{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T04:16:54Z","timestamp":1792556214508,"version":"4.5.0"},"reference-count":219,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2022,1,18]],"date-time":"2022-01-18T00:00:00Z","timestamp":1642464000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Netw. Physiol."],"abstract":"<jats:p>The phenomenon of reduced athletic performance following sustained, intense training (Overtraining Syndrome, and OTS) was first recognized more than 90\u00a0years ago. Although hundreds of scientific publications have focused on OTS, a definitive diagnosis, reliable biomarkers, and effective treatments remain unknown. The present review considers existing models of OTS, acknowledges the individualized and sport-specific nature of signs\/symptoms, describes potential interacting predisposing factors, and proposes that OTS will be most effectively characterized and evaluated via the underlying complex biological systems. Complex systems in nature are not aptly characterized or successfully analyzed using the classic scientific method (i.e., simplifying complex problems into single variables in a search for cause-and-effect) because they result from myriad (often non-linear) concomitant interactions of multiple determinants. Thus, this review 1) proposes that OTS be viewed from the perspectives of complex systems and network physiology, 2) advocates for and recommends that techniques such as trans-omic analyses and machine learning be widely employed, and 3) proposes evidence-based areas for future OTS investigations, including concomitant multi-domain analyses incorporating brain neural networks, dysfunction of hypothalamic-pituitary-adrenal responses to training stress, the intestinal microbiota, immune factors, and low energy availability. Such an inclusive and modern approach will measurably help in prevention and management of OTS.<\/jats:p>","DOI":"10.3389\/fnetp.2021.794392","type":"journal-article","created":{"date-parts":[[2022,1,18]],"date-time":"2022-01-18T05:09:20Z","timestamp":1642482560000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":86,"title":["Overtraining Syndrome as a Complex Systems Phenomenon"],"prefix":"10.3389","volume":"1","author":[{"given":"Lawrence E.","family":"Armstrong","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael F.","family":"Bergeron","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elaine C.","family":"Lee","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"James E.","family":"Mershon","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elizabeth M.","family":"Armstrong","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2022,1,18]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"1331","DOI":"10.1152\/japplphysiol.00973.2003","article-title":"Higher Dietary Carbohydrate Content during Intensified Running Training Results in Better Maintenance of Performance and Mood State","volume":"96","author":"Achten","year":"2004","journal-title":"J. Appl. Physiol."},{"key":"B2","doi-asserted-by":"publisher","first-page":"511","DOI":"10.1016\/j.cell.2005.04.020","article-title":"Systems Biology: its Practice and Challenges","volume":"121","author":"Aderem","year":"2005","journal-title":"Cell"},{"key":"B3","doi-asserted-by":"publisher","first-page":"267","DOI":"10.2217\/epi.11.22","article-title":"Epigenetics and Lifestyle","volume":"3","author":"Alegr\u00eda-Torres","year":"2011","journal-title":"Epigenomics"},{"key":"B4","doi-asserted-by":"publisher","first-page":"1059","DOI":"10.1152\/japplphysiol.01077.2014","article-title":"Voluntary and Forced Exercise Differentially Alters the Gut Microbiome in C57BL\/6J Mice","volume":"118","author":"Allen","year":"2015","journal-title":"J. Appl. Physiol."},{"key":"B5","doi-asserted-by":"publisher","first-page":"253","DOI":"10.1126\/science.aav3932","article-title":"Thirst Regulates Motivated Behavior through Modulation of Brainwide Neural Population Dynamics","volume":"364","author":"Allen","year":"2019","journal-title":"Science"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.3390\/ijms20174231","article-title":"Machine Learning to Understand the Immune-Inflammatory Pathways in Fibromyalgia","volume":"20","author":"Andr\u00e9s-Rodr\u00edguez","year":"2019","journal-title":"Int. J. Mol. Sci."},{"key":"B7","doi-asserted-by":"publisher","first-page":"8304260","DOI":"10.1155\/2019\/8304260","article-title":"Human Systems Biology and Metabolic Modelling: A Review-From Disease Metabolism to Precision Medicine","volume":"2019","author":"Angione","year":"2019","journal-title":"Biomed. Res. Int."},{"key":"B8","doi-asserted-by":"publisher","first-page":"251","DOI":"10.1034\/j.1601-5215.2002.140601.x","article-title":"Stress, Immunity, Cytokines and Depression","volume":"14","author":"Anisman","year":"2002","journal-title":"Acta Neuropsychiatr."},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.3390\/nu11122864","article-title":"Thirst and Drinking Paradigms: Evolution from Single Factor Effects to Brainwide Dynamic Networks","volume":"11","author":"Armstrong","year":"2019","journal-title":"Nutrients"},{"key":"B10","doi-asserted-by":"publisher","first-page":"5724575","DOI":"10.1155\/2018\/5724575","article-title":"Interactions of Gut Microbiota, Endotoxemia, Immune Function, and Diet in Exertional Heatstroke","volume":"2018","author":"Armstrong","year":"2018","journal-title":"J. Sports Med."},{"key":"B11","doi-asserted-by":"publisher","first-page":"185","DOI":"10.2165\/00007256-200232030-00003","article-title":"The Unknown Mechanism of the Overtraining Syndrome","volume":"32","author":"Armstrong","year":"2002","journal-title":"Sports Med."},{"key":"B12","doi-asserted-by":"publisher","first-page":"e0247039","DOI":"10.1371\/journal.pone.0247039","article-title":"Association between Physical Activity and Changes in Intestinal Microbiota Composition: A Systematic Review","volume":"16","author":"Aya","year":"2021","journal-title":"PLoS One"},{"key":"B13","first-page":"4","article-title":"Awakening the Sleeping Giant: Anatomy and Plasticity of the Brain Serotonergic System","volume":"52","author":"Azmitia","year":"1991","journal-title":"J. Clin. Psychiatry"},{"key":"B14","doi-asserted-by":"publisher","first-page":"611550","DOI":"10.3389\/fphys.2020.611550","article-title":"Network Physiology of Exercise: Vision and Perspectives","volume":"11","author":"Balagu\u00e9","year":"2020","journal-title":"Front. Physiol."},{"key":"B15","first-page":"1","volume-title":"Unifying Principles in Complex Systems, Technical Report","author":"Bar-Yam","year":"2003"},{"key":"B16","doi-asserted-by":"publisher","first-page":"803","DOI":"10.1210\/jcem-60-4-803","article-title":"Hypothalamic Dysfunction in Overtrained Athletes*","volume":"60","author":"Barron","year":"1985","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"B17","doi-asserted-by":"publisher","first-page":"702","DOI":"10.1038\/ncomms1705","article-title":"Network Physiology Reveals Relations between Network Topology and Physiological Function","volume":"3","author":"Bashan","year":"2012","journal-title":"Nat. Commun."},{"key":"B18","doi-asserted-by":"publisher","first-page":"1362","DOI":"10.1249\/mss.0000000000001903","article-title":"Machine Learning in Modeling High School Sport Concussion Symptom Resolve","volume":"51","author":"Bergeron","year":"2019","journal-title":"Med. Sci. Sports Exerc."},{"key":"B19","doi-asserted-by":"publisher","first-page":"200","DOI":"10.1186\/1741-7015-11-200","article-title":"So Depression Is an Inflammatory Disease, but where Does the Inflammation Come from?","volume":"11","author":"Berk","year":"2013","journal-title":"BMC Med."