Caffeine is commonly used to improve athletic performance across a variety of sports. Previously, the CYP1A2 gene has been shown to modify the effects of caffeine on endurance performance. The effect of caffeine on strength and power activities is unclear and may differ depending on an individual’s CYP1A2 genotype. A randomized controlled trial was used to determine whether caffeine impacts strength and power, determined by the handgrip and vertical jump tests, respectively, and whether CYP1A2 genotype modifies any effects. Competitive male athletes (age = 25 ± 4 years) completed vertical jump (n = 97), and handgrip tests (n = 102) under three conditions: 0 (placebo), 2, or 4 mg of caffeine per kilogram of body mass (in milligrams per kilogram). CYP1A2 (rs762551) genotype was determined from saliva samples. No differences between caffeine doses and placebo were observed for strength or power; however, significant Caffeine × Gene interactions were observed for all exercise tests. Individuals with the CC genotype experienced a 12.8% decrease in handgrip strength with 4 mg/kg of caffeine compared with placebo (53 ± 11 kg vs. 61 ± 17 kg, p = .02). No differences were observed in those with the AC or AA genotypes. Despite observing a significant Caffeine × Gene interaction for vertical jump performance, no differences were observed between caffeine doses and placebo for all genotypes. In summary, caffeine (4 mg/kg) worsened handgrip strength performance in those with the CC genotype, but no differences were observed in those with the AC or AA genotypes. Athletes may want to consider their CYP1A2 genotype prior to using caffeine to improve muscle strength.

咖啡因通常用于提高各种运动的运动表现。此前，CYP1A2基因已被证明可以改变咖啡因对耐力表现的影响。咖啡因对力量和力量活动的影响尚不清楚，并且可能因个体的CYP1A2基因型而异。一项随机对照试验用于确定咖啡因是否会影响力量和爆发力，分别由手柄和垂直跳跃测试确定，以及CYP1A2基因型是否会改变任何影响。竞技男运动员（年龄 = 25 ± 4 岁）完成了垂直跳跃（n  = 97）和握力测试（n = 102）在三种情况下：0（安慰剂）、2 或 4 毫克咖啡因/千克体重（以毫克/千克为单位）。从唾液样本中确定CYP1A2 (rs762551) 基因型。没有观察到咖啡因剂量和安慰剂之间的强度或力量差异；然而，在所有运动测试中都观察到显着的咖啡因 × 基因相互作用。与安慰剂相比，具有 CC 基因型的个体使用 4 mg/kg 咖啡因的握力下降了 12.8%（53 ± 11 kg 对 61 ± 17 kg，p = .02)。在具有 AC 或 AA 基因型的人中没有观察到差异。尽管观察到垂直跳跃表现有显着的咖啡因×基因相互作用，但对于所有基因型，咖啡因剂量和安慰剂之间没有观察到差异。总之，咖啡因（4 mg/kg）使 CC 基因型患者的握力表现恶化，但在 AC 或 AA 基因型患者中没有观察到差异。在使用咖啡因提高肌肉力量之前，运动员可能需要考虑他们的CYP1A2基因型。