Fig. 4
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 lower-body maximal muscle 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)