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Juerg Feldmann

Fortiori Design LLC
Posts: 1,530

Here an example, where we  have   with NIRS / MOXY a very different view  and would have tested  during this  study  very different.
 Just because we have a normobaric  hypoxic ( 12 % )   situation  doe snot mean, that the muscle itself  works  hypoxic. It just means  that the  O2  situation  during this workout is  somewhat less  "optimal".
 The question during a workout   is, whether we  actually have a  delivery limitation versus a utilization limitation.
  So we have no  real info on the  muscle hypoxic  reaction, when just looking at the O2  situation  in %  like in altitude  or  like in this study.
 If we use  hypoxic  situation we as well do not  benefit  from a SpO2  sensor on the finger  as we   than only see the situation from lungs to blood  but not in the active  exchange area  , where we use  NIRS / MOXY.
 In the above study we  may  simply had a situation, where the contraction forces  was  strong enough to create a delivery problem due to the  muscle tension   so the O2  utilization was depending on the local situation rather than the systemic  O2  intake.
So when we like to  use  arguments like  Hypoxia  or ischemia as an important part of  potential improvement  in strength exercises  we  simply  can't  use  1  reps  as 100 % nor  can we use    any  outside information. 
 we now can use MOXY as a live feedback  with instant information, whether we  create a hypoxia  and what causes the hypoxia.  Now  I  do not argue, that the end result of this study is wrong, but I argue, that the end result may be  as it is because they did not  had a feedback, whether the muscel itself  worked  metabolically really different  due to the O2    differing  tested outside the   muscle.

Effects of low-resistance/high-repetition strength training in hypoxia on muscle structure and gene expression.

Friedmann B1, Kinscherf R, Borisch S, Richter G, Bärtsch P, Billeter R.

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To test the hypothesis that severe hypoxia during low-resistance/high-repetition strength training promotes muscle hypertrophy, 19 untrained males were assigned randomly to 4 weeks of low-resistance/high-repetition knee extension exercise in either normoxia or in normobaric hypoxia ( FiO(2) 0.12) with recovery in normoxia. Before and after the training period, isokinetic strength tests were performed, muscle cross-sectional area (MCSA) measured (magnetic resonance imaging) and muscle biopsies taken. The significant increase in strength endurance capacity observed in both training groups was not matched by changes in MCSA, fibre type distribution or fibre cross-sectional area. RT-PCR revealed considerable inter-individual variations with no significant differences in the mRNA levels of hypoxia markers, glycolytic enzymes and myosin heavy chain isoforms. We found significant correlations, in the hypoxia group only, for those hypoxia marker and glycolytic enzyme mRNAs that have previously been linked to hypoxia-specific muscle adaptations. This is interpreted as a small, otherwise undetectable adaptation to the hypoxia training condition. In terms of strength parameters, there were, however, no indications that low-resistance/high-repetition training in severe hypoxia is superior to equivalent normoxic training.


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