Louise A Turner, Sandra Tecklenburg-Lund, Robert F Chapman, Joel M Stager, Joseph W Duke, Timothy D Mickleborough
Human Performance Laboratory, Department of Kinesiology, Indiana University, Bloomington, IN 47401, USA.
Respiratory physiology & neurobiology 2013 Feb 1The aim of this study was to determine the effect of inspiratory loading on limb locomotor (LM) and respiratory muscle (RM) deoxygenation ([deoxy (Hb+Mb)]) using NIRS during constant-power cycling exercise. Sixteen, male cyclists completed three, 6-min trials. The intensity of the first 3-min of each trial was equivalent to ~80% V(O(2max)) (EX(80%)); during the final 3-min, subjects received an intervention consisting of either moderate inspiratory loading (Load(mod)), heavy inspiratory loading (Load(heavy)), or maximal exercise (Load(EX)). Load(heavy) significantly increased LM [deoxy(Hb+Mb)] from 12.2±9.0 μm during EX(80%) to 15.3±11.7 μm, and RM [deoxy(Hb+Mb)] from 5.9±3.6 μm to 9.5±6.6 μm. LM and RM [deoxy(Hb+Mb)] were significantly increased from EX(80%) to Load(EX); 12.8±9.1 μm to 16.4±10.3 μm and 5.9±2.9 μm to 11.0±6.4 μm, respectively. These data suggest an increase in respiratory muscle load increases muscle deoxy(Hb+Mb) and thus may indicate a reduction in oxygen delivery and/or increased oxygen extraction by the active muscles. Copyright © 2012 Elsevier B.V. All rights reserved.
Louise A Turner, Sandra Tecklenburg-Lund, Robert F Chapman, Joel M Stager, Joseph W Duke, Timothy D Mickleborough. Inspiratory loading and limb locomotor and respiratory muscle deoxygenation during cycling exercise. Respiratory physiology & neurobiology. 2013 Feb 1;185(3):506-14
PMID: 23228896
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