},{"key":"B20","first-page":"26","volume-title":"How Matter Becomes Mind","author":"Bertolero","year":"2019"},{"key":"B21","doi-asserted-by":"publisher","first-page":"1309","DOI":"10.1136\/bjsports-2015-095850","article-title":"Complex Systems Approach for Sports Injuries: Moving from Risk Factor Identification to Injury Pattern Recognition-Narrative Review and New Concept","volume":"50","author":"Bittencourt","year":"2016","journal-title":"Br. J. Sports Med."},{"key":"B22","doi-asserted-by":"publisher","first-page":"24","DOI":"10.1111\/1365-2435.12016","article-title":"Evaluating Stress in Natural Populations of Vertebrates: Total CORT Is Not Good Enough","volume":"27","author":"Breuner","year":"2012","journal-title":"Funct. Ecol."},{"key":"B23","first-page":"1834","article-title":"Normale und pathologische physiologie der leibes\u0215ebungen","volume":"251","author":"Brustmann","year":"1928","journal-title":"M\u00fcenchener Medizinische Wochenschrift"},{"key":"B24","doi-asserted-by":"publisher","first-page":"107","DOI":"10.1136\/bjsm.32.2.107","article-title":"Fatigue and Underperformance in Athletes: the Overtraining Syndrome","volume":"32","author":"Budgett","year":"1998","journal-title":"Br. J. Sports Med."},{"key":"B25","doi-asserted-by":"publisher","first-page":"1025","DOI":"10.1038\/nature08932","article-title":"Catastrophic cascade of Failures in Interdependent Networks","volume":"464","author":"Buldyrev","year":"2010","journal-title":"Nature"},{"key":"B26","doi-asserted-by":"publisher","first-page":"87","DOI":"10.1002\/cphy.c140027","article-title":"Epigenetics\/Programming in the HPA Axis","volume":"6","author":"Buschdorf","year":"2015","journal-title":"Compr. Physiol."},{"key":"B27","doi-asserted-by":"publisher","first-page":"2524","DOI":"10.1249\/mss.0000000000002084","article-title":"Improving the Diagnosis of Nonfunctional Overreaching and Overtraining Syndrome","volume":"51","author":"Buyse","year":"2019","journal-title":"Med. Sci. Sports Exerc."},{"key":"B28","doi-asserted-by":"publisher","first-page":"14","DOI":"10.3390\/sports9020014","article-title":"Impact of Different Exercise Modalities on the Human Gut Microbiome","volume":"9","author":"Bycura","year":"2021","journal-title":"Sports (Basel)"},{"key":"B29","doi-asserted-by":"publisher","first-page":"906","DOI":"10.4085\/1062-6050-148-18","article-title":"Basal Hormones and Biochemical Markers as Predictors of Overtraining Syndrome in Male Athletes: The EROS-BASAL Study","volume":"54","author":"Cadegiani","year":"","journal-title":"J. Athl Train."},{"key":"B30","doi-asserted-by":"publisher","first-page":"1902","DOI":"10.1080\/02640414.2018.1424498","article-title":"Body Composition, Metabolism, Sleep, Psychological and Eating Patterns of Overtraining Syndrome: Results of the EROS Study (EROS-PROFILE)","volume":"36","author":"Cadegiani","year":"","journal-title":"J. Sports Sci."},{"key":"B31","doi-asserted-by":"publisher","first-page":"414","DOI":"10.3389\/fendo.2020.00414","article-title":"Eating, Sleep, and Social Patterns as Independent Predictors of Clinical, Metabolic, and Biochemical Behaviors Among Elite Male Athletes: The EROS-PREDICTORS Study","volume":"11","author":"Cadegiani","year":"2020","journal-title":"Front. Endocrinol."},{"key":"B32","doi-asserted-by":"publisher","first-page":"14","DOI":"10.1186\/s13102-017-0079-8","article-title":"Hormonal Aspects of Overtraining Syndrome: a Systematic Review","volume":"9","author":"Cadegiani","year":"2017","journal-title":"BMC Sports Sci. Med. Rehabil."},{"key":"B33","doi-asserted-by":"publisher","first-page":"648","DOI":"10.1016\/j.jsams.2017.10.033","article-title":"Hormonal Response to a Non-exercise Stress Test in Athletes with Overtraining Syndrome: Results from the Endocrine and Metabolic Responses on Overtraining Syndrome (EROS) - EROS-STRESS","volume":"21","author":"Cadegiani","year":"","journal-title":"J. Sci. Med. Sport"},{"key":"B34","doi-asserted-by":"publisher","first-page":"21","DOI":"10.1186\/s13102-019-0132-x","article-title":"Novel Causes and Consequences of Overtraining Syndrome: the EROS-DISRUPTORS Study","volume":"11","author":"Cadegiani","year":"","journal-title":"BMC Sports Sci. Med. Rehabil."},{"key":"B35","doi-asserted-by":"publisher","first-page":"e000542","DOI":"10.1136\/bmjsem-2019-000542","article-title":"Novel Insights of Overtraining Syndrome Discovered from the EROS Study","volume":"5","author":"Cadegiani","year":"","journal-title":"BMJ Open Sport Exerc. Med."},{"key":"B36","doi-asserted-by":"publisher","first-page":"3937819","DOI":"10.1155\/2020\/3937819","article-title":"Diagnosis of Overtraining Syndrome: Results of the Endocrine and Metabolic Responses on Overtraining Syndrome Study: EROS-DIAGNOSIS","volume":"2020","author":"Cadegiani","year":"2020","journal-title":"J. Sports Med."},{"key":"B37","doi-asserted-by":"publisher","first-page":"417","DOI":"10.2174\/1871527319666200715102430","article-title":"Neural Receptors Associated with Depression: A Systematic Review of the Past 10 Years","volume":"19","author":"Camara","year":"2020","journal-title":"CNS Neurol. Disord. Drug Targets"},{"key":"B38","doi-asserted-by":"publisher","first-page":"648","DOI":"10.3389\/fimmu.2018.00648","article-title":"Debunking the Myth of Exercise-Induced Immune Suppression: Redefining the Impact of Exercise on Immunological Health across the Lifespan","volume":"9","author":"Campbell","year":"2018","journal-title":"Front. Immunol."},{"key":"B39","doi-asserted-by":"publisher","first-page":"105","DOI":"10.1080\/1744666x.2019.1548933","article-title":"There Is Limited Existing Evidence to Support the Common assumption that Strenuous Endurance Exercise Bouts Impair Immune Competency","volume":"15","author":"Campbell","year":"2019","journal-title":"Expert Rev. Clin. Immunol."},{"key":"B40","doi-asserted-by":"publisher","first-page":"41","DOI":"10.1249\/jes.0000000000000096","article-title":"Exercise Is a Novel Promoter of Intestinal Health and Microbial Diversity","volume":"45","author":"Campbell","year":"2017","journal-title":"Exerc. Sport Sci. Rev."},{"key":"B41","doi-asserted-by":"publisher","first-page":"1","DOI":"10.12922\/jshp.0031.2014","article-title":"Overtraining Syndrome: Causes, Consequences, and Methods for Prevention","volume":"2","author":"Carter","year":"2014","journal-title":"J. Sport Human Perf."},{"key":"B42","doi-asserted-by":"publisher","first-page":"34","DOI":"10.1038\/nrg3575","article-title":"Systems Genetics Approaches to Understand Complex Traits","volume":"15","author":"Civelek","year":"2014","journal-title":"Nat. Rev. Genet."},{"key":"B43","doi-asserted-by":"publisher","first-page":"43","DOI":"10.1186\/s12970-016-0155-6","article-title":"Exercise-induced Stress Behavior, Gut-Microbiota-Brain axis and Diet: a Systematic Review for Athletes","volume":"13","author":"Clark","year":"2016","journal-title":"J. Int. Soc. Sports Nutr."},{"key":"B44","doi-asserted-by":"publisher","first-page":"1913","DOI":"10.1136\/gutjnl-2013-306541","article-title":"Exercise and Associated Dietary Extremes Impact on Gut Microbial Diversity","volume":"63","author":"Clarke","year":"2014","journal-title":"Gut"},{"key":"B45","doi-asserted-by":"publisher","first-page":"882","DOI":"10.1038\/nm0898-882","article-title":"Self-organization, Complexity and Chaos: the New Biology for Medicine","volume":"4","author":"Coffey","year":"1998","journal-title":"Nat. Med."},{"key":"B46","doi-asserted-by":"publisher","first-page":"249","DOI":"10.1249\/00005768-198806000-00006","article-title":"Effects of Repeated Days of Intensified Training on Muscle Glycogen and Swimming Performance","volume":"20","author":"Costill","year":"1988","journal-title":"Med. Sci. Sports Exerc."