Placebo effects of caffeine on maximal voluntary concentric force of the knee flexors and extensors
Tallis J, Muhammad B, Islam M, Duncan MJ
Muscle & nerve · 37 citations
How it was studied
- Design
- Randomized controlled trial (indexed by PubMed)
- Studied in
- People
- Main outcome
- Health markers and function
Who paid for it
- Funding
- Independent funding
- University or hospital
- Coventry University
Based on 1 listed funder(s).
Publication
- Published
- 2016-01-28 · Muscle Nerve · vol. 54 · issue 3 · pp. 479–486
- Publisher
- Wiley
- Cited
- 50 citations · more than 90% of similar papers · 2.9× the field average
- References
- 47 works
- Access
- Open access (repository copy) · OTHER-OA
- Research areas
- Muscle metabolism and nutrition · Eating Disorders and Behaviors · Pharmacology and Obesity Treatment
- Keywords
- Caffeine, Placebo, Concentric, Expectancy theory, Psychology, Physical therapy, Physical medicine and rehabilitation, Anesthesia, Medicine, Internal medicine, Social psychology
- MeSH
- muscle, skeletal, knee joint, humans, caffeine, central nervous system stimulants, analysis of variance, single-blind method, perception, placebo effect, muscle contraction, male, muscle strength dynamometer, young adult
4 authors
From GB
- Jason A. Tallis · correspondingCoventry University
- Bilal MuhammadCoventry University
- Mohammed Amirul IslamCoventry University
- Michael Joseph DuncanCoventry University
Abstract
Introduction
We examined the placebo effect of caffeine and the combined effect of caffeine and caffeine expectancy on maximal voluntary strength.
Methods
Fourteen men completed 4 randomized, single-blind experimental trials: (1) told caffeine, given caffeine (5 mg/kg) (CC); (2) told caffeine, given placebo (CP); (3) told placebo, given placebo (PP); and (4) told placebo, given caffeine (PC). Maximal voluntary concentric force and fatigue resistance of the knee flexors and extensors were measured using isokinetic dynamometry.
Results
A significant and equal improvement in peak concentric force was found in the CC and PC trials. Despite participants believing caffeine would evoke a performance benefit, there was no effect of CP.
Conclusion
Caffeine caused an improvement in some aspects of muscle strength, but there was no additional effect of expectancy. Performance was poorer in participants who believed caffeine would have the greatest benefit, which highlights a link between expected ergogenicity, motivation, and personality characteristics. Muscle Nerve 54: 479-486, 2016.
Abstract via Europe PMC. Copyright remains with the authors or publisher.
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