Concept
Perceived exertion
A runner's integrated judgment of how hard the body is working, based on breathing, muscle strain, fatigue, and overall effort.
Why it matters
Perceived exertion responds immediately to conditions and readiness, including factors a pace target cannot see.
How to calibrate it
Compare the feeling with conversation, heart rate, and pace across repeated sessions. The scale becomes more useful with practice.
How it guides pacing
It helps keep easy running easy and identifies when a planned faster pace has become unsustainably hard.
How to use it
Record a simple effort score after key runs and compare it with pace, heart rate, and recovery.
Common misconception
Perceived effort is not just mood or weakness; it is useful feedback, though it still benefits from objective context.