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Development Team Member
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This thread  I like to  just use  for research   back ups  if they come in as well as  for  actual data interpretation we made  from a great  experience  cross-country  coach , who  sent us this information and data collection. 
I will open a  Q  and S thread  where we  can   look for  questions  and as you can see  we  can not   for sure give answers,  but  we  can give  you an S   for suggestions.
This is a  shy attempt  to try to be more organised.

Development Team Member
Posts: 1,501
Let's start with the  VO2   data collection.
 It was a  erg test  and  besides a  great VO2  equipment  the  coach  added  2  MOXY.s  VLL  and VLR  side of the legs of the athlete. It  seems to be a  test  this group is  regular  doing  and so very familiar  with the procedure.
 Here the data's  we normally  would get  from any VO2  test. It seems  they used a  step lengths of 1 1/2 min  for each step.

I  will use  just  the example of  one  of the tests we  got.

VO2 HR  watt.jpg

Grey  are the 1 1/2 min steps in wattage. It was NOT a  5/1/5  idea,  but  it seems,  due to the erg or  what ever set up, there was always a  short lower  load   when ever the  step load was increased.
 That created  for sure in the lower  wattage loads a  reaction in the physiologcial datacollection, but than  got smaller  as  higher the loads.
Blue is  HR
Brown is VO2  / body weight
See  under  Q  and S next step


Development Team Member
Posts: 1,501
Here some more  theoretical  back up  on VO2. For most VO2  is the result  of CO x  a-v O2  difference.
Where CO  stands  for cardiac output  and is often   connected  with  HR  x  SV (  Heart rate  x stroke volume.)
 Example. Resting cardiac  out  put   is 4.8 L / min
  your Resting HR is  60 beats per min  so your  resting  SV is ? Now  at rest   the  SV is  somewhere  around  50 % plus   from the  total blood in the heart  which often is called  EDV  for end  diastolic volume. This  %    which is thrown  out is  called Ejection fraction and it  give in %.
 So in our case we have   a  Resting HR of  60, a CO2  of  4.8 L/ min  and we have a SV  of  ???
 and we  have a EF % 63 %. What is the actual EDV ?
 Under load  there  are a few  options  simply spoken  to improve  or increase  CO.

 HR /  SV  and EF %
More later.
 Here a more in-depth  overview  on  what VO2  really is and  what may influence the   numbers

VO2 graphic and adaptation with traning.jpg 


Development Team Member
Posts: 264
 Example. Resting cardiac  out  put   is 4.8 L / min 
  your Resting HR is  60 beats per min  so your  resting  SV is ? 

SV is CO/HR= 80ml
 and we  have a EF % 63 %. What is the actual EDV ?

EF=SV/EDV*100 EDV=SV/EF EDV=80/0.63 127ml
ESV= EDV-SV =127-80=47 ml

In the skier case, even if the step lenght is too short, we can see that at the second-last step there is a steep increase in VO2 and keeps increasing throughout the step.
In the last one instead, VO2 seems to plateau as well as HR.
Would be interesting to see also a local feedback [smile]


Development Team Member
Posts: 1,501
Would be interesting to see also a local feedback [smile]

Welcome  in the insight  world  of   trying to work  through data collections.

 Okay here the  current stand   and corrected  version  of   one  MOXY  result.
 1. The  LVL  moxy data's   is  corrupted  as we discussed in S  and Q  and  Jiri  and Ruud pointed  out.

So  we    get rid of this  one  and we look at the RVL.
 I am not  sure there on timing  so I simply look just  at  MOXY  data's  and   speculated  that the first min  was   a calibration min before the VO2  equipment started, so  MOXY on for 1 min  and than start. In the graph  you see the correction  is done  and I got  rid  of the  first min data  set.

full watt  and HR  and MOXY  overlapp  for  real test  end..jpg 

Above graph  with  possible calibration. below  what I  work on  now

real  test  time overlap.jpg  

Your comments  thoughts   and ideas    go  and report on Q  and S.

