caa a22 4500 467941998 CHVBK 20180406153015.0 cr unu---uuuuu 170328e20060701xx s 000 0 eng 10.1007/s00421-006-0176-y doi (NATIONALLICENCE)springer-10.1007/s00421-006-0176-y Relating pulmonary oxygen uptake to muscle oxygen consumption at exercise onset: in vivo and in silico studies [Elektronische Daten] [N. Lai, R. Dash, M. Nasca, G. Saidel, M. Cabrera] Assessment of the rate of muscle oxygen consumption, UO2m, in vivo during exercise involving a large muscle mass is critical for investigating mechanisms regulating energy metabolism at exercise onset. While UO2m is technically difficult to obtain under these circumstances, pulmonary oxygen uptake, VO2p, can be readily measured and used as a proxy to UO2m. However, the quantitative relationship between VO2p and UO2m during the nonsteady phase of exercise in humans, needs to be established. A computational model of oxygen transport and utilization—based on dynamic mass balances in blood and tissue cells—was applied to quantify the dynamic relationship between model-simulated UO2m and measured VO2p during moderate (M), heavy (H), and very heavy (V) intensity exercise. In seven human subjects, VO2p and muscle oxygen saturation, StO2m, were measured with indirect calorimetry and near infrared spectroscopy (NIRS), respectively. The dynamic responses of VO2p and StO2m at each intensity were in agreement with previously published data. The response time of muscle oxygen consumption, $$\tau_{{\rm UO}_{{2{\rm m}}}},$$ estimated by direct comparison between model results and measurements of StO2m was significantly faster (P<0.001) than that of pulmonary oxygen uptake, $$\tau_{{\rm VO}_{{2{\rm p}}}},$$ (M: 13±4 vs. 65±7s; H: 13±4 vs. 100±24s; V: 15±5 vs. 82±31s). Thus, by taking into account the dynamics of oxygen stores in blood and tissue and determining muscle oxygen consumption from muscle oxygenation measurements, this study demonstrates a significant temporal dissociation between UO2m and VO2p at exercise onset. Springer-Verlag, 2006 Lai N. Department of Biomedical Engineering, Case Western Reserve University, 44106-6011, Cleveland, OH, USA aut Dash R. Department of Pediatrics, Case Western Reserve University, 44106-6011, Cleveland, OH, USA aut Nasca M. Department of Pediatrics, Case Western Reserve University, 44106-6011, Cleveland, OH, USA aut Saidel G. Department of Biomedical Engineering, Case Western Reserve University, 44106-6011, Cleveland, OH, USA aut Cabrera M. Department of Biomedical Engineering, Case Western Reserve University, 44106-6011, Cleveland, OH, USA aut European Journal of Applied Physiology Springer-Verlag 97/4(2006-07-01), 380-394 1439-6319 97:4<380 2006 97 421 https://doi.org/10.1007/s00421-006-0176-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00421-006-0176-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lai N. Department of Biomedical Engineering, Case Western Reserve University, 44106-6011, Cleveland, OH, USA aut NATIONALLICENCE 700 1- Dash R. Department of Pediatrics, Case Western Reserve University, 44106-6011, Cleveland, OH, USA aut NATIONALLICENCE 700 1- Nasca M. Department of Pediatrics, Case Western Reserve University, 44106-6011, Cleveland, OH, USA aut NATIONALLICENCE 700 1- Saidel G. Department of Biomedical Engineering, Case Western Reserve University, 44106-6011, Cleveland, OH, USA aut NATIONALLICENCE 700 1- Cabrera M. Department of Biomedical Engineering, Case Western Reserve University, 44106-6011, Cleveland, OH, USA aut NATIONALLICENCE 773 0- European Journal of Applied Physiology Springer-Verlag 97/4(2006-07-01), 380-394 1439-6319 97:4<380 2006 97 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer