Resistance training beyond momentary failure

The purpose of this study was to assess whether performing additional partial repetitions beyond momentary failure increased muscle hypertrophy. A total of 23 untrained men completed a 10-week within-participant intervention study comprising two weekly resistance training sessions of 3-4 sets of standing smith machine calf raises. One limb was randomly allocated to the control condition performing sets to momentary failure and the other limb allocated to the test intervention that included additional partial repetitions in the lengthened position. Muscle thickness of the medial gastrocnemius muscle was measured pre- and post-intervention via ultrasound and an a priori hypothesis of greater hypertrophy with additional partial repetitions made. Data were analysed within a Bayesian framework using a mixed effect model with random effects to account for the within participant design. The average treatment effect (ATE) was measured to assess any difference in condition and inferences made based on the ATE posterior distribution and associated Bayes Factor (BF). The results identified an ATE favouring the inclusion of additional partial repetitions (0.62 [95%CrI: 0.21 to 1.0 mm; p(>0)=0.998]) with 'strong' evidence (BF = 13.3) supporting the a priori hypothesis. Thus, when the goal is to train for maximum gastrocnemius hypertrophy over a relatively short time period, we suggest performing sets beyond momentary failure as a likely superior option.