The Influence of CYP1A2 Polymorphism on the Ergogenic Effects of Caffeine Across Different Athletic Modalities: A Systematic Review
DOI:
https://doi.org/10.12775/QS.2026.64.73735Keywords
caffeine, genetic, polymorphism, CYP1A2, physical performance, ergogenic effect, sportAbstract
Background: Caffeine’s ergogenic effect varies among athletes, heavily influenced by the CYP1A2 (-163C>A) gene polymorphism. This systematic review evaluates the mode-specific influence of CYP1A2 genotypes on caffeine's efficacy across diverse athletic modalities.
Material and methods: A systematic search across PubMed, Scopus, and Web of Science identified 10 randomized, double-blind, placebo-controlled trials that evaluated performance outcomes following acute caffeine supplementation, stratified by CYP1A2 genotype.
Results: In continuous endurance and anaerobic power tasks, AA homozygotes ("fast metabolizers") consistently exhibited profound performance enhancements (4.8%–6.8%). Conversely, high caffeine doses (≥4 mg/kg) induced a severe ergolytic effect in CC homozygotes ("slow metabolizers"), causing decrements in endurance (-13.7%) and maximal handgrip strength (-12.8%). Interestingly, this genetic divergence was blunted in complex, skill-based team sports, where caffeine provided broad neuromuscular benefits independent of genotype. Pharmacokinetic data supported these findings, while baseline trainability remained uninfluenced by the polymorphism.
Conclusions: The impact of CYP1A2 on caffeine ergogenicity is highly modality-specific. Universal dosing is inherently flawed; personalized protocols guided by genetic testing are crucial to optimize performance and prevent impairment in susceptible athletes.
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Copyright (c) 2026 Michał Kalisiak, Małgorzata Czechowska, Michał Kasznicki, Wiktor Beśka, Natalia Micek, Jakub Łącki, Emilia Skrzypek, Alicja Rogozińska, Mikołaj Kamela, Karol Jackowiak
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