},{"key":"B47","first-page":"16","article-title":"Fatigue and Staleness","volume":"15","author":"Counsilman","year":"1955","journal-title":"Athletic J."},{"key":"B48","doi-asserted-by":"publisher","first-page":"559","DOI":"10.1038\/nature12820","article-title":"Diet Rapidly and Reproducibly Alters the Human Gut Microbiome","volume":"505","author":"David","year":"2014","journal-title":"Nature"},{"key":"B49","doi-asserted-by":"publisher","first-page":"S29","DOI":"10.1123\/ijsn.5.s1.s29","article-title":"Carbohydrates, Branched-Chain Amino Acids, and Endurance: the central Fatigue Hypothesis","volume":"5","author":"Davis","year":"1995","journal-title":"Int. J. Sport Nutr."},{"key":"B50","doi-asserted-by":"publisher","first-page":"189","DOI":"10.1007\/s40279-013-0114-1","article-title":"Exercise: Putting Action into Our Epigenome","volume":"44","author":"Denham","year":"2014","journal-title":"Sports Med."},{"key":"B51","doi-asserted-by":"publisher","first-page":"2225","DOI":"10.1152\/physrev.00042.2017","article-title":"The Corticotropin-Releasing Factor Family: Physiology of the Stress Response","volume":"98","author":"Deussing","year":"2018","journal-title":"Physiol. Rev."},{"key":"B52","doi-asserted-by":"publisher","first-page":"323","DOI":"10.1016\/0031-9384(94)90141-4","article-title":"Physical Exercise as a Novel Antidepressant Agent: Possible Role of Serotonin Receptor Subtypes","volume":"55","author":"Dey","year":"1994","journal-title":"Physiol. Behav."},{"key":"B53","doi-asserted-by":"publisher","first-page":"286","DOI":"10.1006\/brbi.1997.0508","article-title":"Acute Stress Enhances while Chronic Stress Suppresses Cell-Mediated Immunity In Vivo: a Potential Role for Leukocyte Trafficking","volume":"11","author":"Dhabhar","year":"1997","journal-title":"Brain Behav. Immun."},{"key":"B54","doi-asserted-by":"publisher","first-page":"177","DOI":"10.1016\/j.ygcen.2013.06.014","article-title":"A Consensus Endocrine Profile for Chronically Stressed Wild Animals Does Not Exist","volume":"191","author":"Dickens","year":"2013","journal-title":"Gen. Comp. Endocrinol."},{"key":"B55","doi-asserted-by":"publisher","first-page":"1635","DOI":"10.1126\/science.1110591","article-title":"Diversity of the Human Intestinal Microbial flora","volume":"308","author":"Eckburg","year":"2005","journal-title":"Science"},{"key":"B56","doi-asserted-by":"publisher","first-page":"S41","DOI":"10.1080\/02640419508732276","article-title":"Overtraining: Consequences and Prevention","volume":"13","author":"Eichner","year":"1995","journal-title":"J. Sports Sci."},{"key":"B57","doi-asserted-by":"publisher","first-page":"553","DOI":"10.1111\/j.1749-6632.1997.tb51746.x","article-title":"Heat Intolerance Induced by Antidepressants","volume":"813","author":"Epstein","year":"1997","journal-title":"Ann. N. Y Acad. Sci."},{"key":"B58","doi-asserted-by":"publisher","first-page":"258","DOI":"10.1007\/bf00626289","article-title":"Inter-relationships between Pituitary-Adrenal Hormones and Catecholamines during a 6-day Nordic Ski Race","volume":"64","author":"Fellmann","year":"1992","journal-title":"Europ. J. Appl. Physiol."},{"key":"B59","doi-asserted-by":"publisher","first-page":"100","DOI":"10.1016\/0165-6147(87)90083-6","article-title":"Toxicity of Interferon and Interleukin","volume":"8","author":"Fent","year":"1987","journal-title":"Trends Pharmacol. Sci."},{"key":"B60","doi-asserted-by":"publisher","DOI":"10.1519\/0199-610x(1982)004<0050:tos>2.3.co;2","article-title":"The Overtraining Syndrome","volume":"4","author":"Fleck","year":"1982","journal-title":"Strength Conditioning J."},{"key":"B61","doi-asserted-by":"publisher","first-page":"1164","DOI":"10.1097\/00005768-199807000-00023","article-title":"Monitoring Training in Athletes with Reference to Overtraining Syndrome","volume":"30","author":"Foster","year":"1998","journal-title":"Med. Sci. Sports Exerc."},{"key":"B62","doi-asserted-by":"publisher","first-page":"351","DOI":"10.1136\/bjsports-2011-090664","article-title":"Risk Factors for Hamstring Muscle Strain Injury in Sport: a Systematic Review and Meta-Analysis","volume":"47","author":"Freckleton","year":"2013","journal-title":"Br. J. Sports Med."},{"key":"B63","first-page":"59","article-title":"Overtraining Syndrome","volume-title":"Psychology of Sport Injury","author":"Froelich","year":"1995"},{"key":"B64","doi-asserted-by":"publisher","first-page":"941","DOI":"10.1152\/jappl.1994.77.2.941","article-title":"Catecholamine Responses to Short-Term High-Intensity Resistance Exercise Overtraining","volume":"77","author":"Fry","year":"1994","journal-title":"J. Appl. Physiol. (1985)"},{"key":"B65","doi-asserted-by":"publisher","first-page":"1664","DOI":"10.1152\/japplphysiol.01599.2005","article-title":"beta2-Adrenergic Receptor Downregulation and Performance Decrements during High-Intensity Resistance Exercise Overtraining","volume":"101","author":"Fry","year":"2006","journal-title":"J. Appl. Physiol."},{"key":"B66","doi-asserted-by":"publisher","first-page":"106","DOI":"10.2165\/00007256-199723020-00004","article-title":"Resistance Exercise Overtraining and Overreaching","volume":"23","author":"Fry","year":"1997","journal-title":"Sports Med."},{"key":"B67","first-page":"403","article-title":"The Role of Training Intensity in Resistance Exercise Overtraining and Overreaching","volume-title":"Overtraining in Sport. Human Kinetics","author":"Fry","year":"1998"},{"key":"B68","doi-asserted-by":"crossref","first-page":"578","DOI":"10.1002\/9780470757826.ch37","article-title":"Endocrinology of Overtraining","volume-title":"The Endocrine System in Sports and Exercise","author":"Fry","year":"2005"},{"key":"B69","doi-asserted-by":"publisher","first-page":"32","DOI":"10.2165\/00007256-199112010-00004","article-title":"Overtraining in Athletes","volume":"12","author":"Fry","year":"1991","journal-title":"Sports Med."},{"key":"B70","doi-asserted-by":"publisher","first-page":"32","DOI":"10.1016\/j.biopsych.2012.07.005","article-title":"Stress-induced Neuroinflammation: Role of the Toll-like Receptor-4 Pathway","volume":"73","author":"Garate","year":"2013","journal-title":"Biol. Psychiatry"},{"key":"B71","doi-asserted-by":"publisher","first-page":"142","DOI":"10.1016\/j.psyneuen.2014.03.018","article-title":"Glucocorticoid Receptors in the Nucleus of the Solitary Tract (NTS) Decrease Endocrine and Behavioral Stress Responses","volume":"45","author":"Ghosal","year":"2014","journal-title":"Psychoneuroendocrinology"},{"key":"B72","doi-asserted-by":"publisher","first-page":"127","DOI":"10.3389\/fnbeh.2018.00127","article-title":"A Comprehensive Overview on Stress Neurobiology: Basic Concepts and Clinical Implications","volume":"12","author":"Godoy","year":"2018","journal-title":"Front. Behav. Neurosci."},{"key":"B73","first-page":"111","article-title":"Adrenomedullary, Adrenocortical, and Sympathoneural Responses to Stressors: a Meta-Analysis","volume":"42","author":"Goldstein","year":"2008","journal-title":"Endocr. Regul."},{"key":"B74","doi-asserted-by":"publisher","first-page":"293","DOI":"10.1016\/bs.pmbts.2015.07.001","article-title":"Exercise and the Regulation of Endocrine Hormones","volume":"135","author":"Hackney","year":"2015","journal-title":"Prog. Mol. Biol. Transl Sci."},{"key":"B75","doi-asserted-by":"publisher","first-page":"233","DOI":"10.1007\/bf02386193","article-title":"Serum Hormone Concentrations during Prolonged Training in Elite Endurance-Trained and Strength-Trained Athletes","volume":"59","author":"H\u00e4kkinen","year":"1989","journal-title":"Europ. J. Appl. Physiol."},{"key":"B76","doi-asserted-by":"publisher","first-page":"967","DOI":"10.2165\/00007256-200434140-00003","article-title":"Does Overtraining Exist?","volume":"34","author":"Halson","year":"2004","journal-title":"Sports Med."