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Development Team Member
Posts: 1,501
Short  question
 what is  a
 Typical for asymmetrical pelvis/right bias
Thanks Juerg

Development Team Member
Posts: 1,501

Thanks  and  , after all this great feed backs  here some  of my observations 
 First I like to make  2  sections.
 a)  use   or better integration of MOXY in b equipment fitting   so in this case in bike fitting.
I use   equipment fitting, as in   many  sports  MOXY or NIRS is used  for optimal equipment fitting  and  I am  always surprised  how  hesitant  the bike  or  cycling community  still is  to recognize  that a  equipment fitting has to be a team  approach  between optimal mechanic,  optimal comfort  and optimal  physiological  impacts. Plus  duration off the  activity  we may  do.

 Some example  outside  the  cycling  world. Just examples  without   closer explanations  why.
- Cross country skiing.  Difference  in binding  mount  between  diagonal  and  skate  techniques.
 MOXY placement  Tibialis anterior
- Badminton  Grip size, Moxy placement  wrist extensor  and flexor
- MTB  downhill - Grip  size  same as  above
- Office  chair  seat  angle  Moxy placement  paravertebral  and  upper trapezius.
- White water  kayaking . Paddle  length  as long in regulation and thickness
 And many more   options.
I will come back on how  we use  MOXY  in bike fitting  later but I  rather leave this  for the  cling specialist  a this is  a hot  debated  topic  and  not many  bike fitter like to  have people looking  into their  kitchen

b)  looking at the  data's  we got  to discuss here

smo2  all three.jpg 
Above just a  a  short  review  but   many  already made some great observations
1. In this situation  most likely not a systemic  limitation. This is based I on the stable  non involved muscle reaction. No  need or  no  tendency  to  move   O2  and a  such  blood  to wards the legs  due to  delivery limitation   due to a  systemic limiter.

thb all three.jpg 
The tHb trend in delta  confirms a  minimal involvement and no vasoconstriction trend  after the 4  ( 2  double  load ) where we see in both legs  SmO2  dropping.
 So lets  focus on the legs.  The SmO2  trend seems to be  different but  not that  extreme  if  we leave  absolute SmO2  values  out.
The biggest trend  different if  we  would overlap them  seems to me in the  3rd  and 4  th load  so  second double load
The right legs  is  pushing  an intensity  where the  delivery of  O2  still is higher than the actual utilization.
The left leg  shows  already a higher utilization  with  in the second time same load an ability  to find a metabolic balance.

Now in cycling we have the  disadvantage , that due to the pedal system  one  leg  can actually enjoy the work  form the other leg  and is getting a kind of a pleasant  ride  where  as the  other leg  has to work  much harder.
 A  simple  example   what I mean.
 I  move a  stroke patient   with the right sided  leg involved on a bike. As long  as I can  keep his leg on a pedal  he will be able to bike decently (  some exceptions )  and both legs  will go around with one doing all   or  more or less all the  work. I move  him on  my  independent  pedal system  and   they are in trouble.

So this is the first  question here.
 Is the  right leg   enjoying the   ride  and only towards the end , where the demand I of load is  more the athlete  is  asking  for a better input  form his right leg.?

So  if  we have  as Ruud  suggest power feedback   from left and right  the answer would be  easier .

Now  assuming he   has left and right same   performance (  wattage )  than the  question would be.
 The  left leg  seem  than to have  some delivery problem  and uses  a better utilization  already early on.
Now  delivery  not  for a  systemic   idea ( cardiac  or respiration , but  form a capillarsiation point of view or ins  some cases  form a   blood flow  problem in the femoral arterial   area.( Often overlooked in pro cyclists)
 Problem with this  thought is his tHb  reaction which would show a  vasoconstriction  due to  less capillarisation with same  muscle tension. We  do not see this at all, in fact look at recovery tHb  tends  which look nicer  in  left tHb trend than in the right . So that creates  some problems.
 If  we have  no  capillaristaion  difference but a much lower  utilization  level   which  would indicate a great mitochondria density compared to the right.
 Why . The  studies  done on  capillarsiation density  and mitochondria density  all agree, that  we   first will create  more blood vessels  followed  by increase in mitochondria density. In detraining we would loose  first   mitochondria function and if we  long enough detraining the vascular bed.

