Effects of a Physical-Literacy-Based Educational Intervention on Physical Activity and Body Composition in Preadolescent Children: A School-Based Controlled Trial

Improving physical literacy (PL) is recognized as a potentially effective approach for enhancing overall physical activity (PA) and fitness status, including body composition, but few studies have examined the impact of PL-oriented education on directly measured PA and body composition in children. The aim of this study was to evaluate the effects of a three-month quasi-experimental PL-based educational intervention, delivered as part of the regular physical education (PE) curriculum, in preadolescent children. A total of 119 children aged 9-11 years (51 girls) from southern Croatia participated in the study and were assigned to either a control group (<i>n</i> = 68) or an intervention group (<i>n</i> = 51). The intervention group received a PL-focused educational program integrated into regular PE classes, whereas the control group followed the standard PE curriculum. PA was assessed using accelerometers, and body composition was measured using bioimpedance analysis. A pre-post-retention design was applied (baseline at the start of the school year, post-intervention in December, and retention testing at the end of the school year), and a three-way repeated-measures ANOVA (group × gender × time) was conducted. The intervention prevented declines in vigorous physical activity (VPA) and step count (STEPS) and maintained overall sedentary time (ST) in the experimental group throughout the school year. Significant group × time interaction effects were detected for VPA, STEPS, and ST (F = 4.01, 4.09, and 5.34, respectively; all <i>p</i> < 0.05). No significant effects were found for body composition. In conclusion, the PL-based intervention allowed effective mitigation of the typical seasonal decline in activity levels observed during the school year. Further studies evaluating the effects of similar interventions on other indices of fitness status are warranted.