(19) UNLOCKING GREATER LOAD POTENTIAL: HOW CLUSTER SETS ENABLE HIGHER EXTERNAL LOADS

Purpose: To investigate how CLU sets can allow for increases in external load and the resultant acute velocity and perceptual responses. Methods: Ten strength-power athletes (8 Males; 2 females), with the ability to power clean ≥1.0 times body mass participated in this study. All subjects completed four sessions. In Session 1, subjects completed a one repetition maximum (1RM) power clean test. In sessions 2 through 4, subjects performed TRAD, CLU-1 and CLU-3 protocols in a randomized order. The TRAD protocol consisted of three sets of nine power cleans at 70% of 1RM, which corresponds to 90% of 9RM. The CLU-3 protocol used the same number of sets and repetitions as TRAD but included 30-second intra-set rest after every three repetitions, with a load of 85% of 1RM, which corresponds to 90% of 3RM. The CLU-1 protocol was similar to CLU-3, but used 30-second inter-repetition rest intervals and a load of 90% of 1RM. For CLU-1 and CLU3, the external loads were determined based on the same relative intensity (90% of 1RM and 3RM, respectively) as the TRAD (90% of 9RM) set. Three-minutes of rest was allotted between each set during all protocols. Barbell displacement-time data was recorded using 3D motion capture and used to calculate peak velocity (PV) of the barbell. Rating of perceived exertion (RPE) was also recorded the Borg category ratio scale after each set during each protocol. A mixed-design analysis of covariance (ANCOVA) was conducted for PV, with session (TRAD, CLU-1, CLU-3) and repetition as within-subject factors and external load included as a covariance. RPE data was analyzed using an aligned rank transform procedure with 3 x 3 (Protocol x Time) repeated measures ANOVA. Paired comparisons with Holm’s sequential Bonferroni corrections were performed to identify significant differences. The alpha level was set at 0.05. Hedge’s g effect sizes were calculated to examine the magnitude of the differences in PV. Results: There was a significant session effect for PV (p = 0.005:F = 5.310). Based on post-hoc analyses PV in the TRAD protocol was greater than in the CLU-1 (p< 0.001;g= 0.85) and CLU-3 protocols (p< 0.001;g= 0.71). PV in the CLU-1 protocol was greater than in the CLU-3 protocol (p= 0.03;g= 0.14). While a decline in PV was observed towards the end of both TRAD and CLU-3 sets, PV was maintained throughout the CLU-1 sets (Figure). Additionally, there was a significant protocol effect for RPE (p = 0.003). Based on post-hoc analyses greater RPE was observed during the TRAD protocol compared to the CLU-1 protocol (p < 0.001), with no difference between the TRAD and CLU-3 protocols (p= 0.27). Conclusions: CLU sets allowed for increases in external load and maintenance of PV while reducing perceptual fatigue. Practical Applications: Coaches should consider using higher external loads in CLU sets while ensuring adequate intra-set rest intervals to maintain movement velocity and minimize perceptual fatigue. Acknowledgements: None