caa a22 4500 467941254 CHVBK 20180406153013.0 cr unu---uuuuu 170328e20060301xx s 000 0 eng 10.1007/s00421-005-0107-3 doi (NATIONALLICENCE)springer-10.1007/s00421-005-0107-3 Effects of pedal frequency on estimated muscle microvascular O2 extraction [Elektronische Daten] [Leonardo Ferreira, Barbara Lutjemeier, Dana Townsend, Thomas Barstow] An increase in muscle contraction frequency could limit muscle blood flow $$ {\left( {\ifmmode\expandafter\dot\else\expandafter\.\fi{Q}_{{\text{M}}} } \right)}, $$ compromising the matching of $$ \ifmmode\expandafter\dot\else\expandafter\.\fi{Q}_{{\text{M}}} $$ and muscle oxygen uptake $$ {\left( {\ifmmode\expandafter\dot\else\expandafter\.\fi{V}_{{{\text{O}}_{{{\text{2M}}}} }} } \right)}. $$ This study examined the effects of pedal cadence on skeletal muscle oxygenation at low, moderate and peak exercise. Nine healthy subjects [24.7±6.3years (SD)] performed incremental cycling exercise at 60 and 100rpm. Pulmonary $$ \ifmmode\expandafter\dot\else\expandafter\.\fi{V}_{{{\text{O}}_{{\text{2}}} }} {\left( {\ifmmode\expandafter\dot\else\expandafter\.\fi{V}_{{{\text{O}}_{{{\text{2P}}}} }} } \right)} $$ was measured breath-by-breath and vastus lateralis oxygenation was determined by near-infrared spectroscopy (NIRS). The deoxyhemoglobin signal ([HHb]) from NIRS was used to estimate microvascular O2 extraction (i.e., [HHb] ∝ $$ \ifmmode\expandafter\dot\else\expandafter\.\fi{V}_{{{\text{O}}_{{{\text{2M}}}} }} {\text{/}}\ifmmode\expandafter\dot\else\expandafter\.\fi{Q}_{{\text{M}}} $$ ). The $$ \ifmmode\expandafter\dot\else\expandafter\.\fi{V}_{{{\text{O}}_{{{\text{2P}}}} }} $$ and [HHb] for low, moderate and at peak exercise were determined. The $$ \ifmmode\expandafter\dot\else\expandafter\.\fi{V}_{{{\text{O}}_{{{\text{2P}}}} }} $$ at 60rpm (low=0.64±0.13, moderate=2.03±0.38 and peak=3.39±0.84 l/min) were lower (P<0.01) than at 100rpm (1.29±0.23, 2.14±0.39 and 3.54±0.88l/min, respectively). There was a progressive increase in [HHb] from low to peak exercise. However, there was no significant difference (ANOVA, P=0.94) for the 60 (in μM, low=24.0±9.5, moderate=30.5±13.8 and peak=36.7±16.5) and 100contractions/min (in μM, low=25.7±11.6, moderate=32.1±14.0 and peak=35.4±16.5). We conclude that vastus lateralis O2 extraction was similar at 60 and 100cpm, suggesting that the $$ \ifmmode\expandafter\dot\else\expandafter\.\fi{V}_{{{\text{O}}_{{{\text{2M}}}} }} {\text{/}}\ifmmode\expandafter\dot\else\expandafter\.\fi{Q}_{{\text{M}}} $$ in the microcirculation was not altered and, presumably, no impairment of $$ \ifmmode\expandafter\dot\else\expandafter\.\fi{Q}_{{\text{M}}} $$ occurred with the increase in pedal frequency. Springer-Verlag, 2005 Exercise nationallicence Blood flow nationallicence Contraction frequency nationallicence Muscle oxygenation nationallicence Near-infrared spectroscopy nationallicence Ferreira Leonardo Departments of Kinesiology and Anatomy and Physiology, Kansas State University, 66506-0302, Manhattan, KS, USA aut Lutjemeier Barbara Departments of Kinesiology and Anatomy and Physiology, Kansas State University, 66506-0302, Manhattan, KS, USA aut Townsend Dana Departments of Kinesiology and Anatomy and Physiology, Kansas State University, 66506-0302, Manhattan, KS, USA aut Barstow Thomas Departments of Kinesiology and Anatomy and Physiology, Kansas State University, 66506-0302, Manhattan, KS, USA aut European Journal of Applied Physiology Springer-Verlag 96/5(2006-03-01), 558-563 1439-6319 96:5<558 2006 96 421 https://doi.org/10.1007/s00421-005-0107-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00421-005-0107-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ferreira Leonardo Departments of Kinesiology and Anatomy and Physiology, Kansas State University, 66506-0302, Manhattan, KS, USA aut NATIONALLICENCE 700 1- Lutjemeier Barbara Departments of Kinesiology and Anatomy and Physiology, Kansas State University, 66506-0302, Manhattan, KS, USA aut NATIONALLICENCE 700 1- Townsend Dana Departments of Kinesiology and Anatomy and Physiology, Kansas State University, 66506-0302, Manhattan, KS, USA aut NATIONALLICENCE 700 1- Barstow Thomas Departments of Kinesiology and Anatomy and Physiology, Kansas State University, 66506-0302, Manhattan, KS, USA aut NATIONALLICENCE 773 0- European Journal of Applied Physiology Springer-Verlag 96/5(2006-03-01), 558-563 1439-6319 96:5<558 2006 96 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer