Acute effects of pre-activation method with single and multiple joint exercises on muscular activity and training volume during the bench press exercise

BACKGROUND: The pre-activation method (PA) has been shown to enhance muscle activation due to its low intensity. Moreover, it cannot be performed until muscle failure. However, it is not clear whether exercise selection can influence the results. This study aimed to test two different protocols of PA on muscle activation and the volume of repetitions during the bench press (BP).METHODS: Eleven resistance-trained males underwent anthropometric measures (24.45 +/- 3.93 years; 80.27 +/- 7.74 kg; 1.74 +/- 0.05 m) and completed 3 different experimental conditions in a randomized-crossover design: traditional method (BP at 70% of 1 RM), PA single-joint (dumbbell fly at 30% 1 RM+BP at 70% 1 RM), and PA multijoint (BP at 30% 1 RM+BP at 70% 1 RM). PA was performed with a fixed number of 10 repetitions and BP was performed until muscle failure. The activity of the pectoralis major was measured via surface electromyography (EMG), and normalized units were used for inter-individual analysis. A one-way ANOVA was used to compare EMG data and the number of repetitions across the experimental conditions.RESULTS: EMG data showed no differences for all conditions (PA-SJ=58.87 +/- 12.74; PA-MJ=56.18 +/- 12.29; traditional method=57.44 +/- 13.14; P=0.87). The number of repetitions performed during BP was reduced after both protocols of PA (P=0.036).CONCLUSIONS: Regardless of exercise selection, PA did not promote greater muscle activation or improved number of repetitions during the BP; therefore, PA may not be an effective method for exercise performance in BP.