PMID- 36297102
OWN - NLM
STAT- MEDLINE
DCOM- 20221031
LR  - 20230308
IS  - 2072-6643 (Electronic)
IS  - 2072-6643 (Linking)
VI  - 14
IP  - 20
DP  - 2022 Oct 21
TI  - How Repeatable Is the Ergogenic Effect of Caffeine? Limited Reproducibility of 
      Acute Caffeine (3 mg.kg(-1)) Ingestion on Muscular Strength, Power, and Muscular 
      Endurance.
LID - 10.3390/nu14204416 [doi]
LID - 4416
AB  - This study aimed to determine the effect of 3 mg.kg-1 acute caffeine ingestion on 
      muscular strength, power and strength endurance and the repeatability of 
      potential ergogenic effects across multiple trials. Twenty-two university 
      standard male rugby union players (20 +/- 2 years) completed the study. Using a 
      double-blind, randomized, and counterbalanced within-subject experimental design. 
      Participants completed six experimental trials (three caffeine and three placebo) 
      where force time characteristic of the Isometric Mid-Thigh Pull (IMTP), 
      Countermovement Jump (CMJ) and Drop Jumps (DJ) were assessed followed by 
      assessments of Chest Press (CP), Shoulder Press (SP), Squats (SQ), and Deadlifts 
      (DL) Repetitions Until Failure (RTF at 70% 1 RM). ANOVA indicated that caffeine 
      improved both the CMJ and DJ (p < 0.044) and increased RTF in all RTF assessments 
      (p < 0.002). When individual caffeine trials were compared to corresponding 
      placebo trials, effect sizes ranged from trivial-large favoring caffeine 
      irrespective of a main effect of treatment being identified in the ANOVA. These 
      results demonstrate for the first time that the performance enhancing effects of 
      caffeine may not be repeatable between days, where our data uniquely indicates 
      that this is in part attributable to between sessions variation in caffeine's 
      ergogenic potential.
FAU - Tamilio, Ryan A
AU  - Tamilio RA
AD  - Centre for Applied Biological and Exercise Science, Alison Gingell Building, 
      Coventry University, Priory Street, Coventry CV1 5FB, UK.
FAU - Clarke, Neil D
AU  - Clarke ND
AUID- ORCID: 0000-0002-1909-329X
AD  - Centre for Applied Biological and Exercise Science, Alison Gingell Building, 
      Coventry University, Priory Street, Coventry CV1 5FB, UK.
FAU - Duncan, Michael J
AU  - Duncan MJ
AUID- ORCID: 0000-0002-2016-6580
AD  - Centre for Applied Biological and Exercise Science, Alison Gingell Building, 
      Coventry University, Priory Street, Coventry CV1 5FB, UK.
FAU - Morris, Rhys O
AU  - Morris RO
AD  - Centre for Applied Biological and Exercise Science, Alison Gingell Building, 
      Coventry University, Priory Street, Coventry CV1 5FB, UK.
FAU - Tallis, Jason
AU  - Tallis J
AUID- ORCID: 0000-0001-8904-2693
AD  - Centre for Applied Biological and Exercise Science, Alison Gingell Building, 
      Coventry University, Priory Street, Coventry CV1 5FB, UK.
LA  - eng
PT  - Journal Article
PT  - Randomized Controlled Trial
DEP - 20221021
PL  - Switzerland
TA  - Nutrients
JT  - Nutrients
JID - 101521595
RN  - 3G6A5W338E (Caffeine)
RN  - 0 (Performance-Enhancing Substances)
SB  - IM
MH  - Humans
MH  - Male
MH  - Caffeine/pharmacology
MH  - Cross-Over Studies
MH  - Double-Blind Method
MH  - Eating
MH  - Muscle Strength
MH  - *Performance-Enhancing Substances/pharmacology
MH  - Physical Endurance
MH  - Reproducibility of Results
MH  - Adolescent
MH  - Young Adult
PMC - PMC9611362
OTO - NOTNLM
OT  - ergogenic-aids
OT  - power
OT  - repeatability
OT  - resistance exercise
OT  - strength
COIS- The authors declare no conflict of interest.
EDAT- 2022/10/28 06:00
MHDA- 2022/10/29 06:00
PMCR- 2022/10/21
CRDT- 2022/10/27 01:48
PHST- 2022/09/29 00:00 [received]
PHST- 2022/10/17 00:00 [revised]
PHST- 2022/10/19 00:00 [accepted]
PHST- 2022/10/27 01:48 [entrez]
PHST- 2022/10/28 06:00 [pubmed]
PHST- 2022/10/29 06:00 [medline]
PHST- 2022/10/21 00:00 [pmc-release]
AID - nu14204416 [pii]
AID - nutrients-14-04416 [pii]
AID - 10.3390/nu14204416 [doi]
PST - epublish
SO  - Nutrients. 2022 Oct 21;14(20):4416. doi: 10.3390/nu14204416.