{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T19:22:14Z","timestamp":1790018534207,"version":"4.0.1"},"reference-count":35,"publisher":"Oxford University Press (OUP)","issue":"3-4","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,3,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Warfighters perform highly complex and dangerous combat missions are both physically and cognitively challenging. Meeting these physiological demands are regulated by the autonomic nervous system (ANS). Thus, continuously monitoring ANS activity during combat and training may critically inform military leadership of the current physiological state and ability of their warfighters to effectively execute mission tasks. The purpose of this study was to quantify ANS response throughout 540 minutes (9 hours) of aviation-related combat training drills performed in the UH-60 helicopter.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Materials and Methods<\/jats:title>\n                    <jats:p>Aircrew members recruited from the United States Army Aeromedical Research Laboratory participated in the current study. ANS function was measured using the Warfighter Monitor (WFM, Tiger Tech Solutions, Inc., Miami, FL, United States), an armband monitor equipped with electrocardiographic capabilities. Subjects wore the WFM on the upper arm throughout their 540-minute combat training which consisted of aviation-related tasks. The WFM continuously monitored heart rate (HR), HR variability (HRV), and respiration rate (RR). Two HRV time-domain metrics were calculated: SD of the NN interval (SDNN) and the root mean square of successive differences of NN intervals (rMSSD). Studentized t-tests were performed to evaluate within- and between-group differences in ANS activity.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Thirty-four healthy, aircrew members aged between 18 and 45 years and mostly male, participated in the current study. For pre-flight events, average HRs ranged between 76.1 and 91.2 bpm. On average, HRs increased between +10.2 and +12.9 bpm. HRV metrics were between 72.4 and 91.3 milliseconds for rMSSD and from 101.8\u2013139.9 ms for SDNN. RRs for aircrew members ranged between 12.4 and 13.5 breaths\/min and increased by +1.4 to +1.7 breaths\/min. For in-flight operations, significantly higher HRs (88.2\u2013100.2 bpm) were observed. Similarly, significantly different increases were reported (+14.7 to +26.4 bpm). HRV metrics were significantly lower (rMSSD: 62.8\u201383.7 milliseconds; SDNN: 93.8\u2013116.7 milliseconds). The average and increases in RRs were significantly higher, 12.8\u201317.3 breaths\/min and +1.5 to +4.2 breaths\/min.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Significant increases in sympathetic drive were observed in U.S. warfighter aircrew during combat mission training, reflected by higher HRs, RRs, and lower HRV. The magnitudes in the ANS response, however, differed between pre- and in-flight operations with the latter inducing a larger response, possibly attributed to greater physical and cognitive workloads. These observations may aid warfighters and military leadership in designing effective preparedness training and implementing immediate intervention for managing the heightened sympathetic drive while preventing negative outcomes.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/milmed\/usaf295","type":"journal-article","created":{"date-parts":[[2025,5,30]],"date-time":"2025-05-30T07:45:04Z","timestamp":1748591104000},"page":"e641-e647","source":"Crossref","is-referenced-by-count":1,"title":["Autonomic Nervous System Responses to Aviation Live-Fire Combat Training: An Effective Tool for Operator State Monitoring of United States Warfighter Aircrew"],"prefix":"10.1093","volume":"191","author":[{"given":"Harrison L","family":"Wittels","sequence":"first","affiliation":[{"name":"Tiger Tech Solutions, Inc , Miami Beach, FL 33140,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael Joseph","family":"Wishon","sequence":"additional","affiliation":[{"name":"Tiger Tech Solutions, Inc , Miami Beach, FL 33140,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hector","family":"Davilla","sequence":"additional","affiliation":[{"name":"Tiger Tech Solutions, Inc , Miami Beach, FL 33140,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7191-5086","authenticated-orcid":false,"given":"Samantha M","family":"McDonald","sequence":"additional","affiliation":[{"name":"Tiger Tech Solutions, Inc , Miami Beach, FL 33140,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leonard A","family":"Temme","sequence":"additional","affiliation":[{"name":"U.S. Army Aeromedical Research Laboratory , Fort Novosel, AL 36362,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S Howard","family":"Wittels","sequence":"additional","affiliation":[{"name":"Tiger Tech Solutions, Inc , Miami Beach, FL 33140,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2025,6,11]]},"reference":[{"key":"2026031018430038000_usaf295-B1","doi-asserted-by":"crossref","first-page":"e301","DOI":"10.1093\/milmed\/usab219","article-title":"Predictors of emotional distress in combat military flight engineers","volume":"188","author":"Cohen-Koren","year":"2023","journal-title":"Mil Med"},{"key":"2026031018430038000_usaf295-B2","doi-asserted-by":"crossref","first-page":"137","DOI":"10.17744\/mehc.31.2.161u820r2255t667","article-title":"Combat stress reactions during military deployments: evaluation of the effectiveness of combat stress control treatment","volume":"31","author":"Potter","year":"2009","journal-title":"J Ment Health Couns"},{"key":"2026031018430038000_usaf295-B3","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1016\/j.ijpsycho.2018.03.017","article-title":"Different profiles of decision making and physiology under varying levels of stress in trained military personnel","volume":"131","author":"Gamble","year":"2018","journal-title":"Int J Psychophysiol"},{"key":"2026031018430038000_usaf295-B4","doi-asserted-by":"crossref","first-page":"369","DOI":"10.1037\/a0032334","article-title":"Paradoxical effects of stress and an executive task on decisions under risk","volume":"127","author":"Pabst","year":"2013","journal-title":"Behav Neurosci"},{"key":"2026031018430038000_usaf295-B5","doi-asserted-by":"crossref","first-page":"796","DOI":"10.3357\/ASEM.2494.2009","article-title":"Heart rate and autonomic balance during stand tests before and after fighter combat missions","volume":"80","author":"Dussault","year":"2009","journal-title":"Aviat Space Environ Med"},{"key":"2026031018430038000_usaf295-B6","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1016\/j.physbeh.2018.11.006","article-title":"Psychophysiological response of air mobile protection teams in an air accident manoeuvre","volume":"199","author":"Horme\u00f1o-Holgado","year":"2019","journal-title":"Physiol Behav"},{"key":"2026031018430038000_usaf295-B7","volume-title":"Simulation in Aviation Training","author":"Bell","year":"2002"},{"key":"2026031018430038000_usaf295-B8","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1007\/s10111-013-0257-8","article-title":"Physiological measurement of anxiety to evaluate performance in simulation training","volume":"16","author":"Tichon","year":"2014","journal-title":"Cogn Technol Work"},{"key":"2026031018430038000_usaf295-B9","doi-asserted-by":"crossref","first-page":"103935","DOI":"10.1016\/j.apergo.2022.103935","article-title":"Overnight heart rate variability responses to military combat engineer training","volume":"107","author":"Corrigan","year":"2023","journal-title":"Appl Ergon"},{"key":"2026031018430038000_usaf295-B10","doi-asserted-by":"crossref","first-page":"583336","DOI":"10.3389\/fpubh.2020.583336","article-title":"Relationships between heart rate variability, occupational performance, and fitness for tactical personnel: a systematic review","volume":"8","author":"Tomes","year":"2020","journal-title":"Front Public Health"},{"key":"2026031018430038000_usaf295-B11","doi-asserted-by":"crossref","first-page":"172","DOI":"10.1136\/jramc-2019-001285","article-title":"Autonomic and cortical response of soldiers in different combat scenarios","volume":"167","author":"Tornero Aguilera","year":"2021","journal-title":"BMJ Mil Health"},{"key":"2026031018430038000_usaf295-B12","doi-asserted-by":"crossref","first-page":"925157","DOI":"10.3389\/fpsyg.2022.925157","article-title":"Effects of overnight military training and acute battle stress on the cognitive performance of soldiers in simulated urban combat","volume":"13","author":"Passi","year":"2022","journal-title":"Front Psychol"},{"key":"2026031018430038000_usaf295-B13","doi-asserted-by":"crossref","first-page":"1","DOI":"10.21236\/ADA478702","volume-title":"Predictability of Pilot Performance from Simulated to Real Flight in the UH-60 (Black Hawk) Helicopter.","author":"Schmeisser","year":"2008"},{"key":"2026031018430038000_usaf295-B14","volume-title":"Simulation in Aviation Training","author":"Dahlstrom Dekker","year":"2002"},{"key":"2026031018430038000_usaf295-B15","first-page":"1","volume-title":"Optimizing Simulator-Aircraft Mix for U.S. Army Initial Entry Rotary Wing Training","author":"Steward","year":"1999"},{"key":"2026031018430038000_usaf295-B16","first-page":"1","volume-title":"Attack Reconnaissance Helicopter Operations","author":"Department of the Army","year":"2007"},{"key":"2026031018430038000_usaf295-B17","doi-asserted-by":"crossref","first-page":"1398","DOI":"10.3390\/biology12111398","article-title":"Continuous physiological monitoring of the combined exposure to hypoxia and high cognitive load in military personnel","volume":"12","author":"Temme","year":"2023","journal-title":"Biology"},{"key":"2026031018430038000_usaf295-B18","doi-asserted-by":"crossref","first-page":"343","DOI":"10.3390\/biology13050343","article-title":"Examining the influence of cognitive load and environmental conditions on autonomic nervous system response in military aircrew: a hypoxia-normoxia study","volume":"13","author":"Wittels","year":"2024","journal-title":"Biology"},{"key":"2026031018430038000_usaf295-B19","doi-asserted-by":"crossref","first-page":"e73557","DOI":"10.1371\/journal.pone.0073557","article-title":"Fast QRS detection with an optimized knowledge-based method: evaluation on 11 standard ECG databases","volume":"8","author":"Elgendi","year":"2013","journal-title":"PLOS ONE"},{"key":"2026031018430038000_usaf295-B20","doi-asserted-by":"crossref","first-page":"20220012","DOI":"10.1098\/rsif.2022.0012","article-title":"Robustness of electrocardiogram signal quality indices","volume":"19","author":"Rahman","year":"2022","journal-title":"J R Soc Interface"},{"key":"2026031018430038000_usaf295-B21","doi-asserted-by":"crossref","first-page":"1043","DOI":"10.1161\/01.CIR.93.5.1043","article-title":"Heart rate variability","volume":"93","author":"Task Force of the European Society of Cardiology the North American Society of Pacing Electrophysiology","year":"1996","journal-title":"Circulation"},{"key":"2026031018430038000_usaf295-B22","doi-asserted-by":"crossref","first-page":"265","DOI":"10.3389\/fpubh.2017.00265","article-title":"Hidden signals-the history and methods of heart rate variability","volume":"5","author":"Ernst","year":"2017","journal-title":"Front Public Health"},{"key":"2026031018430038000_usaf295-B23","doi-asserted-by":"crossref","first-page":"258","DOI":"10.3389\/fpubh.2017.00258","article-title":"An overview of heart rate variability metrics and norms","volume":"5","author":"Shaffer","year":"2017","journal-title":"Front Public Health"},{"key":"2026031018430038000_usaf295-B24","doi-asserted-by":"crossref","first-page":"103746","DOI":"10.1016\/j.bspc.2022.103746","article-title":"Realtime PPG based respiration rate estimation for remote health monitoring applications","volume":"77","author":"Selvakumar","year":"2022","journal-title":"Biomed Signal Process Control"},{"key":"2026031018430038000_usaf295-B25","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1109\/RBME.2017.2763681","article-title":"Breathing rate estimation from the electrocardiogram and photoplethysmogram: a review","volume":"11","author":"Charlton","year":"2018","journal-title":"IEEE Rev Biomed Eng"},{"key":"2026031018430038000_usaf295-B26","doi-asserted-by":"crossref","first-page":"7986249","DOI":"10.1155\/2020\/7986249","article-title":"Effect of stress on autonomic and cardiovascular systems in military population: a systematic review","volume":"2020","author":"Bustamante-S\u00e1nchez","year":"2020","journal-title":"Cardiol Res Pract"},{"key":"2026031018430038000_usaf295-B27","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1007\/s10916-017-0748-x","article-title":"Effect of combat stress in the psychophysiological response of elite and non-elite soldiers","volume":"41","author":"Tornero-Aguilera","year":"2017","journal-title":"J Med Syst"},{"key":"2026031018430038000_usaf295-B28","doi-asserted-by":"crossref","first-page":"732","DOI":"10.1519\/JSC.0000000000003495","article-title":"Ready for combat, psychophysiological modifications in a close-quarter combat intervention after an experimental operative high-intensity interval training","volume":"36","author":"Tornero-Aguilera","year":"2022","journal-title":"J Strength Cond Res"},{"key":"2026031018430038000_usaf295-B29","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1002\/smi.2778","article-title":"Psychophysiological response to acute-high-stress combat situations in professional soldiers","volume":"34","author":"Clemente-Suarez","year":"2018","journal-title":"Stress Health"},{"key":"2026031018430038000_usaf295-B30","doi-asserted-by":"crossref","first-page":"583","DOI":"10.7205\/MILMED.169.8.583","article-title":"Analysis of heart rate variability after a ranger training course","volume":"169","author":"Jouanin","year":"2004","journal-title":"Mil Med"},{"key":"2026031018430038000_usaf295-B31","doi-asserted-by":"crossref","first-page":"82","DOI":"10.3390\/healthcare12010082","article-title":"Psychophysiological responses in soldiers during close combat: implications for occupational health and fitness in tactical populations","volume":"12","author":"Stergiou","year":"2023","journal-title":"Healthcare"},{"key":"2026031018430038000_usaf295-B32","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1007\/s10916-018-0922-9","article-title":"Assessment of psychophysiological response and specific fine motor skills in combat units","volume":"42","author":"S\u00e1nchez-Molina","year":"2018","journal-title":"J Med Syst"},{"key":"2026031018430038000_usaf295-B33","doi-asserted-by":"crossref","first-page":"1147","DOI":"10.1016\/j.jsams.2018.06.004","article-title":"Military applications of soldier physiological monitoring","volume":"21","author":"Friedl","year":"2018","journal-title":"J Sci Med Sport"},{"key":"2026031018430038000_usaf295-B34","doi-asserted-by":"crossref","first-page":"718","DOI":"10.3357\/AMHP.4468.2016","article-title":"Sustained military operations and cognitive performance","volume":"87","author":"Vrijkotte","year":"2016","journal-title":"Aerosp Med Hum Perform"},{"key":"2026031018430038000_usaf295-B35","doi-asserted-by":"crossref","first-page":"14767","DOI":"10.3390\/ijerph192214767","article-title":"Characterising psycho-physiological responses and relationships during a military field training exercise","volume":"19","author":"Bulmer","year":"2022","journal-title":"Int J Environ Res Public Health"}],"container-title":["Military Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/milmed\/article-pdf\/191\/3-4\/e641\/63483601\/usaf295.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/milmed\/article-pdf\/191\/3-4\/e641\/63483601\/usaf295.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,10]],"date-time":"2026-03-10T22:43:11Z","timestamp":1773182591000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/milmed\/article\/191\/3-4\/e641\/8161491"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,11]]},"references-count":35,"journal-issue":{"issue":"3-4","published-online":{"date-parts":[[2025,6,11]]},"published-print":{"date-parts":[[2026,3,1]]}},"URL":"https:\/\/doi.org\/10.1093\/milmed\/usaf295","relation":{},"ISSN":["0026-4075","1930-613X"],"issn-type":[{"value":"0026-4075","type":"print"},{"value":"1930-613X","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2026,3]]},"published":{"date-parts":[[2025,6,11]]}}}