Expand: Full RPE Scale & Definitions. RPE stands for Rate of Perceived Exertion. It is a simple 1–10 scale that helps you judge how hard you feel you are working, based on breathing, effort, and fatigue rather than pace or heart rate. RPE scale (1–10) 1–2 Very easy – gentle walk, full conversation, barely warm 3–4 Easy – steady walk/jog, still able to chat in full sentences 5–6 Moderate – comfortable but purposeful running, short sentences 7–8 Hard – challenging, breathing heavy, only a few words at a time 9–10 Very hard – maximum effort, sprinting feel, not sustainable For this programme: Warm ups are RPE 1–2 Running intervals are RPE 5–6 Walking breaks are RPE 1–4 The key message: RPE means listen to your body. Two people can run the same session at different speeds and both be correct, as long as the effort feels right.