Evidence map›Paper›PMID 33413459›Full record

ArticleJournal of the International Society of Sports Nutrition2021

Caffeine increases maximal fat oxidation during a graded exercise test: is there a diurnal variation?

Mauricio Ramírez-Maldonado, Lucas Jurado-Fasoli, Juan Del Coso, Jonatan R Ruiz, Francisco J Amaro-Gahete

Registry-linked trialOpen access · goldAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Journal of the International Society of Sports Nutrition, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT04320446 (Caffeine Increases Maximal Fat Oxidation During Exercise in Endurance-trained Men), which is not on this map. Cited by 23 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
23citing papers in PubMed, 1 pooled it
4.0field-weighted citation impact, top 6% 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.

NCT04320446 nacompletednot on this map

Caffeine Increases Maximal Fat Oxidation During Exercise in Endurance-trained Men: is There a Diurnal Variation

TypeinterventionalSponsorUniversidad de GranadaRan2019 to 2019Enrolled15ConditionsEnergy Metabolism, Athletic PerformanceArmsTest in the morning, Test in the afternoon
3 · Its place in the literature

Who cites it

23 citing papers in PubMed, 1 synthesis or guideline pooled it, 30 citations in OpenAlex.

  1. Pooled it
  2. Trial
  3. Influence of the CYP1A2 c.European journal of nutrition · 2024
    Trial
  4. Trial
  5. Trial
  6. Trial
  7. Effect ofNutrients · 2022
    Trial
  8. Trial
  9. Trial
  10. Review
  11. The Role of Exercise in Fat Oxidation and Its Impact on Adolescent Metabolism.Advances in experimental medicine and biology · 2026
    Review
  12. Association between caffeine intake and fat free mass index: a retrospective cohort study.Journal of the International Society of Sports Nutrition · 2025
    Article
  13. Article
  14. Review
  15. Review
  16. Review
  17. Review
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  20. Review
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 2 institutions in 1 country.

Mauricio Ramírez-MaldonadoPROFITH "PROmoting FITness and Health Through Physical Activity" Research Group, Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain.
Lucas Jurado-FasoliDepartment of Physiology. Faculty of Medicine, University of Granada, Av. Conocimiento S/n, 18011, Granada, Spain.
Juan Del CosoCentre for Sport Studies, Rey Juan Carlos University, Madrid, Spain.
Jonatan R RuizPROFITH "PROmoting FITness and Health Through Physical Activity" Research Group, Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain.
Francisco J Amaro-GaheteDepartment of Physiology. Faculty of Medicine, University of Granada, Av. Conocimiento S/n, 18011, Granada, Spain. amarof@ugr.es.ORCID http://orcid.org/0000-0002-7207-9016
Universidad de Granada · ESUniversidad Rey Juan Carlos · ES

Funding

Universidad de Granada Excellence actions: Unit of Excellence on Exercise and Health (UCEES)-and Plan Propio de Investigación 2018
6 · The paper itself

Abstract

backgroundThere is evidence that caffeine increases the maximal fat oxidation rate (MFO) and aerobic capacity, which are known to be lower in the morning than in the afternoon. This paper examines the effect of caffeine intake on the diurnal variation of MFO during a graded exercise test in active men.

methodsUsing a triple-blind, placebo-controlled, crossover experimental design, 15 active caffeine-naïve men (age: 32 ± 7 years) completed a graded exercise test four times at seven-day intervals. The subjects ingested 3 mg/kg of caffeine or a placebo at 8 am in the morning and 5 pm in the afternoon (each subject completed tests under all four conditions in a random order). A graded cycling test was performed. MFO and maximum oxygen uptake (VO

resultsMFO, Fat

conclusionThese findings confirm the previously reported diurnal variation in the whole-body fat oxidation rate during graded exercise in active caffeine-naïve men, and indicate that the acute ingestion of 3 mg/kg of caffeine increases MFO, Fat

trial registrationNCT04320446 . Registered 25 March 2020 - Retrospectively registered.

Indexed as

Adipose TissueAdultCaffeineCalorimetry, IndirectCross-Over StudiesEpidemiologic Research DesignExerciseExercise TestHumansMaleOxidation-ReductionOxygen ConsumptionPerformance-Enhancing SubstancesPhysical EndurancePlacebosTime FactorsCaffeinePerformance-Enhancing SubstancesPlacebosBody compositionBody weightDietary supplementExercise performanceNutrition

Identifiers

PMID33413459
PMCPMC7792284
OpenAlexW3120267642

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

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.