So  in case  this is it  we  than  can start to look closer   to the situation of  combining VO2  and  NIRS  and I will show  in this  but in the  next case, where the confusing information is getting even better.
 VO2 is a  delayed  ( lag  time feedback on a  speculation  what   may  happened in te htotal system  as we  work out.
 NIRS is a  live  direct feedback   from one  specific  muscle.

What you see here is  reality on  why many classical users   simply give up  as the synchronisation of the  data's is  not  always  easy to  get.

 Below   an example  form Switzerland  on how  we initially synchronised  al the  data's  to understand the interaction.

NIRS ex.jpg 

above Portamon info  NIRS
 Below Physio flow info   cardiac
cardio ex.jpg
and below  respiratory info  and all  from the same athlete
resp info ex.jpg 
I  show this  as it iss  in Italian  so   a  small   sorry  to Daniele  in the  confusion.

Jiri Dostal

Development Team Member
Posts: 51
Before I go to Q and S I have a key technical questions here.
1 -the drop in VLL at 180 seems to me a technical error - move of Moxy or ( most likely) few minures of data loss due lo lack of contact. Why? The drop occurs suddenly with no explanation on wattage and HR. Also VLR has no similar trend there.
2 - VLR is not finished curve - no jump at the end of exercise. This is something we see in 100% of Vo2 max tests.  
3 - total time to max is based on Moax charts 4,2 min, while the VO2 chart shows approx 10:45 to max, we have a lact of data.

Summary - I think, they sent you a corrupted data, and we need to re-align the VLL and VLR to the same timimng and match it to the timing of VO2 chart.

I can bet, that we will see 5 min data gap in VLL.

I will show in the Q and S section some of our work with Vo2max tests

Happy New Year to everyone!



Development Team Member
Posts: 279
Agree! Data is partly corrupt. Best wishes!

Development Team Member
Posts: 1,501
Hahaha   Happy  2016
 Jiri , r Ruud  .  you guys  are " banned   respectively have a time lag  of  48 hours before you are allowed  to respond.

So that's where we  go  from despite some intriguing reactions  who may suggest  otherwise  to a  certain extend.

Last but not least. Jiri  and Ruud,  thanks  for helping out  so  fast  . ( That is the  evolving  team )

I will , if  you allow  me  still, go back  on the Q  and S and show   the readers, where you guys picked it up immediately and for  less   MOXY  experts, where we  had  at least some red  flags.
Here again the latest  version .
If no  change that's  the combination of VO2  data's  and  MOXY

real  test  time overlap.jpg


Development Team Member
Posts: 1,501
Now let's give it a  try to read the most   out  of this athletes data collection. I like to show  you how we  originally   used  VO2   and than added  NIRS  to it  and how we  now  can  try to create a  NIRS  graph  by looking  at  VO2  or on the other side e can read  out of a NIRS  graph  what may happened in  VO2.

a) VO2    can be used  as most  do as a  test idea  to find a peak VO2  number  or  performance.

