ArticlePloS one2026
Caffeine ingestion improves morning neuromuscular performance to evening levels in healthy females.
Article in PloS one, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.
What it found
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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.
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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.
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Who cites it
3 citing papers in PubMed.
- Circadian phenotype is associated with diurnal variation in human exercise performance.European journal of applied physiology · 2026Trial
- Effects of Acute Caffeine Ingestion on Morning Strength, Power and Repeated Sprint Measures in Males: A Standardized Approach.Nutrients · 2026Trial
- Chrono-Exercise Medicine: Why Biological Timing Matters for Human Health.Biomedicines · 2026Article
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Authors and funding
2 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
purposeTo investigate whether caffeine ingestion offsets the circadian-related decline in morning neuromuscular performance in females.
methodsThirteen healthy females completed three experimental trials: i) evening placebo (PMPLAC), ii) morning placebo (AMPLAC), and iii) morning caffeine ingestion (6 mg·kg⁻¹; AMCAFF). A within-subject, repeated-measures, crossover, single-blind placebo design was used, with all subjects serving as their own controls. Each trial consisted of a maximal voluntary isometric contraction (MVIC) of the knee extensors, followed by intermittent isometric contractions (6 s contraction, 4 s rest) until task failure, and a post-fatigue MVIC. Time to exhaustion, torque and peak force, surface electromyography (RMS amplitude, MDF frequency), rate of perceived exertion, and tympanic temperature were all recorded across conditions.
resultsDuring PMPLAC, peak force and time to exhaustion were significantly greater (p < 0.05) than for AMPLAC. Peak force was higher (p < 0.01) in AMCAFF in both pre- (+33%) and post- (+45%) fatigue MVIC trials compared to PMPLAC. Similarly, RMS was higher (p < 0.01) during both AMCAFF and PMPLAC compared to AMPLAC, whereas MDF did not change (p > 0.05) across trials. AMCAFF also improved (p < 0.01) time to exhaustion by 43% compared to AMPLAC, and significantly reduced (p < 0.01) rate of perceived exertion, but without any change (p > 0.05) in temperature.
conclusionsMorning ingestion of 6 mg·kg⁻¹ of caffeine effectively reverses diurnal reductions in neuromuscular performance of females by enhancing peak force and time to exhaustion to evening levels. No change in MDF, but an increased RMS suggests a central rather than peripheral mechanism for caffeine's ergogenic effects.
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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.