{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T04:17:41Z","timestamp":1790914661845,"version":"4.1.0"},"reference-count":44,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,2,17]],"date-time":"2026-02-17T00:00:00Z","timestamp":1771286400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Background\/Objectives: The aim of this study was to compare the different forms of caffeine (CAF) administration in CrossFit\u00ae participants. The countermovement jump (CMJ), the rate of perceived exertion (RPE), the total number of repetitions, and the maximum (HRmax) and mean heart rate (HRmean) were evaluated. Methods: Fourteen males with more than six months of continuous CrossFit\u00ae training (30.9 [5.62] years, 179 [1.33] cm, 78 [5.75] kg, 24.3 [1.33] kg\u00b7m\u22122) participated in this randomized, placebo-controlled, crossover study. Participants were randomized in a repeated measures design using caffeine capsule (CC), caffeine chewing gum (CCG), and caffeine mouth rinse (CMR) protocols, along with a placebo group (PG). Participants were unaware of whether any of the delivery methods contained caffeine. A 7-day washout period before each crossover was used. To ensure ecological validity, we replicated the real-world practice of CAF ingestion 30 min prior to training, mirroring typical athlete pre-workout routines. The participants of CrossFit\u00ae performed the \u2018Cindy\u2019 protocol, and the CMJ as a primary outcome was measured pre- and post-intervention, while the RPE, HR, and the number of repetitions were tracked at the end of the workout for comparisons. Results: No significant differences were found between CAF forms in internal load measures (RPE, HRmax, HRmean) or the number of repetitions. While no changes were observed with other CAF forms, CMR significantly improved the CMJ performance compared to the baseline (\u0394: +3.5; Cohen\u2019s dunb: 0.51], which exceeded the estimated SWC by approximately three-fold. However, the inferential analysis revealed no significant main effects of the caffeine administration method on any measured outcomes. Conclusions: While CAF delivery forms did not improve internal load measures or performance parameters, such as the RPE, HR, or the total number of repetitions, the caffeine mouth rinse (CMR) showed a potentially meaningful improvement in CMJ performance after CrossFit\u00ae training in participants with a certain level of experience.<\/jats:p>","DOI":"10.3390\/nu18040657","type":"journal-article","created":{"date-parts":[[2026,2,17]],"date-time":"2026-02-17T09:22:46Z","timestamp":1771320166000},"page":"657","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Comparing Acute Effects of Caffeine Delivery Forms on Cross-Training Performance: A Randomized Placebo-Controlled Crossover Trial"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6775-9159","authenticated-orcid":false,"given":"Salvador","family":"Vargas-Molina","sequence":"first","affiliation":[{"name":"Department of Human Physiology, Physical Education and Sport, Faculty of Medicine, University of Malaga, 29010 Malaga, Spain"},{"name":"Research Group in Sports Nutrition (DBSS-Nut), Dynamical Business & Science Society\u2014DBSS International SAS, Bogot\u00e1 110311, Colombia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2634-1220","authenticated-orcid":false,"given":"Diego A.","family":"Bonilla","sequence":"additional","affiliation":[{"name":"Research Group in Sports Nutrition (DBSS-Nut), Dynamical Business & Science Society\u2014DBSS International SAS, Bogot\u00e1 110311, Colombia"},{"name":"Hologenomiks Research Group, Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country (UPV\/EHU), 48940 Leioa, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3022-9151","authenticated-orcid":false,"given":"Manuel","family":"Garc\u00eda-Sillero","sequence":"additional","affiliation":[{"name":"Department of Human Physiology, Physical Education and Sport, Faculty of Medicine, University of Malaga, 29010 Malaga, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sergio","family":"Iglesias-Placed","sequence":"additional","affiliation":[{"name":"EADE, Trinity Saint David, C\/Miguel Sel G\u00f3mez de la Cruz, 2, 29018 Malaga, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6482-192X","authenticated-orcid":false,"given":"Mora","family":"Murri","sequence":"additional","affiliation":[{"name":"Instituto de Investigaci\u00f3n Biom\u00e9dica de M\u00e1laga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, 29590 Malaga, Spain"},{"name":"Cardiology and Cardiovascular Surgery Clinical Management Unit (UGC), Virgen de la Victoria University Hospital, Campus de Teatinos s\/n, 29010 Malaga, Spain"},{"name":"Endocrinology and Nutrition UGC, Victoria Virgen University Hospital, 29010 Malaga, Spain"},{"name":"CIBER Physiopathology of Obesity and Nutrition (CIBEROBN), Carlos III Health Institute, 28029 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1996-8276","authenticated-orcid":false,"given":"Fernando","family":"Mart\u00edn-Rivera","sequence":"additional","affiliation":[{"name":"Research Unit in Sports and Health, University of Valencia, Gasc\u00f3 Oliag, 3, 346010 Valencia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7546-7965","authenticated-orcid":false,"given":"Javier","family":"Ben\u00edtez-Porres","sequence":"additional","affiliation":[{"name":"Department of Human Physiology, Physical Education and Sport, Faculty of Medicine, University of Malaga, 29010 Malaga, Spain"},{"name":"Instituto de Investigaci\u00f3n Biom\u00e9dica de M\u00e1laga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, 29590 Malaga, Spain"},{"name":"CIBER Physiopathology of Obesity and Nutrition (CIBEROBN), Carlos III Health Institute, 28029 Madrid, Spain"},{"name":"Internal Medicine Clinical Management Unit (UGC), Hospital Regional Universitario de Malaga, 29010 Malaga, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/s12970-020-00383-4","article-title":"International society of sports nutrition position stand: Caffeine and exercise performance","volume":"18","author":"Guest","year":"2021","journal-title":"J. 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