{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T09:25:39Z","timestamp":1777541139798,"version":"3.51.4"},"reference-count":57,"publisher":"Wiley","issue":"16","license":[{"start":{"date-parts":[[2023,8,21]],"date-time":"2023-08-21T00:00:00Z","timestamp":1692576000000},"content-version":"vor","delay-in-days":20,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["physoc.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Physiological Reports"],"published-print":{"date-parts":[[2023,8]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Introduction<\/jats:title><jats:p>Consuming intracellular osmolytes, like betaine (BET), may attenuate symptoms of heat stress. The purpose of this study was to examine the effects of BET supplementation on fluid balance and heat tolerance after a 7\u2010day loading period and during passive heat exposure.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>A double\u2010blind, placebo controlled, crossover study compared BET or placebo consumption (50\u2009mg\u00b7kg<jats:sup>\u22121<\/jats:sup>, twice daily) for 7\u2009days in young, recreationally active men (N\u2009=\u200911).<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>During the loading period, no significant interactions were found for any marker of fluid balance between or within conditions. During heat exposure, significant time effects but no condition x time interactions, were found for plasma characteristics (i.e., volume, osmolality, sodium, albumin, and total protein). Plasma volume was significantly increased by min 30 in both conditions (PLA: +6.9. \u00b1\u20095.0%, BET: +10.2\u2009\u00b1\u20097.4%) and remained elevated for the remainder of the experimental trial, but was not significantly different between conditions. After 60\u2009min of passive heat exposure, both conditions experienced a similar increase in core temperature (PLA: +0.32\u2009\u00b1\u20090.22\u00b0C, BET: +0.31\u2009\u00b1\u20090.21\u00b0C; <jats:italic>p<\/jats:italic>\u2009=\u20090.912).<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>Supplemental BET did not improve markers of fluid balance or heat tolerance during 7\u2009days of loading or during passive heat exposure.<\/jats:p><\/jats:sec>","DOI":"10.14814\/phy2.15792","type":"journal-article","created":{"date-parts":[[2023,8,22]],"date-time":"2023-08-22T05:47:10Z","timestamp":1692683230000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["The effects of betaine supplementation on fluid balance and heat tolerance during passive heat stress in men"],"prefix":"10.14814","volume":"11","author":[{"given":"Brandon D.","family":"Willingham","sequence":"first","affiliation":[{"name":"Department of Kinesiology Coastal Carolina University  Conway South Carolina USA"},{"name":"Institute of Sports Sciences &amp; Medicine, Nutrition, and Integrative Physiology Florida State University  Florida USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3721-1085","authenticated-orcid":false,"given":"Liliana I.","family":"Renter\u00eda","sequence":"additional","affiliation":[{"name":"Institute of Sports Sciences &amp; Medicine, Nutrition, and Integrative Physiology Florida State University  Florida USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8741-2782","authenticated-orcid":false,"given":"Tristan J.","family":"Ragland","sequence":"additional","affiliation":[{"name":"Institute of Sports Sciences &amp; Medicine, Nutrition, and Integrative Physiology Florida State University  Florida USA"},{"name":"Department of Kinesiology and Health Rutgers University  New Brunswick New Jersey USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1939-7656","authenticated-orcid":false,"given":"Michael J.","family":"Ormsbee","sequence":"additional","affiliation":[{"name":"Institute of Sports Sciences &amp; Medicine, Nutrition, and Integrative Physiology Florida State University  Florida USA"},{"name":"Discipline of Biokinetics, Exercise, and Leisure Sciences University of KwaZulu\u2010Natal  Durban South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2023,8,21]]},"reference":[{"key":"e_1_2_11_2_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.2001.013395"},{"key":"e_1_2_11_3_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.2003.058412"},{"key":"e_1_2_11_4_1","doi-asserted-by":"publisher","DOI":"10.1001\/archinte.167.20.ioi70147"},{"key":"e_1_2_11_5_1","doi-asserted-by":"publisher","DOI":"10.1519\/JSC.0b013e31816a6efb"},{"key":"e_1_2_11_6_1","doi-asserted-by":"publisher","DOI":"10.1123\/ijsn.4.3.265"},{"key":"e_1_2_11_7_1","doi-asserted-by":"publisher","DOI":"10.1007\/s11250-008-9256-9"},{"key":"e_1_2_11_8_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0091831"},{"key":"e_1_2_11_9_1","first-page":"1","article-title":"Deaths attributed to heat, cold, and other weather events in the United States, 2006\u20132010","author":"Berko J.","year":"2014","journal-title":"National Health Statistical Report"},{"key":"e_1_2_11_10_1","first-page":"65","article-title":"Protein thermal stabilization in aqueous solutions of osmolytes","volume":"63","author":"Bruzd\u017aiak P.","year":"2016","journal-title":"Acta Biochimica Polonica"},{"key":"e_1_2_11_11_1","doi-asserted-by":"publisher","DOI":"10.1123\/ijsnem.2014-0138"},{"key":"e_1_2_11_12_1","doi-asserted-by":"publisher","DOI":"10.1007\/s004840050056"},{"key":"e_1_2_11_13_1","doi-asserted-by":"publisher","DOI":"10.1186\/s12970-018-0243-x"},{"key":"e_1_2_11_14_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.autneu.2016.03.001"},{"key":"e_1_2_11_15_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.gene.2015.09.031"},{"key":"e_1_2_11_16_1","doi-asserted-by":"publisher","DOI":"10.3390\/ani6090051"},{"key":"e_1_2_11_17_1","doi-asserted-by":"publisher","DOI":"10.1152\/jappl.1974.37.2.247"},{"key":"e_1_2_11_18_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jtherbio.2018.06.006"},{"key":"e_1_2_11_19_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijbiomac.2012.07.026"},{"key":"e_1_2_11_20_1","volume-title":"Comprehensive physiology","author":"Gagge A. 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