Dr. Bill Evans | Running Performance & Athletic Development on Instagram: "Borg’s Rating of Perceived Exertion (RPE; 6–20) is a psychophysical scale that quantifies the conscious sensation of effort during incremental exercise. The numeric anchors were chosen so ratings would roughly mirror heart rate (~10 bpm per RPE point), but the mapping is approximate and context-dependent. In the largest cohort to date (n=2,560), RPE showed strong associations with objective intensity markers: HR vs. RPE r