 So   let's look  at the biased  ideas  as they give a feedback on  " delivery  and utilization compared  form the start  as  zero    and the relative change.

bias  r Leg.jpg 
D means the pedal position was  down ( 6  o clock)
 You can see the first  4  x  5min  a  good  delivery  and  after that a  actual  higher demeaned than what is delivered  to the right leg. Red above blue  with exception a  so often  at the start  where we know we have a delivery  problem . Nice is as well to see  at the start of  the r  first  4 load  thB  trend. Indicating an initial involvement of    muscle contraction and than he looses the tension  so  tHb  can increase. A  SEMG  would show an early drop in  amplitude  or    activity level  compared to the set  5   and  a little bit  6. Than interesting in 7  we have  again an increase in thB.
 If it is systemic  due to CO2  vasodilatation or  a great  compensation of CO  we will see it on both sides. We have a  slightly  higher end thB  overshoot  after   load   as an indication of  possibly  a higher  CO. If  it would be a  systemic  CO2    as well  we would see a lag  time of SmO2  recovery . So another point  to look and gain systemic    should show up on both sides.
So lets look bays  left  leg.

biased  left leg.jpg

You  can see  a very different picture
The  O1 Hb  with  exception of the  rets period  never  really  shows  a higher  delivery than utilization. tH  trend indicates a  muscle contraction as we start  and than  always the same    fight between contraction  and CO  vasodilatation.
 But we can throw that out immediately, as we  have no  drop in tHb  at the end of the  5 min  so no occlusion outflow.
 never  with a  slightly difference towards the last three  do we see a  decompression  section , where  CO  is  winning against   muscle contraction.
 Again  two option.

If  equal  work  left and right this side  has less vascularisation (  had  thrown  out  due to better utilization)  but !!!  could come back  only  if  the tHB is  not a  free  flow on a lower level but would be an arterial occlusion  so  SmO2  has to drop as no  O2 inflow !!! ) BUT
 throw it out, as we have no occlusion outflow  at the end of  5 min  ( no drop in tHb )
 Now  interesting speculation. At the moment we see a drop in tHb  on the right side without  " recovery " during the load the left leg shows  a  slightly ability  to recover. Is this because   we have better   help and some involvement for a   moment  from the right  side ?

Now  next  what I like to compare.
 First load  and last load Here  to start the pictures  of  SmO2   strat  smo2  legs.jpg 
Overlap  dark  right side   Now  not sure  but here what we know  form  left  right leg  after operations  so we know which one is  the " weaker " leg   and where we lost  structural   substances.

closer look load smo2  thb.jpg 
Now    from one  cook book. tHb  can give a feedback on muscle contraction  quality.

strat  thb  legs.jpg

Dark is  right leg  at the start.
 Dark shows a  muscle compression outflow.
 Left   leg shows as well an initial   compression outflow  followed by a tHb increase
 Question?  decompression   inflow  or  slightly  outflow restriction ?

Now look  at thB   right side   settels in  with  thb  by about 50 +-  seconds. So tHb  flat meaning free flow  so SmO2  if  balanced  should be flat as well or if more delivery than utilization  could go up.  Left side tHb  after ????   about  70 seconded  flat . Now  check the SmO2 trends of  both

 So  question.
 Is  right so much better , that  it only creates a compression  and  left weaker. If  same performance that could be the answer.
 If    left works  more  to compensate  for  the right , than  after an initial help less optimal   work  from the  right side.  Summary . You can see  cook book problem. In the example  of a clear knowledge of the weaker  leg we have  the common feedback of a  slower recovery of SmO2  and  with this PCr. Now    if we  have  situation lie here, where we  could avoid  hard  load  as we have a  compensator  from the other side  we have  a situation, where the much harder  working leg  ( if  this is the case ( has logically a  much slower recovery , as the weaker leg  never pushed  thru its potential. At least  at the start. So next  up  is , whether re see  at the end  , where the  mind power of the athlete  may be able to overrule this  discrepancy  and forces  more out of his  right leg.   So  as funny it  sounds. In the lower  intensity  the  left leg  can do the job and the right legs  sits  back and enjoys .  In te   hard load the mind  may  call  the right leg  for some more  help  and  now the right leg  has to help and  a kind of compensates  the now   already  hard  worked    left leg ??
 Interesting story  isn't'  it.?So stay  tuned.  Last  but not leats. If this story  may have some truth , than we  have a greta example of .
 a)  all out  will force the right leg  to  help but ???

 so   we go into  very low intensity and use  the    MOXY  for feedback  or SEMG  for feedback  to   use the right leg under lower intensity. Reason  high load may aggravate   the problem if it is a pelvic   problem like a promontorium  shift.



