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Juerg Feldmann

Fortiori Design LLC
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Posts: 1,530
 #1 
I  get  more an more  email asking a very good  and critical question.
 tHb :  can we  have an absolute value  to it   and if  how  and if  not  why not.

  Here  our take.
  Our idea of NIRS / MOXY is to open   the  field of MOXY users  to athletes  and coaches in the filed.
  Respectively closing the gap between science  and practical application.
  So yes we    could quantify the  blood volume in specific    test  and  set ups.


 The whole idea, and some may remember  some of our first  " great critics" .
 This is  too complicated.
 Now as we  s=show more an more  how easy and practical  MOXY can be used  we gt  great feedback on    how to make it more complicated.
. So  for the moment we like to use MOXY  for what it is :  A  great   game changer  as a  physiological  live biofeedback equipment to be used  during  workouts  to guide  workouts  ( Strength / interval / endurance ) as well as  for assessment of   athletes  to    create  an updated individual physiological guided training intensity zoning  information. For strength  to guide   intensity duration  and  numbers of sets..
 But to  get back  some answers.  here one of many options  how you could  quantify   Volume.   But how  do you do this during a race. ???
 
 
 

Abstract

We applied near-infrared spectroscopy (NIRS) for the simultaneous measurement of forearm blood flow (FBF) and oxygen consumption (VO2) in the human by inducing a 50-mmHg venous occlusion. Eleven healthy subjects were studied both at rest and after hand exercise during vascular occlusion. FBF was also measured by strain-gauge plethysmography. FBF measured by NIRS was 1.9 +/- 0.8 ml.100 ml-1.min-1 at rest and 8.2 +/- 2.9 ml.100 ml-1.min-1 after hand exercise. These values showed a correlation (r = 0.94) with those obtained by the plethysmography. VO2 values were 4.6 +/- 1.3 microM O2 x 100 ml-1.min-1 at rest and 24.9 +/- 11.2 microM O2 x 100 ml-1.min-1 after hand exercise. The scatter of the FBF and VO2 values showed a good correlation between the two variables (r = 0.93). The results demonstrate that NIRS provides the particular advantage of obtaining the contemporary evaluation of blood flow and VO2, allowing correlation of these two variables by a single maneuver without discomfort for the subject.

Juerg Feldmann

Fortiori Design LLC
Registered:
Posts: 1,530
 #2 
Wowww  caught somebody on line for a chatt  and  yes here the general answer on the   discussion.
 Can Fick not give us   the same information.
.  I  do  think Fick is great but is it  "live"  and is it local  or is it what it is a  summary    like the VO2  max    of the O2  use  of the full team rather than some   more individual feedback on   specific  areas.


 
Performance of near-infrared spectroscopy in measuring local O2 consumption and blood flow in skeletal muscle
, , ,
 
 

Abstract

The aim of this study was to investigate local muscle O2consumption (muscV˙o2) and forearm blood flow (FBF) in resting and exercising muscle by use of near-infrared spectroscopy (NIRS) and to compare the results with the global muscV˙o2 and FBF derived from the well-established Fick method and plethysmography. muscV˙o2 was derived from1) NIRS using venous occlusion, 2) NIRS using arterial occlusion, and 3) the Fick method [muscV˙o2(Fick)]. FBF was derived from 1) NIRS and 2) strain-gauge plethysmography. Twenty-six healthy subjects were tested at rest and during sustained isometric handgrip exercise. Local variations were investigated with two independent and simultaneously operating NIRS systems at two different muscles and two measurement depths. muscV˙o2 increased more than fivefold in the active flexor digitorum superficialis muscle, and it increased 1.6 times in the brachioradialis muscle. The average increase in muscV˙o2(Fick) was twofold. FBF increased 1.4 times independent of the muscle or the method. It is concluded that NIRS is an appropriate tool to provide information about local muscV˙o2 and local FBF because both place and depth of the NIRS measurements reveal local differences that are not detectable by the more established, but also more global, Fick method.

Juerg Feldmann

Fortiori Design LLC
Registered:
Posts: 1,530
 #3 
Another often asked question, when we make presentation  in top teams and groups.
 Why only you guys do that  and why is it not use  more often.
Stupid answer  we can give is : Why did  only Fosbury  flopped in Mexico city. Why  did   only Sitonen  used a one  skate double pole step in hi  victory in the engadin marathon. Why   did it took over 150 years for the British admiralty  to make Vit C mandatory on long ship  travels despite the  findings  150 years earlier to avoid "scorbut"  The smarter answer  would be :
 We  are really not alone at all, There  are more and more great studies coming out. Main problem. Nobody reads them  who actually works  practically  as coaches  and in the field  or  at least very few seem to read it, otherwise we  would not get  this question. Here a nice  one  to show, that when using NIRS you can see a lot more   locally but as well systemically if you place the MOXY on the different  points of interests. See in red our wording we would use.

Changes in blood volume and oxygenation level in a working muscle during a crank cycle.

Takaishi T1, Sugiura T, Katayama K, Sato Y, Shima N, Yamamoto T, Moritani T.

Author information

Abstract

PURPOSE:

This study examined circulatory and metabolic changes in a working muscle during a crank cycle in a pedaling exercise with near-infrared spectroscopy (NIRS).

METHODS:

NIRS measurements sampled under stable metabolic and cadence conditions during incremental pedaling exercise were reordered according to the crank angles whose signals were obtained in eight male subjects.

RESULTS:

The reordered changes in muscle blood volume during a crank cycle demonstrated a pattern change that corresponded to changes in pedal force and electrical muscle activity for pedal thrust. The top and bottom peaks for muscle blood volume change at work intensities of 180 W and 220 W always preceded (88 +/- 32 and 92 +/- 23 ms, respectively) those for muscle oxygenation changes. Significant differences in the level of NIRS parameters (muscle blood volume and oxygenation level) among work intensities were noted with a common shape in curve changes related to pedal force. In addition, a temporary increase in muscle blood volume following a pedal thrust was detected at work intensities higher than moderate. This temporary increase in muscle blood volume might reflect muscle blood flow restriction caused by pedal thrusts.

We describe this  as  blood flow  outflow  restriction due to a venous occlusion trend

CONCLUSION:

The results suggest that circulatory( we name this delivery ) and metabolic( we name this utilization ) conditions of a working muscle can be easily affected during pedaling exercise by work intensity. The present method, reordering of NIRS parameters against crank angle, serves as a useful measure in providing additional findings of circulatory dynamics and metabolic changes in a working muscle during pedaling exercise.

 




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