What role does CYP1A2 play in Sport?

CYP1A2 encodes the enzyme primarily responsible for caffeine metabolism in the liver. In sports, caffeine is a well-known ergogenic aid that can enhance endurance, focus, and power output. The rs762551 variant defines fast (AA) and slow (AC/CC) metabolizers. According to the provided context (MyBody-X / MyFoodbook), slow metabolizers may experience elevated blood pressure with high caffeine intake. This suggests that athletes with the slow variant might not benefit as much from caffeine or could face adverse effects. However, the evidence for using this single gene to personalize caffeine dosing is limited. While some human studies show modest associations, the context does not cite peer-reviewed sources and is derived from a direct-to-consumer marketing document. Therefore, the evidence grade is 'marketing/unclear'. Practical takeaway: Caffeine response is influenced by many factors (diet, tolerance, timing). A direct caffeine metabolism test (e.g., saliva) is more reliable than genotype alone. Safety note: Individuals with hypertension or cardiovascular conditions should limit caffeine regardless of genotype.