurate assessments. We can however infer useful generalizations from the data we gather.

The idea for 4mMol/L as a representation of the AnT came from one of the earliest studies on the subject where 4 was the average lactate at AnT across a large test population. Like maxHR formulas this provides zero predictability accuracy for any given individual. We find the best measure of ones AnT is a field test of max sustainable HR/pace over a long period. This gives you something tangible to take into the field for training.

Ventilation is not the most accurate measure, we admit, and this shows up with Mateo. Now that he has a lactate test he can use that and ditch ventilation. I’d suggest he try to nail the AeT down a little closer rather than trying to interpolate between 2 data points 30 beats apart.

While any test is a trailing indicator of the training effect it does provide our best information as to monitoring and controlling the training moving forward. These systems respond on time scale of weeks to months so use a test like this to plan future training is useful.

Scott

hi all

many thanks to all, very interesting discussion. I’m just trying to start with a more structured approach to training, having read Scott and Steve’s book. Doing the nose-breathing test I ended up in much the same place as mateo, i.e. nose-breathing up to a HR of around 160, whereas I’m quite sure I’m afflicted by the aerobic deficiency syndrom (I’m unable to run even at 6min/km without HR increasing to 150 or so). So I’m quite sure my AeT is quite low and much below 160.
Problem is, more I read on the subject, less it seems lactate testing in the lab is a good way to determine training zones, and for testing progress, it seems expensive to do it every few months.
So, I’m currnently considering:
-trying to use a muscle oxygen monitor to measure aerobic progress, seems easier and cheaper than doing my own lactate testing at home
-relying on feeling for setting AeT(and potentially the measurement from a muscle oxygen monitor), combined with a max-effort test as outlined by Scott for the AnT

If any of you have any experience with muscle oxygen monitors, I’d be very interested!

And also, amazing to have your messages in the forum Scott! The book is so amazingly inspiring, love every page of it.

thanks conman. just ordered a bsx insight before reading your post, quite some people seem to say it gives accurate HR zones. I hope it will at least help me to confirm training works over time by measuring increased aerobic efficiency (and motivate me to train at low enough intensities, which I clearly did not do enough so far).

@Colin, I didn’t write that, but I tend to agree with it. As has been written above, there seems to be little value into trying to nail down an AeT. That’s different than saying lab testing isn’t as good as other methods, as it is probably the best. Again, I think if you’re looking at lactate testing to help you nail down training zones to the gnat’s kitten there are better uses of time, money and energy. JMO.