Moderators of Caffeine's Effects on Jumping Performance in Females: A Systematic Review and Meta-Analysis.

In the main meta-analysis, which included 15 studies and ∼200 participants, we found a small but very precise ergogenic effect of caffeine on vertical jumping performance in females.In a subgroup analysis for phase of the menstrual cycle, the ergogenic effects of caffeine on jumping performance were the largest in the follicular phase.An ergogenic effect of caffeine was consistently found in analyses for testing time of day (morning, evening, mixed morning or evening, or not specified), caffeine dose (≤3 mg/kg or >3 mg/kg) and test type (squat or countermovement jump).