{
  "abstract": "Background\n\nA body of research has shown that deceptively administering a placebo described as caffeine can significantly improve sport performance. We aimed to synthesize and estimate the effect size of the deceptive administration of a placebo described as caffeine on sport performance outcomes (e.g. bench press, cycling time-trial, repeated sprint).Methods\n\nWe searched for studies sampling healthy adults from database creation to July 2026. The standardized mean difference (d) between placebo caffeine and baseline was calculated and Cochrane's risk of bias assessment was used.Results\n\nSeventeen studies were included. Nine studies were judged to be of high-risk of bias and eight unclear. Random-effect models revealed a small-to-moderate effect of placebo caffeine benefiting performance (d = 0.49, 95% CI = 0.28 to 0.69) and meta-regressions indicated that pooled effects were more likely to be greater when researchers were blinded (b = 0.52 ± 0.24, 95% CI = 0.01 to 0.99) and in studies sampling more males (b = -0.93 ± 0.38, 95% CI = -1.68 to -0.19).Discussion\n\nData highlight that placebo effects of caffeine can significantly affect sport performance with a pooled effect estimate suggesting a small-to-moderate effect. However, as per the GRADE assessment, the overall quality of evidence was low. As such, given the high risk of bias across all studies and the variation in confidence interval, stronger research designs are needed to examine placebo effects of caffeine, whereby researchers are blinded to treatment administration and allocation concealment. No funding was received for the review and the protocol can be found here: doi: 10.17605/OSF.IO/W8KY6.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Sport & Exercise, Canterbury Christ Church University, Canterbury, United Kingdom.",
    "Applied Physiology and Nutrition Research Group - School of Physical Education and Sport and Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo, Brazil.",
    "Center of Lifestyle Medicine, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo, Brazil.",
    "Erasmus University Rotterdam, Department of Medical Informatics, Rotterdam, The Netherlands.",
    "Postgraduate Program in Biosciences and Human Health, Minas Gerais State University, Divinopolis, Minas Gerais, Brazil.",
    "Federal University of Juiz de Fora, Department of Physiology, Juiz de Fora, Sao Paulo, Brazil."
  ],
  "article_type": "systematic review",
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Philip Hurst",
      "orcid": "0000-0002-9265-2975"
    },
    {
      "affs": [
        0
      ],
      "name": "Janina Hanssen",
      "orcid": "0009-0008-2782-6909"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "Felipe Marticorena",
      "orcid": "0000-0002-8712-4975"
    },
    {
      "affs": [
        3
      ],
      "name": "Lieke Schiphof-Godart",
      "orcid": "0000-0001-9190-5398"
    },
    {
      "affs": [
        4
      ],
      "name": "Hiago L R Souza",
      "orcid": "0000-0002-2488-7502"
    },
    {
      "affs": [
        5
      ],
      "name": "Moacir Marocolo",
      "orcid": "0000-0002-7715-2534"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "Bryan Saunders",
      "orcid": "0000-0003-0995-9077"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9f5pjy2xk2c5m.bib",
  "cited_by": 0,
  "doi": "10.1080/15502783.2026.2747142",
  "fulltext_url": "https://europepmc.org/articles/PMC13686187",
  "id": "9f5pjy2xk2c5m",
  "issns": [
    "1550-2783"
  ],
  "landing_url": "https://europepmc.org/article/MED/42897966",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2805|Pain Management and Placebo Effect"
    ]
  ],
  "openalex": "W7223024611",
  "pdf_url": "https://europepmc.org/articles/PMC13686187?pdf=render",
  "pmcid": "PMC13686187",
  "pmid": "42897966",
  "published": "2026-10-20",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/9f5pjy2xk2c5m.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:32Z",
      "native_id": "MED:42897966",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42897966"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "openalex:2805|Pain Management and Placebo Effect",
      "subfield": "neuroscience"
    }
  ],
  "title": "Placebo effects of caffeine on sport performance: a systematic review and meta-analysis.",
  "title_text": "Placebo effects of caffeine on sport performance: a systematic review and meta-analysis.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:19:32Z",
  "url": "https://research.draconitic.com/paper/9f5pjy2xk2c5m",
  "venue": "Journal of the International Society of Sports Nutrition",
  "versions": []
}