Caffeine can be a legal way to enhance athletic performance, though studies have shown mixed results. Genetic variation may be the reason caffeine does not work the same for everyone. Many studies have shown that caffeine can increase a person’s athletic performance, but these studies have also shown that these effects are not universal throughout the participants. A new study examines the link between caffeine’s effects and genetic differences between people. Caffeine may give you an extra edge in sports. Dr. Christopher J. Womack, PhD, a researcher and professor at Jam...