Fig. 2
![Fig. 2](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs12970-021-00463-z/MediaObjects/12970_2021_463_Fig2_HTML.png)
Forest plot of effect sizes (i.e., Hedge’s g) for all 19 studies of the effects of dietary NO3− supplementation on maximal muscle power included in the meta-analysis. The size of each symbol is proportional to the weighting of each study, with the horizontal error bar representing the 95% confidence interval (CI). The horizontal diamonds at the bottom of the figure illustrate the overall effect size plus or minus the 95% CI as determined using fixed or random effects models