Effects of Weekly Set Distribution on Volume Load, Lower-Body Strength, and Quadriceps Muscle Thickness in Trained Men

ABSTRACT: Calzavara, J and Barroso, R. Effects of weekly set distribution on volume load, lower-body strength, and quadriceps muscle thickness in trained men. J Strength Cond Res XX(X): 000-000, 2026-This study compared volume load, maximal dynamic strength, and quadriceps muscle thickness after 2 weekly set-distribution models in trained men. Eighteen subjects completed 6 weeks of lower-body resistance training involving the Back Squat, Leg Press, and Leg Extension. Subjects were randomly allocated to RT1, which performed all weekly sets in 1 session, or RT3, which distributed the same number of sets across 3 sessions. Each exercise was performed for 3 weekly sets at 80% of pretest 1RM (1 repetition maximum) to concentric failure. RT3 achieved higher volume load than RT1 in the Back Squat (Δ% = 58%; p = 0.010) and Leg Press (Δ% = 76%; p = 0.013), with a similar trend in the Leg Extension that did not reach statistical significance (Δ% = 38%; p = 0.057). A significant main effect of time indicated that maximal dynamic strength increased across the intervention for all 1RM outcomes (all p < 0.001), with no significant group × time interactions. However, the group × time interactions approached, but did not reach, statistical significance for the Back Squat (p = 0.074) and Leg Press (p = 0.071), with larger pre-to-post changes in RT3, whereas no clear between-protocol pattern was observed for the Leg Extension (p = 0.535). Muscle thickness increased over time at the vastus lateralis and mid-thigh sites (p < 0.001 and p = 0.001, respectively), with no significant group × time interaction at either site (p = 0.215 and p = 0.987, respectively). These findings indicate that distributing weekly sets across 3 sessions can increase volume load without modifying other training variables. However, this higher volume-load response provided only directional support for greater maximal strength gains in RT3 and did not translate into superior muscle thickness gains over 6 weeks.