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Development Team Member
Posts: 59

I am new to SmO2 monitoring and it seems a fascinating device to 
monitor your training.

I have a rather naive question. If one is to do intervals to stimulate
lactate shuttle or lactate energy system:
1. What would an effective training be?
2. How would the graph of SmO2 look like?

It seems that one would want to have SmO2 at some
constant level during the interval and then during
the recovery (rest) period also keep SmO2 at the constant level,
but higher SmO2 value.

Does this make sense? If so, how would one choose the work and rest

Any inights are appreciated.


Development Team Member
Posts: 1,501
I love that this  question is coming up.
 Not because  you ask  for a cook book for a workout , but  you hit  an incredible  crucial  section   for all readers  who  look at the difference between live physiological workouts  and classical  based  speculative  training and intensity ideas.
Unfortunate we only can   over time understand  this concept ,  when we  start  to look at  more critical  existing ideas as they relate  to this  crucial  question.
  But before I  show an incredible greta   section Of  V. Billats  presentation
 Yes more than  20 years back and we  are not further in fact we have groups  abusing  the myth of LT  to  ,  for me at teals, destroy  the incredible benefit   NIRS  could bring into a  training  concept based on individual live  ideas.

I have a rather naive question. If one is to do intervals to stimulate
lactate shuttle or lactate energy system:

It is a  key  question   how  we  function  with physiological  training.  BUT   it iss not  a lactate  system  on its own.
 The training idea have  different goals  as   we so often  look at.
 1. Do  we like to   " shuttle lactate in and out of   muscle areas  so   do we stimulate   the production of  proteins   and the  2 more  famous  once  are  MCT  1 and MCT4  or
2. do  we  " shuttle " or better shift blood  from one  area of the body  to another  area    so   with this as well O2  supply  as this is  always  what we look  for. or 

3. Do we   try to shift energy  in from of lactate  form   the upper body  to the lows body  for example.

This  three  example s to keep the  cook book on a  starter    flame burning. So all three  demand a very  specific  physiological  situation, that  they can take place and that thee idea is stimulate initially  functional  and than  over time structural.   Now

 Seboo  the   grpah below  explains  your reaction   there is  always  initially a functional  reaction    and  that  progress is  relative  fast. To  actually stabilize  the progress  you have  to   get into the  time  frame of a  structural  adaptation  and that is  what we see with regular  calibration in workouts with MOXY

F  and S.jpg

Now  if  we look  at lactate w e may have to accept  thet LT  is a   useless  concept  based on   a lot of believes  and  25  different  churches  as we have  25  different LT concepts. Her  from a  much smarter person a  simple  summary  of what is going  wrong again and again.
 As  long we  do not understand  the  faith of lactate  and  what it is used or not used  for  we can  not   move forward  to a physiological idea  , where  classical ideas simply  can not  accept . 

Many scientists and coaches use the label "anaerobic threshold" interchangeably with these concepts confusing what is supposed to be a scientific coaching principle. Just because the same label is used does not mean analogous concepts are being discussed. Since there would be different coaching and performance implications from each of the above concepts, the blanket use of this term will foster many erroneous coaching prescriptions and procedures.

Lactate accumulation indicates a shift from solely oxidative to an additional glycolytic energy supply. Lactic acid production is due to the activation of glycolysis which is more rapid than activation of oxidative phosphorylation. This is indicated by a steep non-linear increase of blood lactate in relation to power output and time. That accumulation can be attributed to disparities in the rate of lactate production and removal, even for work intensities under those which elicit VO2max. Lactate production is not related to oxygen deficit but rather to the increase of the glycolysis flux. (p. 159)

Lactate is produced constantly, not just during hard exercise. It may be the most dynamic metabolite produced during exercise since its appearance exceeds that of any other metabolite studied. The constancy of the blood lactate level means that entry into and removal of lactate from the blood are in balance.

The turnover of lactic acid during exercise is several times greater for a given blood lactate level than at rest. For a given blood lactate level, lactate removal is several times greater in trained than in untrained persons.

Several factors are responsible for the lactate inflection point during graded exercise.

  • Contraction stimulates glycogenolysis and lactate production.
  • Hormone recruitment affects both glycogenolysis and glycolysis.
  • Recruitment of glycolytic fast-twitch fibers increases lactate production.
  • Blood-flow redistribution from lactate-removing gluconeogenic tissues to lactate-producing glycolytic tissues causes lactate levels to rise as exercise requires continually increasing power output.

Lactate values differ according to several variables: the activity being performed, the site from where the blood sample is taken, the environment itself (both physical and its effect on the athlete's psychology), and the state of glycogen stores prior to testing. Unless these variables and others, such as day-to-day cycles in general physiology, as well as variations in test administration and athlete performance of each test segment, can be controlled and made consistent between test administrations it is likely that score differences will be unreliable. The practice of attributing any observed lactate-test differences, no matter how small, to training effects or as revealing the trained state is extremely dubious at best.

