Improvement in Explosive Strength in Lower Secondary School Students

Gianluca Gravino; Emma Saraiello; Maria Giovanna Tafuri

Improvement in Explosive Strength in Lower Secondary School Students

Gianluca Gravino, Emma Saraiello, Maria Giovanna Tafuri

Abstract

Explosive strength of the lower limbs represents a key component of motor competence during developmental age, with relevant implications not only for performance but also for participation, movement quality, and students’ educational experience. In school settings, progressive and adapted programs can promote neuromuscular development while supporting motivation and perceived competence. The Countermovement Jump is widely used as an operational indicator of the ability to express force/power rapidly, provided that it is administered according to standardized protocols. The aim of this study was to evaluate the effects of a five-month physical education program on lower-limb explosive strength, measured through CMJ on a force platform, and to describe, through interviews, students’ perceptions in terms of change, motivation, and factors facilitating or hindering the experience. A mixed-methods (quantitative–qualitative) study with a pre-test/post-test design was conducted. The quantitative component involved 137 lower secondary school students (mean age 12.3 ± 0.9 years), assessed using CMJ on a force platform (primary outcome: jump height). The testing protocol was standardized and preceded by a familiarization phase. The qualitative component consisted of semi-structured interviews with an intentional subsample of 30 students, analyzed through thematic analysis. The educational program included bodyweight strength exercises, low- to moderate-impact plyometric progressions, and game-based sport activities, with a frequency of two sessions per week. Quantitative analysis showed a significant increase in jump height from pre-test (24.7 ± 4.8 cm) to post-test (29.1 ± 5.0 cm), with a mean improvement of +4.4 cm (+17.8%) and a large effect size (Cohen’s d = 0.92; p < 0.001). Improvements were more pronounced among students with lower initial performance levels. Qualitative findings highlighted a widespread perception of greater strength and stability, improved landing c

Keywords

explosive strength; physical education; mixed-methods approach

References

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Improvement in Explosive Strength in Lower Secondary School Students

Abstract

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