(8) GRADUAL INCREASE IN WEEKLY SETS DOES NOT ELICIT GREATER QUADRICEPS HYPERTROPHY ADAPTATIONS IN RESISTANCE-TRAINED MALES

Resistance training (RT) volume and its impact on hypertrophic adaptations has received considerable attention from the scientific community. In addition, progressive overload is considered essential to induce proper training stimuli over a training cycle and thus avoid a plateau in muscle development. However, the optimal progressive RT volume prescription for maximizing hypertrophy remains unclear.

Purpose: This study investigated the effect of adding sets targeting the quadriceps every 2 weeks in resistance-trained males over a 12-week study period versus performing a constant set volume.

Methods: Twenty resistance-trained males (age 24.6 ± 2.9 years; RT experience 4.9 ± 3.0 years; previous quadriceps volume 15.7 ± 4.2 sets per week; one repetition maximum barbell back squat:body mass ratio 1.8 ± 0.2 a.u.) were deemed eligible. To mitigate confounding effects from previous training volume, participants underwent a two-week volume reduction phase. Afterwards, participants underwent a 2-week familiarization phase where they increased the quadriceps training volume similarly and then began the training intervention. Participants were randomly allocated to one of two groups: Constant Group (CG; n = 10) that performed a fixed volume of 22 sets for the quadriceps per week, or; 4 Sets (G4S; n = 10) progression group that increased four sets per week every 2 weeks. Both groups started the training program with 22 sets for the quadriceps per week. Participants performed a lower-limb training program (including barbell back squat, leg press 45, seated knee extension, Romanian deadlift and seated knee flexion) twice a week (loading scheme of 6-8 and 10-12 repetitions, respectively) for 12 weeks. Intensity of effort was fixed at two repetitions in reserve, with only the last set of each exercise performed to concentric failure. Vastus lateralis cross-sectional area (CSA) and sum of lateral thigh muscle thickness (∑MT) at 30, 50 and 70% of the femur length were assessed at baseline and after 12 weeks of training program.

Results: There was a between-group difference for total training volume (p = 0.0007) and volume load progression slopes (p < 0.0001) favoring the G4S group (Figures 1A and 1B). Mixed models analysis of variance that was a main effect of time for CSA changes (p < 0.001) but no group effects were detected (p = 0.573) (Figure 1C). In addition, there was a main effect of time for ∑MT (p < 0.001) but no group effects (p = 0.687) (Figure 1D).

Conclusions: Our findings suggest that progressively adding sets per week every 2 weeks does not elicit greater quadriceps hypertrophy adaptations in resistance-trained males over a 12-week training period. PRACTICAL APPLICATION: Coaches and practitioners aiming for muscle mass accrual can progress the weekly set number by 4 sets for quadriceps every 2 weeks or perform a fixed RT volume at 22 sets per week. However, opting for a fixed volume provides a more time-efficient training strategy.

Acknowledgements: None