Introduction
Caffeine (CAF) is one of the most widely used psychoactive substances in sports and in efforts to increase performance and alertnessSex-specific differences in responses to CAF supplementation have been widely reportedWhile several studies have been conducted on a variety of exercise patterns and demographics to identify the optimal CAF dosing regimen for exercise performance (i.e., dose, timing, and form), the influence of training status, competitive level, and sex of athletes have been relatively uncontrolledDifferences in performance enhancement following CAF ingestion have also been attributed to differences in training statusIn combat sports, especially taekwondo, athletes are classed based on their sex, body mass, age, and expertise/competitive levelWe hypothesized that male taekwondo athletes would respond to CAF intake more favourably than females at both elite and sub-elite levels, and the competitive advantage gained through caffeine supplementation would be greater for the elite than for sub-elite athletes.