Fig. 2
From: Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis
Forest plot showing differences between the effects of placebo and caffeine trials on measures of maximal muscular strength. The size of the plotted squares reflects the relative statistical weight of each study. The numbers on the x-axis denote the standardized mean differences expressed as Hedge’s g. The horizontal lines denote the respective 95% confidence intervals (CI)