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runner

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Posts: 59
 #1 
Hi,

As a newby to SmO2 monitoring, I would like to learn as much as possible
about the topic before I start asking too simple questions on this forum.
I have alreay read all Moxy introductory literature and watched the 
webinars.

Are there any (introductory) papers (or books) that one should read to understand SmO2 
better? A list of 3-4 papers would be greatly appreciated.

For example, the other day I went for a long and easy (60% of HRmax) run and
I saw many things that seemed counterintuitive to me and I want to read as 
much background as possible to understand SmO2 and exercise better.

Thanks.


juergfeldmann

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 #2 
Sounds   like a great plan  to me  and  you find hundreds  of  references on this forum. I nearly would argue  that this is the place  you will find most likely the most  range of  literature  concerning  NIRS ideas  than  on any other   websites  or  forums.
. There  are   most lily  by now thousands  of NIRS  studies  done  to read through and  many  show   the  often asked  critical  question on  whether  what we see with NIRS is  true  ( and it seems  as it is validate  with  other tools )  but than  leaves us  with many  open questions   on the classical  ideas and tools we used.  This   critical  questions are   great and needed  but they only make  sense, when we  apply the same critical  question to what we  do now. So lets  start there.
 60 %  of  Max  HR
 What  is  100 %  Max  HR  and did  you  do this  before the  race  or is  it an old all out test  you did on a treadmill or in the filed. So in case  it is old, how  do we know today  you would reach the  same max  HR   and  use  that  as 100 %.
 Than  what is  60  % of  max  HR. or better to  calculate  60 %  what is   0 %  HR.  Than  questions like. If  you   look your HR  just now   as you read. And  you have a MOXY on a  quadriceps  muscle as you read  you have a  HR and a SmO2  number  and a tHb trend.

 Now  do some explosive  10  jump  and reach  movements   and look HR  and look tHb  and SmO2  . what do you see.

 Now  stop    and look HR  and  SmO2  and tHB  trends  and look what your respiration is doing ?
 What  do you see. Now  apply this some what to your  "  60 " %  Max HR  run

Do  you see what I mean  and why there may be many   interesting open  question , when applying a  %  of a  calculated idea versus  a live feedback or a reality to a  new training idea.  The much  harder  question is . What  do you achieve  with a  60 %  max  HR  intensity  and is it the same as  when your  friend  runs  with his  60 %  Max HR intensity.


James G Hopker 1*and Louis Passfield 1




There appears to be increasing agreement that the response to a standardised training programme can be remarkably diverse (Mann et al., 2014).

 This has lead some to examine these training “responders” and “non-responders” and its genetic basis (Ehlert et al. 2013). Surprisingly, the alternative hypothesis that training has not been standardised appropriately appears to have been little considered (Mann et al. 2014).

From this perspective the issue becomes not whether a cyclist is a responder or a non-responder, but rather what is his or her optimal training intensity.

For example, it has long been established that cyclists’ time to exhaustion at the same relative intensity can vary hugely. Coyle et al. (1988) found that at 88% VO2max cyclists’ time to exhaustion varied from 12 min to 75 min.

However, the method for prescribing training in most studies remains standardised as a percentage of maximum. 




runner

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 #3 
Quote:
For example, the other day I went for a long and easy (60% of HRmax) run


To elaborate a bit more.

I went for a long and easy run (3h15min with HR between 95 and 115, HRMax = 185)
in a rather cold weather (-8C). I observed a very low SmO2 levels. I played 
with my pace and I could barely get it over 50%. It started at around 50% and SmO2 trend was slowly decreasing and towards the end of the run it was around 35%. 

I finished my session with 30 minutes of indoor rowing on an ergometer. Heart rate 
was again low (around 105-110) and SmO2 was stable at about 47%.
CraigMahony

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Posts: 178
 #4 
Did you look at the tHb trend? The tHb trend indicates what happens with the blood flow. The SmO2 tells us how much of that blood flow is oxygenated. So have a look at the Moxy files and see what the tHb trend was. The combination of the 2 can help make educated guesses at what is happening.
One possibility is that during your run as fatigue crept in the muscles had to contract harder to do the same work. This can reduce blood flow into and out from and the muscle. You can determine this by calculating the OHb and the HHb from the Moxy csv files.
If you need help, post the files so they can be looked at.
runner

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Posts: 59
 #5 
Quote:

Did you look at the tHb trend?