We  use  today VO2  equipment  mainly  to asses the respiratory  system. For people  interested in respiratory activity    there are  other ideas out there.
 I love using  BIO harness as I  can see RF  and  respiratory  quality as well.  So    with a  classical VO2  assessment  we  get RF ( Respiratory  frequency ) and we  may get VE  as the total  air  ventilated.
 This  than can be sued  to  calculate TV - Tidal volume, which is the   amount of  air  you move  per breath  and it is  in L min often shows  already  or   again you can calculate. On  lower priced    equipment like  Fit Mate  we  get VE  and RF  so no problem to get TV.
We will show  later in the  graphs  how   TV  can have  an interesting  reaction   when it changes.
 Now    if  we already  have VO2  than we  often ose  the    O2  and CO2   ( o2  used  and CO2  produced  to see trends  in the direction  of   normocapnia  or   hyper  or hypocapnia.
 Normocapnia  is a  EtCO2 level  we will have under   daily   hopefully normal conditions  and depending on the school  you went  it is somewhere  around 35 - 40 mmHg.
 Now  I you are lower than  35    some  would call that start towards  hypocpania. In short you breath more  than needed  and you get rid  of too much CO2. (  hyper ventilation is    another word  for this. Easy  to  get the feeling  for  this situation. Breathe    hard   deep and fats  for  30 seconds   and you feel  what  hypocapnia  is.
 Hyper ventilation is often confused   with hyper  pneu  or  hyper respiration. Let's see  whether this example makes  sense.
 End of a  rowing race  and you can see  rowers    breathing like crazy.
 So  they do NOT get dizzy  as they  do NOT hyper ventilate. The  hyper-respirate,  driven by the stimulation of a very high CO2  concentration  due to the  hard effort  and CO2   is one  part  who helps  to balance as long as possible H +  concentration.As  CO2  starts  to balance out  they start  to breath slower  and  once they are  normocapnic than  the  breathe very normal. If  they go back to the TV  and RF   from  immediately after the  race  they  would   get very fats  hypocpanic.

Now  if your VE is limited  due to  respiratory  muscle  ability  and  as well mechanical  thoracic  and  costovertebral  motion   and  in some sports  this can be  due to   sport specific position,  than you    will  see a slower  drop in  respiratory  activity.
 If  we have  ice  hockey  player    with a VE  of  140 -  150  and Brian  improves   in his  hockey school the ability  to move 250 - 300 L  / min  than you  can see, what this  means   for " recovery".

I am sure Ruud  will soon  tell some  stories     when we  work on this  ideas  with him.

Now  why is this important.
 CO2  is a    interesting  substance  as it    can influence the way  we  load or in unload  O2.
 If  we  have   Normo  capnic  situation, than we  can decently load  O2  from out side   the blood vessels  so  from the lungs  to the blood  and we as well have a  good option  to unload the O2  from  the blood to the cell. There are  additional factors   which  can  influence  this. Now  to make it more graphic it is the  so often discussed  O2   Dissociation curve,
Here a very  simple  O2  diss curve

02 diss curve 2.jpg 

So in simple  words. if  you move towards the right side  than it is easier  to release O2   from the blood to the cell.
 BUT it is harder  to load  from the  lungs  to the blood.
 Our  school   fitness  11  and 12 grade  use a very simple  practical example  you can do as well if you have a  NIRS.
Here a pic.
CO2 levels duirng holding breath.jpg

Now  just  to  complete this  short  intro.
 The full O2  disscurve looks  somewhat different.

o2 diss  real.jpg

Just as  a hint  to not get lost  ( as usual ) Look on the top rights  side. Where  do you get the O2  from when you start. Remember  any start no matter  how  hard or  slow , starts  with a delivery limitation doe  to lag time  of  cardiac  and respiratory reactions.
 Now  if we  go  with ideas like Suhlman  and others , that w e  immediately use  O2. Where does it come  from ?

 Now  what we have  to add is :
 Hold  your  breath  and you can have a MOXY  anywhere  , on an  arm , leg     where ever you know you  can  have  deep enough penetration  for the NIRS  and you will se e  an interesting reaction on Smo2.
 You can as well add a SpO2  sensor  and you have  a reaction there as  well. What  do you expect  on SmO2  reaction  and  on SpO2  reaction , when you hold  your  breath and why  does it show  up  any where  on a NIRS? Now  if you do this experiment there is a  very interesting trend  you will see.
Here  the next hint.
Now   if you do this  at  rest  it will be very different than when you do it under load.
 Why ?
Now  here   is where TV  comes in.

