Trial reportNutrients2019
Impact of Caffeine Intake on 800-m Running Performance and Sleep Quality in Trained Runners.
Trial report in Nutrients, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 22 papers, 4 of them syntheses 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
22 citing papers in PubMed, 4 syntheses or guidelines pooled it, 40 citations in OpenAlex.
- Effects of caffeine supplementation on post-exercise recovery: a systematic review and three-level meta-analysis of perceptual, functional performance, physiological, and sleep outcomes.Frontiers in physiology · 2026Pooled it
- Efficacy of dietary supplements on sports performance outcomes: a systematic review of evidence in elite athletes.Frontiers in nutrition · 2025Pooled it
- Effects of Caffeine Intake on Endurance Running Performance and Time to Exhaustion: A Systematic Review and Meta-Analysis.Nutrients · 2022Pooled it
- The Impact of Dietary Factors on the Sleep of Athletically Trained Populations: A Systematic Review.Nutrients · 2022Pooled it
- Trial
- Acute caffeine supplementation enhances several aspects of shot put performance in trained athletes.Journal of the International Society of Sports Nutrition · 2022Trial
- Acute Effects of a Low Dose of Caffeine on Physiological and Performance Factors in Young Male Soccer Players: A Randomized Crossover Study.Current developments in nutrition · 2026Article
- Uncovering Sleep Behaviour in Women's Football: What Evidence Do We Have?Sports medicine (Auckland, N.Z.) · 2026Review
- Bidirectional effects of physical activity and sleep on health: evidence and future directions.Frontiers in sports and active living · 2026Review
- Device for Electrochemical Caffeine Analysis in Fluids (DECAF): A Stir-Bar-Embedded Sensor for Real-Time Caffeine Analysis in Commercial and Homemade Beverages.Small (Weinheim an der Bergstrasse, Germany) · 2025Article
- Exploring the Impact and Mechanisms of Coffee and Its Active Ingredients on Depression, Anxiety, and Sleep Disorders.Nutrients · 2025Review
- The Effect of Consuming Caffeine Before Late Afternoon/Evening Training or Competition on Sleep: A Systematic Review with Meta-Analysis.Sports (Basel, Switzerland) · 2025Review
- Associations of caffeine and caffeine metabolites with sex hormones among 6-19-year-old children and adolescents.Scientific reports · 2025Article
- Varying doses of evening caffeine ingestion have different effects on rowing ergometer performance, sleep quality, and wakefulness scores.Frontiers in nutrition · 2025Article
- Prediction of half-marathon performance of male recreational marathon runners using nomogram.BMC sports science, medicine & rehabilitation · 2024Article
- The Effect of Caffeine Supplementation on Female Volleyball Players' Performance and Wellness during a Regular Training Week.Nutrients · 2023Article
- Review
- Article
- The Relationship Between Dietary Intake and Sleep Quality in Endurance Athletes.Frontiers in sports and active living · 2022Article
- International society of sports nutrition position stand: caffeine and exercise performance.Journal of the International Society of Sports Nutrition · 2021Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundCaffeine ingestion improves athletic performance, but impairs sleep quality. We aimed to analyze the effect of caffeine intake on 800-m running performance, sleep quality (SQ), and nocturnal cardiac autonomic activity (CAA) in trained runners.
methodsFifteen male middle-distance runners participated in the study (aged 23.7 ± 8.2 years). In a randomized and comparative crossover study design, the athletes ingested a placebo (PL) or caffeine supplement (CAF; 6 mg∙kg
resultsNo significant differences in CAA and performance variables were found between the two conditions. However, CAF impaired sleep efficiency (
conclusionThe supplementation with caffeine (6 mg∙kg
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.