Walk into any gym, and the first thing you’ll notice is lifters chasing numbers. Squat max. Bench PR. Deadlift triple from last week. Numbers can be motivating. But they can also be misleading.
Because not every heavy set tells the whole story. Some lifters hit a personal record while underslept, underfed, and overstressed. Others miss lifts they crushed a month ago. The missing variable? Effort, not weight. And that’s exactly what RPE is built to measure.
In strength training, RPE, short for Rate of Perceived Exertion, is one of the most valuable tools lifters have, but still one of the least understood. It’s not new, but it’s underused. Especially by everyday gym-goers who could benefit most from it.
Joseph Lucero, a strength coach who works with powerlifters and strength athletes one-on-one, explains it clearly: “The whole purpose of the RPE scale is to communicate how tough a set feels. It lets us fine-tune programming in real time and make smarter decisions from week to week.”
This isn’t about throwing out structured training. It’s about making it more adaptable, sustainable, and honest.
Table of Contents
What Is RPE?
RPE stands for Rate of Perceived Exertion. In simple terms, it’s a scale from 1 to 10 that helps lifters describe how hard a set felt, not based on the weight, but on effort. It's a way to discuss exercise intensity, often with a coach or trainer.
Here’s a general breakdown:
- RPE 10: Max effort. You couldn’t do another rep with good form.
- RPE 9: You had one rep in the tank.
- RPE 8: Two reps left.
- RPE 7: You could’ve done three more.
- RPE 6 and below: Light work. Plenty left in the tank.
Lucero sometimes uses half-points for more precision. “If a lifter says they probably could’ve gotten one more, but maybe not with clean form, we call that a 9.5,” he says.
The key thing to understand: RPE measures effort, not load. You can do a set with 70% of your 1-rep max and still rate it an RPE 9 if you’re fatigued, recovering from illness, or just having an off day. And that’s exactly why it matters.
We also have an RPE calculator. It helps you quickly find your 1RM based on the RPE of your most recent set. This can be especially useful if you're planning your own training program or working with a coach to discuss maximum effort lifts.
Why RPE Beats Chasing Numbers Alone
The traditional approach to strength programming is to base everything on percentages of your 1-rep max. And while that works in theory, it assumes your body performs the same way every day. In reality, stress, sleep, nutrition, hydration, and mood all affect performance.
Lucero puts it bluntly: “Some days 315 feels like nothing. Other days it feels like a mountain. RPE lets you respond to that instead of pretending you’re a machine.”
This is called auto-regulation: The ability to adjust your training based on how you actually feel, not just what the spreadsheet says. That doesn’t mean throwing out structure. It means creating room for variability, which is essential for long-term progress. And it works just as well for a beginning powerlifting program as it does for competitive lifters.
How RPE and RIR Work Together
One way to make RPE more understandable, especially for newer lifters, is to pair it with RIR, or Reps In Reserve. This is exactly what it sounds like: how many more reps you could have done before hitting failure.
The connection is simple:
- RPE 10 = 0 reps in reserve
- RPE 9 = 1 rep in reserve
- RPE 8 = 2 reps in reserve
- And so on
Lucero uses this method to help clients develop body awareness. “Let’s say you hit 15 reps on curls and feel like you could’ve done 5 more. That’s 5 RIR, which means an RPE of 5. You just reverse it. 10 minus 5,” he explains.
This approach helps take the guesswork out of subjective effort. It gives lifters a concrete way to rate their sets, even when they’re not grinding out heavy singles.
Using RPE in Training Blocks
RPE becomes especially powerful when used across training blocks. Lucero structures 12-week programs into three 4-week blocks, each with a different focus: Foundational movement, strength development, or peaking.
Each block ramps intensity up over time. Week one might feature RPE 6–7 work to build volume and control. By week four, the lifter might be hitting RPE 9–10 efforts on key lifts. Then the intensity drops again at the start of the next block.
“Progress isn’t linear. You can’t go hard all the time,” Lucero says. “RPE helps us plan hard weeks and recovery weeks, so the athlete keeps progressing without burning out.”
What About the Borg RPE Scale?
There’s also another type of RPE scale you might hear about. The Borg Scale, developed by Swedish researcher Gunnar Borg and covered in his article, “Psychophysical bases of perceived exertion“. Unlike the lifting version of RPE, the Borg scale ranges from 6 to 20 and was designed to correlate with heart rate.
Multiply your Borg RPE by 10, and you get a rough estimate of heart rate. A Borg RPE of 12, for example, suggests a heart rate of 120 beats per minute, which falls into the moderate-intensity range.
This scale is more often used in endurance sports or cardio settings, but the principle is the same: use internal feedback to rate effort and guide training intensity. That means using a heart rate monitor or other objective methods to track your physiology.
If you're interested in the science behind RPE, RIR, and the Borg scale, check out this Borg and Dahlstrom article from 1962. It covers how different measurements show physical exertion and capacity.
Note that there are also a bunch of old CDC articles on the subject, but many of them have been removed since the start of 2025.
The RPE Calculator: Making It Concrete
If you’re more data-driven, there are RPE calculators that estimate your one-rep max based on how many reps you performed, how heavy the load was, and how hard it felt. In other words, the intensity of your workout.
Let’s say you bench 185 pounds for 6 reps at RPE 8. Plug that into a calculator, and it might estimate your 1-rep max at 225. That gives you a useful reference point. It's not just for max testing, but for planning future working sets.
Lucero encourages lifters to use these tools, but not to become dependent on them. “The calculator helps give you a ballpark, but you still need to build the awareness. Learn what an RPE 8 actually feels like. That’s the long game.”
Why RPE Matters
Here’s the real reason to use RPE: it helps you train smarter, not just harder. It gives you a tool to stay consistent, adapt to life’s curveballs, and avoid burnout. It builds self-awareness and better communication with your coach. And over time, it gives you a deeper understanding of your own limits and how to push them without breaking.
It’s not about avoiding effort. It’s about directing it.
“If you hit 225 for five reps in January and it felt like a 10, but in December it feels like a 7, you didn’t just get stronger. You trained smarter.”
That’s what real progress looks like. Not just a new PR, but a body that performs better, recovers faster, and lasts longer.
Want to Try It?
- Start logging your lifts with RPE ratings.
- Use RIR if you’re not sure where to start.
- Track your progress over time, how the same weights feel from week to week.
- Use RPE to plan lighter and heavier days, not just max-outs.
And if you’re working with a coach, start using RPE as part of your feedback loop. It’s not just a number. It’s a tool to help you lift better, recover smarter, and build strength that lasts.
