Maximal strength performance, efficiency, and myoelectric responses with differing intra-set rest intervals during paired set training

Introduction The purpose of this study was to investigate the effect of different rest intervals within paired sets (PS) on total work and training volume, efficiency (training volume load/session duration time), and myoelectric activity. Method Fifteen trained men participated in this study. Four experimental protocols were applied: P30 (30 s rest), P60 (60 s rest), P90 (90 s rest), and P120 (120 s rest). The PS bout consisted of a bench press (BP)/lat pull down (LPD), 30° incline bench press (BP30)/wide-grip seated row (SR), and triceps extension (TE)/biceps curl (BC) exercises. Surface electromyography (sEMG) activity of the biceps and triceps brachii were recorded. Results Volume load (repetitions x number of exercise sets x loads) was significantly lower for the P30 (5385.8 ± 1224 kg) versus the P60 (6755.6 ± 1398.5 kg), P90 (7358.3 ± 1490.3 kg), and P120 (7463 ± 1310 kg) protocols. No significant differences in sEMG activity was noted between protocols. The efficiency (kg·min−1) of P30 (633.6 ± 144) was significantly higher versus P60 (397.4 ± 82.2), P90 (288.5 ± 58.4), and P120 (219.5 ± 38.5). Conclusion Short intra-set rest intervals (60 s) within PS may be a potential alternative for increasing the volume load, since longer intra-rest (90 s and 120 s) intervals do not provide additional benefits.