Spence, J. (1999). Effects of anabolic-androgenic steroids on muscular strength: A meta-analysis. Medicine and Science in Sports and Exercise, 31(5), Supplement abstract 2071.

A meta-analysis of published works determined the effects of anabolic-androgenic steroids (AAS) on muscular strength and body composition in healthy humans. Data from 48 studies were converted into 150 effects sizes and aggregated within seven outcomes. The most common treatment paradigm across outcomes was a low dose of oral methandrostenolone used for a period ranging from 3 to 8 weeks.

It was found that, in association with a weight-training program, noticeable changes in muscular strength and body composition occurred with a relatively low dose of AASs. Based upon the medium effect sizes for muscular strength, it is reasonable to assert that most published studies are under-powered for the effect they are trying to measure (not enough Ss are used in the study). The study did not account for weight-training alone effects. AAS effects, if any, would have been minimal.

Implication. Anabolic-androgenic steroids do increase muscular strength and body composition in association with weight training. It is likely that much or all of the gains are due to weight training and would have occurred with or without the presence of AAS. A number of studies that found insignificant results are probably the result of insufficient Ss that do not allow the true phenomenon to be statistically detected.

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