ABSTRACT
The main aim was to evaluate the changes in dynamic, reactive, and power strength, and balance (as volleyball performance-related parameters) in pubertal volleyball players when a part of their normal inseason training regimen was replaced by an elastic band training (EBT). 27 male elite volleyball players were randomly allocated to intervention (N = 14; 14.86 ± 0.52 years) or control group (N = 13; 14.74 ± 0.36 years). The intervention consisted of an 8-week EBT program focused on the training of the lower limb, with different volumes and intensities. Countermovement jump (CMJ) and standing long jump (SLJ) were used to assess the power strength, squat one repetition-maximum, and reactive strength index to assess dynamic and reactive strength, respectively. Also, the balance was assessed through different parameters of the foot centre of pressure (CoP) displacements obtained with a force platform. An ANOVA of repeated measurements and post-hoc tests evaluated differences between groups and between baseline and post-intervention. Dynamic and power (CMJ and SLJ) strength, and anteroposterior displacement of the CoP were improved after the intervention. The control group only improved the dynamic strength. No statistically significant difference (p > 0.05) were found in the rest of the variables. EBT improves jump performance and other volleyball performance-related parameters in adolescent male athletes and should be considered to complement regular volleyball in-season training.
ABSTRACT
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-min recovery period. Twelve volleyball players were subjected to conditioning stimuli that included 10 repetitions of half squats with 70% of 1-repetition maximum (RM) (10 × 70), 5 × 70, 5 × 85, 3 × 85, 3 × 90, 1 × 90, and control. Jump height, power, velocity, and force were measured at baseline, 1, 3, 5, 10, and 15 min. 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 ± 2.3 min), mean power (3.6 ± 3.01 min), peak power (2.5 ± 1.8 min), and peak velocity (2.5 ± 1.8 min). Magnitude-based inference revealed that both the 5 × 70 and 3 × 85 protocol elicited changes that exceeded 75% likelihood of exceeding the smallest worthwhile change (SWC) for peak power and velocity. The 10 × 70 and the 5 × 70 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 5 × 70 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 min poststimulation, though declines after 5 min seems probable.
