A Concept Review of Using the RIR-Based RPE Scale in Your Training 

Key Points

1. Although most of us know rating of perceived exertion (RPE) as a scale that measures repetitions in reserve (RIR) during a set of resistance training, that is a relatively new usage of the term.
2. There are many ways to use RPE outside of just basic load assignment. These strategies include autoregulating volume, load progression over time, tracking progress, and predicting a 1RM.
3. While there are limitations and valid critiques of using RPE, using the RIR-based RPE scale requires little effort and comes at no cost. In most cases, even if RPEs are not perfectly accurate, they are still quite useful. 

In today’s fitness industry, we tend to discuss RPE as it relates to RIR during a resistance training set. While the RIR-based RPE scale is the focus of this article, we should understand that the concept of RPE has been around since before the launch of Apple, Inc. in the early 1970s. The original RPE scale was created by Gunnar Borg and was designed to gauge light, moderate, and heavy efforts during aerobic training (1). RPE, as most lifters use it today, is quite new when considering the historical context and actually out of step with mainstream academics. Nonetheless, the popularity of RIR-based RPE has exploded over the last 10+ years due to its great utility and ease of use. However, RPE tends to be viewed in a binary fashion as either “RPE training is good” or “RPE training is bad.” This binary view tends to only take into account using RPE for basic load prescription because the ratings are subjective. The criticism of subjectivity is fair; however, what many still seem to be unaware of is that the utility of RPE extends far beyond basic load prescription. In this concept review, I aim to provide detailed insight into every possible way to use RPE including: load prescription, autoregulating volume, predicting 1RM, tracking progress over time, and weekly load/set/rep progression, among other uses. This article will provide specific practical examples in the form of tables for each use, so that you can directly implement these strategies into training programs for yourself or your clients. This article will also discuss some of the common criticisms of RPE and how someone can improve their rating accuracy. First, let’s start with the aforementioned historical context.

Brief History

Traditionally, RPE has been used in a different context than how the fitness community uses it today. Originally, Gunnar Borg created a 6-20 RPE scale in 1970 (1), during Helms’s freshman year of high school. The scale was created for aerobic exercise, and the ratings were intended to correspond with a runner’s heart rate. For example, the idea was that a rating of 6 would correspond to a heart rate of 60 beats per minute, and 20 with 200 beats per minute; this range of 60 to 200 beats per minute roughly represents a typical spectrum from resting to maximal heart rate. Therefore, the original iteration of RPE was to gauge effort levels during aerobic exercise. Borg then added the C (category) R (Ratio) 10 (CR10) scale in 1982 (2), which gauged effort levels in a simpler 0-10 rating system. Both Borg scales accomplished the same thing, which was allowing aerobic exercisers to gauge a general sense of light, moderate, or heavy effort. However, for resistance training, the application is relatively limited. Fast forward to 2006 and the OMNI scale was created for resistance exercise. The 1-10 OMNI scale was very similar to the CR10 Borg Scale except visual descriptors were added to the “easy,” “moderate,” and “heavy” descriptors. While the visual descriptors were an improvement, these RPE scales still lacked precision for resistance training. The two original Borg scales can be seen in Tables 1 and 2.

The lack of precision of the Borg scales for resistance training was first revealed in the scientific literature in 2012 from Hackett et al (3). Hackett had bodybuilders perform 5 sets to failure at 70% of 1RM on the squat and bench. After 10 reps on each set, the bodybuilders recorded both a Borg RPE (i.e. light, moderate, or heavy effort), noted how many repetitions they felt they had left, and then continued the set to failure. The bodybuilders estimated their reps left until failure (what we now call RIR) with pretty good accuracy; however, they tended to record moderate effort even when going to failure on the Borg scale. Thus, it was concluded that the Borg or “traditional RPE” scales lacked utility for resistance training, as lifters tend to gauge cardiovascular effort when looking at the descriptors (Tables 1 and 2 above) on traditional scales. Although the Hackett study was the first time this concept had been broached in the scientific literature, it would be inaccurate to say that this was the first time it had been presented in general. In fact, around the time of his gold medal powerlifting performance at the World Games, Mike Tuchscherer published the Reactive Training Systems Manual (4), in which he created the idea of having RIR descriptors for RPE. Our laboratory took the work of Tuchscherer and Hackett et al and formalized the RIR-based RPE scale within the scientific literature in 2016 by validating it against velocity (Table 3) (5). The idea, however, originates with Mike T., and it’s important to make sure he gets the credit. Further, this is an excellent example of how the practical realm is sometimes ahead of science and how what is already done in practice can, and sometimes should, impact scientific research.

