{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T16:23:27Z","timestamp":1790267007969,"version":"4.1.0"},"reference-count":62,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2025,12,25]],"date-time":"2025-12-25T00:00:00Z","timestamp":1766620800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Life"],"abstract":"<jats:p>Caffeine is widely used to enhance cognitive performance, but its efficacy may vary with the administration route and circadian timing. This study compared the acute effects of caffeine capsule ingestion and caffeine mouth rinsing on cognitive performance across morning, midday, and evening sessions in well-trained, adolescent male volleyball players. Twenty-four athletes completed three randomized, double-blind, crossover trials involving a caffeine capsule (3 mg\u00b7kg\u22121), a caffeine mouth rinse of the same dose (expectorated), and a placebo. Cognitive performance was assessed using simple and choice reaction time tests and the Stroop task, alongside a side-effects questionnaire. Both caffeine forms improved performance versus the placebo, with the greatest enhancements occurring at midday and moderate benefits evident in the morning. Capsule ingestion produced the most consistent improvements across reaction speed and executive control, whereas mouth rinsing elicited smaller, task-dependent effects, particularly at midday. No consistent or practically relevant benefits were observed for either caffeine condition in the evening, when cognitive performance was naturally highest. Side effects were mild and infrequent, with occasional headaches after capsule ingestion. These findings indicate that caffeine capsules most effectively enhance cognitive performance when baseline alertness is suboptimal, while caffeine mouth rinsing represents a practical ingestion-free alternative with moderate efficacy.<\/jats:p>","DOI":"10.3390\/life16010033","type":"journal-article","created":{"date-parts":[[2025,12,26]],"date-time":"2025-12-26T00:50:21Z","timestamp":1766710221000},"page":"33","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Differential Time-of-Day Effects of Caffeine Capsule and Mouth Rinse on Cognitive Performance in Adolescent Male Volleyball Athletes: A Randomized Crossover Investigation"],"prefix":"10.3390","volume":"16","author":[{"given":"Salma Belhaj","family":"Amor","sequence":"first","affiliation":[{"name":"Physical Activity, Sport and Health Research Unit (UR18JS01), National Observatory of Sports, Tunis 1003, Tunisia"},{"name":"High Institute of Sports and Physical Education of El Kef, University of Jendouba, El Kef 7100, Tunisia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6221-546X","authenticated-orcid":false,"given":"Wissem","family":"Dhahbi","sequence":"additional","affiliation":[{"name":"Research Unit (UR22JS01) \u201cSport Sciences, Health and Movement\u201d, High Institute of Sport and Physical Education of Kef, University of Jendouba, El Kef 7100, Tunisia"},{"name":"Training Department, Police College, Qatar Police Academy, Doha 7157, Qatar"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-4587-533X","authenticated-orcid":false,"given":"Houda","family":"Bougrine","sequence":"additional","affiliation":[{"name":"Physical Activity, Sport and Health Research Unit (UR18JS01), National Observatory of Sports, Tunis 1003, Tunisia"},{"name":"High Institute of Sport and Physical Education of Gafsa, Gafsa University, Gafsa 2112, Tunisia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Manel","family":"Bessifi","sequence":"additional","affiliation":[{"name":"Research Unit (UR22JS01) \u201cSport Sciences, Health and Movement\u201d, High Institute of Sport and Physical Education of Kef, University of Jendouba, El Kef 7100, Tunisia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8488-1698","authenticated-orcid":false,"given":"Vlad Adrian","family":"Geant\u0103","sequence":"additional","affiliation":[{"name":"Department of Physical Education and Sport, Faculty of Physical Education and Sport, Aurel Vlaicu University of Arad, 310025 Arad, Romania"},{"name":"Doctoral School of Sport Science and Physical Education, Pite\u0219ti University Center, National University of Science and Technology Politehnica Bucharest, 110253 Pite\u0219ti, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2805-031X","authenticated-orcid":false,"given":"Vasile Emil","family":"Ursu","sequence":"additional","affiliation":[{"name":"Department of Physical Education and Sport, Faculty of Law and Social Sciences, University \u201c1 Decembrie 1918\u201d of Alba Iulia, 510009 Alba Iulia, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5622-6995","authenticated-orcid":false,"given":"Khaled","family":"Trabelsi","sequence":"additional","affiliation":[{"name":"Research Laboratory Education, Motricit\u00e9, Sport et Sant\u00e9, EM2S, LR19JS01, High Institute of Sport and Physical Education of Sfax, University of Sfax, Sfax 3000, Tunisia"},{"name":"Department of Movement Sciences and Sports Training, School of Sport Science, The University of Jordan, Amman 28002, Jordan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1227-8221","authenticated-orcid":false,"given":"Nizar","family":"Souissi","sequence":"additional","affiliation":[{"name":"Physical Activity, Sport and Health Research Unit (UR18JS01), National Observatory of Sports, Tunis 1003, Tunisia"},{"name":"High Institute of Sport and Physical Education, University of Manouba, Ksar-Said, Mannouba 2010, Tunisia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,25]]},"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. Int. Soc. Sports Nutr."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1007","DOI":"10.1007\/s40279-019-01101-0","article-title":"Caffeine and Exercise: What Next?","volume":"49","author":"Pickering","year":"2019","journal-title":"Sports Med."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Lorenzo Calvo, J., Fei, X., Dom\u00ednguez, R., and Pareja-Galeano, H. (2021). Caffeine and Cognitive Functions in Sports: A Systematic Review and Meta-Analysis. Nutrients, 13.","DOI":"10.3390\/nu13030868"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1016\/S0031-6997(24)01396-6","article-title":"Actions of caffeine in the brain with special reference to factors that contribute to its widespread use","volume":"51","author":"Fredholm","year":"1999","journal-title":"Pharmacol. Rev."},{"key":"ref_5","first-page":"195","article-title":"A two process model of sleep regulation","volume":"1","year":"1982","journal-title":"Hum. Neurobiol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1984","DOI":"10.1519\/JSC.0b013e31825770a7","article-title":"The effect of training at a specific time of day: A review","volume":"26","author":"Chtourou","year":"2012","journal-title":"J. Strength. Cond. Res."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1016\/j.pbb.2019.01.001","article-title":"Effects of caffeine ingestion on the diurnal variation of cognitive and repeated high-intensity performances","volume":"177","author":"Souissi","year":"2019","journal-title":"Pharmacol. Biochem. Behav."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Bougrine, H., Ammar, A., Salem, A., Trabelsi, K., Jahrami, H., Chtourou, H., and Souissi, N. (2024). Optimizing Short-Term Maximal Exercise Performance: The Superior Efficacy of a 6 mg\/kg Caffeine Dose over 3 or 9 mg\/kg in Young Female Team-Sports Athletes. Nutrients, 16.","DOI":"10.3390\/nu16050640"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Bougrine, H., Nasser, N., Abdessalem, R., Ammar, A., Chtourou, H., and Souissi, N. (2023). Pre-Exercise Caffeine Intake Attenuates the Negative Effects of Ramadan Fasting on Several Aspects of High-Intensity Short-Term Maximal Performances in Adolescent Female Handball Players. Nutrients, 15.","DOI":"10.3390\/nu15153432"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"17288","DOI":"10.1038\/s41598-020-74487-x","article-title":"Decision-making and dynamics of eye movements in volleyball experts","volume":"10","author":"Laflamme","year":"2020","journal-title":"Sci. Rep."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Trecroci, A., Duca, M., Cavaggioni, L., Rossi, A., Scurati, R., Longo, S., Merati, G., Alberti, G., and Formenti, D. (2021). Relationship between Cognitive Functions and Sport-Specific Physical Performance in Youth Volleyball Players. Brain Sci., 11.","DOI":"10.3390\/brainsci11020227"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1648","DOI":"10.1249\/MSS.0000000000000271","article-title":"Mouth rinsing and ingesting a bitter solution improves sprint cycling performance","volume":"46","author":"Gam","year":"2014","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"362","DOI":"10.1123\/ijsnem.2020-0083","article-title":"The Effects of Caffeine Mouth Rinsing on Exercise Performance: A Systematic Review","volume":"30","author":"Ehlert","year":"2020","journal-title":"Int. J. Sport. Nutr. Exerc. Metab."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"438","DOI":"10.1080\/10408398.2021.1949576","article-title":"Is caffeine mouth rinsing an effective strategy to improve physical and cognitive performance? A systematic review","volume":"63","author":"Ferreira","year":"2023","journal-title":"Crit. Rev. Food Sci. Nutr."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1007\/s40279-017-0848-2","article-title":"Administration of Caffeine in Alternate Forms","volume":"48","author":"Wickham","year":"2018","journal-title":"Sports Med."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1123\/ijsnem.2013-0103","article-title":"The effect of a caffeinated mouth-rinse on endurance cycling time-trial performance","volume":"24","author":"Doering","year":"2014","journal-title":"Int. J. Sport. Nutr. Exerc. Metab."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"530","DOI":"10.1123\/ijsnem.2025-0040","article-title":"The Effects of Caffeine Mouth Rinsing During the Battery of Soccer-Specific Tests in the Trained Male Soccer Players: Fasted Versus Fed State","volume":"35","author":"Miraftabi","year":"2025","journal-title":"Int. J. Sport. Nutr. Exerc. Metab."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"104","DOI":"10.1016\/j.tics.2005.01.011","article-title":"Imaging the developing brain: What have we learned about cognitive development?","volume":"9","author":"Casey","year":"2005","journal-title":"Trends Cogn. Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"602","DOI":"10.1016\/j.sleep.2006.12.002","article-title":"Sleep, circadian rhythms, and delayed phase in adolescence","volume":"8","author":"Crowley","year":"2007","journal-title":"Sleep Med."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"637","DOI":"10.1016\/j.pcl.2011.03.003","article-title":"Sleep in adolescents: The perfect storm","volume":"58","author":"Carskadon","year":"2011","journal-title":"Pediatr. Clin. N. Am."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1111\/nure.12150","article-title":"Effect of energy drink and caffeinated beverage consumption on sleep, mood, and performance in children and adolescents","volume":"72","author":"Owens","year":"2014","journal-title":"Nutr. Rev."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Bougrine, H., Ammar, A., Salem, A., Trabelsi, K., Jahrami, H., Chtourou, H., and Souissi, N. (2024). Effects of Various Caffeine Doses on Cognitive Abilities in Female Athletes with Low Caffeine Consumption. Brain Sci., 14.","DOI":"10.3390\/brainsci14030280"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Bougrine, H., Ammar, A., Salem, A., Trabelsi, K., \u017bmijewski, P., Jahrami, H., Chtourou, H., and Souissi, N. (2024). Effects of Different Caffeine Dosages on Maximal Physical Performance and Potential Side Effects in Low-Consumer Female Athletes: Morning vs. Evening Administration. Nutrients, 16.","DOI":"10.3390\/nu16142223"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"341","DOI":"10.1053\/smrv.2000.0098","article-title":"Sleep inertia","volume":"4","author":"Tassi","year":"2000","journal-title":"Sleep Med. Rev."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1144","DOI":"10.1080\/07420528.2022.2077747","article-title":"Can caffeine supplementation reverse the impact of time of day on cognitive and short-term high intensity performances in young female handball players?","volume":"39","author":"Bougrine","year":"2022","journal-title":"Chronobiol. Int."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1037\/pha0000364","article-title":"Caffeine enhances sustained attention among adolescents","volume":"29","author":"Cooper","year":"2021","journal-title":"Exp. Clin. Psychopharmacol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"175","DOI":"10.3758\/BF03193146","article-title":"G*Power 3: A flexible statistical power analysis program for the social, behavioral, and biomedical sciences","volume":"39","author":"Faul","year":"2007","journal-title":"Behav. Res. Methods"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1016\/0165-1781(89)90047-4","article-title":"The Pittsburgh Sleep Quality Index: A new instrument for psychiatric practice and research","volume":"28","author":"Buysse","year":"1989","journal-title":"Psychiatry Res."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1016\/0191-8869(91)90110-W","article-title":"Horne & \u00d6stberg morningness-eveningness questionnaire: A reduced scale","volume":"12","author":"Adan","year":"1991","journal-title":"Personal. Individ. Differ."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"521","DOI":"10.2466\/pr0.2001.89.3.521","article-title":"Caffeine consumption questionnaire: A standardized measure for caffeine consumption in undergraduate students","volume":"89","author":"Shohet","year":"2001","journal-title":"Psychol. Rep."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"947","DOI":"10.1007\/s00394-021-02708-8","article-title":"Acute effects of two caffeine doses on bar velocity during the bench press exercise among women habituated to caffeine: A randomized, crossover, double-blind study involving control and placebo conditions","volume":"61","author":"Krzysztofik","year":"2022","journal-title":"Eur. J. Nutr."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"329","DOI":"10.1016\/j.dam.2025.07.049","article-title":"The random generation of Latin rectangles based on the assignment problem","volume":"378","author":"Iftikhar","year":"2026","journal-title":"Discret. Appl. Math."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"155","DOI":"10.2147\/NSS.S188911","article-title":"Sleep inertia: Current insights","volume":"11","author":"Hilditch","year":"2019","journal-title":"Nat. Sci. Sleep."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1038\/clpt.1982.132","article-title":"Caffeine disposition after oral doses","volume":"32","author":"Bonati","year":"1982","journal-title":"Clin. Pharmacol. Ther."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"633","DOI":"10.1139\/apnm-2012-0333","article-title":"Effects of caffeine and carbohydrate mouth rinses on repeated sprint performance","volume":"38","author":"Beaven","year":"2013","journal-title":"Appl. Physiol. Nutr. Metab."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1186\/s12970-021-00462-0","article-title":"Effects of carbohydrate and caffeine mouth rinsing on strength, muscular endurance and cognitive performance","volume":"18","author":"Karayigit","year":"2021","journal-title":"J. Int. Soc. Sports Nutr."},{"key":"ref_37","unstructured":"Evans, K. (2024). The Acute Effects of Caffeine Consumption on Muscle Performance of a 1 Rep Max Bench Press Exercise: A Critically Appraised Topic, Liberty University."},{"key":"ref_38","unstructured":"Sajadi-Ernazarova, K.R., and Hamilton, R.J. (2025). Caffeine Withdrawal, StatPearls Publishing LLC."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1186\/s40798-018-0162-z","article-title":"The effects of time of day and chronotype on cognitive and physical performance in healthy volunteers","volume":"4","author":"Boiling","year":"2018","journal-title":"Sports Med. Open"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"495","DOI":"10.1007\/s11325-023-02895-0","article-title":"Diurnal variation in variables related to cognitive performance: A systematic review","volume":"28","author":"Munnilari","year":"2024","journal-title":"Sleep Breath."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"736","DOI":"10.1080\/07420528.2025.2503866","article-title":"The relationship between circadian type and physical activity as predictors of cognitive performance during simulated nightshifts: A randomised controlled trial","volume":"42","author":"Easton","year":"2025","journal-title":"Chronobiol. Int."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"643","DOI":"10.1037\/h0054651","article-title":"Studies of interference in serial verbal reactions","volume":"18","author":"Stroop","year":"1935","journal-title":"J. Exp. Psychol."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Zhou, Y.B., Ruan, S.J., Zhang, K., Bao, Q., and Liu, H.Z. (2024). Time pressure effects on decision-making in intertemporal loss scenarios: An eye-tracking study. Front. Psychol., 15.","DOI":"10.3389\/fpsyg.2024.1451674"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Broodryk, A., Skala, F., and Broodryk, R. (2025). Light-Based Reaction Speed Does Not Predict Field-Based Reactive Agility in Soccer Players. J. Funct. Morphol. Kinesiol., 10.","DOI":"10.3390\/jfmk10030239"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1037\/0033-2909.109.2.163","article-title":"Half a century of research on the Stroop effect: An integrative review","volume":"109","author":"MacLeod","year":"1991","journal-title":"Psychol. Bull."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/j.edurev.2010.12.001","article-title":"Eta squared and partial eta squared as measures of effect size in educational research","volume":"6","author":"Richardson","year":"2011","journal-title":"Educ. Res. Rev."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Cohen, J. (2013). Statistical Power Analysis for the Behavioral Sciences, Routledge.","DOI":"10.4324\/9780203771587"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1016\/j.neubiorev.2016.09.001","article-title":"A review of caffeine\u2019s effects on cognitive, physical and occupational performance","volume":"71","author":"McLellan","year":"2016","journal-title":"Neurosci. Biobehav. Rev."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"71","DOI":"10.2174\/1570159X13666141210215655","article-title":"Caffeine: Cognitive and physical performance enhancer or psychoactive drug?","volume":"13","author":"Cappelletti","year":"2015","journal-title":"Curr. Neuropharmacol."},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Haskell-Ramsay, C.F., Jackson, P.A., Forster, J.S., Dodd, F.L., Bowerbank, S.L., and Kennedy, D.O. (2018). The Acute Effects of Caffeinated Black Coffee on Cognition and Mood in Healthy Young and Older Adults. Nutrients, 10.","DOI":"10.3390\/nu10101386"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"R1370","DOI":"10.1152\/ajpregu.00205.2002","article-title":"Relationship between alertness, performance, and body temperature in humans","volume":"283","author":"Wright","year":"2002","journal-title":"Am. J. Physiol. Regul. Integr. Comp. Physiol."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"1328","DOI":"10.1126\/science.2734611","article-title":"Bright light induction of strong (type 0) resetting of the human circadian pacemaker","volume":"244","author":"Czeisler","year":"1989","journal-title":"Science"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"613","DOI":"10.1016\/0031-9384(92)90188-8","article-title":"The circadian rhythm of body temperature","volume":"51","author":"Refinetti","year":"1992","journal-title":"Physiol. Behav."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"305ra146","DOI":"10.1126\/scitranslmed.aac5125","article-title":"Effects of caffeine on the human circadian clock in vivo and in vitro","volume":"7","author":"Burke","year":"2015","journal-title":"Sci. Transl. Med."},{"key":"ref_55","doi-asserted-by":"crossref","unstructured":"Zhang, Y., Yang, W., Xue, Y., Hou, D., Chen, S., Xu, Z., Peng, S., Zhao, H., Wang, C., and Liu, C. (2024). Timing Matters: Time of Day Impacts the Ergogenic Effects of Caffeine-A Narrative Review. Nutrients, 16.","DOI":"10.3390\/nu16101421"},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1146\/annurev.neuro.051508.135535","article-title":"The neuropsychopharmacology of fronto-executive function: Monoaminergic modulation","volume":"32","author":"Robbins","year":"2009","journal-title":"Annu. Rev. Neurosci."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"631","DOI":"10.1016\/j.neubiorev.2008.08.016","article-title":"Insights into the neural basis of response inhibition from cognitive and clinical neuroscience","volume":"33","author":"Chambers","year":"2009","journal-title":"Neurosci. Biobehav. Rev."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"1195","DOI":"10.5664\/jcsm.3170","article-title":"Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed","volume":"9","author":"Drake","year":"2013","journal-title":"J. Clin. Sleep Med."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"263","DOI":"10.2147\/RMHP.S156404","article-title":"Effects of caffeine on sleep quality and daytime functioning","volume":"11","author":"Muurlink","year":"2018","journal-title":"Risk Manag. Health Policy"},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"785","DOI":"10.2165\/00007256-200131110-00002","article-title":"Caffeine and exercise: Metabolism, endurance and performance","volume":"31","author":"Graham","year":"2001","journal-title":"Sports Med."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"1243","DOI":"10.1016\/S0278-6915(02)00096-0","article-title":"Effects of caffeine on human behavior","volume":"40","author":"Smith","year":"2002","journal-title":"Food Chem. Toxicol."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"961","DOI":"10.1186\/s12967-024-05737-z","article-title":"Genetic susceptibility to caffeine intake and metabolism: A systematic review","volume":"22","author":"Low","year":"2024","journal-title":"J. Transl. Med."}],"container-title":["Life"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-1729\/16\/1\/33\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,26]],"date-time":"2025-12-26T01:05:30Z","timestamp":1766711130000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-1729\/16\/1\/33"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,12,25]]},"references-count":62,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2026,1]]}},"alternative-id":["life16010033"],"URL":"https:\/\/doi.org\/10.3390\/life16010033","relation":{},"ISSN":["2075-1729"],"issn-type":[{"value":"2075-1729","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,12,25]]}}}