Evidence map›Paper›PMID 25969895›Full record

ArticleScientific reports2015

Caffeine-induced increase in voluntary activation and strength of the quadriceps muscle during isometric, concentric and eccentric contractions.

Martin Behrens, Anett Mau-Moeller, Matthias Weippert, Josefin Fuhrmann, Katharina Wegner, Ralf Skripitz, Rainer Bader, Sven Bruhn

Open access · goldAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Scientific reports, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 51 papers, 4 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
51citing papers in PubMed, 4 pooled it
17.8field-weighted citation impact, top 1% of its field
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

51 citing papers in PubMed, 4 syntheses or guidelines pooled it, 92 citations in OpenAlex.

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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

8 authors at 1 institution in 1 country.

Martin BehrensDepartment of Exercise Science, University of Rostock, Ulmenstrasse 69, 18057 Rostock, Germany.
Anett Mau-MoellerDepartment of Orthopaedics, University Medicine Rostock, Doberaner Strasse 142, 18057 Rostock, Germany.
Matthias Weippert1] Department of Exercise Science, University of Rostock, Ulmenstrasse 69, 18057 Rostock, Germany [2] Institute of Exercise Physiology and Public Health, Trotzenburger Weg 15, 18057 Rostock, Germany.
Josefin FuhrmannDepartment of Exercise Science, University of Rostock, Ulmenstrasse 69, 18057 Rostock, Germany.
Katharina WegnerDepartment of Orthopaedics, University Medicine Rostock, Doberaner Strasse 142, 18057 Rostock, Germany.
Ralf SkripitzDepartment of Orthopaedics, University Medicine Rostock, Doberaner Strasse 142, 18057 Rostock, Germany.
Rainer BaderDepartment of Orthopaedics, University Medicine Rostock, Doberaner Strasse 142, 18057 Rostock, Germany.
Sven BruhnDepartment of Exercise Science, University of Rostock, Ulmenstrasse 69, 18057 Rostock, Germany.
University of Rostock · DE

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

This study investigated effects of caffeine ingestion (8 mg/kg) on maximum voluntary torque (MVT) and voluntary activation of the quadriceps during isometric, concentric and eccentric contractions. Fourteen subjects ingested caffeine and placebo in a randomized, controlled, counterbalanced, double-blind crossover design. Neuromuscular tests were performed before and 1 h after oral caffeine and placebo intake. MVTs were measured and the interpolated twitch technique was applied during isometric, concentric and eccentric contractions to assess voluntary activation. Furthermore, normalized root mean square of the EMG signal was calculated and evoked spinal reflex responses (H-reflex evoked at rest and during weak isometric voluntary contraction) as well as twitch torques were analyzed. Caffeine increased MVT by 26.4 N m (95%CI: 9.3-43.5 N m, P = 0.004), 22.5 N m (95%CI: 3.1-42.0 N m, P = 0.025) and 22.5 N m (95%CI: 2.2-42.7 N m, P = 0.032) for isometric, concentric and eccentric contractions. Strength enhancements were associated with increases in voluntary activation. Explosive voluntary strength and voluntary activation at the onset of contraction were significantly increased following caffeine ingestion. Changes in spinal reflex responses and at the muscle level were not observed. Data suggest that caffeine ingestion induced an acute increase in voluntary activation that was responsible for the increased strength regardless of the contraction mode.

Indexed as

AdultCaffeineElectromyographyEvoked PotentialsFemaleHumansMaleMuscle ContractionMuscle StrengthQuadriceps MuscleYoung AdultCaffeine

Identifiers

PMID25969895
PMCPMC4429543
OpenAlexW2348851344

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

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.