SynthesisJournal of the International Society of Sports Nutrition2026
Placebo effects of caffeine on sport performance: a systematic review and meta-analysis.
Synthesis in Journal of the International Society of Sports Nutrition, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper, 1 of them a synthesis that pooled 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.
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.
Who cites it
1 citing paper in PubMed, 1 synthesis or guideline pooled it.
- Placebo effects of caffeine on sport performance: a systematic review and meta-analysis.Journal of the International Society of Sports Nutrition · 2026Pooled it
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundA 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).
methodsWe searched for studies sampling healthy adults from database creation to July 2026. The standardized mean difference (
resultsSeventeen 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 ( DISCUSSION: Data 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.
Indexed as
Identifiers
What OpenQuestion holds
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.