The document discusses the relationship between physical activity, fitness, and academic performance in children, focusing on the 'Physical Activity Across the Curriculum' (PAAC) program as an effective intervention to integrate physical activity into classroom instruction. It highlights the negative impact of sedentary behavior in schools and provides evidence that active lessons improve academic achievement and decrease BMI without sacrificing instructional time. Barriers to physical activity in schools are identified alongside potential solutions to promote movement-based learning.