A guide on how to use RPE and RIR in your training.
How hard should you train?
It is a question that is debated frequently in fitness circles. On the one hand, there is the old-school bodybuilding approach of training instinctively or simply pushing everything to failure. Workouts like this leave little need to quantify how challenging a set should be.
On the other hand, you have a style that leans into research, showing that training to failure can be unnecessary and counterproductive. In the latter approach, leaving some reps in the tank is part of the program.
Some people can indeed train instinctively and make fantastic progress. However, most people will make better progress following a structured program. Keep in mind this is not a revolutionary concept. A calculated approach is almost always better than just winging it.
I believe having a well-constructed training plan with built-in progression is one of the best things you can do to take your training to the next level.
Going back to our original question, any discussion about how hard we should train starts with intensity. Intensity can be defined and implemented as the intensity of load or effort. The “intensity of load” refers to the percentage of a one-rep max or training max, whereas the “intensity of effort” refers to how near maximal effort the load is, represented by a rating of perceived exertion (RPE) or reps in reserve (RIR).
Both percentage-based training and an autoregulated approach using the RPE scale and RIR have their place. The key is understanding how they fit together to help you get the most out of your training. Knowing which string to pull at the right time is one of the primary aspects of programming. Either way, both methods provide an effective system for determining the correct load on the bar.
Percentage Based Training
Let’s start with the tried-and-true method of percentage-based training. For many years, strength sports and athletics have used a percentage of a one-rep max to determine load. The best way to explain how this works is through an example.
Let’s say your one-rep max squat is 300 lbs, and the program calls for three sets of five reps at 75%. The first step is to find out what 75% of your max is. In this case, 75% of 300 lbs is 225 lbs, so 225 lbs would become your training weight for that exercise.
The benefit of this style of programming is in its simplicity. With percentages, you have a programmed load to use for the day. When you walk into the gym, you know what you have to do. For the most part, it doesn’t matter how you feel. The goal is to follow the program as written.
Don’t get me wrong; this can be negative as well. There are many benefits to incorporating autoregulation, which we will get into shortly. But, unfortunately for a lot of lifters, especially novices, sometimes how you feel can be a lie. I have worked with clients over the years who were tired or unmotivated heading into a workout but surprised themselves by the end of the training session.
Progressive Overload
Percentages also make it very easy to build in weekly progressions. Progressive overload is one of the main driving forces behind making gains in the gym. To make progress, you need to cause the body to adapt. One way this happens is by applying more stress over time. There are many ways to achieve progressive overload, but a linear approach of adding weight to the bar each week is one way to go about it.
Building progressions into the program is not unique to percentage-based training, but percentages make it simple and easy to implement.
If we go back to our example above, here is how a month of training might progress through the weeks following a linear percentage-based approach.
1: 3 sets of 5 reps @75% = 225lbs
2: 5 sets of 5 reps @75% = 225lbs
3: 5 sets 5 reps @77.5% (75+2.5%)= 235lbs
4: 5 sets of 5 reps @80% (75+5%) = 240lbs
Week 5 could be a de-load.
The set-up above is linear periodization 101. Basic but effective.
The Downside of Using Percentages
As I mentioned, percentage-based training is not bulletproof. For one, the lack of autoregulation can be an issue. In the real world, life gets in the way of optimal training. Five sets of five at 80% can feel different during periods of high stress, poor nutrition, and lack of sleep.
Additionally, percentages are not appropriate with every exercise. You will not know your one-rep max on a seated calf raise or a dumbbell curl. Using an RPE/RIR setup makes more sense for assistance exercises.
Also, there is some variation in how many reps people can do at a given percentage. For example, three sets of ten at 70% might be easy for one person but brutally hard for the next. I see this quite often when people change training styles. If you follow a low-rep powerlifting program for an extended period and then switch to a higher-rep bodybuilding routine, the higher reps will be more challenging at a given percentage.
Lastly, percentage-based training is most effective with updated maxes. It won’t do you any good to base your numbers on something you did three years ago. Accurate and updated data is valuable.
How to Start Using Percentages
If you have not done any strength testing in the past three months, it’s a good idea to do so before starting a percentage-based program. The best way to implement strength testing is to do a one-rep max or an AMRAP test, but I recognize that’s not always practical before starting a new program. The other option is to use an estimated 1RM. Think back to your most recent “hard” set under ten reps to come up with that. The closer this is to one, the better. Once we have that, we will use a formula to estimate one-rep max.
Let me give you an example. I recently did a top set of five reps on the bench press with 365lbs.
Formula: Projected Max = (weight x reps x .033) + weight
My Example: Projected Max = (365lbs x 5 reps x .033) + 365lbs
Projected Max = 425lbs
425lbs would be my estimated/projected max. That matches my best one-rep max on the bench. The formula is not perfect but it’s accurate enough to get you started.
The RPE Scale and RIR
If not percentages, then what? In recent years, it has become commonplace to see the intensity of effort measured using the RPE (rating of perceived exertion) scale and/or repetitions in reserve (RIR).
The RPE scale was created in 1970 by a Swedish psychologist named Gunnar Borg. The Borg scale ranged from 6 to 20 and was used primarily for aerobic exercise. However, it wasn’t until powerlifting coach Mike Tuchscherer modified the scale that it gained popularity in the lifting world. Mike adjusted the scale and based it on repetitions in reserve at the end of the set. This adjustment expanded the utility of the RPE scale with resistance training. Essentially, RPE is a rating of how close to failure you get after each set.
The RPE scale:
- RPE 1-4: Very light to light effort. Warm-up weight.