},{"key":"B77","doi-asserted-by":"publisher","first-page":"1245","DOI":"10.1152\/japplphysiol.01368.2003","article-title":"Effects of Carbohydrate Supplementation on Performance and Carbohydrate Oxidation after Intensified Cycling Training","volume":"97","author":"Halson","year":"1985","journal-title":"J. Appl. Physiol."},{"key":"B78","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1007\/978-0-387-21606-5_2","article-title":"Overview of Supervised Learning","volume-title":"The Elements of Statistical Learning","author":"Hastie","year":"2001"},{"key":"B79","doi-asserted-by":"publisher","first-page":"61","DOI":"10.3389\/fnbeh.2013.00061","article-title":"Neural Control of Chronic Stress Adaptation","volume":"7","author":"Herman","year":"2013","journal-title":"Front. Behav. Neurosci."},{"key":"B80","doi-asserted-by":"publisher","first-page":"603","DOI":"10.1002\/cphy.c150015","article-title":"Regulation of the Hypothalamic-Pituitary-Adrenocortical Stress Response","volume":"6","author":"Herman","year":"2016","journal-title":"Compr. Physiol."},{"key":"B81","doi-asserted-by":"publisher","first-page":"248","DOI":"10.3389\/fnmol.2017.00248","article-title":"Translational Identification of Transcriptional Signatures of Major Depression and Antidepressant Response","volume":"10","author":"Herv\u00e9","year":"2017","journal-title":"Front. Mol. Neurosci."},{"key":"B82","first-page":"247","article-title":"Nonlinear Systems in Medicine","volume":"75","author":"Higgins","year":"2003","journal-title":"Yale J. Biol. Med."},{"key":"B83","doi-asserted-by":"publisher","first-page":"1838","DOI":"10.1136\/gutjnl-2014-307305","article-title":"The Gut Microbiota, Dietary Extremes and Exercise","volume":"63","author":"Hold","year":"2014","journal-title":"Gut"},{"key":"B84","volume-title":"Hidden Order: How Adaptation Builds Complexity from Chaos","author":"Holland","year":"1995"},{"key":"B85","doi-asserted-by":"publisher","first-page":"1449","DOI":"10.1053\/j.gastro.2014.01.052","article-title":"Compositional and Functional Features of the Gastrointestinal Microbiome and Their Effects on Human Health","volume":"146","author":"Hollister","year":"2014","journal-title":"Gastroenterology"},{"key":"B86","doi-asserted-by":"publisher","first-page":"477","DOI":"10.1016\/s0893-133x(00)00159-7","article-title":"The Corticosteroid Receptor Hypothesis of Depression","volume":"23","author":"Holsboer","year":"2000","journal-title":"Neuropsychopharmacology"},{"key":"B87","doi-asserted-by":"crossref","first-page":"494","DOI":"10.1007\/978-3-030-33376-8_27","article-title":"The Endocrine System in Overtraining","volume-title":"Endocrinology of Physical Activity and Sport","author":"Hooper","year":"2020"},{"key":"B88","doi-asserted-by":"publisher","first-page":"741","DOI":"10.1249\/00005768-199306000-00015","article-title":"Hormonal Responses of Elite Swimmers to Overtraining","volume":"25","author":"Hooper","year":"1993","journal-title":"Med. Sci. Sports Exerc."},{"key":"B89","doi-asserted-by":"publisher","first-page":"106","DOI":"10.1249\/00005768-199501000-00019","article-title":"Markers for Monitoring Overtraining and Recovery","volume":"27","author":"Hooper","year":"1995","journal-title":"Med. Sci. Sports Exerc."},{"key":"B90","doi-asserted-by":"publisher","first-page":"447","DOI":"10.3390\/medicina46070064","article-title":"Constraints-controlled Metastable Dynamics of Exercise-Induced Psychobiological Adaptation","volume":"46","author":"Hristovski","year":"2010","journal-title":"Medicina (Kaunas)"},{"key":"B91","doi-asserted-by":"publisher","first-page":"552","DOI":"10.1519\/jsc.0000000000000644","article-title":"Effect of Intestinal Microbiota on Exercise Performance in Mice","volume":"29","author":"Hsu","year":"2015","journal-title":"J. Strength Cond Res."},{"key":"B92","doi-asserted-by":"publisher","first-page":"8695","DOI":"10.1021\/acs.jafc.6b03725","article-title":"Soy and Gut Microbiota: Interaction and Implication for Human Health","volume":"64","author":"Huang","year":"2016","journal-title":"J. Agric. Food Chem."},{"key":"B93","doi-asserted-by":"publisher","first-page":"pyw001","DOI":"10.1093\/ijnp\/pyw001","article-title":"Stress-Related Immune Markers in Depression: Implications for Treatment","volume":"19","author":"Hughes","year":"2016","journal-title":"Int. J. Neuropsychopharmacol."},{"key":"B94","doi-asserted-by":"publisher","first-page":"22","DOI":"10.1016\/0006-3223(90)90016-u","article-title":"Reduction of Immune Function in Life Stress and Depression","volume":"27","author":"Irwin","year":"1990","journal-title":"Biol. Psychiatry"},{"key":"B95","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1007\/978-3-319-03518-5_10","article-title":"Network Physiology: Mapping Interactions between Networks of Physiologic Networks","volume-title":"Networks of Networks: The Last Frontier of Complexity","author":"Ivanov","year":"2014"},{"key":"B96","doi-asserted-by":"publisher","first-page":"165","DOI":"10.1152\/physrev.1992.72.1.165","article-title":"Structure and Function of the Brain Serotonin System","volume":"72","author":"Jacobs","year":"1992","journal-title":"Physiol. Rev."},{"key":"B97","doi-asserted-by":"publisher","first-page":"715","DOI":"10.1002\/cphy.c130036","article-title":"Hypothalamic-pituitary-adrenocortical axis: Neuropsychiatric Aspects","volume":"4","author":"Jacobson","year":"2014","journal-title":"Compr. Physiol."},{"key":"B98","doi-asserted-by":"publisher","first-page":"461","DOI":"10.1113\/expphysiol.1994.sp003780","article-title":"Evidence for Downregulation of Hypothalamic 5-hydroxytryptamine Receptor Function in Endurance-Trained Athletes","volume":"79","author":"Jakeman","year":"1994","journal-title":"Exp. Physiol."},{"key":"B99","doi-asserted-by":"publisher","first-page":"534","DOI":"10.1055\/s-2007-1021312","article-title":"Physiological Changes in Male Competitive Cyclists after Two Weeks of Intensified Training","volume":"13","author":"Jeukendrup","year":"1992","journal-title":"Int. J. Sports Med."},{"key":"B100","first-page":"403","volume-title":"Neuroendocrine Aspects of Overtraining. Overtraining in Sport. Human Kinetics","author":"Keizer","year":"1998"},{"key":"B101","doi-asserted-by":"publisher","first-page":"392","DOI":"10.3389\/fncel.2015.00392","article-title":"Breaking Down the Barriers: the Gut Microbiome, Intestinal Permeability and Stress-Related Psychiatric Disorders","volume":"9","author":"Kelly","year":"2015","journal-title":"Front Cel Neurosci"},{"key":"B102","first-page":"16","volume-title":"A. Let\u00f6r\u00e9sr\u00f6l","author":"Kereszty","year":"1947"},{"key":"B103","first-page":"218","article-title":"Overtraining","volume-title":"Encyclopedia of Sport Sciences and Medicine","author":"Kereszty","year":"1971"},{"key":"B104","volume-title":"Normale und pathologische physiologie der leibes\u0215ebungen","author":"Knoll","year":"1933"},{"key":"B105","doi-asserted-by":"publisher","first-page":"248","DOI":"10.1136\/bjsm.24.4.248","article-title":"Rest in Underperforming Elite Competitors","volume":"24","author":"Koutedakis","year":"1990","journal-title":"Br. J. Sports Med."},{"key":"B106","first-page":"69","article-title":"Factors Involved with Overtraining for Strength and Power","volume-title":"Overtraining in Sport","author":"Kraemer","year":"1998"},{"key":"B107","doi-asserted-by":"publisher","first-page":"146","DOI":"10.1249\/00005768-198904000-00006","article-title":"Training Responses of Plasma Beta-Endorphin, Adrenocorticotropin, and Cortisol","volume":"21","author":"Kraemer","year":"1989","journal-title":"Med. Sci. Sports Exerc."