Today we’re going to talk about two methods for quantifying strength training, the RIR and RPE Perceived Exertion Scales.
- 1 How to quantify Strength Training?
- 2 What are RIR and RPE in Weight Training?
- 3 Who can use the Rate of Perceived Exertion (RPE) Scale?
- 4 How to Use the Rate of Perceived Exertion in Training?
- 5 Example RPE regulation for micro cycle in bench press
- 6 Summary and conclusions
- 7 Bibliography
- 8 Related Entries
How to quantify Strength Training?
Strength is the only basic physical quality that improves the others and depends on intrinsic and extrinsic factors, among those that stand out:
- The transversal area of the muscle;
- The length-tension curve of muscle sarcomeres;
- The arrangement of the muscle fibres, and the types of them;
- Neuromuscular efficiency;
- Individual biomechanics; and
- The speed of contraction.
The maximum strength is the maximum amount of strength a person can exert when faced with a certain load or a certain sporting action, and therefore an athlete or a person who trains frequently has as many maximum strength values as loads they can handle.
Going a little bit further, in every sport it’s not just the force applied in relation to the speed of the movement that’s of interest, but it’s also important to consider the force that can manifest itself in a given time, especially in very short periods of time.
The inability to command high threshold stimuli often results, to a large extent, from not being regularly exposed to high loads and/or from not performing the movements against resistance at the maximum possible concentric speed.
Quantifying intensity through 1RM alone has important limitations, such as not taking into account training load between sessions or changes in running speed for the same load.
In addition, setting medium to long term objectives limits the daily assessment of adaptations during that period.
What are RIR and RPE in Weight Training?
To solve this problem, there is a type of quantification complementary to the typical percentage of 1RM (%1RM) which we call “subjective”, and which is based on applying values to the sensations we have in the surveys, and with them maintaining a record of the training process.
What is RPE?
RPE is the acronym for Rating of Perceived Exertion.
It’s based on a scale of 1-10, where each value corresponds to a set of repetitions that could be made after those made in the set.
What’s the OMNI scale?
The true and primary name of this scale was Omni-Res, but for practicality in language and practice, RPE is used (Figure 1 and Table 1).
Figure 1: OMNI-Res Scale.
What’s an RIR?
RIR, for it’s part, is the acronym for Repetitions In Reserve
These two concepts are directly related in most subjects and according to the percentages of specific loads.
Normally, (not always, but in the vast majority of cases) since the RPE is based on applying values to which a given RIR corresponds; for example, RPE 8 is equivalent to an RIR (+2), since both leave 2 repetitions in the chamber (Table 1).
|RPE – RIR Relationship|
|10||Maximum Effort; RIR = 0|
|9||RIR = 1|
|8||RIR = 2|
|7||RIR = 3|
|5-6||RIR = 4-6|
|3-4||RIR = 6-8|
|1-2||Little of no perceived effort; RIR > 8|
Table 1: Relationship between RPE and RIR.
Who can use the Rate of Perceived Exertion (RPE) Scale?
This type of scale of subjective quantification has been studied both in strength athletes dedicated to competition and in experienced and beginner athletes, where correlations range from 0.88 to 0.91 (i.e. very high), which shows that even without having used it before, it’s a method that after a short period of time of learning and intuition, we find its good use in daily practice.
Table 2: Relationship between RPE, RIR, repetitions made and %1RM.
How to Use the Rate of Perceived Exertion in Training?
We’re going to show examples of two methods:
Method 1: Lowering the bar weight
A target RPE is calculated, for example, RPE = 8 with a weight of “anything” to the repetitions we want to work on (example: range 6 – 8).
Let’s say that on that day, the weight to which we associate that target RPE is 100 kg and we’ve planned to reach 20% fatigue, which is the maximum limit of speed loss to work the maximum force at that load and/or the minimum threshold to generate considerable hypertrophy in the medium term.
Method 2: Variable sets and repetitions up to a target RPE
We calculate a zone of RPE in which we want to train, for example, starting at RPE = 7 and ending with an RPE = 9, without doing bar weight loss as in the previous method.
Step 1: 1ª set
We load the bar with 120 kg and start with an initial RPE = 7.
This means we’ll perform repetitions in the first sets of the exercise until after finishing one of these repetitions we have the feeling of RPE = 7 (probably close to RIR = 3-4). That will be our target number of repetitions in the following sets.
Step 2: Rest
The minimum time necessary to carry out the next sets with guarantees of completing the number of repetitions of the previous sets.
