Assess educators' ability to design a 20-minute playground fitness circuit for grades 3–5 that builds cardiovascular endurance. The plan should specify a dynamic warm-up, three main timed activity stations with progressions and age-appropriate intensity cues (e.g., talk test/RPE), adaptations and safety modifications for common needs, equipment and space requirements, transition/class management strategies, a cool-down with stretching, and a brief rationale linking activities to endurance outcomes and safety/assessment notes.