Genetic Modifiers of Caffeine Intake and Athletic Performance

Numerous studies have investigated the effect of caffeine on athletic performance, but the findings have not been consistent. This is due, in part, to the differences in response that has been observed both within and between studies. Previous research in our lab has shown that genetic variations affecting caffeine metabolism modify the association between caffeine and heart disease. We hypothesize that the inconsistencies among studies relating caffeine and athletic performance may be due to genetic differences in caffeine metabolism or response. Male athletes will take part in an intervention of caffeine versus placebo, using a randomized double-blinded placebo-controlled design, which will test various exercise protocols (power, strength, anaerobic capacity, endurance) that are associated with performance across multiple sports. We will conduct a genome-wide association study, which is an approach that involves scanning for markers across the genomes of our study participants together, not individuals, to find genetic variations associated with a particular trait such as VO2 max, lactate clearance efficiency, muscle fiber type and changes in exercise performance following caffeine. We will also examine known genetic variations that are associated with caffeine metabolism and response, to determine if these genes also affect response to exercise after ingesting caffeine. Subjects will be paid $50.