Development Team Member
Posts: 1,501
Now  here a  critical view on  our  own ideas of  "  zoning"  . When we  take this case.  try to make a  ZONING  for right and left  leg.
 When  we talk about  zoning I mean look at the2  "lines"   Line  or   area  1. . Where we see a  clear trend  form  SmnO2 increase as a sign of   more delivery than utilization to  a the area  , where we   see a balanced  approach  between delivery   and utilization so flat  SmO2.

 Than  "line  " 2  where we see the balances  flat SmO2   moves towards a   dropping trend  so more utilization than  delivery.
 So  MOXY   lone  1    and MOXY  line  2
  We still look for some great   flashy  names  for this area  we easy  can use  and they make a  bright light  when we  talk about them.
 I had  once , as many know, the idea  of  ARI  to STEI and so on.
 My mistake  really  as  again the trends  are not   bound  to tuna be used for  certain    simulations. I  can stimulate as we know by now hypoxy  in a very low intensity  or in a very high intensity. Difference. In the low intensity  it is my decision.
 In the high intensity it  may be forced  upon  my body  due to the  intensity level.  In this case we see, that  if  we use  one leg    we have a different " zoning"  tuna  when we use the other leg.
 So by using just intensity, we may  overload    the wrong systems or leg. This is  why we  can  use MOXY  to play around  and I will show in thsi case what we  could try.

Development Team Member
Posts: 18
I'll PM you more information.  
Chris Balser

Development Team Member
Posts: 1,501
Okay  back  to this  great   information in this  assessment.
 1. We  not even looked at  the  " zoning " yet.
2. You  can see in the length of  my  feed backs  that I have  no clue  yet  which leg  really is the   stronger or the weaker I  have  as  all of us a  50 %  change  to pic  the proper  leg  but that is not what makes  fun.

So  we still have the   two options , where  the right leg is  actually much  better working    and the left one  falls apart  relative  early.
 What we  do not know is, whether this is a  functional problem  with the hint  we have of a  pelvic  positional problem ?  or is it a structural   picture  we see, here  because this pelvic  problem may be    existing since many month or  even years  so we have  a  very different muscle fiber situation.

 Below  an example     I  already showed.   again  including SEMG  graph  pattern in a  very simple  form.

The right leg is the  healthy leg  and the left leg is a  situation  after 5 month  waiting  for an ACL  repair  and  now  8  weeks into rehab.
 Here  what the readings  could mean
The test was  an all out  voluntary  muscle contraction.
 Not    a very  smart  way  as it is  not  functional  but often used  for insurance  purposes. Very limited by  motivational  influences  as well   so always be careful with   feed backs .

TSI  right side  much    lower so indication  of a  much  more effective  desaturation.
 Look the  green trace , which is  here tHb  or  blood flow.
Right  leg  great initial  muscle contraction  and  compression so outflow  and than reaches  an arterial occlusion (  jumps  over the  venous occlusion reaction due to a very  aggressive contraction. Than releases  it  and we have a   occlusion  overflow  reaction  .
 So is the  lower TSI really  a better utilization or  is it forced  due to the  arterial occlusion. ? 
 The left leg  you see  as well a  compression outflow  but much less  aggressive contraction. ( Pain  , afraid   or  not  really motivated  to go  back to work ? ) After the compression  a  better   contraction leading to a  outflow restriction and finally  to a  short  arterial occlusion where we see the second  dip in TSI %  as well and than  back  to baseline  flow. You see  tow  red  and tow  blue  traces   showing as T1  and T3  meaning  T3  as deep as we  can get  with NIRS  and T1  on the  surface  so more  reaction in the skin.

 Now  below the  simple picture of  5  of this contraction  assessments.


So  if  we  was " cheating "  he was pretty good as it is very difficult to create this regular  result  by controlling your  contractions.

