lactate test results and nose breathing

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  • #4040

    First I’d like to say thank you for all the information in the book and this website. I did the plan last season and I went from getting injured all the time and being VERY slow under my aerobic threshold to putting in 25 hours a week of training and soloing two 7000 metre peaks back to back. the system works!

    My heart rate whilst nose breathing has improved enormously since I started, from 142bpm to around 160bpm, so I decided to do a lactate test to check where my thresholds are. The results are slightly confusing…

    As I was doing the test, the doctor was amazed that my lactate levels stayed really low (around 1.5 mmol/l) up until around 145bpm, when it went up to 2 mmol/l. He told me that this marks the aerobic threshold. the anaerobic one, which he marked it at 4 mmol/l, was at 168bpm. after that it shot up dramatically.

    a few questions arise in my head… I am able to nose breathe very confortably well above my AeT (up to 150-155bpm easily). I can actually do it (although it is laboured) up to 165 bpm, then it’s very obvious that there is a change of gear and I have to breathe with my mouth. is the doctor not setting my zones right? does the nose breathing indicator not work for me?

    last season I worked out that my AeT was around 142bmp (both with the MHR percentage and nose breathing). at that HR my speed has increased enourmously, but I expected the HR of my AeT threshold to also go up a lot. is that a misunderstanding?

    the doctor seemed very impressed and told me that he had never seen that lactate absortion in amateur athletes before. Even though my ego loved it, realistically the data falls pretty much exactly where the standard percentages are. am I missing something?

    thank you very much!

    my exact data is:
    102 bpm- 1.7 mmol/l
    133 bpm- 1.5 mmol/l
    160 bmp- 2.8 mmol/l
    170 bpm- 5 mmol/l

  • Inactive
    Anonymous on #4181

    Scott Ferguson (PhD Physiology) is wrapping up an article on Threshold Confusion. So, stand by!

    Also, I am am just putting the finishing touches on a 4 part article series on testing to determine you metabolic response to exercise and what/why I recommend. Let me summarize some of that here:

    1)Gold Standard Test: Gas Exchange Test done by a competent lab. Uses expired gases to determine fat/vs carb ratio at various intensities, AeT and Ant/Lactate Threshold (LT) and finally VO2max.
    The RER, Respiratory Exchange Ratio is used to determine these metabolic thresholds. Many labs combine this test with a blood lactate test as confirmation.
    2) Blood lactate test. Silver Standard. By far the simplest and cheapest accurate way to find AeT. Not so useful for AnT and I recommend an field test as explained elsewhere on this site.
    3) Ventilation markers. I have used these for 20+ years to test athletes with a good endurance training history up to an including at the Olympic level. Nose breathing correlates 95% with AeT in this population. However, since starting to work with folks who do not have a good endurance training background in the past 3 years, I have found many cases (as mentioned in the above posts) where there was very poor/no correlation. In fact; the worse the aerobic deficiency, the less ventilation correlation I see. I have asked several exercise physiologists “why”? but so far no one knows.
    So, in cases where ADS (aerobic deficiency syndrome) is obvious or likely I strongly recommend a real test and not relying on a ventilation test or simple % of maxHR formula.

    Other thoughts:
    It is the real metabolic events of AeT and AnT/LT that must form the anchor points for any accurate training zone system. Without knowledge of these points you are guessing. A lactate test is very good way to do this. It is relatively cheap, can be done in the field using sport specific means and when administered well can show most of what you will get in the gas exchange test. These tests can be repeated during the training cycle to show changes in the metabolic response and hence training effect.

    The BSX Insight and MOXY work by measuring O2 sat in the working muscles and then relating that to intensity. Both these products originally promised to give real time lactate readings by using an algorithm that correlated O2 Sat to lactate. But the algorithms could not and to my knowledge still can’t provide a good correlation. The technology is promising and the SmO2 is probably very accurate but just because we can measure a quantity does not mean we know how that quantity relates to something else we are interested in knowing about. I have tried both devices and was disappointed with their correlation to any of the well tested methods of gas exchange tests or lactate tests or field test. I don’t recommend their use to any of the athletes I work with. The tests mentioned above will provide all the info needed and do it in a way you can directly transfer to your training.


    Anonymous on #4182


    I would disagree that there is little valuing in nailing down the AeT. I think that this is THE most important physiological marker for any endurance athlete to have a handle on. This is a measure of the work capacity of your aerobic system. It is of fundamental importance in determining training intensity zones and for marking improvements in the the aerobic base which must support any and all higher intensity training. I use this test on every athlete I have worked with from total beginners to the several Olympic athletes and elite alpinists.

    Ponder this:
    The running marathon is an event that is competed at each individuals AeT. Think about that for a minute: The 3 hour marathoner is running at the same intensity (metabolic stress) as the 2:08 marathoner! The elite marathoner is not running at any higher intensity than the casual runner. But the elite marathoner’s aerobic work capacity is so much higher that his pace while only producing 2mMol/L is sub 5 minute miles.

    As I have mentioned in other posts: Until I see the AeT come to within 10% of the AnT/LT I do not begin to add high intensity work to the training plan. This is because there is still a lot of low hanging fruit to be had just by improving aerobic capacity. And until this is maximized the athlete will neither have the aerobic support to manage much high intensity nor to make the most gains from its use.

    Good luck,

    roger on #4183

    Scott, thanks so much for these two posts which add a lot of clarity.
    I think the concerns I read about with respect to lacate testing was related to the test protocol, lab vs field test etc. So I’ll try to find a good test center.

    Concerning the nose breathing: As said, when doing the test proposed on this site, I am able to nose-breath up to 160 bpm during an extended period of time. That being said, in the absence of a test for AeT I’ve started running while only nose-breathing, and doing this at a natural-feeling pace limits me to a super-slow 7.5min/km @135bpm – and I can well imagine this being my AeT (also, I think I can do daily 1hr workouts at this effort without feeling too tired the next day). So maybe nose-breathing is still a good indicator for me, but not when testing it to the limit. Anyway, I really like the combination of high-volume low-effort Z1 endurance training and strength training.

    I am wondering what kind of progress I can expect from my Z1 workouts, but I understand that this is highly individual (slow/fast responders) so I guess I need to wait and see. This is also what seems to make it so important to know the AeT – because the feedback loop in “train – measure – adapt training method/intensity” is so slow.

    Related to this: If you recommend Lactate testing, I guess this needs to be done at least half-yearly, so it’s actually very well worth it to try doing it with an own device rather than in a lab cost-wise?

    Finally, it seems I just threw money out of the window for a BSX insight, but maybe it will allow me at least to measure progress by comparing periodic measurements?

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