},{"key":"B108","doi-asserted-by":"publisher","first-page":"339","DOI":"10.2165\/00007256-200535040-00004","article-title":"Hormonal Responses and Adaptations to Resistance Exercise and Training","volume":"35","author":"Kraemer","year":"2005","journal-title":"Sports Med."},{"key":"B109","article-title":"Overtraining in Sport: Terms, Definitions, and Prevalence","volume-title":"Overtraining in Sport","author":"Kreider","year":""},{"key":"B110","first-page":"403","article-title":"Overtraining in Sport","volume-title":"Overtraining in Sport. Human Kinetics","author":"Kreider","year":""},{"key":"B111","doi-asserted-by":"publisher","first-page":"34","DOI":"10.1016\/j.mib.2018.07.003","article-title":"Low Diversity Gut Microbiota Dysbiosis: Drivers, Functional Implications and Recovery","volume":"44","author":"Kriss","year":"2018","journal-title":"Curr. Opin. Microbiol."},{"key":"B112","doi-asserted-by":"publisher","first-page":"79","DOI":"10.2165\/00007256-198806020-00003","article-title":"Overtraining in Elite Athletes","volume":"6","author":"Kuipers","year":"1988","journal-title":"Sports Med."},{"key":"B113","doi-asserted-by":"publisher","first-page":"196","DOI":"10.1016\/0006-8993(94)90650-5","article-title":"The Habituation of Brainstem Catecholaminergic Groups to Chronic Daily Restraint Stress Is Stress Specific like that of the Hypothalamo-Pituitary-Adrenal axis","volume":"638","author":"Lachuer","year":"1994","journal-title":"Brain Res."},{"key":"B114","doi-asserted-by":"publisher","first-page":"749","DOI":"10.1139\/apnm-2014-0452","article-title":"Exercise Training Modifies Gut Microbiota in normal and Diabetic Mice","volume":"40","author":"Lambert","year":"2015","journal-title":"Appl. Physiol. Nutr. Metab."},{"key":"B115","doi-asserted-by":"publisher","first-page":"541","DOI":"10.1038\/nature12506","article-title":"Richness of Human Gut Microbiome Correlates with Metabolic Markers","volume":"500","author":"Le Chatelier","year":"2013","journal-title":"Nature"},{"key":"B116","doi-asserted-by":"publisher","first-page":"166","DOI":"10.1016\/0006-3223(94)00258-5","article-title":"Plasma Neurotransmitters, Blood Pressure, and Heart Rate during Supine-Resting, Orthostasis, and Moderate Exercise Conditions in Major Depressed Patients","volume":"38","author":"Lechin","year":"1995","journal-title":"Biol. Psychiatry"},{"key":"B117","doi-asserted-by":"publisher","first-page":"854","DOI":"10.1249\/00005768-199307000-00015","article-title":"Overtraining in Endurance Athletes: a Brief Review","volume":"25","author":"Lehman","year":"1993","journal-title":"Med. Sci. Sports Exerc."},{"key":"B118","doi-asserted-by":"publisher","first-page":"1140","DOI":"10.1097\/00005768-199807000-00019","article-title":"Autonomic Imbalance Hypothesis and Overtraining Syndrome","volume":"30","author":"Lehmann","year":"1998","journal-title":"Med. Sci. Sports Exerc."},{"key":"B119","doi-asserted-by":"publisher","first-page":"444","DOI":"10.1055\/s-2007-1024711","article-title":"Training-overtraining. A Prospective, Experimental Study with Experienced Middle- and Long-Distance Runners","volume":"12","author":"Lehmann","year":"1991","journal-title":"Int. J. Sports Med."},{"key":"B120","first-page":"7","article-title":"Training and Overtraining: an Overview and Experimental Results in Endurance Sports","volume":"37","author":"Lehmann","year":"1997","journal-title":"J. Sports Med. Phys. Fitness"},{"key":"B121","doi-asserted-by":"publisher","first-page":"186","DOI":"10.1136\/bjsm.27.3.186","article-title":"Influence of 6-week, 6 Days Per Week, Training on Pituitary Function in Recreational Athletes","volume":"27","author":"Lehmann","year":"1993","journal-title":"Br. J. Sports Med."},{"key":"B122","first-page":"19","article-title":"Physiological Responses to Short- and Long-Term Overtraining in Endurance Athletes","volume-title":"Overtraining in Sport","author":"Lehmann","year":"1998"},{"key":"B123","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1007\/978-0-585-34048-7_2","article-title":"Selected Parameters and Mechanisms of Peripheral and central Fatigue and Regeneration in Overtrained Athletes","volume-title":"Overload, Performance Incompetence, and Regeneration in Sport","author":"Lehmann","year":"1999"},{"key":"B124","doi-asserted-by":"publisher","first-page":"169","DOI":"10.1007\/bf00717956","article-title":"Training-overtraining: Influence of a Defined Increase in Training Volume vs Training Intensity on Performance, Catecholamines and Some Metabolic Parameters in Experienced Middle- and Long-Distance Runners","volume":"64","author":"Lehmann","year":"1992","journal-title":"Eur. J. Appl. Physiol. Occup. Physiol."},{"key":"B125","doi-asserted-by":"publisher","first-page":"233","DOI":"10.1136\/bjsm.26.4.233","article-title":"Training-overtraining: Performance, and Hormone Levels, after a Defined Increase in Training Volume versus Intensity in Experienced Middle- and Long-Distance Runners","volume":"26","author":"Lehmann","year":"1992","journal-title":"Br. J. Sports Med."},{"key":"B126","doi-asserted-by":"publisher","first-page":"268","DOI":"10.1159\/000104854","article-title":"HPA and Immune Axes in Stress: Involvement of the Serotonergic System","volume":"13","author":"Leonard","year":"2006","journal-title":"Neuroimmunomodulation"},{"key":"B127","doi-asserted-by":"publisher","first-page":"219","DOI":"10.1038\/nri.2017.7","article-title":"Dysbiosis and the Immune System","volume":"17","author":"Levy","year":"2017","journal-title":"Nat. Rev. Immunol."},{"key":"B128","doi-asserted-by":"publisher","first-page":"265","DOI":"10.4161\/gmic.28261","article-title":"Metagenomic Systems Biology and Metabolic Modeling of the Human Microbiome","volume":"5","author":"Levy","year":"2014","journal-title":"Gut Microbes"},{"key":"B129","doi-asserted-by":"publisher","first-page":"220","DOI":"10.1038\/nature11550","article-title":"Diversity, Stability and Resilience of the Human Gut Microbiota","volume":"489","author":"Lozupone","year":"2012","journal-title":"Nature"},{"key":"B130","doi-asserted-by":"publisher","first-page":"obz017","DOI":"10.1093\/iob\/obz017","article-title":"Glucocorticoids and \"Stress\" Are Not Synonymous","volume":"1","author":"MacDougall-Shackleton","year":"2019","journal-title":"Integr. Org. Biol."},{"key":"B131","doi-asserted-by":"publisher","first-page":"179","DOI":"10.1016\/j.jshs.2016.05.001","article-title":"Endurance Exercise and Gut Microbiota: A Review","volume":"6","author":"Mach","year":"2017","journal-title":"J. Sport Health Sci."},{"key":"B132","doi-asserted-by":"publisher","first-page":"502","DOI":"10.1111\/j.1440-1711.2000.t01-7-.x","article-title":"Overtraining Effects on Immunity and Performance in Athletes","volume":"78","author":"MacKinnon","year":"2000","journal-title":"Immunol. Cel Biol"},{"key":"B133","doi-asserted-by":"publisher","first-page":"229","DOI":"10.1016\/0165-1781(93)90081-q","article-title":"Psychomotor Retardation, Anorexia, Weight Loss, Sleep Disturbances, and Loss of Energy: Psychopathological Correlates of Hyperhaptoglobinemia during Major Depression","volume":"47","author":"Maes","year":"1993","journal-title":"Psychiatry Res."},{"key":"B134","doi-asserted-by":"publisher","first-page":"154","DOI":"10.1007\/bf03033069","article-title":"Serotonin-immune Interactions in Major Depression: Lower Serum Tryptophan as a Marker of an Immune-Inflammatory Response","volume":"247","author":"Maes","year":"1997","journal-title":"Eur. Arch. Psychiatry Clin. Neurosci."},{"key":"B135","doi-asserted-by":"publisher","first-page":"83","DOI":"10.1037\/0033-295x.105.1.83","article-title":"Cytokines for Psychologists: Implications of Bidirectional Immune-To-Brain Communication for Understanding Behavior, Mood, and Cognition","volume":"105","author":"Maier","year":"1998","journal-title":"Psychol. Rev."