- RPE 5-6: Light effort, could do 4-6 more repetitions.
- RPE 7: Speed was fairly quick, could have done 3 more reps.
- RPE 7.5: Could definitely do 2 more reps, maybe 3.
- RPE 8: You could have done 2 more reps.
- RPE 8.5: Could definitely do 1 more rep, maybe 2.
- RPE 9: You could have done 1 more rep or more weight.
- RPE 9.5: Could not have done more reps, could do slightly more weight.
- RPE 10: Absolute maximal effort. No more weight or reps are possible.
You can also use repetitions in reserve (RIR) as well. RIR is just the number of repetitions shy of failure at the end of the set.
0 RIR = 0 reps shy of failure, could not do any more reps.
1 RIR = 1 rep shy of failure, could do one more rep.
2 RIR = 2 reps shy of failure, could do two more reps.
3 RIR – 3 reps shy of failure, could do three more reps.
With both RPE and RIR, at the end of a set, ask yourself, “If I absolutely had to, how many more reps could I have gotten with good form?” That will help you come up with your rating.
Side note: RPE vs RIR
These terms are often used interchangeably. The RPE scale in terms of resistance training is anchored in repetitions in reserve. RPE and RIR are very similar under normal conditions. Both are used to rate the difficulty of an exercise and in some contexts considered the same thing. However, RPE is more about how hard a set feels so it can be used in a broader sense. You can use RPE to rate exercises that don’t even have repetitions, think of farmer walks, prowler work, timed hangs and holds, etc. RPE can also be used to gauge the difficulty of a training session as a whole.
I like using RPE for lower rep work (under five reps), top sets, and main exercises – squat, bench press, deadlift, and the close variations. On the other hand, I like using RIR for higher rep sets and assistance movements. Try not to overthink this. The goal is simply to communicate effort and put the right weight on the bar, cable, or machine more times than not.
Autoregulation
The beauty of RPE-based training comes down to autoregulation. Autoregulation refers to the ability to change a program based on your response to different stressors in your life. Training is a stressor, but so are family problems, lack of sleep, an increased workload in school, etc. A program must consider these variables, and RPE is one way of doing that.
This concept allows you to adjust work for less than optimal days easily and adjust for volume and intensity blocks, among other neat ways of changing programming.
You are always going to have good and bad days. While it’s true sometimes you need to push through the “bad” days, other times it’s just not possible. Depending on several factors, the external load on the bar can feel a lot heavier or lighter than it is.
Some of these factors are:
- Fatigue from previous training sessions.
- Cumulative fatigue from the entire training cycle.
- Lack of sleep the night before.
- Lack of calories or hydration the day before or day of.
- Work/school/relationship stress.
- Different training times.
In my opinion, using the RPE scale is effective as a stand-alone method of weight selection or as an addition to percentage-based work. Remember that RPE doesn’t need to be perfect to be effective. The goal is to get in the ballpark. If you do that and are consistent, it will be successful.
Rating of Perceived Exertion in Practice
So how do you use the RPE scale? Again, I feel the best way to explain it is through an example.
Let’s use the same numbers as we did before.
The workout calls for sets of five on the squat. Instead of starting at 75% of a one-rep max, an RPE program might have you start at an RPE of six or seven.
In our last example, 75% was 225lbs.
For the RPE-based program, you would select a weight that you could only complete three or four more reps with (RPE of 6-7). See the RPE scale above if you are confused about where I came up with that number.
225lbs might be too light or too heavy, depending on the day.
Maybe 245lbs is the weight you can only get three additional reps with, or possibly you didn’t get much sleep the night before so 205lbs would be more appropriate.
There are many ways to utilize RPE; that is just one example. You can even set it up to adjust the weight on the fly after each set to stay at the prescribed RPE. Or, you can do a top set at a given RPE with percentage (5-10%) drops on the following sets. Adjusting volume and performing sets until they reach a prescribed RPE stopping point is also an option. Going into all of the ways to use RPE is beyond the scope of this article, but there are many creative ways it can be employed. Using autoregulation creates a lot more variability from workout to workout.
Common Issues with RPE
The first week on an RPE-based program is always the hardest. It takes a little practice to get dialed in. But, once you get comfortable with it, it can become a great tool. With that being said, it is a subjective measure. There will always be some level of interpretation involved.
This brings me to an important point. Getting a good handle on RPE and RIR helps one understand muscular failure. I am specifically talking to beginners, but even experienced lifters can get comfortable and lose the ability to gauge RPE. To help prevent this, AMRAPs and 10 RPE / 0 RIR sets should occasionally be used to recalibrate the scale.
Another common issue with RPE-based training is getting caught up in specific numbers. You see this the most with the milestone lifts—225, 315, 405, etc. Try to detach from the weight and focus on the effort. It is easier said than done, but don’t let your ego take over.
Lastly, the higher the reps get and the further from failure, the less accurate the subjective ratings are. For example, a set of 3 at 9 RPE is likely more accurate than a set of 12 at 6 RPE. I want to point out again RPE doesn’t need to be perfect to be effective. The goal is to just be in the ballpark.
Wrapping Up
Quality training programs are built around volume, frequency, specificity, and Intensity. Any discussion around how hard we should train has to start with intensity. Both percentage-based training and an autoregulated approach using the RPE scale and RIR have their place. The key is understanding how they fit together to help you get the most out of your training. Regardless of what method you use, remember progressive overload is the key to progress. You have to do more work over time to see results. Always aim to beat the logbook. Hard work and consistency are what it takes.
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