What Even is “Rate of Perceived Exertion” (RPE)?
RPE, or Rate of Perceived Exertion, is a way to measure training intensity based on effort rather than strict percentages. Instead of relying on a fixed number like lifting 80% of your max, RPE allows you to adjust based on how you feel on a given day. It is flexible, individualized, and when used correctly, far more accurate for real-world training than rigid percentages alone.
How RPE Works
Think of RPE as a 1 to 10 scale that reflects how close you are to failure:
RPE 10 = Max effort, no more reps possible. If you tried, you would fail.
RPE 9 = You could grind out maybe one more rep.
RPE 8 = About two reps left in the tank.
RPE 7 = Still working, but you could probably manage three more reps.
RPE 6 and below = Light to moderate effort with plenty of reps left.
RPE 0 = Does not really exist; unless you are literally standing still in the gym, you are still using energy.
This scale gives you a built-in way to gauge intensity without being locked into a specific percentage that might not match how you are actually performing that day.
Why Train Close to Failure (RPE 9 to 10)?
Muscle and strength gains do not happen just because you went to the gym. They happen when you push your body hard enough to recruit your strongest muscle fibers, known as high-threshold motor units. These fibers are lazy and only show up when your body is under real stress, close to failure.
Science shows that training too far from failure, such as stopping at RPE 5 or 6, often is not enough to spark the adaptations you are chasing. By pushing to RPE 9 or 10 on certain lifts, you guarantee those fibers get recruited. That means more strength, more hypertrophy, and better progress over time.
That does not mean every set should be a grind to failure, but you need to live near that edge regularly if you want real results.
Why I Use RPE Instead of Percentages
As a coach, I lean heavily on RPE because your body is not a robot. It is not a calculator either. It doesn’t care about the percentage or the number. It cares about the stimulus of that weight or movement (i.e., how it’s affecting the body).
Performance fluctuates day to day, depending on factors such as sleep, nutrition, stress, and recovery. On a rough day, 80% of your max could feel like an RPE 10, barely moving the bar. When in reality, you should be able to hit 80% with some effort, but nowhere near maximum effort. On a strong day, that same 80% might feel like an RPE 7, smooth, controlled, and nowhere near what 80% should feel like. So then what do you do??
RPE bridges that gap by letting you autoregulate:
It allows you to adjust training in real time. You are not locked into the numbers on paper.
It builds awareness of effort. You learn what pushing yourself actually feels like.
It helps you avoid burnout. You can still progress without burying yourself in unnecessary fatigue.
This makes training more sustainable and accurate in the long run, as progress becomes about adaptation, listening to your body, and adjusting without judgment.
How to Learn RPE
For beginners, RPE takes practice. Most people underestimate how many reps they truly have left. Here is how to get better:
Occasionally, train to true failure. Safely push a set until you literally cannot do another rep. That is RPE 10. Now you have a reference point.
Record your lifts. Watching back your form and bar speed helps you check whether your “RPE 8” really looked like an 8, or if it was more like a 6.
Reflect after sets. Ask yourself honestly if you could have done one more rep, two, or even five. Over time, this awareness sharpens.
With consistent practice, RPE becomes second nature. You will know exactly how hard you are working, you will train smarter, and you will make steady, sustainable progress without constantly running yourself into the ground.