Step 3: 2ª set
The number of repetitions of the previous sets are made and the RPE (perception of exertion) that we have when making the last repetition is registered.
Step 4: Repeat steps 2 and 3
Until the last repetition of a set gives us a perceived exertion RPE = 9, at which point the exercise ends.
The following table addresses these relationships to identify how much fatigue we accumulate as we increase the RPE with the same weight (Table 2).
|Fatigue % – RPE increase with the same weight|
|RPE Increase||Example||Accumulated Fatigue|
|0.5||8.0 to 8.5||2-3%|
|1||8.0 to 9.0||4-6%|
|1,5||8.0 to 9.5||6-9%|
|2||8.0 to 10||9-12%|
Table 2: Approximate fatigue associated with an increased sense of perceived exertion with the same weight lifted.
Example RPE regulation for micro cycle in bench press
We present an example of subjective training scales, in this case applying RPE, on a 1 week micro cycle of a Bench Press with 10-12RM.
|Session 1||1º End the first set when RPE = 7 -> Stay with this number of repetitions (x)|
|2º Rest for approx 2 mins.|
|3º Do sets of x repetitions until RPE = 9 final speed < 0.27 m/s).|
|4º Continue with the rest of the training.|
|Session 2||1º End the first set when RPE = 7 -> Stay with this number of repetitions (x).|
|2º Rest for approx 2 mins.|
|3º Do sets of x repetitions until RPE = 9.5 (final speed < 0.27 m/s).|
|4º Continue with the rest of the training.|
Summary and conclusions
Subjective scales such as the RIR or RPE should be considered in conjunction with speed measurements to obtain a more accurate estimate of individual relative load (% 1RM) rather than generalised group equations, which could serve as a basis for estimation, but not beyond.
In other words, an RPE = 8 could mean an RIR = 2-4 depending on the exercise, the intensity and the subject (general training experience, absolute 1RM in that exercise, specific experience of using the particular scale…).
- Balsalobre-Fernández, C, Muñoz-López, M, Marchante, D, & García-Ramos, A (2018). Repetitions in Reserve and Rate of Perceived Exertion Increase the Prediction Capabilities of the Load-Velocity Relationship. The Journal of Strength & Conditioning Research, 32(10): 2693-2994.
- González-Badillo JJ & Gorostiaga E (2002). Fundamentos del entrenamiento de la fuerza. Barcelona: INDE.
- González-Badillo JJ & Ribas J. (2002). Bases de la programación del entrenamiento de fuerza. Barcelona: INDE.
- Helms, E.R, Storey, A., Cross, M.R., Brown, S.R, Lenetsky, S., Ramsay, H., Dillen, C., and Zourdos, M.C (2017). RPE and velocity relationships for the back squat, bench press, and deadlift in powerlifters. The Journal of Strength and Conditioning Research 31(2): 292–297, 2017.
- Pareja-Blanco F, Rodríguez-Rosell D, Sánchez-Medina L, Gorostiaga EM & González-Badillo JJ (2014). Effect of movement velocity during resistance training on neuromuscular performance. International Journal of Sports Medicine; 35(11), 916-924.
- Pareja-Blanco, F, Alcazar, J, Sánchez, J., Cornejo-Daza, P., Piqueras, F., Mora-Vela, R., Sanchez-Moreno, M., Bachero-Mena, B., Ortega-Becerra, M. & Alegre, L. (2020). Velocity Loss as a Critical Variable Determining the Adaptations to Strength Training. Medicine & Science in Sports & Exercise.
- Robertson, R. J., Goss, F. L., Rutkowski, J., Lenz, B., Dixon, C., Timmer, J., … & Andreacci, J. (2003). Concurrent validation of the OMNI perceived exertion scale for resistance exercise. Medicine & Science in Sports & Exercise, 35(2), 333-341.
- Rodríguez-Rosell, D., Yáñez-García, J. M., Mora-Custodio, R., Pareja-Blanco, F., Ravelo-García, A. G., Ribas-Serna, J., & González-Badillo, J. J. (2020). Velocity-based resistance training: Impact of velocity loss in the set on neuromuscular performance and hormonal response. Applied Physiology, Nutrition, and Metabolism.
- Zourdos, M. C., Klemp, A., Dolan, C., Quiles, J. M., Schau, K. A., Jo, E., … & Blanco, R. (2016). Novel resistance training–specific rating of perceived exertion scale measuring repetitions in reserve. The Journal of Strength & Conditioning Research, 30(1), 267-275.
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