The Association of Gene Polymorphisms Linked to Caffeine Use with Athletic Performance

Caffeine's use as a performance-enhancing supplement among professional athletes progressively increased after it was taken off the World Anti-Doping Agency's (WADA) list of banned substances. The present review looks at the interactions caused by different levels of caffeine ergogenicity in athletes and gene polymorphisms that affect caffeine ergogenic effect in the current literature. Therefore, a comprehensive analysis of the studies available in the literature and the respective study results have evaluated caffeine ergogenicity in athletes and gene polymorphisms. The search for studies was performed through five databases. Individual responses to caffeine consumption may differ from person to person due to multigene and multifactorial interactions. Adenosine A2A receptor (ADORA2A) and Cytochrome P450 1A2 (CYP1A2) are two genes thought to have the most effects on caffeine's ergogenicity. The function of these two genes accounts for most inter-individual variations in studies after caffeine ingestion. Based on the findings, it is understood that the contribution of caffeine use to individual performance development varies over time due to changes in both environmental and epigenetic interactions, as well as parameters such as circadian rhythm, training loads, nutritional routine, habitual caffeine use, drug intake, expectation, time of consumption, and heredity. As a result, individual caffeine responses are highly complex and involve multiple modifiers.