Evidence map›Paper›PMID 42905127›Full record

Trial reportEuropean journal of sport science2026

The Effect of Acute Beetroot Juice and Caffeine Supplementation on Specific Judo Performance During a Simulated Competition Day in Judo Athletes.

Sefer Karabağ, Heidar Sajedi, Onur Güler, Vahdet Alaeddinoğlu, Ergün Çakır, Davar Khodadadi, Selahattin Akpınar

Abstract readRandomized Controlled Trial
In one paragraph

Trial report in European journal of sport science, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
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.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

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

7 authors.

Sefer KarabağSarıkamış Anatolian Imam Hatip High School, Ministry of National Education, Sarıkamış, Kars, Turkey.ORCID https://orcid.org/0000-0003-3553-0282
Heidar SajediDepartment of Movement and Training Sciences, Sport Science Faculty, Duzce University, Duzce, Turkey.ORCID https://orcid.org/0000-0002-0088-303X
Onur GülerDepartment of Sports Health Sciences, Graduate School of Winter Sports and Sports Sciences, Ataturk University, Erzurum, Turkey.ORCID https://orcid.org/0009-0009-6154-5809
Vahdet AlaeddinoğluDepartment of Reaction Sciences, Faculty of Sports Sciences, Ataturk University, Erzurum, Turkey.ORCID https://orcid.org/0000-0001-8432-0105
Ergün ÇakırDepartment of Coaching Education, Faculty of Sports Sciences, Van Yuzuncu Yıl University, Van, Turkey.ORCID https://orcid.org/0000-0001-5895-5297
Davar KhodadadiFaculty of Physical Education and Sports Sciences, Islamic Azad University Central Tehran Branch, Tehran, Iran.ORCID https://orcid.org/0000-0003-0546-6515
Selahattin AkpınarDepartment of Movement and Training Sciences, Sport Science Faculty, Duzce University, Duzce, Turkey.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Beetroot juice (BJ) and caffeine (CAF) are well-established ergogenic aids for exercise performance. However, little is known about their efficacy and interaction within the specific context of a judo competition day. This study investigated the acute effects of BJ, CAF, and their combination (BJCAF) on judo-specific performance across a simulated competition day. Using a randomized, double-blind, placebo-controlled crossover design, 35 competitive judo athletes (age 23 ± 5 years; body mass 74 ± 13 kg) completed 4 sessions (BJ, CAF, BJCAF, and placebo), each consisting of 5 trials of judo randori and a Special Judo Fitness Test (SJFT), followed by neuromuscular and cognitive assessments. Compared with placebo, CAF enhanced SJFT performance, neuromuscular function, and cognition in trials 1-3 but not in trial 5 (p < 0.05). Conversely, BJ improved these same metrics in trial 5 (p < 0.05). BJCAF enhanced SJFT performance across trials 1-3 and 5, cognitive functions in trials 1, 2, and 4, and neuromuscular performance in all trials (p < 0.05). Importantly, in trial 5, both BJ and BJCAF conditions yielded improved SJFT performance, neuromuscular function, and cognitive outcomes compared to CAF alone (p < 0.05). The results demonstrate that the ergogenic effect of CAF was not maintained throughout the simulated competition day, whereas BJ provided late-stage benefits. Co-ingestion effectively counteracted the later-session decline observed with CAF alone while maintaining its early advantages. This highlights the importance of considering temporal dynamics and metabolic costs when designing nutritional strategies for multi-bout, high-intensity sports tournaments such as judo.

Indexed as

Athletic PerformanceBeta vulgarisCaffeineDietary SupplementsFruit and Vegetable JuicesMartial ArtsPerformance-Enhancing SubstancesAdultCognitionCross-Over StudiesDouble-Blind MethodFemaleHumansMaleYoung AdultCaffeinePerformance-Enhancing Substancesbeetroot juicecaffeinecognitive functionmuscle oxygenationneuromuscular functionsimulated judo competition

Identifiers

PMID42905127
PMCPMC13685822

What OpenQuestion holds

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Registered trials

None linked

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.