Progressive Overload and Muscle Hypertrophy: Its Relation to Muscle Use in Training Session

Kassiano, W, Manske, I, Miguel, A, Dias, RNdS, Siqueira, JP, Dantas, L, Prado, A, Costa, B, and Cyrino, ES. Progressive overload and muscle hypertrophy: Its relation to muscle use in training session. J Strength Cond Res XX(X): 000–000, 2026—To investigate the effects of progressive overload on skeletal muscle hypertrophy and its relationship with muscle use during training. The study comprised 2 components: a training intervention (part 1) and 2 acute resistance exercise bouts (part 2). Forty-one untrained young women had each arm randomized to progressive overload ( n = 29), no-progressive overload (N-PO, n = 23), or a time-matched nonexercise control (Ctrl, n = 30). In part 1, subjects performed unilateral elbow flexion (3 sets of 8–12 repetitions, 3 d·wk −1 ) for 8 weeks. Progressive overload (PO) increased load when the upper repetition limit was reached, whereas N-PO maintained constant load and repetitions. Elbow flexor muscle thickness was measured pre- and post-training at 60 and 70% of arm length and summed (∑EF). In part 2, subjects performed an acute exercise bout at pre- and post-testing. Muscle thickness was measured before and immediately after exercise as a proxy for muscle use. Both training conditions increased muscle thickness vs. Ctrl, with greater increases in PO than N-PO. Acute thickness increases were similar between conditions at pretesting, but at post-testing were greater in the Ctrl and N-PO than PO, with no differences between Ctrl and N-PO. Progressive overload augments muscle hypertrophy, likely by maintaining higher muscle use during exercise.