If  we look  a the  the ideas  of  using SmO2  as a indirect  feedback on  recovery of  PCr. than the picture    would look as we showed before.

strat  smo2  legs.jpg 

Now  the fun part is, This would indicate a  better  recovery  for the right leg.
BUT  did they  worked  the same   intensity , do they  have the same  fiber , composition. Is there the same   intermuscular  coordination here. meaning the hip extensor  of  both sides  contribute the same  power or  is one side much more  fixed on  just   leg extensor  and the other has a much better team approach.? So you can see  we  could make a very smart  and great formulated  explanation, paired  with a name  and some Ph.D  titles  and some impressive numbers on how many   world  class athletes  we tests  and  people  most likely  would  buy in the explanation.
 Reality is, It is  so  super interesting  and complex  , that we  can discuss  with  many open options but  very little  hope , that we   find a  perfect answer.
 Time  and re assessments  are needed  including some   nice ideas of  muscle biopsies  and  even  some  specific  assessment possibly in this case on pelvic  reactions.  So let's  stick on what we see  and  have a closer look at this two still open options.

 Let's  look at a  section Ruud  had  some cherries on . Start  and end  of the  5/1/5/

start r leg  thb  smo2.jpg 
Close look at the start of the right leg .
1. The usual  fast drop in SmO2  so use of  O2  doe  to lack  of delivery  at  any start  situation.  The  10 - 20  second  tome lag  before the  delivery  can   come up with the needed O2    so  re oxygenation after the initial  effort.
2.  tHb  as an indirect feedback on blood flow  and possibly  muscle contraction quality.
 We see a normal  drop in tHb as  an indication of  an initial  muscle compression which is  stringer than the current vasodilatation effect  from different  sources like   for example the cardiac  out put. Than  stabilization of  tHB  due o increase in CO.

Now  let's look the left leg.

start left leg  thb  smo2.jpg

SmO2  we  had overlapped  so very  equal  demand  of  O2  left  and right
tHb  . we see  as well the initial  compression outflow but than followed  by a  outflow restriction. ( true    the question could be is it a  decompression   back flow ?
 If  than  we would see due to the relaxation  often a  short  hesitation in SmO2  drop . As, well as thB  drops  again , Occlusion out flow , versus   additional  muscle contraction.  SmO2  would show that in an additional muscle contraction SmO2  would  drop again.

So here  again the  question?
 If  same   power   than the right leg  needed much less motor unit  recruitment  and therefor  we  see only a compression with   still in and outflow, versus the left   who needs a much higher  %  of    motor unit to create the needed power so    compression followed  by  outflow restriction.
  Hmm this  than  would shift tee  idea   back to  right  good  left  weaker ??  Now  here  another r  point we can loo  at is during loads  in higher intensities..   If    and just if  the right leg  as  above  shown  may  have a better  initial recruitment pattern  to start the load , than we  may see this in higher intensity in a   over  activation at the start  with a re correction during load.
 meaning tHb  and SmO2  w may  actually  change   versus  working on the  limit  where it  will show a  stable picture.
thb all circles.jpg 
Now  the  dark    right leg  shows ( see  circles) n three sections  an interesting  pattern  with  an initial  drop in tHB  as a sign of  an muscle compression  followed by  and increase. (  either   outflow restriction  with pooling followed by an  occlusion outflow?
 Or  compression  to string  with a  readjustment and relaxation  and  again a  readjustment to finish the load.  Now  if it is  an occlusion trend than  SmO2  or  better seen in O2Hb  would steady  drop. If it is  an initial hard  push  to start with a readjustment and some relaxation of the    muscle activity  we will see a  rexoygenation trend  as  flat O2 Hb  or even increase O2Hb   before it would drop again.

Now let's see.

bias  r Leg.jpg 

Now  you are the referee !!! This  leads us to the next  discussion " Zoning"  or better trends.
 Here  some color  to avoid  words.

left  and right   intensity zoning.jpg

Now I  did  for  fun a  closer look  back . So each color  represent a  specific SmO2 r trend  indicating  what ?
 Now look  at  the right leg  when we look at it  from a  SmO2  trend ideas.

