Effects of Training Volume in the Bench-Press Exercise Performed With Interrepetition Rest Periods on Strength Gains and Neuromuscular Adaptations

Purpose: To investigate the effects of 3 training volumes in the bench-press exercise performed with interrepetition rest periods, matched for fatigue, on strength gains and neuromuscular adaptations.

Methods: Forty-three resistance-trained men were randomized into 3 groups: low (LOW), moderate (MOD), and high (HIG) volume. The intensities increased from 70% to 85% of 1-repetition maximum (1RM) over the 8-week training period. Each session consisted of only 1 set with short interrepetition rest periods. LOW performed only 3 repetitions per session (8-wk total: 48 repetitions); MOD completed 15, 12, 10, and 8 repetitions per session with 70%, 75%, 80%, and 85% 1RM, respectively (8-wk total: 180); and HIG performed 24, 21, 18, and 15 repetitions per session with 70%, 75%, 80%, and 85% 1RM, respectively (8-wk total: 312). Progressive loading and fatigue tests were conducted in the bench-press exercise before and after the training period. Electromyography (EMG) signals from the triceps brachii were registered during these tests.

Results: HIG and MOD showed higher velocity loss than LOW (16% vs 12%). No significant group × time interaction was observed for any variable. All groups improved significantly in all strength-related variables, except for maximal unloaded velocity, where only MOD obtained significant gains. Only LOW and MOD induced significant improvements in EMG. MOD obtained the greatest effect sizes in almost all strength variables.

Conclusions: No significant differences were found in the performance gains obtained by each group despite the wide differences in the total volume accumulated by each group.