{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,6,25]],"date-time":"2026-06-25T13:54:39Z","timestamp":1782395679398,"version":"3.54.5"},"posted":{"date-parts":[[2026,6,23]]},"group-title":"Physiology","reference-count":90,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T00:00:00Z","timestamp":1782172800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"NIH","award":["NIH-R01AR050429"],"award-info":[{"award-number":["NIH-R01AR050429"]}]},{"name":"NIH","award":["NIH-R01AR077440"],"award-info":[{"award-number":["NIH-R01AR077440"]}]},{"name":"Red Gates Foundation"},{"name":"Lyerly Foundation"},{"DOI":"10.13039\/100000041","name":"American Diabetes Association","doi-asserted-by":"crossref","award":["1-26-PDF-0629"],"award-info":[{"award-number":["1-26-PDF-0629"]}],"id":[{"id":"10.13039\/100000041","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/100008749","name":"American College of Sports Medicine","doi-asserted-by":"crossref","award":["#5364"],"award-info":[{"award-number":["#5364"]}],"id":[{"id":"10.13039\/100008749","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,6,23]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:p>\n                  Regular exercise induces adaptations in skeletal muscle and other organ systems to improve physical performance and overall health. Exercise results in phosphorylation of 5\u2019 AMP-activated protein kinase (AMPK) at threonine 172 (T172) of the \u03b12 subunit; however, the role of this activation in cellular and functional adaptations has not been elucidated. To this end, we subjected non-activatable\n                  <jats:italic>Ampk\u03b12<\/jats:italic>\n                  (\n                  <jats:italic>T172A<\/jats:italic>\n                  ) knock-in (KI) adult mice and wild-type (WT) littermates to 4 weeks of voluntary wheel running (VWR). Exercise training led to significant improvements in endurance capacity, maximal oxygen consumption (\n                  <jats:inline-formula>\n                    <jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" xlink:href=\"733224v1_inline1.gif\"\/>\n                  <\/jats:inline-formula>\n                  O\n                  <jats:sub>2<\/jats:sub>\n                  max), and glucose tolerance, as well as skeletal muscle IIb-to-IIa fiber type shift in both WT and KI mice. Contrastingly, VWR resulted in increased mitochondrial OxPhos protein expression, mitochondrial volume density, and capillary density in skeletal muscle of WT but not KI mice. Exercise-induced improvements of mitochondrial respiration and conductance revealed by high-resolution respirometry of isolated mitochondria were blunted in KI mice. Therefore, for the first time, we reveal that AMPK\u03b12 T172 activation is required for exercise training-induced mitochondrial biogenesis, improvement of mitochondrial respiratory function, and angiogenesis in skeletal muscle, but that these adaptations are not solely responsible for improved\n                  <jats:inline-formula>\n                    <jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" xlink:href=\"733224v1_inline2.gif\"\/>\n                  <\/jats:inline-formula>\n                  O\n                  <jats:sub>2<\/jats:sub>\n                  max and exercise endurance capacity.