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Juerg Feldmann

Fortiori Design LLC
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Posts: 1,530
 #1 
Here a nice study . It helps us, as over many years we argued, that with IPAHD we can actually find an optimal way of assessing homeostasis disruption.
 The problem is, that  the "classical" researcher try to  find out , whether NIRS ( SmO2 ) fits the old idea of  MAX lass. We discussed this in many  topics  many times before. Lactate is a great metabolic  bio marker but due to the different influences on the lactate values we test  on an ear or finger we can only use trends rather than actual numbers.
 The Idea of MAX lass as such is the most effective way to find a  daily balance but it is invasive and costly and slightly pain full and very very time consuming. The solution realy is NIRS and with MOXY it is now affordable for  any person on the road and for any test center.
 So here a great study to enjoy. It is not Biased like I am it is  just an independent study finally to read and to support our sometimes crazy ideas.
 

Determination of maximal lactate steady state in healthy adults: can NIRS help?

Source

Department of Neurological, Neuropsychological, Morphological and Exercise Sciences, School of Exercise and Sport Sciences, University of Verona, Italy.

Abstract

PURPOSE:

We tested the hypothesis that the maximal lactate steady state (MLSS) can be accurately determined in healthy subjects based on measures of deoxygenated hemoglobin (deoxyHb), an index of oxygen extraction measured noninvasively by near-infrared spectroscopy (NIRS).

METHODS:

Thirty-two healthy men (mean ± SD age = 48 ± 17 yr, range = 23-74 yr) performed an incremental cycling test to exhaustion and square wave tests for MLSS determination. Cardiorespiratory variables were measured bbb and deoxyHb was monitored noninvasively on the right vastus lateralis with a quantitative NIRS device. The individual values of V˙O2 and HR corresponding to the MLSS were calculated and compared to the NIRS-derived MLSS (NIRSMLSS) that was, in turn, determined by double linear function fitting of deoxyHb during the incremental exercise.

RESULTS:

V˙O2 and HR at MLSS were 2.25 ± 0.54 L·min (76% ± 9% V˙O2max) and 133 ± 14 bpm (81% ± 7% HRmax), respectively. Muscle O2 extraction increased as a function of exercise intensity up to a deflection point, NIRSMLSS, at which V˙O2 and HR were 2.23 ± 0.59 L·min (76% ± 9% V˙O2max) and 136 ± 17 bpm (82% ± 8% HRmax), respectively. For both V˙O2 and HR, the difference of NIRSMLSS from MLSS values was not significant and the measures were highly correlated (r = 0.81 and r = 0.76). The Bland-Altman analysis confirmed a nonsignificant bias for V˙O2 and HR (-0.015 L·min and 3 bpm, respectively) and a small imprecision of 0.26 L·min and 8 bpm.

CONCLUSIONS:

A plateau in muscle O2 extraction was demonstrated in coincidence with MLSS during an incremental cycling exercise, confirming the hypothesis that this functional parameter can be accurately estimated with a quantitative NIRS device. The main advantages of NIRSMLSS over lactate-based techniques are the noninvasiveness and the time/cost efficiency.

 

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