Effects of Pre-Exhaustion of a Secondary Synergist on a Primary Mover in a Compound Exercise

Subjects have performed the bench press with and without PRE of PM with a dumbbell chest flying exercise (2 dumbbells are simultaneously moved vertically from a position of shoulders horizontally abducted at 90° to nearly 0°) [12].Electromyographic (EMG) data were recorded for the pectoralis major (PM), anterior deltoid (DA), and triceps brachii (TB).No significant changes in the tonic control of PM and DA were noted between the two treatment groups, however, TB did have a significantly (p < .05)higher motor unit activation when the chest was pre-exhausted with a dumbbell chest flying exercise. Methods SubjectsMales between 20 and 35 years of age (24, ± 1.5 years) were invited to participate.On average subjects weighed 88 ± 8 kg, were 183 ± 6.3 cm in height, and performed resistance training at least three times per week during the previous twelve AbstractThe purpose of this study was to investigate the effects of preexhausting a synergistic secondary mover prior to performing a compound exercise.Pre-exhaustion involves intentionally fatiguing a large muscle group in isolation prior to performing a compound exercise that utilizes the same muscle (e.g.performing glenohumeral joint horizontal adduction with a machine flying exercise immediately prior to barbell bench press in order to increase activation of pectoralis major.Surface electromyography was utilized to analyze the effects of pre-exhaustion of the triceps brachii on the pectoralis major while performing the barbell bench press.Data from the pectoralis major for 12 males were recorded during the barbell bench press; subjects performed this exercise with and without pre-exhaustion of the triceps brachii.A significant increase in electromyographic activity was noted in the pectoralis major (z = -2.353,p = 0.019) following pre-exhaustion of the triceps, indicating that pre-exhaustion of a synergistic secondary mover may result in higher neuromuscular activation of the primary mover in a compound exercise.Additional research with a larger sample size will provide more conclusive findings.