The effects of two-week modified plyometric training in vertical jumping of volleyball players

This experimental-quantitative study aimed to evaluate the effect of a two-week modified plyometric training (PT) program, conducted during the pre-competitive period, on the vertical jump performance of student-volleyball athletes at CEFI. Ethical standards of trustworthiness and rigor were observed throughout the study. Ten (10) participants were purposively selected using criterion sampling based on the following criteria: they must be volleyball players during the 2022–2023 school year; they must be between 13 and 23 years of age; and they must have no recent history of severe injury, fracture, or surgery within the past two weeks. Data were gathered through pre-tests and post-tests, along with the implementation of a two-week modified plyometric training protocol, which included a video guide for coaches and players. The findings of the study provided valuable insights into the impact of plyometric training on the vertical jump performance of volleyball players. Analysis of the data revealed a notable improvement in vertical jump height, from a pre-test mean of 22.35 inches to a post-test mean of 25.00 inches, indicating an increase of 2.65 inches after just two weeks of training. This result led to the rejection of the study's null hypothesis, which stated that there would be no significant difference between the pre-test and post-test vertical jump outcomes.