\n                <\/jats:p>\n                <jats:sec>\n                  <jats:title>Significance Statement<\/jats:title>\n                  <jats:p>\n                    Exercise is the most effective lifestyle intervention for promoting health and preventing chronic diseases through adaptive changes in skeletal muscle and many other tissues\/organs. AMPK is an energy sensor and signaling regulator for exercise-induced skeletal muscle adaptation, yet its functional role and the impact on exercise capacity have been studied in mouse genetic models wherein protein stoichiometry is disrupted. Using non-activatable\n                    <jats:italic>Ampk\u03b12(T172A)<\/jats:italic>\n                    knock-in mice, we ascertained that AMPK\u03b12 activation via T172 phosphorylation is required for endurance training-induced mitochondrial and angiogenic adaptations in skeletal muscle. Importantly, these adaptations are not required for improved exercise capacity, challenging the prevailing concept that increased mitochondrial content and function and microvasculature are the sole driving factors for the performance gains with endurance training.\n                  <\/jats:p>\n                <\/jats:sec>","DOI":"10.64898\/2026.06.18.733224","type":"posted-content","created":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T22:50:17Z","timestamp":1782255017000},"source":"Crossref","is-referenced-by-count":0,"title":["Exercise training improves exercise capacity independent of AMPK\u03b12 T172-mediated adaptations in skeletal muscle"],"prefix":"10.64898","author":[{"given":"Xuansong","family":"Mao","sequence":"first","affiliation":[{"name":"Fralin Biomedical Research Institute Center for Exercise Medicine Research at Virginia Tech Carilion, Roanoke, Virginia 24016, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ryan N.","family":"Montalvo","sequence":"additional","affiliation":[{"name":"Fralin Biomedical Research Institute Center for Exercise Medicine Research at Virginia Tech Carilion, Roanoke, Virginia 24016, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kenya","family":"Takahashi","sequence":"additional","affiliation":[{"name":"Fralin Biomedical Research Institute Center for Exercise Medicine Research at Virginia Tech Carilion, Roanoke, Virginia 24016, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Frank W.","family":"Booth","sequence":"additional","affiliation":[{"name":"Department of Pathobiology and Integrative Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri 65211, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"George A.","family":"Brooks","sequence":"additional","affiliation":[{"name":"Department of Integrative Biology, Integrative Biology, University of California, Berkeley, California 94602, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhen","family":"Yan","sequence":"additional","affiliation":[{"name":"Fralin Biomedical Research Institute Center for Exercise Medicine Research at Virginia Tech Carilion, Roanoke, Virginia 24016, USA"},{"name":"Department of Human Nutrition, Foods, and Exercise, College of Agriculture and Life Sciences, Virginia Tech, Blacksburg, Virginia 24061, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2026062506450668000_2026.06.18.733224v1.1","unstructured":"Patel PN , Horenstein MS , Zwibel H. Exercise Physiology. StatPearls. Treasure Island (FL) 2026."},{"key":"2026062506450668000_2026.06.18.733224v1.2","doi-asserted-by":"publisher","DOI":"10.1016\/0003-9861(81)90312-X"},{"key":"2026062506450668000_2026.06.18.733224v1.3","doi-asserted-by":"publisher","DOI":"10.1002\/cphy.c110007"},{"key":"2026062506450668000_2026.06.18.733224v1.4","doi-asserted-by":"publisher","DOI":"10.1001\/jama.2009.681"},{"key":"2026062506450668000_2026.06.18.733224v1.5","doi-asserted-by":"publisher","DOI":"10.1503\/cmaj.051351"},{"key":"2026062506450668000_2026.06.18.733224v1.6","doi-asserted-by":"publisher","DOI":"10.1136\/bjsports-2020-102955"},{"key":"2026062506450668000_2026.06.18.733224v1.7","doi-asserted