{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T00:00:47Z","timestamp":1791417647292,"version":"4.3.3"},"reference-count":40,"publisher":"American Physiological Society","issue":"12","funder":[{"DOI":"10.13039\/100000050","name":"HHS | NIH | National Heart, Lung, and Blood Institute (NHBLI)","doi-asserted-by":"publisher","award":["HL-103786"],"award-info":[{"award-number":["HL-103786"]}],"id":[{"id":"10.13039\/100000050","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000050","name":"HHS | NIH | National Heart, Lung, and Blood Institute (NHBLI)","doi-asserted-by":"publisher","award":["HL-116579"],"award-info":[{"award-number":["HL-116579"]}],"id":[{"id":"10.13039\/100000050","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000050","name":"HHS | NIH | National Heart, Lung, and Blood Institute (NHBLI)","doi-asserted-by":"publisher","award":["HL-091830"],"award-info":[{"award-number":["HL-091830"]}],"id":[{"id":"10.13039\/100000050","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Veterans Affairs Merit Grant","award":["E6910R"],"award-info":[{"award-number":["E6910R"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["American Journal of Physiology-Regulatory, Integrative and Comparative Physiology"],"published-print":{"date-parts":[[2015,6,15]]},"abstract":"<jats:p> We investigated the role of exercise intensity and associated central motor drive in determining corticomotoneuronal excitability. Ten participants performed a series of nonfatiguing (3 s) isometric single-leg knee extensions (ISO; 10\u2013100% of maximal voluntary contractions, MVC) and cycling bouts (30\u2013160% peak aerobic capacity, W<jats:sub>peak<\/jats:sub>). At various exercise intensities, electrical potentials were evoked in the vastus lateralis (VL) and rectus femoris (RF) via transcranial magnetic stimulation (motor-evoked potentials, MEP), and electrical stimulation of both the cervicomedullary junction (cervicomedullary evoked potentials, CMEP) and the femoral nerve (maximal M-waves, M<jats:sub>max<\/jats:sub>). Whereas M<jats:sub>max<\/jats:sub> remained unchanged in both muscles ( P &gt; 0.40), voluntary electromyographic activity (EMG) increased in an exercise intensity-dependent manner for ISO and cycling exercise in VL and RF (both P &lt; 0.001). During ISO exercise, MEPs and CMEPs progressively increased in VL and RF until a plateau was reached at \u223c75% MVC; further increases in contraction intensity did not cause additional changes ( P &gt; 0.35). During cycling exercise, VL-MEPs and CMEPs progressively increased by \u223c65% until a plateau was reached at W<jats:sub>peak<\/jats:sub>. In contrast, RF MEPs and CMEPs progressively increased by \u223c110% throughout the tested cycling intensities without the occurrence of a plateau. Furthermore, alterations in EMG below the plateau influenced corticomotoneuronal excitability similarly between exercise modalities. In both exercise modalities, the MEP-to-CMEP ratio did not change with exercise intensity ( P &gt; 0.22). In conclusion, increases in exercise intensity and EMG facilitates the corticomotoneuronal pathway similarly in isometric knee extension and locomotor exercise until a plateau occurs at a submaximal exercise intensity. This facilitation appears to be primarily mediated by increases in excitability of the motoneuron pool. <\/jats:p>","DOI":"10.1152\/ajpregu.00021.2015","type":"journal-article","created":{"date-parts":[[2015,4,15]],"date-time":"2015-04-15T22:56:32Z","timestamp":1429138592000},"page":"R998-R1007","source":"Crossref","is-referenced-by-count":46,"title":["Intensity-dependent alterations in the excitability of cortical and spinal projections to the knee extensors during isometric and locomotor exercise"],"prefix":"10.1152","volume":"308","author":[{"given":"J. C.","family":"Weavil","sequence":"first","affiliation":[{"name":"Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S. K.","family":"Sidhu","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, University of Utah, Salt Lake City, Utah;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"T. S.","family":"Mangum","sequence":"additional","affiliation":[{"name":"Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R. S.","family":"Richardson","sequence":"additional","affiliation":[{"name":"Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah;"},{"name":"Department of Internal Medicine, University of Utah, Salt Lake City, Utah;"},{"name":"Geriatric Research, Education, and Clinical Center, Salt Lake City Veterans Affairs Medical Center, Salt Lake City, Utah"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M.","family":"Amann","sequence":"additional","affiliation":[{"name":"Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah;"},{"name":"Department of Internal Medicine, University of Utah, Salt Lake City, Utah;"},{"name":"Geriatric Research, Education, and Clinical Center, Salt Lake City Veterans Affairs Medical Center, Salt Lake City, Utah"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"24","reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1097\/00005768-200002000-00030"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.2011.213769"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.2006.113936"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.01596.2005"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(85)92413-4"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1983.50.1.313"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1002\/mus.880150203"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1007\/BF00229889"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1016\/0013-4694(90)90002-2"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1152\/jn.00684.2005"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1989.sp017626"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-7793.1998.625bq.x"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.1249\/MSS.0b013e3182625423"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.1249\/MSS.0b013e31821b00c5"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.01070.2003"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1113\/expphysiol.2009.047902"},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuron.2006.11.008"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00880.2001"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.1152\/jn.90380.2008"},{"key":"B20","doi-asserted-by":"publisher","DOI":"10.1152\/jn.01230.2005"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.2007.140426"},{"key":"B22","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-7793.1999.0867p.x"},{"key":"B23","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1994.sp020018"},{"key":"B24","doi-asserted-by":"publisher","DOI":"10.1007\/s002219900318"},{"key":"B25","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.90586.2008"},{"key":"B26","doi-asserted-by":"publisher","DOI":"10.1113\/expphysiol.1991.sp003485"},{"key":"B27","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.46.5.1376"},{"key":"B28","doi-asserted-by":"publisher","DOI":"10.1002\/mus.21064"},{"key":"B29","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00486.2012"},{"key":"B30","doi-asserted-by":"publisher","DOI":"10.1152\/jn.00212.2011"},{"key":"B31","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.2014.275438"},{"key":"B32","doi-asserted-by":"publisher","DOI":"10.1007\/BF00238572"},{"key":"B33","doi-asserted-by":"publisher","DOI":"10.1016\/j.jelekin.2005.07.001"},{"key":"B34","doi-asserted-by":"publisher","DOI":"10.1007\/s002210050243"},{"key":"B35","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.01116.2003"},{"key":"B36","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.2002.016782"},{"key":"B37","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.2003.044099"},{"key":"B38","doi-asserted-by":"publisher","DOI":"10.1002\/ana.410290413"},{"key":"B39","doi-asserted-by":"publisher","DOI":"10.1177\/1073858404264680"},{"key":"B40","doi-asserted-by":"publisher","DOI":"10.1016\/S0301-0082(98)00081-1"}],"container-title":["American Journal of Physiology-Regulatory, Integrative and Comparative Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.physiology.org\/doi\/pdf\/10.1152\/ajpregu.00021.2015","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,9,8]],"date-time":"2019-09-08T13:30:51Z","timestamp":1567949451000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.physiology.org\/doi\/10.1152\/ajpregu.00021.2015"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,6,15]]},"references-count":40,"journal-issue":{"issue":"12","published-print":{"date-parts":[[2015,6,15]]}},"alternative-id":["10.1152\/ajpregu.00021.2015"],"URL":"https:\/\/doi.org\/10.1152\/ajpregu.00021.2015","relation":{},"ISSN":["0363-6119","1522-1490"],"issn-type":[{"value":"0363-6119","type":"print"},{"value":"1522-1490","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015,6,15]]}}}