Secondary Analysis to Evaluate Performance Expression Stability of Alternative Complex-Contrast Training Set...

This study aimed to evaluate the performance expression stability (PES) of sixteen alternative complex-contrast training (CCT) set strategies. Three separate cross-sectional studies (n = 14-17) evaluated the effects of different intra-contrast rest periods (ICRP; ≤300 s) and rest redistribution (RR) strategies (≤60 s) within CCT sets on the application of vertical jump propulsive force were examined using dual force platforms. To establish PES for propulsive force-time variables, repetitions one and two of the baseline set were analyzed using within-participant (coefficient of variation, CV; standard error of measurement; smallest worthwhile change; relative mean bias) and between-participant (intra-class correlation coefficient, ICC_3,1; Pearson's correlation coefficient, r) stability metrics. Results showed that all CCT set strategies facilitate stable performance expression between participants and facilitated the detection of practically meaningful changes for propulsive impulse, peak force, mean force, and propulsion time (ICC_3,1 = 0.64-0.99, r = 0.80-0.99, CV = 1.12-9.98%), while rate of force development metrics demonstrated less consistent between- and within-participant stability (ICC_3,1 = 0.55-0.97, r = 0.46-0.96, CV = 7.52-27.66%). The findings indicate that alternative CCT set strategies facilitate the stable expression of propulsive force-time performance in vertical jumps, although individualized prescriptions are essential for optimizing rate of force development outcomes. Performance expression stability insights provide a practical tool for balancing the effectiveness and potential for performance enhancement of vertical jump propulsion across alternative CCT set strategies. Practitioners may use these results to improve the prescription and monitoring of CCT-based strength and power mesocycles.