},{"key":"B136","doi-asserted-by":"publisher","first-page":"195","DOI":"10.1080\/17461390902818260","article-title":"A Multi-Component Assessment Model for Monitoring Training Distress Among Athletes","volume":"9","author":"Main","year":"2009","journal-title":"Eur. J. Sport Sci."},{"key":"B137","doi-asserted-by":"publisher","first-page":"330","DOI":"10.1136\/gutjnl-2015-309990","article-title":"The Gut Microbiota and Host Health: a New Clinical Frontier","volume":"65","author":"Marchesi","year":"2016","journal-title":"Gut"},{"key":"B138","doi-asserted-by":"publisher","first-page":"873","DOI":"10.1152\/physrev.00041.2006","article-title":"Physiology and Neurobiology of Stress and Adaptation: central Role of the Brain","volume":"87","author":"McEwen","year":"2007","journal-title":"Physiol. Rev."},{"key":"B139","doi-asserted-by":"publisher","first-page":"277","DOI":"10.1111\/imr.12556","article-title":"The Nutrition-Gut Microbiome-Physiology axis and Allergic Diseases","volume":"278","author":"McKenzie","year":"2017","journal-title":"Immunol. Rev."},{"key":"B140","doi-asserted-by":"crossref","DOI":"10.1007\/978-0-585-34048-7_15","volume-title":"Overtraining And the central Nervous System: The Missing Link? Overload, Performance Incompetence, and Regeneration in Sport","author":"Meeusen","year":"1999"},{"key":"B141","doi-asserted-by":"publisher","first-page":"186","DOI":"10.1249\/MSS.0b013e318279a10a","article-title":"Prevention, Diagnosis, and Treatment of the Overtraining Syndrome: Joint Consensus Statement of the European College of Sport Science and the American College of Sports Medicine","volume":"45","author":"Meeusen","year":"2013","journal-title":"Med. Sci. Sports Exerc."},{"key":"B142","doi-asserted-by":"publisher","first-page":"857","DOI":"10.1139\/h07-080","article-title":"Brain Neurotransmitters in Fatigue and Overtraining","volume":"32","author":"Meeusen","year":"2007","journal-title":"Appl. Physiol. Nutr. Metab."},{"key":"B143","doi-asserted-by":"publisher","first-page":"140","DOI":"10.1007\/s00421-003-0940-1","article-title":"Hormonal Responses in Athletes: the Use of a Two Bout Exercise Protocol to Detect Subtle Differences in (Over)training Status","volume":"91","author":"Meeusen","year":"2004","journal-title":"Eur. J. Appl. Physiol."},{"key":"B144","doi-asserted-by":"publisher","first-page":"642","DOI":"10.1136\/bjsm.2008.049981","article-title":"Diagnosing Overtraining in Athletes Using the Two-Bout Exercise Protocol","volume":"44","author":"Meeusen","year":"2010","journal-title":"Br. J. Sports Med."},{"key":"B145","doi-asserted-by":"publisher","first-page":"215","DOI":"10.1097\/jsm.0b013e3180592a48","article-title":"A Dynamic Model of Etiology in Sport Injury: the Recursive Nature of Risk and Causation","volume":"17","author":"Meeuwisse","year":"2007","journal-title":"Clin. J. Sport Med."},{"key":"B146","doi-asserted-by":"publisher","first-page":"176","DOI":"10.1111\/j.1600-0447.1988.tb06319.x","article-title":"Post-influenzal Psychiatric Disorder in Adolescents","volume":"78","author":"Meijer","year":"1988","journal-title":"Acta Psychiatr. Scand."},{"key":"B147","first-page":"1310","article-title":"Overtraining","volume-title":"Encyclopedia of Sport Sciences and Medicine","author":"Mellerowicz","year":"1971"},{"key":"B148","doi-asserted-by":"publisher","first-page":"486","DOI":"10.1111\/j.1749-6632.1990.tb16904.x","article-title":"Role of Serotonin in Depression","volume":"600","author":"Meltzer","year":"1990","journal-title":"Ann. N. Y Acad. Sci."},{"key":"B149","first-page":"97","article-title":"Overtraining in Athletics","volume":"1","author":"Michael","year":"1961","journal-title":"The J. Sports Med. Phys. Fitness"},{"key":"B150","doi-asserted-by":"publisher","first-page":"107","DOI":"10.1136\/bjsm.21.3.107","article-title":"Psychological Monitoring of Overtraining and Staleness","volume":"21","author":"Morgan","year":"1987","journal-title":"Br. J. Sports Med."},{"key":"B151","doi-asserted-by":"publisher","first-page":"408","DOI":"10.1249\/00005768-198808000-00014","article-title":"Mood Disturbance Following Increased Training in Swimmers","volume":"20","author":"Morgan","year":"1988","journal-title":"Med. Sci. Sports Exerc."},{"key":"B152","doi-asserted-by":"publisher","first-page":"455","DOI":"10.3389\/fmicb.2016.00455","article-title":"Gut Microbiota Diversity and Human Diseases: Should We Reintroduce Key Predators in Our Ecosystem","volume":"7","author":"Mosca","year":"2016","journal-title":"Front. Microbiol."},{"key":"B153","doi-asserted-by":"publisher","first-page":"491","DOI":"10.1136\/bjsports-2014-093502","article-title":"The IOC Consensus Statement: beyond the Female Athlete Triad-Relative Energy Deficiency in Sport (RED-S)","volume":"48","author":"Mountjoy","year":"2014","journal-title":"Br. J. Sports Med."},{"key":"B154","doi-asserted-by":"publisher","first-page":"46","DOI":"10.1016\/j.neubiorev.2014.05.007","article-title":"Oxidative & Nitrosative Stress in Depression: Why So Much Stress?","volume":"45","author":"Moylan","year":"2014","journal-title":"Neurosci. Biobehavioral Rev."},{"key":"B155","doi-asserted-by":"publisher","first-page":"110139","DOI":"10.1016\/j.pnpbp.2020.110139","article-title":"Depression: Biological Markers and Treatment","volume":"105","author":"Nedic Erjavec","year":"2021","journal-title":"Prog. Neuro-Psychopharmacology Biol. Psychiatry"},{"key":"B156","doi-asserted-by":"publisher","first-page":"131","DOI":"10.1080\/19490976.2015.1011875","article-title":"Exercise and the Microbiota","volume":"6","author":"O'Sullivan","year":"2015","journal-title":"Gut Microbes"},{"key":"B157","doi-asserted-by":"publisher","first-page":"1677","DOI":"10.12988\/ces.2018.84166","article-title":"Survey of Biometric Pattern Recognition via Machine Learning Techniques","volume":"11","author":"Ortiz","year":"2018","journal-title":"ces"},{"key":"B158","doi-asserted-by":"publisher","first-page":"6","DOI":"10.1136\/bjsm.1.1.6","article-title":"Problems in Training Oarsmen - Staleness","volume":"1","author":"Owen","year":"1964","journal-title":"Bull. - Br. Assoc. Sport Med."},{"key":"B159","doi-asserted-by":"publisher","first-page":"429","DOI":"10.1007\/s40279-013-0138-6","article-title":"Physical Exercise and Epigenetic Modulation: Elucidating Intricate Mechanisms","volume":"44","author":"Pareja-Galeano","year":"2014","journal-title":"Sports Med."},{"key":"B160","doi-asserted-by":"publisher","first-page":"139","DOI":"10.1016\/j.neubiorev.2019.04.010","article-title":"Stress, Epigenetics and Depression: A Systematic Review","volume":"102","author":"Park","year":"2019","journal-title":"Neurosci. Biobehav Rev."},{"key":"B161","doi-asserted-by":"publisher","first-page":"45","DOI":"10.1056\/nejm192307121890201","article-title":"Some Medical Aspects of the Training of College Athletes","volume":"189","author":"Parmenter","year":"1923","journal-title":"Boston Med. Surg. J."},{"key":"B162","doi-asserted-by":"publisher","first-page":"S122","DOI":"10.1055\/s-2007-1024863","article-title":"A Communicational Link between Skeletal Muscle, Brain, and Cells of the Immune System","volume":"11","author":"Parry-Billings","year":"1990","journal-title":"Int. J. Sports Med."},{"key":"B163","doi-asserted-by":"publisher","first-page":"145","DOI":"10.1080\/14623943.2017.1361923","article-title":"Overtraining and the Complexities of Coaches\u2019 Decision-Making: Managing Elite Athletes on the Training Cusp","volume":"19","author":"Pope","year":"2018","journal-title":"Reflective Pract."