{"id":"https://openalex.org/W7155368398","doi":"https://doi.org/10.1016/j.nutres.2026.04.007","title":"Synergistic effects of caffeine, l-theanine, and diaphragmatic breathing on esports performance: A randomized controlled crossover trial","display_name":"Synergistic effects of caffeine, l-theanine, and diaphragmatic breathing on esports performance: A randomized controlled crossover trial","publication_year":2026,"publication_date":"2026-04-23","ids":{"openalex":"https://openalex.org/W7155368398","doi":"https://doi.org/10.1016/j.nutres.2026.04.007","pmid":"https://pubmed.ncbi.nlm.nih.gov/42176572"},"language":"en","primary_location":{"id":"doi:10.1016/j.nutres.2026.04.007","doi":"https://doi.org/10.1016/j.nutres.2026.04.007","is_oa":false,"landing_page_url":"https://doi.org/10.1016/j.nutres.2026.04.007","pdf_url":null,"source":{"id":"https://openalex.org/S123713480","display_name":"Nutrition Research","issn_l":"0271-5317","issn":["0271-5317","1879-0739"],"is_oa":false,"is_in_doaj":false,"is_core":true,"listed_in":["cwts-core","dongbi-d","doyens","jufo-1","ki-jl-1","medline","norway-1","poland-70","russia-white-list-1"],"host_organization":"https://openalex.org/P4310320990","host_organization_name":"Elsevier BV","host_organization_lineage":["https://openalex.org/P4310320990"],"host_organization_lineage_names":["Elsevier BV"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Nutrition Research","raw_type":"journal-article"},"volume":null,"type":"article","indexed_in":["crossref","pubmed"],"open_access":{"is_oa":false,"oa_status":"closed","oa_url":null,"any_repository_has_fulltext":false},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5083128198","display_name":"Sedat Arslan","orcid":"https://orcid.org/0000-0002-3356-7332","observed_orcids":["https://orcid.org/0000-0002-3356-7332"]},"institutions":[{"id":"https://openalex.org/I131835042","display_name":"Bursa Uluda\u011f \u00dcni\u0307versi\u0307tesi\u0307","ror":"https://ror.org/03tg3eb07","country_code":"TR","type":"education","lineage":["https://openalex.org/I131835042"]}],"countries":["TR"],"is_corresponding":true,"raw_author_name":"Sedat Arslan","raw_affiliation_strings":["Department of Nutrition and Dietetics, Faculty of Health Sciences, Bursa Uludag University, Bursa, T\u00fcrkiye. Electronic address: sedatarslan@uludag.edu.tr"],"raw_orcid":"https://orcid.org/0000-0002-3356-7332","affiliations":[{"raw_affiliation_string":"Department of Nutrition and Dietetics, Faculty of Health Sciences, Bursa Uludag University, Bursa, T\u00fcrkiye. Electronic address: sedatarslan@uludag.edu.tr","institution_ids":["https://openalex.org/I131835042"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5085742371","display_name":"Bur\u00e7in Ak\u00e7ay","orcid":"https://orcid.org/0000-0002-0883-0311","observed_orcids":["https://orcid.org/0000-0002-0883-0311"]},"institutions":[{"id":"https://openalex.org/I3133171086","display_name":"Band\u0131rma Onyedi Eyl\u00fcl University","ror":"https://ror.org/02mtr7g38","country_code":"TR","type":"education","lineage":["https://openalex.org/I3133171086"]}],"countries":["TR"],"is_corresponding":false,"raw_author_name":"Bur\u00e7in Ak\u00e7ay","raw_affiliation_strings":["Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Band\u0131rma Onyedi Eyl\u00fcl University, Bal\u0131kesir, Turkey"],"raw_orcid":"https://orcid.org/0000-0002-0883-0311","affiliations":[{"raw_affiliation_string":"Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Band\u0131rma Onyedi Eyl\u00fcl University, Bal\u0131kesir, Turkey","institution_ids":["https://openalex.org/I3133171086"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5008387205","display_name":"Ozan Bahad\u0131r T\u00fcrkmen","orcid":"https://orcid.org/0000-0002-1799-3286","observed_orcids":["https://orcid.org/0000-0002-1799-3286"]},"institutions":[{"id":"https://openalex.org/I3133171086","display_name":"Band\u0131rma Onyedi Eyl\u00fcl University","ror":"https://ror.org/02mtr7g38","country_code":"TR","type":"education","lineage":["https://openalex.org/I3133171086"]}],"countries":["TR"],"is_corresponding":false,"raw_author_name":"Ozan Bahad\u0131r T\u00fcrkmen","raw_affiliation_strings":["Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Band\u0131rma Onyedi Eyl\u00fcl University, Bal\u0131kesir, Turkey"],"raw_orcid":"https://orcid.org/0000-0002-1799-3286","affiliations":[{"raw_affiliation_string":"Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Band\u0131rma Onyedi Eyl\u00fcl University, Bal\u0131kesir, Turkey","institution_ids":["https://openalex.org/I3133171086"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5073183446","display_name":"Ebru Kaya Mutlu","orcid":"https://orcid.org/0000-0002-8595-5513","observed_orcids":["https://orcid.org/0000-0002-8595-5513"]},"institutions":[{"id":"https://openalex.org/I3133171086","display_name":"Band\u0131rma Onyedi Eyl\u00fcl University","ror":"https://ror.org/02mtr7g38","country_code":"TR","type":"education","lineage":["https://openalex.org/I3133171086"]}],"countries":["TR"],"is_corresponding":false,"raw_author_name":"Ebru Kaya Mutlu","raw_affiliation_strings":["Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Band\u0131rma Onyedi Eyl\u00fcl University, Bal\u0131kesir, Turkey"],"raw_orcid":"https://orcid.org/0000-0002-8595-5513","affiliations":[{"raw_affiliation_string":"Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Band\u0131rma Onyedi Eyl\u00fcl University, Bal\u0131kesir, Turkey","institution_ids":["https://openalex.org/I3133171086"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":2,"corresponding_author_ids":["https://openalex.org/A5083128198"],"corresponding_institution_ids":["https://openalex.org/I131835042"],"apc_list":{"value":4090,"currency":"USD","value_usd":4090},"apc_paid":null,"fwci":10.971,"has_fulltext":false,"cited_by_count":3,"citation_normalized_percentile":{"value":0.98374761,"is_in_top_1_percent":false,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":97,"max":98},"biblio":{"volume":"151","issue":null,"first_page":"26","last_page":"36"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11264","display_name":"Coffee research and impacts","score":0.9970999956130981,"subfield":{"id":"https://openalex.org/subfields/2736","display_name":"Pharmacology (medical)"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},"topics":[{"id":"https://openalex.org/T11264","display_name":"Coffee research and impacts","score":0.9970999956130981,"subfield":{"id":"https://openalex.org/subfields/2736","display_name":"Pharmacology (medical)"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},{"id":"https://openalex.org/T10813","display_name":"Sport Psychology and Performance","score":0.0008999999845400453,"subfield":{"id":"https://openalex.org/subfields/3204","display_name":"Developmental and Educational Psychology"},"field":{"id":"https://openalex.org/fields/32","display_name":"Psychology"},"domain":{"id":"https://openalex.org/domains/2","display_name":"Social Sciences"}},{"id":"https://openalex.org/T10157","display_name":"Sports Performance and Training","score":0.0005000000237487257,"subfield":{"id":"https://openalex.org/subfields/2732","display_name":"Orthopedics and Sports Medicine"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/caffeine","display_name":"caffeine","score":0.6970000267028809},{"id":"https://openalex.org/keywords/l-theanine","display_name":"theanine","score":0.8880000114440918},{"id":"https://openalex.org/keywords/diaphragmatic-breathing","display_name":"diaphragmatic breathing","score":0.9990000128746033},{"id":"https://openalex.org/keywords/reaction-time","display_name":"reaction time","score":0.9900000095367432},{"id":"https://openalex.org/keywords/auditory-reaction-time","display_name":"auditory reaction time","score":0.9629999995231628},{"id":"https://openalex.org/keywords/visual-reaction-time","display_name":"visual reaction time","score":0.9860000014305115},{"id":"https://openalex.org/keywords/cognitive-performance","display_name":"cognitive performance","score":0.7009999752044678},{"id":"https://openalex.org/keywords/ergogenic-aids","display_name":"ergogenic aids","score":0.6959999799728394},{"id":"https://openalex.org/keywords/synergistic-supplementation","display_name":"synergistic supplementation","score":0.550000011920929}],"concepts":[{"id":"https://openalex.org/C71924100","wikidata":"https://www.wikidata.org/wiki/Q11190","display_name":"Medicine","level":0,"score":0.6833999752998352},{"id":"https://openalex.org/C20463939","wikidata":"https://www.wikidata.org/wiki/Q811123","display_name":"Diaphragmatic breathing","level":3,"score":0.6611999869346619},{"id":"https://openalex.org/C87813604","wikidata":"https://www.wikidata.org/wiki/Q1242899","display_name":"Crossover study","level":4,"score":0.5799000263214111},{"id":"https://openalex.org/C42219234","wikidata":"https://www.wikidata.org/wiki/Q131130","display_name":"Anesthesia","level":1,"score":0.565500020980835},{"id":"https://openalex.org/C39300077","wikidata":"https://www.wikidata.org/wiki/Q9530","display_name":"Breathing","level":2,"score":0.5281999707221985},{"id":"https://openalex.org/C168563851","wikidata":"https://www.wikidata.org/wiki/Q1436668","display_name":"Randomized controlled trial","level":2,"score":0.426800012588501},{"id":"https://openalex.org/C122507166","wikidata":"https://www.wikidata.org/wiki/Q628906","display_name":"Crossover","level":2,"score":0.3804999887943268},{"id":"https://openalex.org/C534529494","wikidata":"https://www.wikidata.org/wiki/Q7891","display_name":"Respiratory system","level":2,"score":0.3677999973297119},{"id":"https://openalex.org/C123792249","wikidata":"https://www.wikidata.org/wiki/Q5165875","display_name":"Control of respiration","level":3,"score":0.3319999873638153},{"id":"https://openalex.org/C182215343","wikidata":"https://www.wikidata.org/wiki/Q472287","display_name":"Respiration","level":2,"score":0.30720001459121704},{"id":"https://openalex.org/C126322002","wikidata":"https://www.wikidata.org/wiki/Q11180","display_name":"Internal medicine","level":1,"score":0.2856000065803528},{"id":"https://openalex.org/C2993600536","wikidata":"https://www.wikidata.org/wiki/Q9654","display_name":"Diaphragm muscle","level":3,"score":0.28380000591278076},{"id":"https://openalex.org/C164705383","wikidata":"https://www.wikidata.org/wiki/Q10379","display_name":"Cardiology","level":1,"score":0.274399995803833},{"id":"https://openalex.org/C164292776","wikidata":"https://www.wikidata.org/wiki/Q5271779","display_name":"Diaphragm (acoustics)","level":3,"score":0.26649999618530273}],"mesh":[{"descriptor_ui":"D000328","descriptor_name":"Adult","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D002110","descriptor_name":"Caffeine","qualifier_ui":"Q000008","qualifier_name":"administration & dosage","is_major_topic":true},{"descriptor_ui":"D002110","descriptor_name":"Caffeine","qualifier_ui":"Q000494","qualifier_name":"pharmacology","is_major_topic":true},{"descriptor_ui":"D003071","descriptor_name":"Cognition","qualifier_ui":"Q000187","qualifier_name":"drug effects","is_major_topic":false},{"descriptor_ui":"D003964","descriptor_name":"Diaphragm","qualifier_ui":"Q000502","qualifier_name":"physiology","is_major_topic":false},{"descriptor_ui":"D005971","descriptor_name":"Glutamates","qualifier_ui":"Q000008","qualifier_name":"administration & dosage","is_major_topic":true},{"descriptor_ui":"D005971","descriptor_name":"Glutamates","qualifier_ui":"Q000494","qualifier_name":"pharmacology","is_major_topic":true},{"descriptor_ui":"D006801","descriptor_name":"Humans","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D008297","descriptor_name":"Male","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D011930","descriptor_name":"Reaction Time","qualifier_ui":"Q000187","qualifier_name":"drug effects","is_major_topic":false},{"descriptor_ui":"D012119","descriptor_name":"Respiration","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D016037","descriptor_name":"Single-Blind Method","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D018592","descriptor_name":"Cross-Over Studies","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D054874","descriptor_name":"Athletic Performance","qualifier_ui":"Q000502","qualifier_name":"physiology","is_major_topic":true},{"descriptor_ui":"D055815","descriptor_name":"Young Adult","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D056352","descriptor_name":"Athletes","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D058573","descriptor_name":"Performance-Enhancing Substances","qualifier_ui":"Q000494","qualifier_name":"pharmacology","is_major_topic":true}],"locations_count":3,"locations":[{"id":"doi:10.1016/j.nutres.2026.04.007","doi":"https://doi.org/10.1016/j.nutres.2026.04.007","is_oa":false,"landing_page_url":"https://doi.org/10.1016/j.nutres.2026.04.007","pdf_url":null,"source":{"id":"https://openalex.org/S123713480","display_name":"Nutrition Research","issn_l":"0271-5317","issn":["0271-5317","1879-0739"],"is_oa":false,"is_in_doaj":false,"is_core":true,"listed_in":["cwts-core","dongbi-d","doyens","jufo-1","ki-jl-1","medline","norway-1","poland-70","russia-white-list-1"],"host_organization":"https://openalex.org/P4310320990","host_organization_name":"Elsevier BV","host_organization_lineage":["https://openalex.org/P4310320990"],"host_organization_lineage_names":["Elsevier BV"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Nutrition Research","raw_type":"journal-article"},{"id":"pmid:42176572","doi":null,"is_oa":false,"landing_page_url":"https://pubmed.ncbi.nlm.nih.gov/42176572","pdf_url":null,"source":{"id":"https://openalex.org/S4306525036","display_name":"PubMed","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I1299303238","host_organization_name":"National Institutes of Health","host_organization_lineage":["https://openalex.org/I1299303238"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Nutrition research (New York, N.Y.)","raw_type":"Journal Article"},{"id":"pmh:1226beac-f680-4a7c-a13d-d9d8c04ebb25","doi":null,"is_oa":false,"landing_page_url":"https://avesis.uludag.edu.tr/publication/details/1226beac-f680-4a7c-a13d-d9d8c04ebb25/oai","pdf_url":null,"source":{"id":"https://openalex.org/S7407055210","display_name":"Bursa Uludag University - AVESIS","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"info:eu-repo/semantics/article"}],"best_oa_location":null,"sustainable_development_goals":[{"display_name":"Good health and well-being","id":"https://metadata.un.org/sdg/3","score":0.9537000060081482}],"study_designs":[{"display_name":"Randomized Controlled Trial","id":"https://openalex.org/study-designs/randomized-controlled-trial"},{"display_name":"Clinical Trial","id":"https://openalex.org/study-designs/clinical-trial"}],"awards":[{"id":"https://openalex.org/G1016413747","display_name":null,"funder_award_id":"222S307","funder_id":"https://openalex.org/F4320322626","funder_display_name":"T\u00fcrkiye Bilimsel ve Teknolojik Ara\u015ft\u0131rma Kurumu"}],"funders":[{"id":"https://openalex.org/F4320322626","display_name":"T\u00fcrkiye Bilimsel ve Teknolojik Ara\u015ft\u0131rma Kurumu","ror":"https://ror.org/04w9kkr77"}],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":37,"referenced_works":["https://openalex.org/W1850237044","https://openalex.org/W1964833004","https://openalex.org/W2011154018","https://openalex.org/W2021566056","https://openalex.org/W2026019224","https://openalex.org/W2034914015","https://openalex.org/W2049335959","https://openalex.org/W2062214423","https://openalex.org/W2064424477","https://openalex.org/W2114830105","https://openalex.org/W2191743362","https://openalex.org/W2509584581","https://openalex.org/W2525786873","https://openalex.org/W2580112888","https://openalex.org/W2618570363","https://openalex.org/W2621012322","https://openalex.org/W2741409242","https://openalex.org/W2804421160","https://openalex.org/W2805577596","https://openalex.org/W2884299972","https://openalex.org/W2936876625","https://openalex.org/W2951451374","https://openalex.org/W3012473345","https://openalex.org/W3038079211","https://openalex.org/W3081800586","https://openalex.org/W3091600260","https://openalex.org/W3091961811","https://openalex.org/W3133820395","https://openalex.org/W3154416471","https://openalex.org/W3158037145","https://openalex.org/W3160834637","https://openalex.org/W3198981862","https://openalex.org/W4255157993","https://openalex.org/W4280646685","https://openalex.org/W4293145258","https://openalex.org/W4363610659","https://openalex.org/W4391175335"],"related_works":["https://openalex.org/W4391175335","https://openalex.org/W4400513838","https://openalex.org/W3040873180","https://openalex.org/W7125691990","https://openalex.org/W4412871072","https://openalex.org/W4410443283","https://openalex.org/W3038079211","https://openalex.org/W4413769892","https://openalex.org/W7155489285","https://openalex.org/W7203449752"],"abstract_inverted_index":null,"counts_by_year":[{"year":2026,"cited_by_count":3}],"updated_date":"2026-11-04T10:54:05.112534","created_date":"2026-04-24T00:00:00"}
