The health-related benefits of physical activity are well established for all age groups. It also has positive effects on memory, executive function and school performance in children and adolescents. However, it is known that 81% of individuals between the ages of 11-17 live a life that is not physically active enough. The World Health Organization recommends interventions to increase physical activity. In this study, 48 students from 5th, 6th and 7th grades will be selected from randomly selected secondary schools in Karaman central district and will be divided into experimental and control groups. In this randomized controlled study, behavior change intervention with the 5A model will be applied to the experimental group, and no intervention will be applied to the control group. Physical activity levels, physical and psychosocial health of children in both groups will be evaluated at the beginning of the intervention, at Week 8 and at Week 28. Physical activity diary, "Physical activity scale for 4-8 Grades" scale will be used to measure children's physical activity levels. For their physical health, body composition, strength, flexibility and functional capacity will be evaluated. Quality of life with the "Pediatric Quality of Life 4.0 Inventory" for psychosocial health; Cognitive functions will be evaluated with "CNS Vital Signs Cognitive Performance and Attention Tests". This study aims to evaluate the sustainability effect of the 5A intervention on physical activity and its impact on physical health and psychosocial health.

Behavioral interventions for health promotion are widely used for preventive health practices. There are many studies on topics such as smoking, diet, obesity and oral care. However, we see that studies improving physical activity behavior in children are limited. Considering that physical activity is an important health-related behavior that should be acquired from childhood, we predict that studies on this subject will have an important place in the literature. In addition, it is stated in the guidelines that while the effect of physical activity behavior on health-related parameters in children is clear, more evidence is still needed on its effect on cognitive functions. With our study, we aim to examine the sustainability, physical and psychosocial effects of developing physical activity behavior in children using the 5A model and contribute to the literature.

Inclusion Criteria:

• Being a middle school student
• Being between the ages of 10-12
• Getting <3.16 points from the "Physical activity scale for grades 4-8"

Exclusion Criteria:

• Having a condition where exercise is contraindicated
• Families or children do not give consent to participate in the study.
• Having a psychosocial problem that prevents adaptation to work