right leg  smo2  thb   i step  zoning.jpg 

You see what I mean. If  we  use  SmO2  trends  (  excluding some specific  reactions )  than the right leg in fact  changed during  loads the " zoning".
 Two options again.
 It got   help  from the left side  and could afford to relax   or it is  much  stronger, so it initiated the load  readjusted  and than finished  it of  due to the lack of  an optimal support  form the left leg , where we do not see this reaction.
 Or  the   left leg is   working  all the time so hard  that it  simply  can not afford  to relax ?
  Now    we come to the  interesting section  of how  to  correct    what ever is  asymmetric  so we do not   increase the problem but solve  it.
 How  do we use  classical ideas of  zoning for this  problem or  do we  move  perhaps  more towards physiological feedbacks.
 . a)  we can  but  we already have the discussion, look for  right an d left  independent power feedback.
 Now the discussion is  on all the  wattage  people to argue  with each other whether that  is working and whether we  can trust the wattage   feedbacks.
 Or  we  can simply start playing  with MOXY  and if  we have SEMG  and  do  specific  intra  and intermuscular  games to see how  the   legs  react. 
Chef  versus  franchisee.


Development Team Member
Posts: 1,501
I  forgot .
Please do not ask  me  which leg is the better  as I have only  50 %  chance  to pick the  proper  answer.

Development Team Member
Posts: 1,501
I  got a  very  funny  and friendly e mail telling  or  asking me, that the   farm stories  are  fun , but the   conclusion, that  the non involved muscle, in this case  here ( or  any other cases  we show )  indicates a   more   loco motor  limitation  than a systemic  limitation, needs  some better back ups  from accepted science , than just a great story.

 Absolutely agree.
 Here  what the farmers  almanac  states.
 . a)  if  there is a  systemic  limitation like  a limitation  from the  delivery systems( Cardiac or respiration) than we see a vasoconstriction  in the non  or minimal involved  muscle;  as a  drop in tHb  and a  drop  often in SmO2  as well.
b)  if the  delivery systems  ( Cardiac  and respiratory    and often include  the capillary  system )  are not the limitation,  than the body  can afford  to  sent blood  to any  region  he leis  as there is not  risk  of   a lack of delivery  or a out of  control blood pressure  reaction. So  we do NOT see a  drop in tHb and SmO2.

 Now  here  an interesting  paper outside the farmer  almanac  story book.

Running title: Leg arm blood flow during upright cycling.

Address Correspondence to:

J.A.L. Calbet

Departamento de Educación Física

Campus Universitario de Tafira

35017 Las Palmas de Gran Canaria

Canary Islands


Fax: 00-34-928-458867




To determine central and peripheral haemodynamic responses to upright leg cycling

exercise, nine physically active males underwent measurements of arterial blood

pressure and gases, as well as femoral and subclavian vein blood flows and gases during

incremental exercise to exhaustion (Wmax). Cardiac output (CO) and leg blood flow

(BF) increased in parallel with exercise intensity. In contrast, arm BF remained at 0.8

l.min-1 during submaximal exercise, increasing to 1.2±0.2 l.min-1, at maximal exercise

(P<0.05), when arm O2 extraction reached 73±3%. The leg received a greater

percentage of the CO with exercise intensity, reaching a value close to 70% at 64% of

Wmax, which was maintained until exhaustion. The percentage of CO perfusing the

trunk decreased with exercise intensity to 21% at Wmax, i.e. to ~ 5.5 l.min-1. For a

given local VO2 leg vascular conductance (VC) was 5-6 fold higher than arm VC,

despite marked haemoglobin de-oxygenation in the subclavian vein. At peak exercise

arm VC was not significantly different than at rest. Leg VO2 represented around 84% of

the whole body VO2 at intensities ranging from 38 to 100 % of Wmax. Arm VO2

contributed between 7 and 10% to the whole body VO2. From 20 to 100% of Wmax, the

trunk VO2 (including the gluteus muscles) represented between 14-15% of the whole

body VO2.
In summary, vasoconstrictor signals efficiently oppose the vasodilatory

metabolites in the arms suggesting that during whole body exercise in the upright

position blood flow is differentially regulated in the upper and lower extremities

Now allow  me  some  critical  add on  here.
 We  see this  as well but in our case here teh above  paper  would   not  fit   as we have no  change in upper body  reaction  which indicates for us a  sufficient  delivery ability, but a  limitation in the loco motor system.

Now    due to the origin of the email I like to add.

 I  have  in the high season  5  -  9  goats . This is considered a h HOBBY  farm  so no way I  ca  talk and or  compete  with my  ideas  in eh go art farmers    groups. I  can  tell some case  studies  from this  small sample size  but  in no way can we make a  decent  rule  on how to  go about  the farming.

