Does the plateau in the NIRS-derived [HHb] signal in the vastus lateralis represent the upper limit in O2 extraction during ramp incremental cycling?
Date
2018-09-10
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Abstract
Oxygen (O2) extraction and O2 delivery represent the two critical components for muscle metabolism and have been extensively studied. The near-infrared spectroscopy (NIRS) derived O2 extraction signal ([HHb]) has been widely used for characterizing the peripheral response to exercise. Research examining this signal in response to ramp-incremental cycling has identified a linear increase followed by a plateau ([HHb]PLATEAU) prior to the achievement of maximal oxygen uptake (V̇O2max). Despite the common occurrence of this plateau, beyond speculation no research has been conducted to examine the underlying mechanisms causing the plateau in this signal. The studies in this thesis contribute to the understanding of the mechanisms that mediate the [HHb]PLATEAU by examining the maximal achievable level of O2 extraction at the end of a ramp-incremental test in different populations. In this two-part study 26 subjects were tested and divided into groups based on sex and training status. The results from the first part of this study demonstrated the existence of a reserve in O2 extraction and suggest that the [HHb]PLATEAU does not represent the upper limit of extraction in the vastus lateralis muscle. Additionally, the second part of this study revealed that sex and training status do not influence the amplitude of the reserve.
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Keywords
blood flow, [HHb], near-infrared spectroscopy, oxygen extraction, exercise
Citation
Inglis, E. C. (2018). Does the plateau in the NIRS-derived [HHb] signal in the vastus lateralis represent the upper limit in O2 extraction during ramp incremental cycling? (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/32915