It was almost completely flat (around 12.8, very minor oscillations around it)
during the entire 4hr session.

The last 2.5 hrs when the SmO2 trend was going down, ThB was completely flat.
See attached ThB chart. [Note: ignore spikes to 0, the Moxy sensor was losing
connection with the watch]

Attached Images
Click image for larger version - Name: ThB.jpg, Views: 16, Size: 217.17 KB 

juergfeldmann

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Posts: 1,501
 #6 
One part you can as well look  besides the  great feedback  from Criag.
 Run at a decent  temperature   same speed indoors  and look the tHb and SmO2  trends  and  try to mount the  moxy  at the same place.
 Look at the  penetration depth  you have in  most of the NIRS, Than look at the  slow  pace  you run  so a very low  energy demand in the  first place and a  relative  cold   temperature. So  you for sure will create minimal   blood flow in the  skin  which   would  be easy to see with a  Portamon  and MOXY  combination, but as well minimal blood  flow in the upper muscle surface area.
  this is one weakness of  NIRS  as well. So  the O2 needed  for  the  intensity   you did was low  enough to  maintain a relative low  blood flow  to the surface  to protect  core temperature. The low  pace as well  and if you are  a  smooth runner  you will create  minimal  effort  on many running muscles. If  you had  the MOXY on the VL   and  you run  that slow you have a very  small knee  angel motion  and you are more likely in a more extend  motion so  VL  is not a  main priority  muscle.   The  next  you have to look is  , whether  you are in that slow pace  a  heel  striker versus a mid  foot  or  even fore foot runner  if  you run a much  fatter pace or  whether you maintain the same running technique  no matter the speed  you  run. One  additional part in -  8  degrees  is how  you breath ? What was the tHb on rowing.:
   Now  to the  HR  levels. What is  your  MAX  HR on the rower.  ?  Now  just  for fun to the 60 %  HR  max intensity.  185 = 100 %  so  your  60 %  HR  is  111 +-5   to be  able to  hold  the  " zone ".  Now  if  we take this  formula  than  0 % in speed  would be  not moving  and )  which makes sense  but the   0 % in HR  would be zero  HR or  zero beats.
 We  do not have many athletes  who  can do  that and still be able  after the  found their  [wink] %  HR  still go  for a  run.  That's  where  Karvonen  made some smarter  suggestion if  you use  MAX  HR as a  training guide  and you base it on %  This  would  move  you  in a  HR  are of most likely in a HR   range  of  135 +- . Still  a nice  idea  but slight out dated  and out of  touch  with physiological  guidance.

ryinc

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Posts: 369
 #7 
Hi Runner

Welcome to thw forum.

To respond to your original question - i dont think there is one (or three) comprehensive papers that explains it all at a high level, the papers are normally very specific to an item of research.

The forum has a wealth of information (including lonks to papers) but it is scattered across the case studies and questions and answers sections.

I would suggest reading through the e-books on the moxy website although they are very introductory in nature. There is an online course at the moxy academy you might want to checkout (i have not done it).

There are of course experiments that you can do too as Juerg has suggested.

In general there are a small group of contributing forum members and people are generally willing to have a go at answering any question (so dont feel shy to ask). Sometimea the simpler questions land up being in depth discussion which teaches us all.
CraigMahony

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Posts: 178
 #8 
Hi runner

Your tHb graph looks flat. That is partly because of scaling. The tHb never changes by much, any changes are small but indicative.If you look at similar graphs on other posts you will see a very much zoomed in view of the tHb. A drop of just a few decimal points is all you might see. So try changing the scale and see if the view is any different.
juergfeldmann

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Posts: 1,501
 #9 
Craig  thanks  for   this great point  I completely missed  it , great  to have you in the  kitchen 
juergfeldmann

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Posts: 1,501
 #10 
I had  2 emails  one  fromm a rowing coach and one  from a  triathlon coach to my   section :
 The  next  you have to look is  , whether  you are in that slow pace  a  heel  striker versus a mid  foot  or  even fore foot runner  if  you run a much  fatter pace or  whether you maintain the same running technique  no matter the speed  you  run.