-by":"publisher","DOI":"10.1016\/j.cmet.2026.02.017"},{"key":"2026062506450668000_2026.06.18.733224v1.8","doi-asserted-by":"publisher","DOI":"10.1016\/S0021-9258(18)96046-1"},{"key":"2026062506450668000_2026.06.18.733224v1.9","doi-asserted-by":"publisher","DOI":"10.1146\/annurev.ph.38.030176.001421"},{"key":"2026062506450668000_2026.06.18.733224v1.10","doi-asserted-by":"publisher","DOI":"10.1152\/ajplegacy.1972.222.2.373"},{"key":"2026062506450668000_2026.06.18.733224v1.11","doi-asserted-by":"publisher","DOI":"10.1172\/JCI106730"},{"key":"2026062506450668000_2026.06.18.733224v1.12","doi-asserted-by":"publisher","DOI":"10.1152\/jappl.1994.76.6.2253"},{"key":"2026062506450668000_2026.06.18.733224v1.13","doi-asserted-by":"publisher","DOI":"10.1097\/00005768-200001000-00012"},{"key":"2026062506450668000_2026.06.18.733224v1.14","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2508286123"},{"key":"2026062506450668000_2026.06.18.733224v1.15","doi-asserted-by":"publisher","DOI":"10.1002\/ar.1091590106"},{"key":"2026062506450668000_2026.06.18.733224v1.16","doi-asserted-by":"publisher","DOI":"10.1152\/jappl.2001.91.3.1176"},{"key":"2026062506450668000_2026.06.18.733224v1.17","doi-asserted-by":"publisher","DOI":"10.1152\/ajpcell.00247.2004"},{"key":"2026062506450668000_2026.06.18.733224v1.18","doi-asserted-by":"publisher","DOI":"10.1152\/jappl.1984.56.4.831"},{"key":"2026062506450668000_2026.06.18.733224v1.19","doi-asserted-by":"publisher","DOI":"10.1113\/EP085319"},{"key":"2026062506450668000_2026.06.18.733224v1.20","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00625.2011"},{"key":"2026062506450668000_2026.06.18.733224v1.21","doi-asserted-by":"publisher","DOI":"10.3390\/cells13050393"},{"issue":"2","key":"2026062506450668000_2026.06.18.733224v1.22","first-page":"84","article-title":"The relationship between skeletal muscle mitochondrial citrate synthase activity and whole body oxygen uptake adaptations in response to exercise training","volume":"6","year":"2014","journal-title":"Int J Physiol Pathophysiol Pharmacol"},{"key":"2026062506450668000_2026.06.18.733224v1.23","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00445.2013"},{"key":"2026062506450668000_2026.06.18.733224v1.24","doi-asserted-by":"publisher","DOI":"10.3390\/cells8030237"},{"key":"2026062506450668000_2026.06.18.733224v1.25","doi-asserted-by":"publisher","DOI":"10.1093\/gerona\/glz142"},{"key":"2026062506450668000_2026.06.18.733224v1.26","doi-asserted-by":"publisher","DOI":"10.1093\/gerona\/glr096"},{"key":"2026062506450668000_2026.06.18.733224v1.27","doi-asserted-by":"publisher","DOI":"10.1152\/ajpregu.00347.2010"},{"key":"2026062506450668000_2026.06.18.733224v1.28","doi-asserted-by":"publisher","DOI":"10.1093\/gerona\/glw017"},{"key":"2026062506450668000_2026.06.18.733224v1.29","doi-asserted-by":"publisher","DOI":"10.1146\/annurev-physiol-060721-095517"},{"key":"2026062506450668000_2026.06.18.733224v1.30","doi-asserted-by":"publisher","DOI":"10.4093\/dmj.2013.37.1.1"},{"key":"2026062506450668000_2026.06.18.733224v1.31","doi-asserted-by":"publisher","DOI":"10.1038\/nrm3311"},{"key":"2026062506450668000_2026.06.18.733224v1.32","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M109.021048"},{"key":"2026062506450668000_2026.06.18.733224v1.33","doi-asserted-by":"publisher","DOI":"10.2337\/db19-0050"},{"key":"2026062506450668000_2026.06.18.733224v1.34","doi-asserted-by":"publisher","DOI":"10.1096\/fj.14-266650"},{"key":"2026062506450668000_2026.06.18.733224v1.35","doi-asserted-by":"publisher","DOI":"10.1152\/ajpendo.1996.270.2.E299"},{"key":"2026062506450668000_2026.06.18.733224v1.36","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