{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T15:17:05Z","timestamp":1783437425977,"version":"3.54.6"},"reference-count":36,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T00:00:00Z","timestamp":1783382400000},"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. Nutr."],"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Competitive freediving involves repeated voluntary breath-holding, during which hypoxic events such as loss of motor control (LMC) or blackout (BO) may occur. Although nutrition may influence metabolic responses to hypoxia, evidence in competitive freedivers remains limited. This study aimed to investigate the relationship between dietary habits and self-reported hypoxic events in Spanish competitive freedivers.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>A cross-sectional study was conducted in 71 competitive freedivers (19 women: 39.4\u202f\u00b1\u202f9.3\u202fyears; 52 men: 41.9\u202f\u00b1\u202f8.6\u202fyears). Participants completed a questionnaire on training characteristics and hypoxic events. Events were classified as LMC or BO, and participants were categorized according to the most severe event experienced. Dietary habits were assessed using a validated food frequency questionnaire (PREDIMED). Associations were examined using chi-square or Fisher\u2019s exact tests, and significant variables were included in a binomial logistic regression adjusted for age, sex, and years of practice.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Overall, participants showed moderate consumption across dietary groups, with higher intake of fruits, vegetables, and protein-rich foods; and low intake of ultra-processed foods and alcohol. Male divers consumed moderate amounts of protein-rich foods, whereas female counterparts reported lower intake [\n                      <jats:italic>\n                        \u03c7\n                        <jats:sup>2<\/jats:sup>\n                      <\/jats:italic>\n                      (2)\u202f=\u202f8.53,\n                      <jats:italic>p<\/jats:italic>\n                      \u202f=\u202f0.014; Fisher\u2019s exact test,\n                      <jats:italic>p<\/jats:italic>\n                      \u202f=\u202f0.010]. Overall, 21 freedivers (29.6%) reported at least one hypoxic event. The occurrence of hypoxic events were associated with years of practice (\n                      <jats:italic>p<\/jats:italic>\n                      \u202f=\u202f0.003) and consumption of stimulant beverages (\n                      <jats:italic>p<\/jats:italic>\n                      \u202f=\u202f0.013). Beginners experienced fewer events than expected, whereas divers with &amp;gt;4 to 10\u202fyears of practice were overrepresented. In the adjusted model, years of practice remained significantly associated with hypoxic events [OR\u202f=\u202f3.06, 95% CI (1.43, 6.53),\n                      <jats:italic>p<\/jats:italic>\n                      \u202f=\u202f0.004]. Moderate stimulant beverage consumption emerged as a potential associated factor [OR\u202f=\u202f12.54, 95% CI (1.27, 123.9),\n                      <jats:italic>p<\/jats:italic>\n                      \u202f=\u202f0.031].\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Hypoxic events in competitive freedivers were primarily associated with years of practice, suggesting that cumulative exposure may be a relevant risk factor. Overall dietary habits showed no clear relationship with hypoxic events, although stimulant beverage consumption may warrant further investigation.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fnut.2026.1849515","type":"journal-article","created":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T15:03:41Z","timestamp":1783436621000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Dietary habits and self-reported hypoxic events in competitive freedivers: an observational study"],"prefix":"10.3389","volume":"13","author":[{"given":"Jordi","family":"Sarola-Gassiot","sequence":"first","affiliation":[{"name":"National Institute of Physical Education of Catalonia (INEFC), University of Barcelona (UB)","place":["Barcelona, Spain"]},{"name":"Health Department, Fundaci\u00f3 TecnoCampus Matar\u00f3-Maresme, Research Group in Hypoxia, Dietetics, Nutrition and Kinanthropometry (ReGHyDiNuK), Matar\u00f3","place":["Barcelona, Spain"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alfredo","family":"Irurtia","sequence":"additional","affiliation":[{"name":"National Institute of Physical Education of Catalonia (INEFC), University of Barcelona (UB)","place":["Barcelona, Spain"]},{"name":"INEFC-Barcelona Research Group on Sport Sciences (GRCEIB), National Institute of Physical Education of Catalonia (INEFC), University of Barcelona (UB)","place":["Barcelona, Spain"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ishar","family":"Dalmau-Santamaria","sequence":"additional","affiliation":[{"name":"Health Department, Fundaci\u00f3 TecnoCampus Matar\u00f3-Maresme, Research Group in Hypoxia, Dietetics, Nutrition and Kinanthropometry (ReGHyDiNuK), Matar\u00f3","place":["Barcelona, Spain"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lara","family":"Rodr\u00edguez-Zamora","sequence":"additional","affiliation":[{"name":"School of Health and Medical Sciences, Division of Sport Sciences, \u00d6rebro University","place":["\u00d6rebro, Sweden"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,7,7]]},"reference":[{"key":"ref1","first-page":"88","article-title":"Predicting performance in competitive apnoea diving. Part I: static apnoea","volume":"39","author":"Schagatay","year":"2009","journal-title":"Diving Hyperb Med"},{"key":"ref2","first-page":"11","article-title":"Predicting performance in competitive apnea diving. Part II: dynamic apnea","volume":"40","author":"Schagatay","year":"2010","journal-title":"Diving Hyperb Med"},{"key":"ref3","first-page":"216","article-title":"Predicting performance in competitive apnea diving. Part III: deep diving","volume":"41","author":"Schagatay","year":"2011","journal-title":"Diving Hyperb Med"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"160","DOI":"10.1080\/13854040590947407","article-title":"Apnea diving: long-term neurocognitive sequelae of repeated hypoxemia","volume":"20","author":"Ridgway","year":"2006","journal-title":"Clin Neuropsychol"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"951","DOI":"10.1152\/japplphysiol.00708.2022","article-title":"Case studies in physiology: is blackout in breath-hold diving related to cardiac arrhythmias?","volume":"134","author":"Mulder","year":"1985","journal-title":"J Appl Physiol (1985)"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"100060","DOI":"10.1016\/j.jphyss.2026.100060","article-title":"Hypoxic blackout in dynamic apnea: a case report","volume":"76","author":"Mulder","year":"2026","journal-title":"J Physiol Sci"},{"key":"ref7","first-page":"55","article-title":"Adverse events in competitive breath-hold diving","volume":"33","author":"Fitz-Clarke","year":"2006","journal-title":"Undersea Hyperb Med"},{"key":"ref8","doi-asserted-by":"publisher","first-page":"295","DOI":"10.1055\/s-2006-924361","article-title":"Loss of motor control and\/or loss of consciousness during breath-hold competitions","volume":"28","author":"Lindholm","year":"2007","journal-title":"Int J Sports Med"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"S157","DOI":"10.1080\/17461391.2012.664172","article-title":"Fasting improves static apnea performance in elite divers without enhanced risk of syncope","volume":"14","author":"Schagatay","year":"2012","journal-title":"Eur J Sport Sci"},{"key":"ref10","doi-asserted-by":"publisher","first-page":"53","DOI":"10.1016\/j.resp.2012.05.007","article-title":"Acute dietary nitrate supplementation improves dry static apnea performance","volume":"182","author":"Engan","year":"2012","journal-title":"Respir Physiol 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breath-hold divers","volume":"15","author":"Drvi\u0161","year":"2025","journal-title":"Appl Sci"},{"key":"ref15","doi-asserted-by":"publisher","first-page":"e34","DOI":"10.1056\/NEJMoa1800389","article-title":"Primary prevention of cardiovascular disease with a Mediterranean diet supplemented with extra-virgin olive oil or nuts","volume":"378","author":"Estruch","year":"2018","journal-title":"N Engl J Med"},{"key":"ref16","doi-asserted-by":"publisher","first-page":"5191","DOI":"10.3892\/ijmm.2022.5191","article-title":"The impact of diet upon mitochondrial physiology (review)","volume":"50","author":"Kyriazis","year":"2022","journal-title":"Int J Mol Med"},{"key":"ref17","doi-asserted-by":"publisher","first-page":"1270","DOI":"10.1042\/bst0311270","article-title":"Modulation of carbohydrate and fat utilization by diet, exercise and environment","volume":"31","author":"Jeukendrup","year":"2003","journal-title":"Biochem Soc 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Epidemiol"},{"key":"ref21","doi-asserted-by":"publisher","first-page":"8","DOI":"10.1186\/1550-2783-4-8","article-title":"International Society of Sports Nutrition position stand: protein and exercise","volume":"4","author":"Campbell","year":"2007","journal-title":"J Int Soc Sports Nutr"},{"key":"ref22","doi-asserted-by":"publisher","first-page":"1204","DOI":"10.1152\/japplphysiol.00103.2014","article-title":"The role of muscle mass in exercise-induced hyperemia","volume":"116","author":"Garten","year":"1985","journal-title":"J Appl Physiol (1985)"},{"key":"ref23","doi-asserted-by":"publisher","first-page":"2053","DOI":"10.1249\/mss.0000000000003731","article-title":"Energetics of underwater swimming in apnea","volume":"57","author":"Vinetti","year":"2025","journal-title":"Med Sci Sports Exerc"},{"key":"ref24","doi-asserted-by":"publisher","first-page":"887","DOI":"10.3390\/foods14050887","article-title":"Gender differences in protein consumption and body composition: the influence of 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Hypothesis and theory","volume":"15","author":"Pernett","year":"2025","journal-title":"Front Physiol"},{"key":"ref29","doi-asserted-by":"publisher","first-page":"103721","DOI":"10.1016\/j.resp.2021.103721","article-title":"Effects of sex differences on breath-hold diving performance","volume":"293","author":"Peng","year":"2021","journal-title":"Respir Physiol Neurobiol"},{"key":"ref30","doi-asserted-by":"publisher","first-page":"2483","DOI":"10.1007\/s00421-023-05250-z","article-title":"Unlocking the depths: multiple factors contribute to risk for hypoxic blackout during deep freediving","volume":"123","author":"Mulder","year":"2023","journal-title":"Eur J Appl Physiol"},{"key":"ref31","doi-asserted-by":"publisher","first-page":"125","DOI":"10.31459\/turkjkin.1263307","article-title":"Effect of caffeine on the cardiovascular system and performance: a systematic review","volume":"9","author":"Aksov\u0131\u0107","year":"2023","journal-title":"Turk J Kinesiol"},{"key":"ref32","doi-asserted-by":"publisher","first-page":"6","DOI":"10.1007\/BF02691277","article-title":"Mechanism of the human diving response","volume":"29","author":"Gooden","year":"1994","journal-title":"Integr Physiol Behav Sci"},{"key":"ref33","doi-asserted-by":"publisher","first-page":"537","DOI":"10.1007\/s00421-023-05295-0","article-title":"Caffeine intake enhances peak oxygen uptake and performance during high-intensity cycling exercise in moderate hypoxia","volume":"124","author":"Lei","year":"2024","journal-title":"Eur J Appl Physiol"},{"key":"ref34","doi-asserted-by":"publisher","first-page":"423","DOI":"10.1007\/s00213-009-1668-3","article-title":"A comparison of the effects of caffeine following abstinence and normal caffeine use","volume":"207","author":"Addicott","year":"2009","journal-title":"Psychopharmacology"},{"key":"ref35","doi-asserted-by":"publisher","first-page":"e4727","DOI":"10.1002\/nbm.4727","article-title":"Cerebral hemodynamic response to caffeine: effect of dietary caffeine consumption","volume":"35","author":"Peng","year":"2022","journal-title":"NMR Biomed"},{"key":"ref36","doi-asserted-by":"publisher","first-page":"31","DOI":"10.1093\/sleepadvances\/zpag031","article-title":"The effect of caffeinated beverage consumption on the relationship between sleep quality and major adverse cardiovascular events: sleep heart health study","volume":"7","author":"Varpaei","year":"2026","journal-title":"Sleep Adv"}],"container-title":["Frontiers in Nutrition"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fnut.2026.1849515\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T15:03:43Z","timestamp":1783436623000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fnut.2026.1849515\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,7]]},"references-count":36,"alternative-id":["10.3389\/fnut.2026.1849515"],"URL":"https:\/\/doi.org\/10.3389\/fnut.2026.1849515","relation":{},"ISSN":["2296-861X"],"issn-type":[{"value":"2296-861X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,7]]},"article-number":"1849515"}}