This is  a very common   question  but for me one of  the reason , why many  may  improve incredible in their LSD  performance but than it does not  translates into race performance  and than  the discussion comes  up every time on " periodization"  and on HIIT  as LSD  not improves  certain things.  Again this is NOT a training  suggestion forum  it is a NIRS interpretation forum. So here some points  you can use NIRS  to  understand  that it is  NOT  the HIIT  who  creates  really  the   improvement  a few  weeks before but  the  way  many train 80 %  plus in a very different inter muscular  and intramuscular  coordination pattern in endurance sport. We  touched that subject  in the way a  cyclist  or a runner would  use  a very different   muscular  harmonies   to improve  his hip  muscle involvement ., ( a  dilemma  for a triathlete )
  So below a  NIRS  case using Portamon  from many years back  during a  triathlon seminar  I did  with Mary Ann Kelly in California.

We  showed  the situation  where we  have thee same performance  [wink] Speed ) in  running  but we changed  the  muscular  coordination pattern  at that speed.
 In this  case  the  racing  pace  would be for a  marathon a   2.48   end time so  4 min/ km.. The LSD  speed   was normally around 5.30 - / km so a 4 h +-  marathon  time. 
 This  sounds  crazy  but we I worked  whit 2. 10  runners  and  we often trained  with a similar  %  slower than race pace  so  3 min marathon race pace  and 4 min  LSD  training pace. Or in NIRS  terminology  or physiological terminology. We  train in the OXY intensity as we have  complete  control in what we like to stimulate  and what not  versus training in  deoxy intensity,  where we have  to follow  what  nature tells us it needs to be done  to sustain the speed or wattage  we believe is needed to  stimulate . Again and Again it is not the performance   you choose to stimulate, it is your  decision  to  decide  what you like to stimulate  and this will than  end up  with a certain performance on that specific  day , which allows  you to make your decision and   you are not forced  to  use  compensators,  as you  may unwillingly overload  the limiter much earlier in that  day.

So belwo  how it looks . Let s start this time  with  TSI  % in green . TSI  %  can but not always reacts like SmO2  %  and there  are different reasons  why. So   that's  why it looks  slightly different.




total 60  tsi.jpg



T
his is  always  the  same speed  first   a  few longer   loads in different techniques  and than  shorter interval with the change from  one  to the other technique.
 remember it is a  5.30 speed  and one   NIRS picture is  when he runs  5.30  and one   picture is  where he  still runs  55.30 but the NIRS feedback is thee same as  if he runs his  4 min race pace.

Now  below a  closer look.

1 run 1 walk.jpg



I
f  you  look close  enough and we  can  normally zoom in even closer  you will be able to count the  steps / min. The  fascinating  part is  theta  the  drop  or  increase in tHb   is  caused by a very different  reaction  and that where most likely one reasons shows  up  why  the  80 %  time  spent in one speed  may not translate in the performance we how in the race pace.  In one  speed  thee tHb  drops  due to  compression out  flow  and goes up due  to decompression inflow. IN the other speed  tHb  goes up  due to occlusion trend  and down  due  to occlusion ( pooling ) outflow. This changes  complete  the metabolic  delivery and utilization reactions and we  train a very different  survival idea   due to a very different running technique.  To  close this  small section up below a  better feedback using  O2Hb  and HHb  and  tHb difference  an d tHb

complete  60 min w r.jpg 
I hope  I was able to activate  the brain  blood flow  for this  2  coaches as if  you think through that  and you  discuss this  with our  own believes  you will  come to a  point, where  you critical will challenge  your   old believes    at home no exposure not feeling  about  failure as  what we did  was not wrong it was  simply the best  we    could do with  what we  have  on information  from  some few  brains  out there  working on incredible  ideas   and we simply benefit  by  combining  the ideas to a practical approach.

juergfeldmann

Development Team Member
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Posts: 1,501
 #11 
Got  1 email back.
Question on efficiency.
 Absolutely.
The main question is, whether you like to be efficient in a  workout  like a long run  or  whether you like to use  the workout  even if  it is inefficiency, or  even hope  you train inefficiency in  certain situations ,  because  you like to  learn to race efficient ?

 An example outside of our  kitchen  to show efficiency  and inefficiency.  Sure  here  very classic  one  very old  but still true..

You explain  yourself.  This is  out  of  Hollmann /Hettinger  ( Arbeitsphysiology )
Gehen is  walking . Laufen is  running. base  axis  is  speed in km / h
Hollman walk jog.jpg 

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