Caffeine, CYP1A2 Genotype, and Endurance Performance in Athletes

Area of Science:

• Exercise Physiology
• Nutrigenomics
• Pharmacogenetics

Background:

• Caffeine is a widely studied ergogenic aid for athletic performance.
• Previous research on caffeine's effects on exercise has yielded inconsistent results.
• Genetic variations, particularly in the CYP1A2 gene, may explain individual differences in caffeine response.

Purpose of the Study:

• To investigate if CYP1A2 gene variation modifies the ergogenic effects of caffeine.
• To examine caffeine's impact on 10-km cycling time trial performance in relation to CYP1A2 genotype.
• To determine personalized caffeine recommendations for endurance athletes based on genetic makeup.

Main Methods:

• A randomized, double-blinded, placebo-controlled study involving 101 male athletes.
• Participants completed a 10-km cycling time trial after ingesting 0, 2, or 4 mg/kg of caffeine.
• Saliva DNA was genotyped for the CYP1A2 gene -163A > C polymorphism (rs762551).

Main Results:

• Caffeine at 4 mg/kg significantly decreased overall cycling time by 3% compared to placebo.
• A significant interaction between caffeine dosage and CYP1A2 genotype was observed (P < 0.0001).
• Athletes with the AA genotype showed improved cycling times with 2 and 4 mg/kg caffeine, while CC genotype athletes experienced performance reduction at 4 mg/kg. AC genotype showed no effect.

Conclusions:

• CYP1A2 genotype significantly influences the ergogenic effects of caffeine on 10-km cycling performance.
• Caffeine enhances performance in AA genotype individuals, has no effect in AC, and impairs performance in CC genotype individuals at higher doses.
• Genetic testing for CYP1A2 polymorphism may aid in personalized caffeine supplementation strategies for athletes.