Stian Larsen ^1* Paul Swinton ² Nordis Østerås Sandberg ¹ Benjamin Sandvik Kristiansen ¹ Andrea Bao Fredriksen ¹ Hallvard Nygaard Falch ¹ Roland van den Tillaar ^1* Milo Wolf ³

• ¹ Department of Sport Sciences and Physical Education, Nord University, Levanger, Norway
• ² School of Health Sciences, Robert Gordon University, Aberdeen, United Kingdom
• ³ Lehman College, Bronx, New York, United States

Muscle hypertrophy is often a desired goal of resistance training, and strategies that extend training beyond momentary failure may enhance muscular adaptations. The Thus, the purpose of this study was to assess whether performing additional past-failure partial repetitions beyond momentary failure increased muscle hypertrophy. Twenty-three untrained men completed a 10week within-participant intervention study comprising two weekly resistance training sessions of 4 sets of standing smith machine calf raises. One limb was randomly allocated to the control condition performing sets to momentary failure (PLANTARMF) and the other limb allocated to the test intervention that included additional past-failure partial repetitions in the lengthened position (DORSIvf). Muscle thickness of the medial gastrocnemius muscle was measured preand post-intervention via ultrasound. 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).Main findings were that the PLANTARMF and DORSIVF: legs increased medial gastrocnemius hypertrophy with 6.7 % and +9.6 %, respectively. 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.