Increasing set volume relative to baseline does not augment skeletal muscle adaptations when compared to maintenance of baseline training volume in recreationally trained individuals.

Purpose: This study compared the effects of prescribing an increased number of sets relative to baseline (ITV) to a maintenance of baseline training volume (BTV), in previously trained individuals.

Methods: Forty-two adults with more than 6 months of elbow flexion resistance training experience had each arm randomized to either the ITV or BTV condition. Participants performed 2-weekly sessions of unilateral standing dumbbell elbow flexion exercise for 12 weeks, 8 of which were supervised. Muscle thickness of the elbow flexors at 50, 60, and 70% the distance of the upper arm and one repetition-maximum (1RM) strength for the unilateral standing dumbbell elbow flexion exercise were assessed pre- and post-intervention.

Results: For the 50% site, there was no evidence that the changes were different between BTV and ITV [∆BTV vs ∆ITV (cm) = 0.022 (95% CI - 0.096, 0.140)]. However, there was evidence that both conditions observed a greater change compared to the control. For the 60% site, there was no evidence that the changes were different between BTV and ITV [∆BTV vs ∆ITV (cm) = - 0.010 (95% CI - 0.155, 0.96)]. However, there was evidence that both conditions observed a greater change compared to the control. For the 70% site, there was no evidence that the changes were different between BTV and ITV [∆BTV vs ∆ITV (cm) = 0.004 (95% CI - 0.092, 0.101)]. However, there was evidence that both conditions observed a greater change compared to the control. For changes in 1RM, there was evidence that the change was greater in the BTV [∆BTV vs ∆Control (kg) = 1.915 (95% CI 1.219, 2.611)] and ITV [∆ITV vs ∆Control (kg) = 1.780 (95% CI 1.084, 2.475)] conditions compared to control.

Conclusion: Prescribing an increased dose of sets relative to baseline did not augment muscular adaptations when compared to a maintenance of BTV, in recreationally trained individuals. Both training conditions were similarly effective in promoting significant increases in muscle thickness and 1RM strength of the elbow flexors.