Effect of a rest-pause vs. traditional squat on electromyography and lifting volume in trained women.

Purpose: Rest-pause (4 s unloaded rest between repetitions) single session training effects on lifting volume, and muscle activity via electromyography (EMG) are currently vague in the literature and can benefit strength and conditioning professionals for resistance training program design. This study compared differences in volume lifted and muscle activity between a rest-pause vs. traditional protocol.

Methods: Trained females (N = 13) completed both a rest-pause and traditional squat protocol consisting of four sets to movement failure at 80% pretest 1 repetition maximum load with 2-min rest between sets. Total volume and muscle activity of the vastus lateralis, vastus medialis, rectus femoris, and gluteus maximus were measured on both training days. Differences in muscle activity were viewed as a percent change (%∆).

Results: A paired samples t test indicated total volume lifted was higher in the rest-pause compared to the traditional protocol (2532 vs. 2036 kg; p < .05). Furthermore, paired samples t tests showed muscle activity %∆ of the gluteus maximus was greater in the traditional protocol compared to the rest-pause protocol (p < .05). No other muscle activity differences were observed in the remaining muscles.

Conclusions: The rest-pause allows for greater volume lifted via increased repetitions compared to a traditional protocol in trained women. The rest-pause method may be superior to a traditional method of training during a hypertrophy mesocycle, where a primary focus is total volume lifted. Furthermore, %∆ muscle activity in the GM will be greater while performing a traditional back squat protocol in comparison to a rest-pause.