Fig. 1From: A Randomised, Placebo-Controlled, Crossover Study Investigating the Optimal Timing of a Caffeine-Containing Supplement for Exercise PerformanceOverview of the experimental protocol. CAFF, a commercially available beverage containing 200 mg of caffeine; PLA, placebo drink; HR, heart rate; RPE, rating of perceived exertion; VAS, visual analogue scales for alertness and paraesthesia. Treatments were randomly assigned in a crossover designBack to article page