Practical Implications

When scientists cannot agree upon a concept's definition, let alone the appropriate label to use, as well as the appropriate method/protocol of assessment, then the practical use of the "general implications" of the concept is foundationally prohibited. Until this situation is clarified and discrepancies removed, field testing for "lactate-threshold" should be avoided. There are more profitable and useful activities for athletes and coaches to be engaged in.

Of significance to coaching is the concept itself. The common misunderstanding that the anaerobic threshold is the state where aerobic activity is dominant and maximal and anaerobic activity constant but "insignificant" is very prevalent. There are few competitive activities or events where such a circumstance is desirable.

Most activities do not require all body parts to be involved in an activity at the same intensity level. A cyclist will work the legs extremely hard but, by comparison, the rest of the body will function comfortably in an aerobic zone of metabolic activity. A swimmer pounding out stroke after stroke in a 1500 m race works the arms at an intensity that employs a high level of anaerobic energy supply but the rest of the body is "relaxed" and functioning at quite a basic aerobic level. Even in running, in a marathon the legs work hard while the arms and upper body "save energy." In these activities, lactate is produced by the primary working muscles and resynthesized by the muscles engaged in mild supportive activity. Those muscles cleanse or "sponge" out lactate so that the blood supply to the hard working muscles is quite low in acidity when returned to those muscles. Thus, any lactate measure is a measure of the "general functioning" of the body, not the actual work performed by the primary sporting muscles. Differences in technique most probably would account for a significant portion of many inter-individual differences in lactate assessments than work levels or movement economy.

In many "aerobic" sports the actual prime mover muscle groups work at an anaerobic level rather than aerobically as is inferred from anaerobic threshold testing. The common perception of anaerobic threshold does not give any information or understanding of what actually is happening in important aspects of a performance. Even the slightest improvement in movement economy (technique) in the "anaerobic prime movers" could make a significant difference to performance.

So  you can easy  see the three options I  outlined   on the top  based on the  physiological  faith of  the  lactate   shuttle idea. ( Introduced  1985   by the  way. G Brooks )

An unavoidable dilemma. Sport scientists are ethically bound to represent the worth of lactate testing and the inferences that are commonly proposed. This is what is known.

  1. Lactate concepts and measures are limited/specific to each testing protocol.
  1. Results from one protocol cannot be used to generalize or infer values to other testing protocols.
  2. If one cannot infer from one lactate testing protocol to another then it is illogical to generalize lactate testing results to a competitive performance.
  3. It is a greater stretch of the imagination to leap conceptually from an inferentially-limited measure under controlled conditions to the dynamic circumstances of a competitive or practice setting.
  4. At most, lactate and lactate threshold measurements reveal changes but have limited to possibly non-existent inferential capacities about future performances (even training performances let alone competitive performances).
  5. Lactate and lactate threshold measurements can reveal that they have changed as a result of training, but, if those changes are unrelated to competitive performances what is their value?
  6. There are no national or international competitive events that reward medals for lactate threshold changes, levels, or testing protocols.

So   you can see  the  fun task  for the future coaches .   review  what we believe  and  than critically    ad NIRS  to it and be open , that many  questions will show  up , which can not be answered  with   what we believe in.  Below is one  of the firsts  world  wide  live assessment with a VO2  equipment which is now  paired with MOXY  so  great  to proof  what we show  since many  years    as we  did not  had  the luxury of  having  this  in one   piece  of equipment.

Look the  graph  below. I will dedicate   full thread  to this  Swiss group, who  works  with Swinco  on this incredible concept  but  there are some critical  information's  we have to   get over.  Look  close  at the  start on   SmO2  reaction and   VO2  reaction ?????
Now  ad  lactate to it and  take  lactate after  30  seconds in this  assessment. What  values  do you get  from lactate and   from VO2  and  what   from NIRS. Where do we have the first big  fundamental  question ?

mathias   datas vo2l  SmO2  and VO2.jpg 

ast  to close this  future discussion  up . below a  lactate " shuttle "  or better    energy  usable  interval workout  from  world  class cyclist   10 years ago.  What  you see are  NIRS Portamon ( artinis )  data  form 3  interval  ideas  the  top  trace  green is TSI  %  The green in the red  blue  graph is tHb  and  red is  O2HB  and blue is  HHb as  usual
 all intervals had  the same  400 watt load but we  used different    recovery    modes in between loads.
 The lactate was in all three  loads   tested  at the end of  the  total interval  section and than  3 min later again. The key was  to  proof  for us, that we  can actually  either  " burn off "  lactate  which is a  terrible idea,  so the idea of cooling down to get rid  of lactate or  the ideas  to massage lactic  acid  out by massage people sounds great, but it  would be a terrible waste of a great  energy source  if it would be possible..
 So  you can see, that we successful  where able to create a   training /recovery  idea , where  we no just    where able to "hold" lactate  in the system as an  energy source  needed  for the next sprint or  load  or workout  section, but we  actually where able to increase  it  so not to use it as an  energy source. 

3min step test 1.jpg

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