The Effects of the Use of Plyometric Exercises with and without the Ball in the Development of Explosive Strength in Volleyball.

Volleyball primarily focuses on technical and tactical training with a ball. However, there is growing interest in integrating fitness training into volleyball practice, particularly to enhance explosive strength through plyometric methods, but there is a lack of a direct scientific comparison between training with and without the ball. This study aimed to compare the effects of two training protocols on volleyball players. One protocol combined plyometric exercises with technical gestures (wall drills) using the ball, while the other protocol excluded the ball during plyometric exercises. Twenty male volleyball players (aged 18.6 ± 0.3 years, height 189.8 ± 2.2 cm, weight 79.4 ± 1.6 kg) were divided into experimental (with ball) and control (without ball) groups. The analysis of the results highlights significant improvements in both the squat jumps (SJs) and the countermovement jumps with arm swing (CMJas) for both groups. While there were no significant differences between the groups for SJ, significant differences emerged in CMJas, indicating varied training effects. Specifically, the interaction effect was significant (p = 0.004), demonstrating a meaningful distinction in performance improvements between the two groups. The effect size of the interaction is moderate (η_p² = 0.37, 95% CI: 0; 0.91). These results suggest that incorporating a ball into plyometric training can be beneficial for developing explosive strength in a different way, thereby improving performance due to the motivational stimulus provided. However, given the specificity of the sample and the training protocols used, further studies are needed to confirm these results and evaluate their applicability to a larger sample of volleyball players.