 Your  TV is measured  at the mouth. so the   air you breath  per breath in ml or liter  tested  is   all the air  from your mouth  to the  gas exchange area in your  alveoli. Unfortunately there is a  transportation stretch there, where you just  move the air  but  you do not exchange O2  or  CO2.
 This  can vary  depending on body  size   around  250 +-  mil . So  why is this crucial as it  should not change  at rest  and at   load .
 So  you breath  70+-  x  per min   and you move 1.7 l  TV = 119  L / min VE  from this 1.7 L  250 ml  are  moved  just  to get  form the outside  to the inside  with no actual  help to exchange O2  or  CO2  but  with the need  for O2   for the respiratory system. so 70 x 250 ml = 15 L +   air is moved  for no  real benefit  but   for a  O2  cost.. If this athlete  could  reduce  RF to 50 and  increase  TV to 2.5  we would have   a VE o f125 L /min . so more  air  already  and 20 less  muscle contractions. But as well  we move only 12.5 L  of  air  for " nothing" and  at the end  actually  move 113  L  of  air    where we  exchange  O2  and CO2.
 Now you combine  all of the  above and you  may see, why we  where looking  whether  VO2  respiratory feedback  and NIRS feedback  may  connect  somewhere easy.

So here  the VO2  peak data's  again.
VO2 HR  watt.jpg 

No  concern of  synchronisation here. We  had  one comment  from Danile  , that   despite  only having 1 1/2 min  step length we see some trend  towards  the end . HR  seem  to "get flat and VO2  somewhat   got  steeper, For  sure no MAX  as a  max  would  mean a plateau. So VO2  peak.
Some  would say  despite  short  steps . I would argue  due to short steps  and  certain limiters  and compensators  we see this trend.

Here a  VO2  " peak "  from  the same group  another skier
hr watt VO2.jpg 
Now   not  a lot  of feedback  on what we  really can do with this  for training applications > Forum is still open.

So  what we where looking is  how this  athletes  " move "  air   O2  and CO2. measured  at the mouth.

 Here our  first athlete
RF  tv.jpg

and here the second  athlete.

RF  and TV.jpg 

 Now  think  how this may influence  O2  and CO2  balance  and remember   CO  is a  major  driver  of RF  The  CO2  and O2  trend looks   from the first  athlete like this.
o2  co2.jpg 

 and  from the second  athlete  it looks  like this.

o2  and  co2  at the  mouth  and RF.jpg
I  added the RF  to this  as it is  fun to see.

Now  hint. We test this  at the mouth. So   try to draw a  NIRS  picture  towards the end of this  VO2 max tests using SmO2  and  tHb of  an involved . This will be  a   section next  week  for our  students. Logical loud thinking  and  justification  why  we  would draw the pic  the  way they  think.


Development Team Member
Posts: 1,501
Got  some great  emails  back  and  I will  just move  forward  to the  one  case  of  cross country  skiing.
 What I k now  for sure now is, that the MOXY  was  mounted  on the vastus laterials  left and right  or  at least close  to  VL. What we have to wacth is  , that  some may move  too much  lateral and than catch a lot of  the  iliotibial band  which than can create  not optimal feedbacks.

 Here  one  request:
  O2 pulse  info  or  VO2/HR  In   very simple  terms   O2  pulse  can be used or is  used     from some people  to estimate  SV  but  a-v  O2  difference  is  in the formula  involved  as well.
 Now  we use  VO2/HR  and VO2/ RF  for some  easy  simple  not very scientifique  overview, whether we   despite a  higher load  still move  per HR  more O2  or  per RF  more  O2.

Here  from athlete one  we  started the  discussion  followed  by the  same info  from athlete  2.
vo2  hr  rf.jpg

vo2 rf hr.jpg 

The lower  number  here  in blue  is VO2/HR  the higher number is VO2/RF here in brown  on  left axis

Thanks  for the request.


Development Team Member
Posts: 1,501
Than I got  one  email  with the request or  statement.

" Can you  simply tell this  cross-country  coach  what you think  is the LIMITER in his  racers  instead of  showing endless graphs   nobody  can  get smart of it."