Although not the focus of this concept review, I would be remiss to exclude in this historical discussion the usage of the session RPE scale. Session RPE was brought to the forefront by Dr. Carl Foster in 2001 (6). It’s a 0-10 scale typically administered 30 minutes following exercise and asks the individual about their global fatigue level using descriptors such as: “easy,” “moderate,” “hard,” and “maximal.” Let’s look at an example of the utility of this scale in the context of resistance training: If two programs produced the same long-term hypertrophy and strength, but one produced a lower session RPE, then it might make sense to recommend the program that caused less fatigue or even consider adding volume or intensity to the less-fatiguing program (we’ve previously written about this).

Recently, I’ve seen people suggest there could be a difference in RPE and RIR. In reality, if using the RIR-based RPE scale, there isn’t a difference. They are the same. However, historically, there is indeed a difference, but this doesn’t mean that the terminology of “RPE” and “RIR” won’t have different connotations to people even though the scale treats them the same way. Toward the end of this article, we will return to the terminology and discuss how sometimes it may be better to use one term over the other, even if they are technically referring to the same thing. Now that we understand the history, the remainder of this article will focus on the exact usage of the RIR-based RPE scale and will be chock-full of practical examples.

Specific Ways to Implement RPE

The remainder of this article will explain every way in which RPE can be used so that you can implement it into your training in the appropriate manner. Before we get to each subsection, please remember that RPE is just one form of autoregulation, which is defined as gathering feedback about training to make informed decisions (7). For example, a form of autoregulation outside of RPE is flexible training templates. Additionally, thanks to two recent studies, one from Dr. Helms (8) and the other from Graham and Cleather (9 – reviewed in MASS), we know that autoregulating training load with RPE/RIR over the long-term is also a good idea for strength when compared strictly to percentages. Let’s get started with a breakdown of each way to use RPE, starting with the most basic.

Basic Load Prescription with RPE

The most basic way to implement RPE is to simply replace percentage-based load prescription with RPE-based load prescription. For example, instead of programming 4 sets of 8 at 70% on a compound movement, you could program 4 sets of 8 at 6-8 RPE. This means that you would simply choose a load that would land you within the 6-8 RPE range. The utility of this is that since strength fluctuates daily due to various readiness factors (i.e. poor sleep, anxiety, scheduling issues, etc.), using RPE allows you to increase or decrease the load as needed. In the same way, RPE also allows you to lift heavier when you are feeling good. In fact, the Helms (8) and Graham and Cleather (9) studies found that allowing lifers to choose a load based upon RPE allowed subjects to train at a higher average intensity throughout the respective 8- and 12-week training studies, which led to greater 1RM strength in various compound movements.

Additionally, the number of reps that can be performed at a given intensity is highly individual. Recent studies have reported ranges of 6-28 (average = 16 ± 4) (10)  and 6-26 (average = 14 ± 4) (11) reps performed on the squat at 70% of 1RM. Therefore, replacing percentages with RPE can account for the between-individual differences. Even if you like to use percentages as a coach, using RPE in the first few weeks with a new client (if they are well-trained and reasonably accurate with RPE) will give you an idea of how many reps a lifter can do at a certain percentage. Then, based on how many reps are performed at a specific load, you can now individualize a percentage program. Table 4 shows a basic RPE load prescription example.

Table 4 is just one example of a basic RPE-based load prescription. The example is quite practical, as it takes into account long-term periodization and programming strategies outlined here, in that there is an overall decrease in the number of repetitions (i.e. decrease in volume) and an increase in RPE as intensity increases from block to block. When incorporating assistance work with the main lifts in the above example, I would generally follow a similar RPE format, but keep the reps a bit higher so that you are not doing triples and singles on single-joint movements in the final mesocycle. Overall, this example takes into account day-to-day fluctuations in strength levels, the individual ability to perform reps, and it allows for intra-session load adjustments. When adjusting load intra-session, if you miss the RPE target on a set, I think it’s good to have a guide for how to adjust load. Therefore, in Table 5, I have included the table from Dr. Helms’s dissertation that provides this load adjustment guide. You don’t have to follow this table exactly, but it provides the general idea of how to change the load for the next set when you miss the target RPE range. Lastly, I find it a good idea to include an RPE range as your target rather than an exact RPE target when performing multiple sets with RPE-load prescription, as it will become difficult to hit an exact RPE target each time. Besides, it’s just not that important to maintain an exact proximity to failure; rather, it’s important to understand the intent of RPE, which is generally to either be far from failure, a few reps from failure, or at failure. A range saves you from having to adjust the load every single set. Table 5 essentially stipulates that if your set is within the RPE range, you can choose what you would like to do for your next set; however, for every 0.5 RPE points outside of the range your set lands, then you should adjust the load 2% up or down for your next set. Table 5 uses an example of a target RPE range of 6-8, but of course this concept can be applied with any target RPE range.

