Supplementation
Employing a double-blind randomised crossover design, participants attended the exercise laboratory on 3-separate days, each 1-week apart. Participants were asked not to eat in the 2-h before testing and not to consume caffeine or alcohol in the 24-h prior to testing. During the intervention, participants were also asked to maintain their regular diet and not to consume any supplements. On each visit, participants drank a different supplement in a randomised order: caffeine (5 mg/kg) (Caffeine, Loughborough, Fisher Scientific), guarana (125 mg/kg) (Guarana Powder, Brighton, The Guarana Company Ltd.) or placebo (65 mg/kg) (protein powder containing undenatured whey protein isolate and instantising agent). The caffeine dose in both caffeine and guarana supplement is in line with the suggested protocol of use by the International Olympic CommitteeA 