The previous examples highlight the fact that examining only statistical significance disregards the small sample sizes associated with RT research tend to make them underpowered to detect statistical probability (an a priori alpha level of 0.05) when an actual effect may, in fact, exist (i.e. type II error). In an attempt to enhance statistical power and objectively quantify the effects of volume on muscle hypertrophy, Krieger (18) pooled the results of all studies comparing single- versus multiple-set training and analyzed the combined effect sizes by meta- regression. A total of 8 studies met inclusion criteria at the time of the literature search (October 2009). Results showed a significantly greater hypertrophic benefit to performing multiple versus single sets; however, the magnitude of effect was modest (effect size difference of 0.10), possibly because of the low number of studies included in the analysis. The relatively smallCopyright ! 2017 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.3ACCEPTEDdifference in effect sizes raised the question of the practical meaningfulness of multi-set routines, as they are more time-demanding than single-set RT schemes.Recently, Schoenfeld et al. (31) set out to update the previous meta-analysis (18), given a plethora of new research on the topic since publication of that paper. The researchers chose to analyze volume on the basis of the number of sets performed per week per muscle group, surmising it to be a more relevant measure of training volume. A total of 15 studies meeting inclusion criteria showed a significant benefit to performing higher versus lower training volumes. Moreover, a clear dose-response relationship between the number of sets per muscle per week and muscle growth was found when RT volume was stratified into