 Now     to apply that to  exercise physiology.
  A  sample size  of  9  athletes   as in the above  paper  or  as in many  published  and accepted paper  is    about the same situation.  This is a great  case  information  from a great  study group   collecting super  good data in very specific  condition,  but in no way  does it tell really what  can go on.
 We need    hundreds  of  samples in a  full   variety  of  people  to  actually   come to a  statement  otherwise  ,as  in this case , we see   a non reaction of a  non involved muscle,  whereas a great case  study as above  would argue the opposite.

 Here  for  Hobby farmers  a  fun  practical application.
  a) if you have a  client  or yourself  show a  non involved muscle not reaction in a step test as  an indication of  not limited  delivery system  you can  do the following idea.

 Pre fatigue  the cardiac  or the respiratory system.  It is much easier to  pre  fatigue  or overload the  respiratory system as we  can do this without using  loco-motor  muscle  we may  than need  for  cycling  and we  can  do that  by keeping the cardiac  work on a very low level.
  So   you can do this one  day before  or immediately before a  5/1/5  or a  step test.
  Your  VO2  max  test  information tells you that  at the  VO2  peak  you  breath  RF  of  40  and TV  of  2.5  so you move  100 l VE  / min
Now  you  do a  normocapnic  (  pCO2  of  35 - 38 mmHg ) hyper pneu    ( RF  of  above  40 or  40  but TV if  possible  above  2. 5  so  3 L. so you breath  120 L  VE / min or more . If you can  try to get 150 L  if possible. Chekc your  VC6  and VC 1  and you can se e what you potentially  could do.
  Now  you  do this  for  30  min or longer. You ventilate  140 +-  liter by sitting   in font of the TV looking a   NHL  game  and   overload  your respiration.
 Than  go back  and  fix MOXY in a involved muscle and  leg  and see  whether there is a difference in the reaction in a  5/1/5   assessment  between  leg  and non involved muscle on the one side  and  absolute performance on the other side. ?

 Small hint.  Publish it in the   magazine  the " breath less goat " ,as it is only a  case study.

Here the  link

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Posts: 1,501
Had a  fast respond  with the point.
: Does this  study of the vasoconstriction proof, that there was a delivery limitation like  respiration  or  cardiac. ?  a)  I  showed  somewhere before a   set of  studies, who show , that respiration  as a limitation in some cases can create  the famous  metaboreflex (  A.Dempsey Boutellier / Spengler  and more.)  By the way   the biggest  difference between Pro cyclist and  top amateur cyclists is  in h respiratory  ability  .  !!

 Now  the above study is  an incredible great   paper  showing the  limitation  was  in  most of the  cases  the cardiac   system.
 Hera  short  part of the Discussion and summary of the discussion.

This reduction in the rate of increase in exercise intensity may have facilitated the plateau in cardiac output and the decline in stroke volume reported by Mortensen et al. (35).

In summary,
during incremental exercise to exhaustion in the cycle ergometer task

failure is preceded by an increase of mean arterial pressure that is accompanied by a

reduction in the rate of increase in cardiac output. The fact that stroke volume remained

at maximum values from 64% to maximal exercise intensity indicates appropriate

venous return and ventricular filling. My  comment .  when we looked  at  cardiac hemodynamic  and   we  had a  drop in SV  than we  had as well a  drop in tHb  . Or really it is the opposite , when we had  a  drop in tHb  we  saw a  drop in SV  ( less pre load ) . Now  this was only true  when we  had eh drop in tHb  left and right leg and not just in one  single VL  or  calf muscle but  identical  drop in a the least 4  main  leg muscle groups.
. A  single   moxy  tHb  drop  can indicate a  drop in SV  but as well it could be  a local   reaction. So always   be careful.
 You can use HR as  an additional  indicator.
 If we have a drop in SV  by the same load  we have to maintain CO   an increase in HR  if that  is still possible. Summary a  drop in tHb in one  MOXY  unit   with an increase in HR  at the same time is a  possible idi8cation fo a  drop in SV.

