Volume, intensity and timing of muscle power potentiation are variable

Whereas muscle potentiation is consistently demonstrated with evoked contractile properties, the potentiation of functional and physiological measures is inconsistent. The objective was to compare a variety of conditioning stimuli volumes and intensities over a 15-minute recovery period. Twelve volleyball players were subjected to conditioning stimuli that included 10 repetitions of half squats with 70% of 1 repetition maximum (RM)(10x70), 5x70, 5x85, 3x85, 3x90, 1x90, and control. Jump height, power, velocity and force were measured at baseline, 1, 3, 5, 10, and 15 minutes. Data were analysed with a 2-way repeated measure ANOVA and magnitude-based inferences. The ANOVA indicated significant decreases in jump height, power and velocity during recovery. This should not be interpreted that no potentiation occurred. Each dependent variable reached a peak at a slightly different time: peak jump height (2.8 min±2.3), mean power (3.6 min±3.01), peak power (2.5 min±1.8), and peak velocity (2.5 min±1.8). Magnitude-based inference revealed both the 5x70 and 3x85 protocol elicited changes that exceeded 75% likelihood of exceeding the smallest worthwhile change (SWC) for peak power and velocity. The 10x70 and the 5x70 had a substantial likelihood of potentiating peak velocity and mean power above the SWC respectively. Magnitude-based inferences revealed that while no protocol had a substantial likelihood of potentiating the peak vertical jump, the 5x70 had the most consistent substantial likelihood of increasing the peak of most dependent variables. We were unable to consistently predict if these peaks occurred at 1-, 3, or 5 minutes post-stimulation though declines after 5 minutes seems probable.