Impact of CYP1A2 Genotypes on the Ergogenic Effects and Subjective Mood States of Caffeine Ingestion in Resistance-Trained Women

Nutrients. 2024 Aug 20;16(16):2767. doi: 10.3390/nu16162767.

Abstract

Caffeine's metabolism is determined by CYP1A2 genotypes: AC/CC (SLOW) and AA (FAST). This trial evaluated CYP1A2 genotypes' impact on exercise and cognitive effects in 36 resistance-trained females assessed under placebo (PL) and caffeine (6 mg/kg bw anhydrous caffeine-CAF) conditions, before ingestion and throughout the session. 23andMe® (San Francisco, CA, USA) determined genotypes using saliva. Data were analyzed using two-way RMANOVA and paired-samples t-tests (p < 0.05). A significant main effect for genotype existed for leg press repetitions to failure (RTF) for CAF (p = 0.038), with the FAST group performing more repetitions than the SLOW (p = 0.027). There was a significant condition x genotype interaction for the subjective outcome index score (p = 0.045), with significant differences for time (p < 0.01) and between genotype (p < 0.001). Follow-up analysis revealed a higher total score (p = 0.028) following CAF for the FAST group and a lower total score (p < 0.01) in the SLOW group. Dizziness was reported following CAF in the SLOW group (p = 0.014; Cohen's d = 0.725). Aside from leg press RTF, subjective outcome index score, and dizziness, the genotype groups experienced similar responses to resistance exercise performance and subjective mood states following caffeine ingestion.

Keywords: CYP1A2; caffeine; females; resistance training.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Affect* / drug effects
  • Caffeine* / administration & dosage
  • Caffeine* / pharmacology
  • Cytochrome P-450 CYP1A2* / genetics
  • Cytochrome P-450 CYP1A2* / metabolism
  • Double-Blind Method
  • Female
  • Genotype*
  • Humans
  • Performance-Enhancing Substances / administration & dosage
  • Performance-Enhancing Substances / pharmacology
  • Resistance Training*
  • Young Adult

Substances

  • Caffeine
  • Cytochrome P-450 CYP1A2
  • CYP1A2 protein, human
  • Performance-Enhancing Substances