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Analysis of institutional authors

Calvo, JlAuthor

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April 19, 2021
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Review

Caffeine and Cognitive Functions in Sports: A Systematic Review and Meta-Analysis

Publicated to: Nutrients. 13 (3): 868-18 - 2021-03-01 13(3), DOI: 10.3390/nu13030868

Authors:

Calvo, Jorge Lorenzo; Fei, Xueyin; Dominguez, Raul; Pareja-Galeano, Helios;
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Affiliations

Actividad Físico-Deportiva en Poblaciones Específicas. Universidad Politécnica de Madrid - Author
‎ Univ Europea Madrid, Fac Sports Sci, Madrid 28670, Spain - Author
‎ Univ Lavras, Studies Res Grp Neuromuscular Responses GEPREN, BR-37200000 Lavras, Brazil - Author
‎ Univ Politecn Madrid, Fac Ciencias Actividad Fis & Deporte, Sports Dept, Madrid 28040, Spain - Author
‎ Univ Seville, Dept Motricidad Humana & Rendimiento Deporte, Seville 41013, Spain - Author
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Abstract

Cognitive functions are essential in any form of exercise. Recently, interest has mounted in addressing the relationship between caffeine intake and cognitive performance during sports practice. This review examines this relationship through a structured search of the databases Medline/PubMed and Web of Science for relevant articles published in English from August 1999 to March 2020. The study followed PRISMA guidelines. Inclusion criteria were defined according to the PICOS model. The identified records reported on randomized cross-over studies in which caffeine intake (as drinks, capsules, energy bars, or gum) was compared to an identical placebo situation. There were no filters on participants' training level, gender, or age. For the systematic review, 13 studies examining the impacts of caffeine on objective measures of cognitive performance or self-reported cognitive performance were selected. Five of these studies were also subjected to meta-analysis. After pooling data in the meta-analysis, the significant impacts of caffeine only emerged on attention, accuracy, and speed. The results of the 13 studies, nevertheless, suggest that the intake of a low/moderate dose of caffeine before and/or during exercise can improve self-reported energy, mood, and cognitive functions, such as attention; it may also improve simple reaction time, choice reaction time, memory, or fatigue, however, this may depend on the research protocols.
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Keywords

AdultAthletesAthletic performanceCaffeineCognitionCognitive functionErgogenic drinksFemaleHumansMalePerformance-enhancing substancesRandomized controlled trials as topicSport

Quality index

Bibliometric impact. Analysis of the contribution and dissemination channel

The work has been published in the journal Nutrients due to its progression and the good impact it has achieved in recent years, according to the agency WoS (JCR), it has become a reference in its field. In the year of publication of the work, 2021, it was in position 15/90, thus managing to position itself as a Q1 (Primer Cuartil), in the category Nutrition & Dietetics.

From a relative perspective, and based on the normalized impact indicator calculated from World Citations provided by WoS (ESI, Clarivate), it yields a value for the citation normalization relative to the expected citation rate of: 1.15. This indicates that, compared to works in the same discipline and in the same year of publication, it ranks as a work cited above average. (source consulted: ESI Nov 13, 2025)

This information is reinforced by other indicators of the same type, which, although dynamic over time and dependent on the set of average global citations at the time of their calculation, consistently position the work at some point among the top 50% most cited in its field:

  • Weighted Average of Normalized Impact by the Scopus agency: 3.58 (source consulted: FECYT Mar 2025)

Specifically, and according to different indexing agencies, this work has accumulated citations as of 2025-12-21, the following number of citations:

  • WoS: 20
  • Scopus: 63
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Impact and social visibility

From the perspective of influence or social adoption, and based on metrics associated with mentions and interactions provided by agencies specializing in calculating the so-called "Alternative or Social Metrics," we can highlight as of 2025-12-21:

  • The use, from an academic perspective evidenced by the Altmetric agency indicator referring to aggregations made by the personal bibliographic manager Mendeley, gives us a total of: 303.
  • The use of this contribution in bookmarks, code forks, additions to favorite lists for recurrent reading, as well as general views, indicates that someone is using the publication as a basis for their current work. This may be a notable indicator of future more formal and academic citations. This claim is supported by the result of the "Capture" indicator, which yields a total of: 300 (PlumX).

With a more dissemination-oriented intent and targeting more general audiences, we can observe other more global scores such as:

  • The Total Score from Altmetric: 55.
  • The number of mentions on the social network Facebook: 2 (Altmetric).
  • The number of mentions on the social network X (formerly Twitter): 68 (Altmetric).
  • The number of mentions in news outlets: 1 (Altmetric).

It is essential to present evidence supporting full alignment with institutional principles and guidelines on Open Science and the Conservation and Dissemination of Intellectual Heritage. A clear example of this is:

  • The work has been submitted to a journal whose editorial policy allows open Open Access publication.
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Leadership analysis of institutional authors

This work has been carried out with international collaboration, specifically with researchers from: Brazil.

There is a significant leadership presence as some of the institution’s authors appear as the first or last signer, detailed as follows: First Author (LORENZO CALVO, JORGE) .

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