Applications of the dose-response for muscular strength development: a review of meta-analytic efficacy and reliability for designing training prescription.

There has been a proliferation in recent scholarly discussion regarding the scientific validity of single vs. multiple sets of resistance training (dose) to optimize muscular strength development (response). Recent meta-analytical research indicates that there exist distinct muscular adaptations, and dose-response relationships, that correspond to certain populations. It seems that training status influences the requisite doses as well as the potential magnitude of response. Specifically, for individuals seeking to experience muscular strength development beyond that of general health, an increase in resistance-training dosage must accompany increases in training experience. The purpose of this document is to analyze and apply the findings of 2 meta-analytical investigations that identified dose-response relationships for 3 populations: previously untrained, recreationally trained, and athlete; and thereby reveal distinct, quantified, dose-response trends for each population segment. Two meta-analytical investigations, consisting of 177 studies and 1,803 effect sizes (ES) were examined to extract the dose-response continuums for intensity, frequency, volume of training, and the resultant strength increases, specific to each population. ES data demonstrate unique dose-response relationships per population. For untrained individuals, maximal strength gains are elicited at a mean training intensity of 60% of 1 repetition maximum (1RM), 3 days per week, and with a mean training volume of 4 sets per muscle group. Recreationally trained nonathletes exhibit maximal strength gains with a mean training intensity of 80% of 1RM, 2 days per week, and a mean volume of 4 sets. For athlete populations, maximal strength gains are elicited at a mean training intensity of 85% of 1RM, 2 days per week, and with a mean training volume of 8 sets per muscle group. These meta-analyses demonstrate that the effort-to-benefit ratio is different for untrained, recreationally trained, and athlete populations; thus, emphasizing the necessity of appropriate exercise prescription to optimize training effect. Exercise professionals may apply these dose-response trends to prescribe appropriate, goal-oriented training programs.