caa a22 4500 467941025 CHVBK 20180406153012.0 cr unu---uuuuu 170328e20060301xx s 000 0 eng 10.1007/s00421-005-0037-0 doi (NATIONALLICENCE)springer-10.1007/s00421-005-0037-0 Blood flow does not limit skeletal muscle force production during incremental isometric contractions [Elektronische Daten] [D. Wigmore, K. Propert, J. Kent-Braun] It has been suggested that a transient limitation in blood flow during intermittent muscular contractions can contribute to muscle fatigue, and that this limitation is greater as contraction intensity increases. We investigated skeletal muscle blood flow and fatigue in 13 healthy, untrained men (21-27years) during 16min of intermittent (4s contract, 6s relax) isometric dorsiflexor contractions. Contractions began at 10% of pre-exercise maximal voluntary contraction (MVC) force and increased by 10% every 2min. Hyperemia (i.e., post-contraction blood flow, measured by venous occlusion plethysmography) and MVC were measured at the end of each stage. Muscle volume measures were obtained using magnetic resonance imaging. After 10min of exercise, submaximal force and post-contraction hyperemia plateaued. MVC fell from 8min of exercise onwards (p=0.004), and this onset of fatigue preceded the plateau in submaximal force and hyperemia. Despite a large range in dorsiflexor muscle size (66.3-176.4cm3) and strength (112.5-421.8N), neither muscle size nor strength were related to fatigue. The temporal dissociation between changes in blood flow and the onset of fatigue (fall of MVC) suggest that limited blood flow was not a factor in the impaired force production observed during intermittent isometric dorsiflexor contractions in healthy young men. Additionally, post-contraction hyperemia increased linearly with increasing contraction intensity, reflecting a match between blood flow and force production throughout the protocol that was independent of fatigue. Springer-Verlag, 2005 Muscle fatigue nationallicence Venous occlusion plethysmography nationallicence Oxygenation nationallicence Dorsiflexor muscles nationallicence Wigmore D. Department of Exercise Science, University of Massachusetts, 01003, Amherst, MA, USA aut Propert K. Department of Exercise Science, University of Massachusetts, 01003, Amherst, MA, USA aut Kent-Braun J. Department of Exercise Science, University of Massachusetts, 01003, Amherst, MA, USA aut European Journal of Applied Physiology Springer-Verlag 96/4(2006-03-01), 370-378 1439-6319 96:4<370 2006 96 421 https://doi.org/10.1007/s00421-005-0037-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00421-005-0037-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wigmore D. Department of Exercise Science, University of Massachusetts, 01003, Amherst, MA, USA aut NATIONALLICENCE 700 1- Propert K. Department of Exercise Science, University of Massachusetts, 01003, Amherst, MA, USA aut NATIONALLICENCE 700 1- Kent-Braun J. Department of Exercise Science, University of Massachusetts, 01003, Amherst, MA, USA aut NATIONALLICENCE 773 0- European Journal of Applied Physiology Springer-Verlag 96/4(2006-03-01), 370-378 1439-6319 96:4<370 2006 96 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer