Tilpasninger til styrketræning og koffeinindtag
12. juli 2026 opdateret af: Abdullah Demirli, Istanbul University - Cerrahpasa
Undersøgelse af forskellige koffeintilskudsstrategiers effekt på modstandstræningsinducerede tilpasninger
Denne randomiserede, dobbeltblindede, placebo-kontrollerede crossover-undersøgelse undersøger effekterne af tre forskellige koffeintilskudsstrategier på modstandstræning-inducerede tilpasninger hos 180 koffein-naive, inaktive unge voksne mænd.
Deltagerne vil gennemgå to 4-ugers overvågede modstandstræningsprogrammer adskilt af en 2-ugers udvasknings-/crossover-periode.
De tre koffeinstrategier er: (1) konstant daglig lav-moderat dosering (3 mg/kg/dag), (2) gradvis stigende dosis (3 til 6 mg/kg over ugerne), og (3) kun træningsdags-koffein (3 mg/kg/dag).
Primære resultater inkluderer ikke-invasive målinger af integreret anabolisme og hypertrofi (D2O-afledt plasma proteomisk fraktionel synteserate, DXA muskelvolumen) og styrkemålinger.
Sekundære resultater inkluderer hormonelle responser (insulin, kortisol, testosteron, IGF-1), søvn-/genopretningsparametre og bivirkninger.
Studieoversigt
Status
Afsluttet
Betingelser
Detaljeret beskrivelse
BAGGGRUND: Koffein er et velkendt akut ergogent hjælpemiddel, som pålideligt forbedrer udholdenhed, kraft og modstandstræningspræstation, når det indtages i typiske ergogene doser (ca. 3-6 mg/kg omkring 60 minutter før træning).
Det er dog uklart, om koffein udøver direkte biologiske effekter på muskelproteinbalancen og hypertrofi.
Regelmæssig indtagelse af koffein skaber delvis fysiologisk tolerance, hvilket gør det muligt, at kronisk supplementering giver andre resultater end akut dosering.
FORMÅL: Denne undersøgelse adresserer tre translationelle spørgsmål: (1) Forstærker konstant daglig lav-moderat dosering træningstilpasninger?
(2) Giver en gradvist stigende doseringsstrategi større effekter ved at overvinde tolerance?
(3) Bevarer kun-træningsdags-koffein de akutte ergogene effekter, samtidig med at tolerance og søvnforstyrrelser begrænses?
METODER: 180 koffein-naive, fysisk inaktive unge voksne mænd i alderen 18-30 år vil blive tilfældigt tildelt en af tre koffeinsupplementeringsstrategier (n=60 pr. strategi).
Inden for hver strategi vil 30 deltagere modtage koffein og 30 vil modtage placebo i 4 uger.
Efter en 2-ugers udvaskning/krydsoverførsel vil interventionerne blive skiftet.
Alle deltagere vil gennemgå overvåget modstandstræning 3 gange om ugen.
RESULTATER: Primære endpoints inkluderer deuteriumoxid (D2O)-afledt plasma proteomisk fraktionel synteserate (FSR), DXA-målt fedtfri vævsmasse og muskelvolumen, maksimal styrke (1RM eller 3RM for bænkpres og squat) og træningsvolumenmetrikker.
Sekundære resultater inkluderer hormonelle og metaboliske tidsforløb, søvnkvalitet, subjektive genopretningsscore og overvågning af bivirkninger.
STATISTISK ANALYSE: Lineære blandede modeller vil blive brugt til at analysere dataene.
Undersøgelsestype
Interventionel
Tilmelding (Faktiske)
120
Fase
- Ikke anvendelig
Kontakter og lokationer
Dette afsnit indeholder kontaktoplysninger for dem, der udfører undersøgelsen, og oplysninger om, hvor denne undersøgelse udføres.
Studiesteder
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Avcilar
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Istanbul, Avcilar, Tyrkiet (Türkiye), 34010
- Istanbul University-Cerrahpasa, Faculty of Sport Sciences Performance Laboratory
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Deltagelseskriterier
Forskere leder efter personer, der passer til en bestemt beskrivelse, kaldet berettigelseskriterier. Nogle eksempler på disse kriterier er en persons generelle helbredstilstand eller tidligere behandlinger.
Berettigelseskriterier
Aldre berettiget til at studere
- Voksen
Tager imod sunde frivillige
Ja
Beskrivelse
Inklusionskriterier:
- Mandligt køn og alder mellem 18-30 år
- Ingen historie med koffeinforbrug eller meget lavt vanemæssigt indtag (<50 mg/dag)
- Ingen deltagelse i et struktureret styrketræningsprogram inden for de sidste 6 måneder
- Body mass index (BMI) mellem 18,5-30 kg/m2
- Villighed til regelmæssigt at deltage i alle trænings- og testsessioner
- Aflæggelse af skriftligt informeret samtykke efter fuldt at være blevet informeret om undersøgelsen
Eksklusionskriterier:
- Tilstedeværelse af kardiovaskulære, metaboliske, nyre-, lever- eller andre alvorlige kroniske sygdomme
- Diagnosticerede psykiatriske lidelser eller svær koffeinintolerance/allergi
- Brug af medicin, der påvirker koffeinmetabolismen eller muskelanabolismen (f.eks. betablokkere, antidepressiva, anabole steroider)
- Muskuloskeletale skader, der forhindrer sikkert styrketræning
- Rygning eller alkoholforbrug på niveauer, der kan påvirke undersøgelsens resultater
- Samtidig deltagelse i en anden træningsinterventionsundersøgelse
- Manglende evne til at tolerere DXA-scanning, blodprøvetagning eller D2O-indtagsprocedurer
Studieplan
Dette afsnit indeholder detaljer om studieplanen, herunder hvordan undersøgelsen er designet, og hvad undersøgelsen måler.
Hvordan er undersøgelsen tilrettelagt?
Design detaljer
- Primært formål: Grundvidenskab
- Tildeling: Randomiseret
- Interventionel model: Parallel tildeling
- Maskning: Tredobbelt
Våben og indgreb
Deltagergruppe / Arm |
Intervention / Behandling |
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Eksperimentel: Strategy 1: Constant Daily Dose
Participants receive caffeine at a constant daily dose of 4 mg/kg/day for 10 weeks.
Supervised resistance training is performed 3 times per week for 10 weeks.
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Oral caffeine capsule at 4 mg/kg body weight, consumed daily approximately 60 minutes before training sessions (on training days) or at the same time of day (on rest days).
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Eksperimentel: Strategy 2: Escalating Dose
Participants receive caffeine at a gradually escalating dose, starting at 2 mg/kg/day in week 1 and increasing to 6 mg/kg/day by week 10 (1 mg/kg every 2 weeks).
Supervised resistance training is performed 3 times per week for 10 weeks.
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• Oral caffeine starting at 2 mg/kg/day and increasing incrementally to reach 6 mg/kg/day by week 10.
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Eksperimentel: Strategy 3: Training Days Only
Participants receive caffeine at 4 mg/kg only on training days (3 times per week) for 10 weeks.
Supervised resistance training is performed 3 times per week for 10 weeks.
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Oral caffeine capsule at 4 mg/kg body weight, consumed only on training days approximately 60 minutes before exercise.
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Placebo komparator: Placebo
Participants receive 250 mg/day cellulose for 10 weeks.
Supervised resistance training is performed 3 times per week for 10 weeks.
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Oral placebo capsule (250 mg cellulose), consumed daily approximately 60 minutes before training sessions (on training days) or at the same time of day (on rest days).
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Hvad måler undersøgelsen?
Primære resultatmål
Resultatmål |
Foranstaltningsbeskrivelse |
Tidsramme |
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Change in Lean Body Mass Measured by DXA
Tidsramme: Baseline and post-test (after completing 10 weeks of interventions)
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Change in total lean body mass measured using dual-energy X-ray absorptiometry (DXA), reported in kilograms.
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Baseline and post-test (after completing 10 weeks of interventions)
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Change in Fat Mass Measured by DXA
Tidsramme: Baseline and post-test (after completing 10 weeks of interventions)
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Change in fat mass measured using DXA.
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Baseline and post-test (after completing 10 weeks of interventions)
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Maximal Strength
Tidsramme: Baseline, and post-test (after completing 10 weeks of interventions)
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Measure by one-repetition maximum (1-RM) on a lower body (Smith machine Back Squat) and two upper body (Bench Press machine and Lat Pulldown machine) exercises.
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Baseline, and post-test (after completing 10 weeks of interventions)
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Total Training Volume Load
Tidsramme: During the intervention period (all training sessions).
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Total training volume load calculated as the sum of lifted load using the formula (kilograms × repetitions × sets) accumulated during each intervention period.
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During the intervention period (all training sessions).
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Change in Skeletal Muscle Thickness
Tidsramme: Baseline and post-test (after completing 10 weeks of interventions)
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Change in skeletal muscle thickness measured using B-mode ultrasound, reported in mm.
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Baseline and post-test (after completing 10 weeks of interventions)
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Sekundære resultatmål
Resultatmål |
Foranstaltningsbeskrivelse |
Tidsramme |
|---|---|---|
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Muscular endurance
Tidsramme: Baseline, and post-test (after completing 10 weeks of interventions)
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It will be measured by a repetitions-to-failure test on the Smith machine back squat using a load corresponding to 60% of the current 1RM.
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Baseline, and post-test (after completing 10 weeks of interventions)
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Neuromuscular function
Tidsramme: Baseline and post-test (after completing 10 weeks of interventions)
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It will be measured by the countermovement jump (CMJ) test on a force platform.
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Baseline and post-test (after completing 10 weeks of interventions)
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Resting concentrations of testosterone
Tidsramme: Baseline, and post-test (after completing 10 weeks of interventions)
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They will be measured using standard biochemical analyses.
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Baseline, and post-test (after completing 10 weeks of interventions)
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Plasma epinephrine responses to exercise
Tidsramme: During the first training session of Week 1 and the final training session of Week 10, at three time points: (1) pre-supplementation, (2) immediately before exercise and (3) immediately after exercise.
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They will be measured using standard biochemical analyses.
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During the first training session of Week 1 and the final training session of Week 10, at three time points: (1) pre-supplementation, (2) immediately before exercise and (3) immediately after exercise.
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Recovery
Tidsramme: Before each of the 30 training sessions during the study.
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It will be assessed using the validated 0-10 Perceived Recovery Status Scale (0 to 2: very poorly recovered, 3 to 4: poorly recovered, 5 to 6: adequately recovered, 7 to 8: well recovered, and 9 to 10: fully recovered).
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Before each of the 30 training sessions during the study.
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Adverse Events
Tidsramme: From initiation of the 4-week caffeine abstinence period through completion of the post-intervention assessments, monitored throughout the study (approximately 16 weeks).
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Adverse events will be assessed using a standardized questionnaire administered throughout the study.
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From initiation of the 4-week caffeine abstinence period through completion of the post-intervention assessments, monitored throughout the study (approximately 16 weeks).
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Sleep quality
Tidsramme: Baseline and post-test (after completing 10 weeks of interventions).
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It will be assessed by the Pittsburgh Sleep Quality Index (PSQI).
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Baseline and post-test (after completing 10 weeks of interventions).
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Rate of perceived exertion
Tidsramme: After each supervised training session, participants were assessed throughout the 10-week intervention period (30 training sessions).
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Assessed using the Borg Category-Ratio (CR10) Scale, ranging from 0 ("nothing at all") to 10 ("maximal").
Participants will report their perceived exertion after each supervised training session.
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After each supervised training session, participants were assessed throughout the 10-week intervention period (30 training sessions).
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Resting concentrations of insulin-like growth factor-1 (IGF-1)
Tidsramme: Baseline, and post-test (after completing 10 weeks of interventions)
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They will be measured using standard biochemical analyses.
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Baseline, and post-test (after completing 10 weeks of interventions)
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Resting concentrations of cortisol
Tidsramme: Baseline, and post-test (after completing 10 weeks of interventions)
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They will be measured using standard biochemical analyses.
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Baseline, and post-test (after completing 10 weeks of interventions)
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Resting concentrations of creatine kinase
Tidsramme: Baseline, and post-test (after completing 10 weeks of interventions)
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They will be measured using standard biochemical analyses.
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Baseline, and post-test (after completing 10 weeks of interventions)
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Serum cortisol responses to exercise
Tidsramme: During the first training session of Week 1 and the final training session of Week 10, at three time points: (1) pre-supplementation, (2) immediately before exercise and (3) immediately after exercise.
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They will be measured using standard biochemical analyses.
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During the first training session of Week 1 and the final training session of Week 10, at three time points: (1) pre-supplementation, (2) immediately before exercise and (3) immediately after exercise.
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Plasma norepinephrine responses to exercise
Tidsramme: During the first training session of Week 1 and the final training session of Week 10, at three time points: (1) pre-supplementation, (2) immediately before exercise and (3) immediately after exercise.
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They will be measured using standard biochemical analyses.
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During the first training session of Week 1 and the final training session of Week 10, at three time points: (1) pre-supplementation, (2) immediately before exercise and (3) immediately after exercise.
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Samarbejdspartnere og efterforskere
Det er her, du vil finde personer og organisationer, der er involveret i denne undersøgelse.
Sponsor
Samarbejdspartnere
Publikationer og nyttige links
Den person, der er ansvarlig for at indtaste oplysninger om undersøgelsen, leverer frivilligt disse publikationer. Disse kan handle om alt relateret til undersøgelsen.
Generelle publikationer
- Guest NS, VanDusseldorp TA, Nelson MT, Grgic J, Schoenfeld BJ, Jenkins NDM, Arent SM, Antonio J, Stout JR, Trexler ET, Smith-Ryan AE, Goldstein ER, Kalman DS, Campbell BI. International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021 Jan 2;18(1):1. doi: 10.1186/s12970-020-00383-4.
- Lovallo WR, Whitsett TL, al'Absi M, Sung BH, Vincent AS, Wilson MF. Caffeine stimulation of cortisol secretion across the waking hours in relation to caffeine intake levels. Psychosom Med. 2005 Sep-Oct;67(5):734-9. doi: 10.1097/01.psy.0000181270.20036.06.
- Matsumura T, Takamura Y, Fukuzawa K, Nakagawa K, Nonoyama S, Tomoo K, Tsukamoto H, Shinohara Y, Iemitsu M, Nagano A, Isaka T, Hashimoto T. Ergogenic Effects of Very Low to Moderate Doses of Caffeine on Vertical Jump Performance. Int J Sport Nutr Exerc Metab. 2023 Jul 26;33(5):275-281. doi: 10.1123/ijsnem.2023-0061. Print 2023 Sep 1.
- Brook MS, Wilkinson DJ, Mitchell WK, Lund JN, Szewczyk NJ, Greenhaff PL, Smith K, Atherton PJ. Skeletal muscle hypertrophy adaptations predominate in the early stages of resistance exercise training, matching deuterium oxide-derived measures of muscle protein synthesis and mechanistic target of rapamycin complex 1 signaling. FASEB J. 2015 Nov;29(11):4485-96. doi: 10.1096/fj.15-273755. Epub 2015 Jul 13.
- Pickering C, Kiely J. Are low doses of caffeine as ergogenic as higher doses? A critical review highlighting the need for comparison with current best practice in caffeine research. Nutrition. 2019 Nov-Dec;67-68:110535. doi: 10.1016/j.nut.2019.06.016. Epub 2019 Jun 26.
- Grgic J, Trexler ET, Lazinica B, Pedisic Z. Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis. J Int Soc Sports Nutr. 2018 Mar 5;15:11. doi: 10.1186/s12970-018-0216-0. eCollection 2018.
- Grgic J, Grgic I, Pickering C, Schoenfeld BJ, Bishop DJ, Pedisic Z. Wake up and smell the coffee: caffeine supplementation and exercise performance-an umbrella review of 21 published meta-analyses. Br J Sports Med. 2020 Jun;54(11):681-688. doi: 10.1136/bjsports-2018-100278. Epub 2019 Mar 29.
Datoer for undersøgelser
Disse datoer sporer fremskridtene for indsendelser af undersøgelsesrekord og resumeresultater til ClinicalTrials.gov. Studieregistreringer og rapporterede resultater gennemgås af National Library of Medicine (NLM) for at sikre, at de opfylder specifikke kvalitetskontrolstandarder, før de offentliggøres på den offentlige hjemmeside.
Studer store datoer
Studiestart (Faktiske)
20. februar 2026
Primær færdiggørelse (Faktiske)
30. maj 2026
Studieafslutning (Faktiske)
7. juni 2026
Datoer for studieregistrering
Først indsendt
30. januar 2026
Først indsendt, der opfyldte QC-kriterier
7. februar 2026
Først opslået (Faktiske)
13. februar 2026
Opdateringer af undersøgelsesjournaler
Sidste opdatering sendt (Faktiske)
14. juli 2026
Sidste opdatering indsendt, der opfyldte kvalitetskontrolkriterier
12. juli 2026
Sidst verificeret
1. juli 2026
Mere information
Begreber relateret til denne undersøgelse
Yderligere relevante MeSH-vilkår
- Neurologiske manifestationer
- Sygdomme i nervesystemet
- Neuromuskulære manifestationer
- Patologiske Tilstande, Anatomiske
- Atrofi
- Patologiske tilstande, tegn og symptomer
- Tegn og symptomer
- Hypertrofi
- Muskelatrofi
- Heterocykliske forbindelser
- Heterocykliske forbindelser, 2-ring
- Heterocykliske forbindelser, smeltet ring
- Alkaloider
- Purinoner
- Puriner
- Xanthines
- Koffein
Andre undersøgelses-id-numre
- 2026/01-1792
Plan for individuelle deltagerdata (IPD)
Planlægger du at dele individuelle deltagerdata (IPD)?
JA
IPD-planbeskrivelse
Alle ekstraherede personlige data (IPD) fra disse oplysninger vil blive delt sammen med støttedata til publiceringsresultaterne.
Dataordbøger relateret til dataindstillinger gemmes også.
IPD-delingstidsramme
Dataanmodninger vil blive accepteret 6 måneder efter artiklen er udgivet; data vil være tilgængelige i 36 måneder.
IPD-delingsadgangskriterier
Datadelingsanmodninger skal fremsættes af forskere med videnskabelig begrundelse og etisk godkendelse.
Anmodninger vil blive evalueret, og dem, der vurderes passende, vil blive underskrevet med en fortrolighedsaftale og en dataanvendelsesaftale.
Anmodninger modtages via abdullah.demirli@iuc.edu.tr
e-mail-adresse.
IPD-deling Understøttende informationstype
- STUDY_PROTOCOL
- SAP
- ANALYTIC_CODE
Lægemiddel- og udstyrsoplysninger, undersøgelsesdokumenter
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Disse oplysninger blev hentet direkte fra webstedet clinicaltrials.gov uden ændringer. Hvis du har nogen anmodninger om at ændre, fjerne eller opdatere dine undersøgelsesoplysninger, bedes du kontakte register@clinicaltrials.gov. Så snart en ændring er implementeret på clinicaltrials.gov, vil denne også blive opdateret automatisk på vores hjemmeside .