Caffeine is probably the most widely used pharmacological substance in the world. We all know how good that first cup of coffee in the morning can feel. Caffeine has been used widely in sport for over 20 years. It is thought to improve performance by interacting with adenosine receptors on the surface of cells, which causes an increase in alertness and a reduction in the perception of effort during strenuous activity. Australian pentathlete Alex Watson was famously sent home in disgrace from the 1988 Seoul Olympic Games for testing positive to caffeine. Back then, caffeine use in sport was restricted because it was thought that athletes needed to consume a lot of caffeine to improve performance and such high doses might result in adverse health effects in the long term. In 2004 caffeine use in sport has become unrestricted, and the focus of much research in the laboratory and out in the field. Our studies have shown that caffeine use by endurance athletes is very common, with almost 90% of athletes planning to use caffeine before or during the Hawaii Ironman triathlon. Laboratory tests have shown that you can get good results with relatively low doses of caffeine. The most effective dose before endurance exercise is 3mg per kilogram of body weight. For most people this equates to just two cups of coffee or two NoDoz tablets, taken an hour before exercise. Overall, the science indicates that a ‘hit’ of caffeine before your next endurance event will improve your performance! Dr Michael Leveritt Dr Michael Leveritt is a Senior Lecturer in Nutrition and Dietetics at The University of Queensland.