This document provides guidance for a physical education lesson on middle distance running for students in key stage 3 (ages 11-14). It outlines learning objectives, such as understanding stride patterns and the effects of middle distance running on the respiratory system. The activity content involves exploring different running speeds through medley relays and interval training. Students should develop the ability to sustain an 800m run at their ability level and understand how their performance will improve with continued training. Assessment criteria focus on students' ability to make decisions, modify techniques, and adapt their training to maximize performance.