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The influence of a CYP1A2 polymorphism on the ergogenic effects of caffeine
Open accessAbstract
BACKGROUND: Although caffeine supplementation improves performance, the ergogenic effect is variable. The cause(s) of this variability are unknown. A (C/A) single nucleotide polymorphism at intron 1 of the cytochrome P450 (CYP1A2) gene influences caffeine metabolism and clinical outcomes from caffeine ingestion. The purpose of this study was to determine if this polymorphism influences the ergogenic effect of caffeine supplementation. METHODS: Thirty-five trained male cyclists (age = 25.0 ± 7.3 yrs, height = 178.2 ± 8.8 cm, weight = 74.3 ± 8.8 kg, VO2max = 59.35 ± 9.72 ml·kg-1·min-1) participated in two computer-simulated 40-kilometer time trials on a cycle ergometer. Each test was performed one hour following ingestion of 6 mg·kg-1 of anhydrous caffeine or a placebo administered in double-blind fashion. DNA was obtained from whole blood samples and genotyped using restriction fragment length polymorphism-polymerase chain reaction. Participants were classified as AA homozygotes (N = 16) or C allele carriers (N = 19). The effects of treatment (caffeine, placebo) and the treatment × genotype interaction were assessed using Repeated Measures Analysis of Variance. RESULTS: Caffeine supplementation reduced 40 kilometer time by a greater (p < 0.05) magnitude in AA homozygotes (4.9%; caffeine = 72.4 ± 4.2 min, placebo = 76.1 ± 5.8 min) as compared to C allele carriers (1.8%; caffeine = 70.9 ± 4.3 min, placebo = 72.2 ± 4.2 min). CONCLUSIONS: Results suggest that individuals homozygous for the A allele of this polymorphism may have a larger ergogenic effect following caffeine ingestion.
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“Furthermore, evolving confirmation of genetic and other sources of individual variability in caffeine metabolism provides support for the well-known observations that some athletes are lowresponders [123] to caffeine or suffer side effects.”
From New strategies in sport nutrition to increase exercise performance (2016) · cites this paper as [123]
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“Caffeine is widely consumed as part of a normal diet, and there is clear evidence-for-efficacy regarding its ergogenic properties in a variety of sports [150–152], although the extent of the ergogenic effect is largely dependent on inter-individual genetic variance [153].”
From International Society of Sports Nutrition Position Stand: nutritional considerations for single-stage ultra-marathon training and racing (2019) · cites this paper as [153]
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Metadata
- Authors
- Womack, C. J., Saunders, M. J., Bechtel, M. K., Bolton, D. J., Martin, M., Luden, N. D., Dunham, W., & Hancock, M.
- Affiliations
- James Madison University (US)
- Corresponding author
- Womack, Christopher J
- ORCID
- Luden, Nicholas D
- Venue
- Journal of the International Society of Sports Nutrition
- Publisher
- Informa UK Limited
- Published
- 2012-02-06
- Volume
- 9
- Issue
- 1
- Pages
- 7-7
- ISSN
- 1550-2783 (ISSN-L)
- PMC
- PMC3334681
- OpenAlex
- W2130611622
- Cited by
- 178
- References
- 17
- Citations by year
- 2026: 7 · 2025: 15 · 2024: 23 · 2023: 12 · 2022: 12 · 2021: 13 · 2020: 16 · 2019: 14 · 2018: 22 · 2017: 10 · 2016: 10 · 2015: 10 · 2014: 5 · 2013: 5 · 2012: 2
- FWCI
- 5.18
- Type
- journal article
- Language
- en
- Update notices
- correction (2022-04-01)
- Open access
- gold
- doi.org
- Licence
- Locations
- Journal of the International Society of Sports Nutrition (publishedVersion, cc-by)
- Europe PMC (PubMed Central) (publishedVersion, cc-by)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
- Funders
- James Madison University
- University of Toronto
- Topics
- Health Sciences › Medicine › Pharmacology (medical) › Coffee research and impacts
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Genetics and Physical Performance
- Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Pharmacology › Pharmacogenetics and Drug Metabolism
- Keywords
- caffeine, CYP1A2, single nucleotide polymorphisms, caffeine metabolism, ergogenic aids, genetic variation, time trial performance, cyclists, genotype × treatment interaction, caffeine supplementation
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