Sign up Latest Topics

  Author   Comment  
Juerg Feldmann

Fortiori Design LLC
Posts: 1,530
As  many of you can imagine,  working now  over  10 years daily  very intense  with NIRS  and MOXy  will create a very high numbers of questions , but as well as results  contradicting  what  I learned   or  what we  still learn  and what we see  .
 Here  just a fun part In a big discussion we have internally over the value  on  the   way  we  find   so called " training "  or  intensity   zones.
. Here a  small inside view   what we  do daily as a fun  section of our  live.

Common Methods for Identifying Training Zones


Prior to Muscle Oxygen Monitoring becoming practical for use by athletes, there were 5 common types of methods for determining Training Intensity Zones for athletes.  Each of these has many variations.

1)      Rating of Perceived Exertion

2)      Maximum Heart Rate

3)      VO2 Max

4)      Lactate Threshold

5)      Functional Threshold Power


In future posts, I will step through each of these to describe how they work and how each method relates to determining training intensity zones with Moxy.

 That will be  fun to read !



Part 2 – Rating of Perceived Exertion


Rating of Perceived Exertion is the simplest method for setting training intensity zones.  Essentially, the athlete self-reports how hard they are exercising.  It is inherently subjective as since there is no way to externally verify what the athlete is feeling.


There are many different ways of rating exertion.  One of the more formal and widely used scales is called the Borg Rating of Perceived Exertion.  In this system, the athlete rates their exertion on a scale of 6 to 20 based on the following table.



The 6-20 numbering system is intended to help estimate heart rate by multiplying the exertion number by 10.There are other numerical scales that have the athlete rate their perceived exertion from 1 to 10.


Perceived exertion is sometimes based on some form of the “Talk Test” rather than a numerical scale.  The intensity ratings are based on the level of comfort with singing, speaking in sentences, speaking just a few words or not being able to speak at all.


The most common version of the talk test is an attempt to set the optimum exercise intensity for non-athletes.  If you are able to carry on a conversation comfortably, the intensity is too low.  If you are unable to talk comfortably, intensity is too high.  If you are right on the edge, the intensity is just right.


This is true  and it is  super interesting, if  we  start  to think above and beyond the surface.

  Question. What or why  can we use the talking or respiration   pattern  for    the Borg  scale ??

What makes us  during or  at the end of an exercise  feel uncomfortable. . What is a person telling you when he quits a  workout .

 “ I  am  out  of  breathe”

 You never hear somebody telling you :  “ I am running out  of heart beats  or stroke volume”

 The discomfort  and as such the rating of    load  is  coming   mainly  form feedback  created  or   avoided  by the ability of the respiratory system  to balance   the H +  situation.

 Any  level  out of  “ normocapnia”  creates  discomfort.

  You  can load very  very little  100 watt  on a person who normally  easy can go  250 watt and can make him telling you  he is on the Borg scale on 20.

 Let him bike  but  don’t allow him to breath  as  he likes  but  half the amount  or  double the amount  so he is  either hypo  or hypercapnia.  Both will give a feedback over SmO2 .  Hypocpania   low CO2  will  show  an increase in SmO2    (  so most believe great  I have more O2  , if they  take lactate even  at 100 watt only  they  will have an increase in lactate  as a sign that O2  independent energy supply  had to kick in as    O2  was loaded to Hb  but it was not  optimal bioavailable so even 100 watt   needed support  formO2  independent energy supply to keep ATP  level  on a acceptable level.

 If  you    go  slow  and   under breathing  ( hyper capnia  ) you will see SmO2  dropping  lower and lower ( if  you can handle the discomfort )  and SpO2  will drop  and lactate  will after a while going up. This time  because it  is getting harder  and harder with the is  low  pO2  to  extract  from the Hb  despite  a high  CO2 level..

 So Borg really is a direct reflection on the respiratory system  ability  to keep you happy    or better normocapnia.  As long you can balance H + you will  see lactate going up   and up  and no matter on a lactate threshold.

 As  soon you get  out  of normocapnia   you will   see that the discomfort   goes up with lactate  but not due top the lactate but  due to the  mismatch  of CO2  ( pH level  and  the bodies  ability to only have a small tolerance  on  variation.



(Brooks, G. A. and D. A. Roth, Med Sci Sports Exerc 21(2):S35-207, 1989; Roth, D. A. and G. A. Brooks, Med Sci Sports Exerc 21(2):S35-206, 1989). Moreover, maintenance of a more normal blood pH during strenuous exercise would decrease the performer's perceived level of exertion. The conversion of lactate to glucose in the liver and kidneys also has alkalizing effects by removing two protons for each glucose molecule formed, 2C3H5O3 + 2H+ ¨ C6H12O6. Thus, whether by oxidation or conversion to glucose, clearance of exogenously supplied lactate lowers the body concentration of H+, raising pH."(22)


 Hard to believe isn’t it  ¼  century later  and we still have  nto progressed  and so hard to  talk  with    many  well  now   guys in the field. 

  add on :
Why  do you think we avoid  cool down  between intervalls  as an active    part and use  respiration in specific  form  in between. ?

Respiration  and respiratory training, more than just for fun.




: "Because lactate is combusted [metabolized] as an acid (C3H6O3), not an anion (C3H5O3), the combustion of an externally supplied salt of lactic acid, CHO3H5O3- + H+ + 3O2 ¨ 3H2O + 3CO2 effects the removal of the proton taken up during endogenous lactic acid production (Gladden, L. B. and J. W. Yates, J Appl Physiol 54:1254-1260, 1983). A side benefit of alkalizing the plasma


by feeding lactate would be to enhance movement (efflux) of lactic acid from active muscles into plasma, a process which is inhibited by low (relative to muscle) blood pH.



Previous Topic | Next Topic

Quick Navigation:

Easily create a Forum Website with Website Toolbox.

HTML hit counter -