Thus, close to task failure cardiac output appears to be insufficient to match oxygen delivery to oxygen demand in the main locomotory muscles but also in the less active arm muscles, as reflected by the high levels of oxygen extraction and the activation of the anaerobic metabolism in legs and arms.
If they  add NIRS  than  they could have seen a drop in SmO2  as a part of  what they call anaerobic metabolism  as  there  is a much higher utilization , than delivery  but only possible as long we  can  extract O  or  in other words, as long we see  SmO2  dropping.

However, vasoconstrictor signals efficiently oppose the vasodilatory metabolites in the

arms as reflected by a progressive reduction in arm vascular conductance for a given

metabolic rate. Thus, during whole body exercise in the upright position blood flow is

differentially regulated in the upper and lower extremities. Finally, this study supports,

although indirectly, the concept that in healthy humans VO2max is limited by cardiac

output and skeletal muscle blood flow.

The other section of interest  is te recovery dynamic  of  arm  and legs  after  a  load lie this ,  and again NIRS a  a  very simple tool ca  give some feedback on this  when we look in the context  of the  whole body.


 Closing the gap  between science and practical application.
 This  discussion  shows , why we    love NIRS  and in specific  MOXY  as we  can not use all the great tools this  study  groups use  . but with a  minimal investment as a  coach or  as a training center  and  an opt  en mind  you can  create a  assessment  and trailing feedback tool  super individualized  and  with a lot of  fun  to work on.
 For the price of a   simple great,  but limited VO2  equipment you can get 8  MOXY's  so  you can test 8  people  at the same  time  for the same price  per prosper as you do one VO2  max  or lactate tests. Now  you test 8    x  150 $.  and you have  ( biased  me )  much more feedback  for your client  and ca use the test equipment   during actual workouts  as well .


Development Team Member
Posts: 18
Interesting note:

Cristian was just diagnosed with FAI.  We will be reducing his crank length and re-testing shortly.  Doubt we will see much change beyond smoothing his pedal-stroke, but worth examination.   
I'll have my Moxy in about 1-week and plan to use it in conjunction with fitting and sEMG to determine the best measure of paraspinal activity when cycling. 
Reports to follow[wink]

Chris Balser

Development Team Member
Posts: 1,501
Thanks    but can you explain  what FAI  stands  for  as I have no clue.

Development Team Member
Posts: 1,501
I  was hoping somebody  would respond  on this here  but lets  try  again.
 FAI  can mean different ideas. When we look  from an orthopaedic point is  could mean femoral acetabular  impingement.  So which leg   was it the right leg.
  Or  form a  vascular  terminology  it is used  for m femoral arterial impingement. For this one  I have some interesting data's    on how it showed  up  from a MOXY  triaing center  from Boulder  Coloroado.  From a the orthopedic one I  have 3 month of daily  assessments  from   Pro  ice hockey player  form Europe , I had  over summer in Canada  for rehab  after  an acetabular  operation   to get him ready  for the season  again. So  will be nice  to have a feedback here  for  readers   on what leg  he had I his  FAI no  matter which one   we will have a very similar  reaction.  on  NIRS  when compared left and right.

Development Team Member
Posts: 49
Even this is an older tread it seemed to be the correct one to post this question in.

My question is related to the comparison between these two considerations that I'm sure at times work against each other

A) fitting a bicycle to a client using a few moxy monitors, checking the utilization between VL, RF, Glutes, Hamstrings, etc.... and finding the most optimal position to avoid over utilization

B) fitting a bicycle with posture and balance in mind - for example Steve Hogg has an article related to Phasic vs. Postural muscles

His bike fitting method stems from a gentleman named Vladimir Janda and theories of postural vs phasic muscles.  

If in order to preserve the phasic muscles the optimal seat position is forward, but that position then places extra stress on the VL and RF..... then you move the saddle back.... placing extra strain on the phasic muscles holding yourself up....

I recently changed by bike fit recently mostly because I got new cycling shoes and wanted to try a different saddle.   I had option A on my mind because of getting involved on this forum, but felt better overall focusing on option B during my fit.   Partly because of lack of data/knowledge with using a Moxy as a new user, and party because other adjustments could be made with my cleat position, pedal stroke, etc that would achieve goals of option A.

Food for thought


Development Team Member
Posts: 1,501
His bike fitting method stems from a gentleman named Vladimir Janda and theories of postural vs phasic muscles.  

Fascinating  that this name  shows up on the forum.  I was a student  of  Janda  when I did  my university education on  manual therpay.
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