TY - JOUR
T1 - Inspiratory loading and limb locomotor and respiratory muscle deoxygenation during cycling exercise
AU - Turner, Louise A.
AU - Tecklenburg-Lund, Sandra
AU - Chapman, Robert F.
AU - Stager, Joel M.
AU - Duke, Joseph W.
AU - Mickleborough, Timothy D.
PY - 2013/2/1
Y1 - 2013/2/1
N2 - The 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% V̇O2max (EX80%); during the final 3-min, subjects received an intervention consisting of either moderate inspiratory loading (Loadmod), heavy inspiratory loading (Loadheavy), or maximal exercise (LoadEX). Loadheavy significantly increased LM [deoxy(Hb+Mb)] from 12.2±9.0μm during EX80% to 15.3±11.7μm, and RM [deoxy(Hb+Mb)] from 5.9±3.6μm to 9.5±6.6μm. LM and RM [deoxy(Hb+Mb)] were significantly increased from EX80% to LoadEX; 12.8±9.1μm to 16.4±10.3μm and 5.9±2.9μm to 11.0±6.4μm, 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.
AB - The 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% V̇O2max (EX80%); during the final 3-min, subjects received an intervention consisting of either moderate inspiratory loading (Loadmod), heavy inspiratory loading (Loadheavy), or maximal exercise (LoadEX). Loadheavy significantly increased LM [deoxy(Hb+Mb)] from 12.2±9.0μm during EX80% to 15.3±11.7μm, and RM [deoxy(Hb+Mb)] from 5.9±3.6μm to 9.5±6.6μm. LM and RM [deoxy(Hb+Mb)] were significantly increased from EX80% to LoadEX; 12.8±9.1μm to 16.4±10.3μm and 5.9±2.9μm to 11.0±6.4μm, 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.
KW - Muscle oxygenation
KW - Near-infrared spectroscopy
KW - Resistive breathing
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U2 - 10.1016/j.resp.2012.11.018
DO - 10.1016/j.resp.2012.11.018
M3 - Article
C2 - 23228896
AN - SCOPUS:84871733931
SN - 1569-9048
VL - 185
SP - 506
EP - 514
JO - Respiratory Physiology and Neurobiology
JF - Respiratory Physiology and Neurobiology
IS - 3
ER -