},{"key":"B164","doi-asserted-by":"publisher","first-page":"1","DOI":"10.3390\/nu12010042","article-title":"Mild Dehydration Identification Using Machine Learning to Assess Autonomic Responses to Cognitive Stress","volume":"12","author":"Posada-Quintero","year":"2019","journal-title":"Nutrients"},{"key":"B165","first-page":"73","article-title":"Probleme des \u0215bertrainings","author":"Prokop","year":"1952","journal-title":"Proc. Int. Conf. Sport Health"},{"key":"B166","doi-asserted-by":"publisher","first-page":"84","DOI":"10.1055\/s-2007-1021025","article-title":"Development of a Scale for Use in Monitoring Training-Induced Distress in Athletes","volume":"15","author":"Raglin","year":"1994","journal-title":"Int. J. Sports Med."},{"key":"B167","doi-asserted-by":"publisher","first-page":"1873","DOI":"10.1007\/s00421-011-2166-y","article-title":"The Effect of 4-week Training Period on Plasma Neuropeptide Y, Leptin and Ghrelin Responses in Male Rowers","volume":"112","author":"Ramson","year":"2012","journal-title":"Eur. J. Appl. Physiol."},{"key":"B168","doi-asserted-by":"publisher","first-page":"1010","DOI":"10.1016\/j.drudis.2014.03.003","article-title":"Dynamic Epigenetic Responses to Muscle Contraction","volume":"19","author":"Rasmussen","year":"2014","journal-title":"Drug Discov. Today"},{"key":"B169","doi-asserted-by":"publisher","first-page":"445","DOI":"10.1001\/archpsyc.58.5.445","article-title":"Cytokine-associated Emotional and Cognitive Disturbances in Humans","volume":"58","author":"Reichenberg","year":"2001","journal-title":"Arch. Gen. Psychiatry"},{"key":"B170","doi-asserted-by":"publisher","first-page":"1241214","DOI":"10.1126\/science.1241214","article-title":"Gut Microbiota from Twins Discordant for Obesity Modulate Metabolism in Mice","volume":"341","author":"Ridaura","year":"2013","journal-title":"Science"},{"key":"B171","doi-asserted-by":"publisher","first-page":"85","DOI":"10.1038\/nrg3868","article-title":"Methods of Integrating Data to Uncover Genotype-Phenotype Interactions","volume":"16","author":"Ritchie","year":"2015","journal-title":"Nat. Rev. Genet."},{"key":"B172","doi-asserted-by":"publisher","first-page":"2953","DOI":"10.1039\/c6mb00476h","article-title":"Integrative Analysis of Human Omics Data Using Biomolecular Networks","volume":"12","author":"Robinson","year":"2016","journal-title":"Mol. Biosyst."},{"key":"B173","doi-asserted-by":"crossref","first-page":"521","DOI":"10.1007\/978-3-030-48806-2_12","article-title":"Epigenetics in Exercise","volume-title":"Basic Exercise Physiology","author":"Saghiv","year":"2020"},{"key":"B174","doi-asserted-by":"publisher","first-page":"239","DOI":"10.1146\/annurev-food-030212-182554","article-title":"Impact of Diet on Human Intestinal Microbiota and Health","volume":"5","author":"Salonen","year":"2014","journal-title":"Annu. Rev. Food Sci. Technol."},{"key":"B175","doi-asserted-by":"publisher","first-page":"15","DOI":"10.4088\/jcp.v59n1007b","article-title":"Noradrenergic versus Serotonergic Antidepressants: Predictors of Treatment Response","author":"Schatzberg","year":"1998","journal-title":"J. Clin. Psychiatry"},{"key":"B176","doi-asserted-by":"publisher","first-page":"1198","DOI":"10.1016\/j.cell.2018.02.044","article-title":"The Human Gut Microbiome: From Association to Modulation","volume":"172","author":"Schmidt","year":"2018","journal-title":"Cell"},{"key":"B177","doi-asserted-by":"publisher","first-page":"89","DOI":"10.1093\/icb\/icaa026","article-title":"The Promises and the Challenges of Integrating Multi-Omics and Systems Biology in Comparative Stress Biology","volume":"60","author":"Schwartz","year":"2020","journal-title":"Integr. Comp. Biol."},{"key":"B178","doi-asserted-by":"publisher","first-page":"1440","DOI":"10.1038\/nn.3839","article-title":"Putting Big Data to Good Use in Neuroscience","volume":"17","author":"Sejnowski","year":"2014","journal-title":"Nat. Neurosci."},{"key":"B179","volume-title":"The Stress of Life","author":"Selye","year":"1976"},{"key":"B181","doi-asserted-by":"publisher","first-page":"603","DOI":"10.1111\/acel.12486","article-title":"Does Skeletal Muscle Have an 'epi'\u2010memory? the Role of Epigenetics in Nutritional Programming, Metabolic Disease, Aging and Exercise","volume":"15","author":"Sharples","year":"2016","journal-title":"Aging Cell"},{"key":"B182","doi-asserted-by":"publisher","first-page":"148","DOI":"10.1002\/9780470513361.ch9","article-title":"Adrenergic and Serotonergic Receptor Responsiveness in Depression","volume":"123","author":"Siever","year":"1986","journal-title":"Ciba Found. Symp."},{"key":"B183","doi-asserted-by":"publisher","first-page":"270","DOI":"10.1519\/jsc.0000000000003103","article-title":"Effects of Physical Exercise on the Expression of MicroRNAs: A Systematic Review","volume":"34","author":"Silva","year":"2020","journal-title":"J. Strength Cond Res."},{"key":"B184","doi-asserted-by":"publisher","first-page":"31","DOI":"10.1159\/000448957","article-title":"Gut Microbiota, Bacterial Translocation, and Interactions with Diet: Pathophysiological Links between Major Depressive Disorder and Non-communicable Medical Comorbidities","volume":"86","author":"Slyepchenko","year":"2017","journal-title":"Psychother Psychosom"},{"key":"B185","doi-asserted-by":"publisher","first-page":"317","DOI":"10.1097\/00005768-200002000-00011","article-title":"Cytokine Hypothesis of Overtraining: a Physiological Adaptation to Excessive Stress?","volume":"32","author":"Smith","year":"2000","journal-title":"Med. Sci. Sports Exerc."},{"key":"B186","doi-asserted-by":"publisher","first-page":"29","DOI":"10.1055\/s-2007-1021141","article-title":"A Physiological\/psychological Indicator of Over-reaching during Intensive Training","volume":"14","author":"Snyder","year":"1993","journal-title":"Int. J. Sports Med."},{"key":"B187","doi-asserted-by":"publisher","first-page":"1063","DOI":"10.1249\/00005768-199507000-00016","article-title":"Overtraining Following Intensified Training with normal Muscle Glycogen","volume":"27","author":"Snyder","year":"1995","journal-title":"Med. Sci. Sports Exerc."},{"key":"B188","doi-asserted-by":"publisher","first-page":"135","DOI":"10.1016\/j.neuroscience.2011.12.014","article-title":"Deletion of Forebrain Glucocorticoid Receptors Impairs Neuroendocrine Stress Responses and Induces Depression-like Behavior in Males but Not Females","volume":"203","author":"Solomon","year":"2012","journal-title":"Neuroscience"},{"key":"B189","doi-asserted-by":"publisher","first-page":"418","DOI":"10.1016\/j.tics.2004.07.008","article-title":"Organization, Development and Function of Complex Brain Networks","volume":"8","author":"Sporns","year":"2004","journal-title":"Trends Cogn. Sci."},{"key":"B190","doi-asserted-by":"publisher","first-page":"382","DOI":"10.1007\/s00421-003-0960-x","article-title":"New Aspects of the Hormone and Cytokine Response to Training","volume":"91","author":"Steinacker","year":"2004","journal-title":"Eur. J. Appl. Physiol."},{"key":"B191","doi-asserted-by":"publisher","first-page":"2251","DOI":"10.1007\/s40279-021-01491-0","article-title":"Overtraining Syndrome (OTS) and Relative Energy Deficiency in Sport (RED-S): Shared Pathways, Symptoms and Complexities","volume":"51","author":"Stellingwerff","year":"2021","journal-title":"Sports Med."},{"key":"B192","doi-asserted-by":"publisher","first-page":"35","DOI":"10.1519\/00124278-199102000-00006","article-title":"Overtraining: A Review of the Signs, Symptoms and Possible Causes","volume":"5","author":"Stone","year":"1991","journal-title":"J. Strength Conditioning Res."},{"key":"B193","doi-asserted-by":"publisher","first-page":"147","DOI":"10.1016\/bs.adgen.2015.11.004","article-title":"Integrative Analysis of Multi-Omics Data for Discovery and Functional Studies of Complex Human Diseases","volume":"93","author":"Sun","year":"2016","journal-title":"Adv. Genet."