Women experience the same ergogenic response to caffeine as men

This study aimed to determine if 1) consumption of caffeine improves endurance cycling performance in women, and 2) sex differences exist in the magnitude of the ergogenic and plasma responses to caffeine supplementation.Twenty-seven (11 women and 16 men) endurance-trained cyclists and triathletes participated in this randomized, double-blind, placebo-controlled, crossover study. Participants completed an incremental exercise test to exhaustion, two familiarization trials and two performance trials. Ninety minutes prior to the performance trials participants ingested opaque capsules containing either 3 mg·kg body mass of anhydrous caffeine or a placebo. They then completed a set amount of work (75% of peak sustainable power output) in the fastest possible time. Plasma was sampled at baseline, pre- and post-exercise for caffeine. Strict standardization and verification of diet, hydration, training volume and intensity, and for women, contraceptive hormone phase was implemented.Performance time was significantly improved following caffeine administration in women (placebo: 3863±419s, caffeine: 3757±312s; p=0.03) and men (placebo: 3903±341s, caffeine: 3734±287s;