Caffeine is considered a nutritional ergogenic that is abundantly found in nature. Nowadays, it is regularly consumed by billions of people in the world because it is very common in many foods. Even though it does not have a nutritional value, its use has been common in sports, for increased performance, particularly in middle and long duration exercises. So, the present study has the objective of searching literature, in which were analyzed many articles about experiments with caffeine in different kinds of exercise to demonstrate the physical performance increase. Despite the lack of agreement among researches about the effectiveness of this substance to optimize physical performance, many athletes have been using caffeine without a docto...