Well fair  and open statement  and I like it.
There  are  always different opinion  and over the last  40 years  I learned, that we  can  make a cookbook  or a  guide  for  Dummies   but   with the  close  groups  I  love to work  with  and yes we  are slower  to sell ,but  we  try to create a foundation  as NIRS  in this stage is  a great tool  for  smart coaches  and training centers  but it will need  some time  and brain commitment  to  get to full benefit  out  of it.
I like to avoid a  220 -  age  idea, which  than moves  even into the " scientific  community   despite  the  fact , that the founder  still has to smile  about that.

220 - age Hasket rule.jpg

  Okay  so here  the request.
 Cross country  skier   two  so second  case we  discuss.
 I  like that one  as  the first one is  interested  , the  second one is very intriguing.

Here just  2  pictures  ) ( sorry )  do no look at them  just    scroll down   for the  information  you believe the coach needs.

For  graph  workers  I lie to show you   the left  and right  biased  graph  of the full VO2  test length  NIRS  data  collection. I like the  biased one  as we  do not get  distracted  form  numbers  and just look at trends.

  bias VLR.jpg 

 RVL  and the  red  trace   is  similar    trend  like  a SmO2. This shows  a  relative typical   steady  drop of  O2  which  we often see in  endurance  athletes.
 Look at Jiri's   graphs   where he  compares    ice hockey players   and endurance athletes.

 The tHb  shows  an  intriguing trend  and you can see  slightly  that  we have a  optical BP by  +- 300  where we see a  increase in tHb

Now  we know   it was a  VO2  max  test. Most likely with a  first  uncontrolled warm up. (  speculation as I have no feedback  from the coach on this ) The speculation is based on the tHb  trend  at the beginning. (  what would  we  expect  tHb trend  to be  when we  would start  cold  turkey )  sorry   Brain needed )

So  for the coach based on this  graph.
 Delivery limitation all through. (  caused  by the test protocol .)
 The test  had  to be terminated  because  of a respiratory limitation.
 Another  Delivery could be  cardiac out put. Problem .  Because a   protocol , any protocol  even our  once , are Brain less  we have a problem  to  find a  reduction in SEMG  due  to cardiac limitation  respectively  central governor  protection. We  have  one  way  to  see a   protection,  when we use  SEMG on  other muscles or  MOXY on other muscles.

Now  as usual  that's not it.
 Here the LVL

bias  vll.jpg

The left leg of this  cross-country skier  shows a  typical   biased  graph  I see  nearly  daily in my clinic . So it  is not  completely fair   to  point  that out  and I   take a risk to be completely off.

This  leg  has a  problem.. And it is  a  problem build up over longer time meaning that there was some injuries involved  so that the muscle really changed  fibber  constellation  and  capillarisation    structural  situation.
 Meaning that there was  a long  lasting  recovery  situation or  multiple  injuries  in a a  relative    short time after  the other with not  optimal  rehabilitation of the   muscle  at all.

 This is a picture e I have  currently  form a top athlete  who  comes  to our  rehab   as the result  of  what ever happened  did  not  work . So second time  re ops  of  ACL  and PCL reconstruction.  ACL   hamstrings  graft ,  PCL  Allo graft.
 Problem is   that we  can rehab a  muscle based on performance  ( Cybex  )  for example  or  we  can rehab a   muscle based on physiological  ability  before we look at performance.

The  " performance"  was great  after the first rehab. The physiology  was not there  at all.
 So  this  skier  has  2  areas  to work on.
 1. Respiratory   limiter  so increase  respiratory  ability.
2. A-symmetrical   muscle   ability , which will create a problem  over time   and the first one  will be in the   spinal  area.

Recommendation which nobody will follow . Scratch the  season  and  work on health ( leg  rehab    before moving back into high performance  activity.)
 ( This only if there is a long term plan  of  commitment  to this sport. If  it is  the  last year  season  don't  worry, have  fun  and   expect  not to much.

Hope  this is  what the mail asked me  to  do ?
 I am not  happy  but  there are different ideas  out there to work  with   technology.

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