},{"key":"B194","doi-asserted-by":"publisher","first-page":"270","DOI":"10.1055\/s-2007-972632","article-title":"Changes in Plasma Tryptophan\/branched Chain Amino Acid Ratio in Responses to Training Volume Variation","volume":"18","author":"Tanaka","year":"1997","journal-title":"Int. J. Sports Med."},{"key":"B195","doi-asserted-by":"publisher","first-page":"153","DOI":"10.1249\/00003677-197900070-00007","article-title":"Endocrine Response to Exercise","volume":"7","author":"Terjung","year":"1979","journal-title":"Exerc. Sport Sci. Rev."},{"key":"B196","first-page":"84","article-title":"Exercise and Immune System as Modulators of Intestinal Microbiome: Implications for the Gut-Muscle axis Hypothesis","volume":"25","author":"Ticinesi","year":"2019","journal-title":"Exerc. Immunol. Rev."},{"key":"B197","doi-asserted-by":"publisher","first-page":"6ra14","DOI":"10.1126\/scitranslmed.3000322","article-title":"The Effect of Diet on the Human Gut Microbiome: a Metagenomic Analysis in Humanized Gnotobiotic Mice","volume":"1","author":"Turnbaugh","year":"2009","journal-title":"Sci. Transl Med."},{"key":"B198","doi-asserted-by":"publisher","first-page":"804","DOI":"10.1038\/nature06244","article-title":"The Human Microbiome Project","volume":"449","author":"Turnbaugh","year":"2007","journal-title":"Nature"},{"key":"B199","doi-asserted-by":"publisher","first-page":"407","DOI":"10.1097\/00005768-199803000-00011","article-title":"Impaired Pituitary Hormonal Response to Exhaustive Exercise in Overtrained Endurance Athletes","volume":"30","author":"Urhausen","year":"1998","journal-title":"Med. Sci. Sports Exerc."},{"key":"B200","doi-asserted-by":"publisher","first-page":"251","DOI":"10.2165\/00007256-199520040-00004","article-title":"Blood Hormones as Markers of Training Stress and Overtraining","volume":"20","author":"Urhausen","year":"1995","journal-title":"Sports Med."},{"key":"B201","doi-asserted-by":"publisher","first-page":"95","DOI":"10.2165\/00007256-200232020-00002","article-title":"Diagnosis of Overtraining","volume":"32","author":"Urhausen","year":"2002","journal-title":"Sports Med."},{"key":"B180","first-page":"1","volume-title":"Depression Is a Treatable Illness","year":"1993"},{"key":"B202","doi-asserted-by":"publisher","first-page":"178","DOI":"10.1097\/00042752-199807000-00004","article-title":"Hormonal Responses to Endurance Training and Overtraining in Female Athletes","volume":"8","author":"Uusitalo","year":"1998","journal-title":"Clin. J. Sport Med."},{"key":"B203","doi-asserted-by":"publisher","first-page":"49","DOI":"10.1519\/0744-0049(1992)014<0074:troaei>2.3.co;2","article-title":"EXERCISE PHYSIOLOGY CORNER: The Role of Anaerobic Exercise in Overtraining","volume":"14","author":"van Borselen","year":"1992","journal-title":"Strength Conditioning J."},{"key":"B204","doi-asserted-by":"publisher","first-page":"235","DOI":"10.1038\/s41398-020-00920-4","article-title":"Basal and LPS-Stimulated Inflammatory Markers and the Course of Individual Symptoms of Depression","volume":"10","author":"van Eeden","year":"2020","journal-title":"Transl Psychiatry"},{"key":"B205","first-page":"379","article-title":"Effect of Four Weeks of Hard Physical Training on Certain Physiological and Morphological Parameters of Basket-ball Players","volume":"18","author":"Verma","year":"1978","journal-title":"J. Sports Med. Phys. Fitness"},{"key":"B206","doi-asserted-by":"publisher","first-page":"23","DOI":"10.1126\/science.111.2872.23","article-title":"The Theory of Open Systems in Physics and Biology","volume":"111","author":"Von Bertalanffy","year":"1950","journal-title":"Science"},{"key":"B207","doi-asserted-by":"publisher","first-page":"775","DOI":"10.1037\/h0077698","article-title":"Differences in Food, Water, and Food-Deprivation Water Intake in 16 Strains of Rats","volume":"94","author":"Walsh","year":"1980","journal-title":"J. Comp. Physiol. Psychol."},{"key":"B208","doi-asserted-by":"publisher","first-page":"509","DOI":"10.1007\/s40279-019-01070-4","article-title":"Physical Exercise and Epigenetic Modifications in Skeletal Muscle","volume":"49","author":"Widmann","year":"2019","journal-title":"Sports Med."},{"key":"B209","doi-asserted-by":"publisher","first-page":"274","DOI":"10.1038\/s42255-021-00348-0","article-title":"Gut Microbiome Pattern Reflects Healthy Ageing and Predicts Survival in Humans","volume":"3","author":"Wilmanski","year":"2021","journal-title":"Nat. Metab."},{"key":"B210","first-page":"80","article-title":"A Time to Reflect","volume-title":"Runners World","author":"Wischnia","year":""},{"key":"B211","first-page":"76","article-title":"Comeback at Comrades","volume-title":"Runners World","author":"Wischnia","year":""},{"key":"B212","doi-asserted-by":"publisher","first-page":"1015","DOI":"10.1097\/00005768-199608000-00011","article-title":"Adaptation of the Hypothalamopituitary Adrenal axis to Chronic Exercise Stress in Humans","volume":"28","author":"Wittert","year":"1996","journal-title":"Med. Sci. Sports Exerc."},{"key":"B213","first-page":"33","article-title":"Ein beitrag zur frage des \u0215bertrainings","volume":"2","author":"Wolf","year":"1957","journal-title":"Sportmedizin"},{"key":"B214","doi-asserted-by":"publisher","first-page":"105","DOI":"10.1126\/science.1208344","article-title":"Linking Long-Term Dietary Patterns with Gut Microbial Enterotypes","volume":"334","author":"Wu","year":"2011","journal-title":"Science"},{"key":"B215","doi-asserted-by":"publisher","first-page":"683","DOI":"10.3389\/fcell.2020.00683","article-title":"Severity Detection for the Coronavirus Disease 2019 (COVID-19) Patients Using a Machine Learning Model Based on the Blood and Urine Tests","volume":"8","author":"Yao","year":"2020","journal-title":"Front. Cel Dev. Biol."},{"key":"B216","doi-asserted-by":"publisher","first-page":"1541","DOI":"10.1111\/sms.13060","article-title":"Influence of Excessive Exercise on Immunity, Metabolism, and Gut Microbial Diversity in an Overtraining Mice Model","volume":"28","author":"Yuan","year":"2018","journal-title":"Scand. J. Med. Sci. Sports"},{"key":"B217","doi-asserted-by":"publisher","first-page":"276","DOI":"10.1016\/j.tibtech.2015.12.013","article-title":"Trans-Omics: How to Reconstruct Biochemical Networks across Multiple 'Omic' Layers","volume":"34","author":"Yugi","year":"2016","journal-title":"Trends Biotechnol."},{"key":"B218","doi-asserted-by":"publisher","first-page":"121","DOI":"10.1002\/1520-6629(198304)11:2<121:aid-jcop2290110206>3.0.co;2-v","article-title":"Life Events and Perceptions of Life Quality: Developments in a Two-Factor Approach","volume":"11","author":"Zautra","year":"1983","journal-title":"J. Community Psychol."},{"key":"B219","doi-asserted-by":"publisher","first-page":"722","DOI":"10.1016\/j.pnpbp.2010.04.011","article-title":"Glucocorticoids, Cytokines and Brain Abnormalities in Depression","volume":"35","author":"Zunszain","year":"2011","journal-title":"Prog. Neuro-Psychopharmacology Biol. Psychiatry"}],"container-title":["Frontiers in Network Physiology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fnetp.2021.794392\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,1,18]],"date-time":"2022-01-18T05:10:03Z","timestamp":1642482603000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fnetp.2021.794392\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,1,18]]},"references-count":219,"alternative-id":["10.3389\/fnetp.2021.794392"],"URL":"https:\/\/doi.org\/10.3389\/fnetp.2021.794392","relation":{},"ISSN":["2674-0109"],"issn-type":[{"value":"2674-0109","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,1,18]]},"article-number":"794392"}}