Evidence map›Paper›PMID 36297102›Full record

Trial reportNutrients2022

How Repeatable Is the Ergogenic Effect of Caffeine? Limited Reproducibility of Acute Caffeine (3 mg.kg

Ryan A Tamilio, Neil D Clarke, Michael J Duncan, Rhys O Morris, Jason Tallis

Open access · goldAbstract readRandomized Controlled Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in Nutrients, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 12 papers, 3 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
12citing papers in PubMed, 3 pooled it
2.4field-weighted citation impact, top 12% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

12 citing papers in PubMed, 3 syntheses or guidelines pooled it, 14 citations in OpenAlex.

  1. Pooled it
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  4. Caffeine's influence on vertical jump height: a real-life collegiate student-athlete approach.Journal of the International Society of Sports Nutrition · 2025
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors at 1 institution in 1 country.

Ryan A TamilioCentre for Applied Biological and Exercise Science, Alison Gingell Building, Coventry University, Priory Street, Coventry CV1 5FB, UK.
Neil D ClarkeCentre for Applied Biological and Exercise Science, Alison Gingell Building, Coventry University, Priory Street, Coventry CV1 5FB, UK.ORCID 0000-0002-1909-329X
Michael J DuncanCentre for Applied Biological and Exercise Science, Alison Gingell Building, Coventry University, Priory Street, Coventry CV1 5FB, UK.ORCID 0000-0002-2016-6580
Rhys O MorrisCentre for Applied Biological and Exercise Science, Alison Gingell Building, Coventry University, Priory Street, Coventry CV1 5FB, UK.
Jason TallisCentre for Applied Biological and Exercise Science, Alison Gingell Building, Coventry University, Priory Street, Coventry CV1 5FB, UK.ORCID 0000-0001-8904-2693
Coventry University · GB

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

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.

Indexed as

Performance-Enhancing SubstancesAdolescentCaffeineCross-Over StudiesDouble-Blind MethodEatingHumansMaleMuscle StrengthPhysical EnduranceReproducibility of ResultsYoung AdultCaffeinePerformance-Enhancing Substancesergogenic-aidspowerrepeatabilityresistance exercisestrength

Identifiers

PMID36297102
PMCPMC9611362
OpenAlexW4307266385

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.