00416.2006"},{"key":"2026062506450668000_2026.06.18.733224v1.37","doi-asserted-by":"publisher","DOI":"10.3389\/fphys.2015.00085"},{"key":"2026062506450668000_2026.06.18.733224v1.38","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0705070104"},{"key":"2026062506450668000_2026.06.18.733224v1.39","doi-asserted-by":"publisher","DOI":"10.1152\/ajpcell.00481.2009"},{"key":"2026062506450668000_2026.06.18.733224v1.40","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0909131106"},{"key":"2026062506450668000_2026.06.18.733224v1.41","doi-asserted-by":"publisher","DOI":"10.1038\/nature00904"},{"key":"2026062506450668000_2026.06.18.733224v1.42","doi-asserted-by":"publisher","DOI":"10.1113\/EP090874"},{"key":"2026062506450668000_2026.06.18.733224v1.43","doi-asserted-by":"publisher","DOI":"10.1152\/ajpendo.00227.2013"},{"key":"2026062506450668000_2026.06.18.733224v1.44","doi-asserted-by":"publisher","DOI":"10.1152\/ajpendo.00157.2015"},{"key":"2026062506450668000_2026.06.18.733224v1.45","doi-asserted-by":"publisher","DOI":"10.1152\/ajpendo.00243.2006"},{"key":"2026062506450668000_2026.06.18.733224v1.46","doi-asserted-by":"publisher","DOI":"10.1038\/ijo.2010.220"},{"key":"2026062506450668000_2026.06.18.733224v1.47","doi-asserted-by":"publisher","DOI":"10.2337\/db07-0255"},{"key":"2026062506450668000_2026.06.18.733224v1.48","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0606557104"},{"key":"2026062506450668000_2026.06.18.733224v1.49","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M110.102434"},{"key":"2026062506450668000_2026.06.18.733224v1.50","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1105062108"},{"key":"2026062506450668000_2026.06.18.733224v1.51","doi-asserted-by":"publisher","DOI":"10.1126\/sciadv.aeb3338"},{"key":"2026062506450668000_2026.06.18.733224v1.52","doi-asserted-by":"publisher","DOI":"10.1152\/ajpendo.00462.2003"},{"issue":"1","key":"2026062506450668000_2026.06.18.733224v1.53","first-page":"E83","article-title":"Endurance training affects lactate clearance, not lactate production","volume":"244","year":"1983","journal-title":"The American journal of physiology"},{"key":"2026062506450668000_2026.06.18.733224v1.54","doi-asserted-by":"publisher","DOI":"10.1152\/jappl.1999.87.5.1684"},{"key":"2026062506450668000_2026.06.18.733224v1.55","doi-asserted-by":"publisher","DOI":"10.1007\/BF00589248"},{"key":"2026062506450668000_2026.06.18.733224v1.56","doi-asserted-by":"publisher","DOI":"10.1111\/j.1748-1716.1977.tb10361.x"},{"key":"2026062506450668000_2026.06.18.733224v1.57","doi-asserted-by":"publisher","DOI":"10.1007\/BF00421658"},{"key":"2026062506450668000_2026.06.18.733224v1.58","first-page":"395","article-title":"Growth of capillaries during long-term activity in skeletal muscle","volume":"11","year":"1973","journal-title":"Bibl Anat"},{"key":"2026062506450668000_2026.06.18.733224v1.59","doi-asserted-by":"publisher","DOI":"10.1016\/j.ceb.2016.03.013"},{"key":"2026062506450668000_2026.06.18.733224v1.60","doi-asserted-by":"publisher","DOI":"10.1016\/j.cmet.2015.09.001"},{"key":"2026062506450668000_2026.06.18.733224v1.61","doi-asserted-by":"publisher","DOI":"10.15252\/embj.2019102578"},{"key":"2026062506450668000_2026.06.18.733224v1.62","doi-asserted-by":"publisher","DOI":"10.1016\/S1097-2765(01)00251-9"},{"key":"2026062506450668000_2026.06.18.733224v1.63","doi-asserted-by":"publisher","DOI":"10.1038\/sj.emboj.7600667"},{"key":"2026062506450668000_2026.06.18.733224v1.64","doi-asserted-by":"publisher","DOI":"10.1152\/ajpendo.2001.281.6.E1340"},{"key":"2026062506450668000_2026.06.18.733224v1.65","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.252625599"},{