Effects of a Nine-Month Physical Activity Intervention on Morphological Characteristics and Motor and Cognitive Skills of Preschool Children

(1) Background: Regular physical activity (PA) plays an important role during early childhood physical and psychological development. This study investigates the effects of a 9-month PA intervention on physiological characteristics and motor and cognitive skills in preschool children. (2) Methods: Preschool children (n = 132; age 4 to 7 years) attending regular preschool programs were nonrandomly assigned to PA intervention (n = 66; 60 min sessions twice per week) or a control group (n = 66; no additional organized PA program) for 9 months. Exercise training for the intervention group included various sports games, outdoor activities, martial arts, yoga, and dance. Anthropometry, motor skills (7 tests), and cognitive skills (Raven’s Colored Progressive Matrices and Cognitive Assessment System) were assessed before and after an intervention period in both groups. Data were analyzed using repeated-measures ANOVA. (3) Results: Body weight significantly increased in both groups over time. Compared to the changes observed in the control group, the intervention group significantly increased in chest circumference (p = 0.022). In contrast, the control group demonstrated an increase in waist circumference (p = 0.001), while these measures in the intervention group remained stable. Participants in the intervention group improved running speed (p = 0.016) and standing broad jump (p = 0.000). The flexibility level was maintained in the intervention group, while a significant decrease was observed in the control group (p = 0.010). Children from the intervention group demonstrated progress in the bent-arm hang test (p = 0.001), unlike the control group subjects. Varied improvements in cognitive skills were observed for different variables in both intervention and control groups, with no robust evidence for PA-intervention-related improvements. (4) Conclusions: Preschool children’s participation in a preschool PA intervention improves their motor skills.