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Memorias de investigación
Research Publications in journals:
Rebuttal to point - counterpoint: The kinetics of oxygen uptake during muscular exercise do / do not manifest time-delayed phases
Year:2009
Research Areas
  • Physical education and sport
Information
Abstract
I expected the Stirling and Zakynthinaki Counterpoint (2) to provide alternative physiological explanations for the discernibly different oxygen uptake (V¿ O2) kinetics at different exercise intensities. Some of their points seem warranted: the lack of justification for an exponential phase () 1 fit and the ¿slow-phase¿ exponential fit reflecting a process with a single time constant () and gain. But so many of their assertions demand challenge. For example, they state that the problems regarding the decrease of ¿R¿ as an indicator of what they term TD2, ¿are due to trying to fit time-delayed phases to data with no such features.¿ Well, there are such features! The 1¿2 transition often coincides with a time-delayed transient R decrease (4); where not, it is not that the delayed component is not there but that it is ¿smeared¿ by increased perfusion from other regions and/or transient hyperventilation. Its presence is physiologically justified: the transient alkalosis (1, 3), resulting from proton trapping as [phosphocreatine] decreases, retains CO2 intramuscularly. When the 1¿2 transition cannot be clearly determined from R, a portion of the 1 response should not be allowed to influence the 2- estimation: this is a physiological control parameter not a parameter of convenience (6), as are the 1 and slow-component s. Deleting a portion of the early response slightly greater than the real delay may influence the confidence of the 2- estimation; deleting too little will affect its value¿a greater concern. Also, we disagree with their assertion
International
Si
JCR
Si
Title
JOURNAL OF APPLIED PHYSIOLOGY
ISBN
8750-7587
Impact factor JCR
3,658
Impact info
Volume
Journal number
0
From page
1667
To page
1668
Month
ENERO
Ranking
Participants
  • Autor: James Robert Stirling . (UPM)
  • Autor: María Zakinthinaki . (UPM)
Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Deporte Rendimiento
  • Departamento: Deportes
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