"key":"2026062506450668000_2026.06.18.733224v1.66","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.2008.159871"},{"key":"2026062506450668000_2026.06.18.733224v1.67","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0501444102"},{"key":"2026062506450668000_2026.06.18.733224v1.68","doi-asserted-by":"publisher","DOI":"10.1152\/ajpheart.01105.2004"},{"key":"2026062506450668000_2026.06.18.733224v1.69","doi-asserted-by":"publisher","DOI":"10.1038\/nature00904"},{"key":"2026062506450668000_2026.06.18.733224v1.70","doi-asserted-by":"publisher","DOI":"10.1152\/ajpregu.00241.2022"},{"key":"2026062506450668000_2026.06.18.733224v1.71","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M114.554394"},{"key":"2026062506450668000_2026.06.18.733224v1.72","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.2012.245944"},{"key":"2026062506450668000_2026.06.18.733224v1.73","doi-asserted-by":"publisher","DOI":"10.1152\/ajpregu.00409.2009"},{"key":"2026062506450668000_2026.06.18.733224v1.74","doi-asserted-by":"publisher","DOI":"10.1016\/S0092-8674(00)80611-X"},{"key":"2026062506450668000_2026.06.18.733224v1.75","doi-asserted-by":"publisher","DOI":"10.1152\/ajpcell.00532.2005"},{"key":"2026062506450668000_2026.06.18.733224v1.76","doi-asserted-by":"publisher","DOI":"10.1152\/ajpendo.00209.2016"},{"key":"2026062506450668000_2026.06.18.733224v1.77","doi-asserted-by":"publisher","DOI":"10.1152\/ajpendo.00306.2024"},{"key":"2026062506450668000_2026.06.18.733224v1.78","doi-asserted-by":"publisher","DOI":"10.1152\/ajpendo.2000.278.4.e571"},{"issue":"1","key":"2026062506450668000_2026.06.18.733224v1.79","first-page":"30","article-title":"Maximal oxygen uptake: \u201cold\u201d and \u201cnew\u201d arguments for a cardiovascular limitation","volume":"24","year":"1992","journal-title":"Med Sci Sports Exerc"},{"key":"2026062506450668000_2026.06.18.733224v1.80","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.01395.2005"},{"key":"2026062506450668000_2026.06.18.733224v1.81","doi-asserted-by":"publisher","DOI":"10.1016\/j.jacc.2012.02.055"},{"key":"2026062506450668000_2026.06.18.733224v1.82","doi-asserted-by":"publisher","DOI":"10.1093\/gerona\/gls196"},{"key":"2026062506450668000_2026.06.18.733224v1.83","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-017-00520-9"},{"key":"2026062506450668000_2026.06.18.733224v1.84","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00358.2018"},{"key":"2026062506450668000_2026.06.18.733224v1.85","doi-asserted-by":"publisher","DOI":"10.1096\/fj.201903055R"},{"key":"2026062506450668000_2026.06.18.733224v1.86","doi-asserted-by":"publisher","DOI":"10.1016\/j.jshs.2025.101100"},{"key":"2026062506450668000_2026.06.18.733224v1.87","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2025932118"},{"key":"2026062506450668000_2026.06.18.733224v1.88","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-020-74718-1"},{"key":"2026062506450668000_2026.06.18.733224v1.89","doi-asserted-by":"publisher","DOI":"10.1016\/j.celrep.2018.08.091"},{"key":"2026062506450668000_2026.06.18.733224v1.90","doi-asserted-by":"publisher","DOI":"10.3390\/cells11152292"}],"container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.64898\/2026.06.18.733224","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,25]],"date-time":"2026-06-25T13:45:20Z","timestamp":1782395120000},"score":1,"resource":{"primary":{"URL":"http:\/\/biorxiv.org\/lookup\/doi\/10.64898\/2026.06.18.733224"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,23]]},"references-count":90,"URL":"https:\/\/doi.org\/10.64898\/2026.06.18.733224","relation":{},"subject":[],"published":{"date-parts":[[2026,6,23]]},"subtype":"preprint"}}