Autoregulating Volume (RPE Stop)

Autoregulation can also be implemented to achieve the appropriate volume. Using RPE to autoregulate volume has been described using the term “RPE stop.” You can implement RPE stops in two ways: 1) to autoregulate the number of reps in a set, or 2) to autoregulate the number of sets in a session for a specific exercise. These strategies are similar to velocity loss (12), which we have discussed before.

To implement the first strategy and autoregulate reps in a set with an RPE stop, you would pick a percentage or an exact weight and do as many reps as possible on each set but stop each set when you reach a predetermined RPE. If aiming to accumulate volume, you would stop at about a 7-8 RPE, and if training with low volume at high intensities (i.e. 2-4 reps at 85-90% of 1RM), you may stop a set at around a 9 RPE. I actually think RPE stops have utility over velocity loss. Specifically, and as we pointed out last month, if your first rep on a 70% of 1RM squat set is 0.65 m/s, a 40% loss puts you at 0.39 m/s, which probably lands someone between a 5 and 8 RPE. However, your first (or fastest rep velocity) will be lower on subsequent sets. So, let’s say on your fourth set, your first rep velocity is 0.55 m/s, then a 40% velocity loss has you stopping the set at 0.33 m/s, which is much closer to failure than the 0.39 m/s on the first set. Therefore, an RPE stop will always have you stop the set at the desired amount of RIR (assuming the RPE is accurate), and it is inherently individualized, whereas individual velocity profiles must be determined, otherwise velocity can be misapplied across a group.

The second usage of an RPE stop is to autoregulate total set volume. In this model, we take a certain load (i.e. 70% of 1RM) and perform 8 reps per set, but without a predetermined number of sets. Now, we would perform as many sets as we can until we exceed a predetermined RPE, let’s say an 8 RPE. I would recommend capping the number of sets so that you don’t end up performing 10 sets of high rep squats one session if you have a high work capacity. This might be 5 sets for compound lifts when accumulating volume (i.e. moderate reps and lower peak RPE) or 3 sets for compound lifts when in an intensity block (i.e. low reps and high peak RPE). Of course, the amount of sets is also dependent on an individual’s recovery. Table 6 shows an example of both RPE stop methods.

Another advantage of RPE stops is that they have built-in progressive overload. For example, in method one, if your goal is volume you can just stick with the same weight for a few weeks and aim for more reps. Then, once you hit a certain number of total reps across all 4 sets (as per the example), you can increase the load. In method two, if your goal is 5 sets at an 8 RPE or less, you can continue to perform this load each week until you complete all 5 sets successfully, then increase the load.

Total Reps and Rest-Pause with RPE

For assistance work, RPE can be just as valuable as it is for the main lifts. Even though strictly using generalized percentages isn’t great for programming the main lifts, a lifter could create an individualized percentage chart. However, for assistance work, we typically do not know our 1RM; thus, we are left with our perception of difficulty to determine loading. For assistance work, you can certainly use basic load assignment (Table 4); however, a total rep or non-failure rest-pause strategy works well and is similar to an RPE stop. For example, if your 12RM on dumbbell bench press is about 40kg, you could set a threshold of 35 total reps and perform each set to an 8-9 RPE until you reach the threshold of 35 reps. In week 1 of your training block, it might take you 4 sets to reach the 35 reps. You could continue each week with the same load until you reach the 35 reps in 3 sets, then increase the total reps threshold or increase the load to achieve progressive overload. The above example can also be used in the rest-pause variety, just simply take 20-30 seconds between sets. Using RPE during rest-pause allows you to avoid the typical failure training associated with rest-pause training, so it should cause less fatigue in the 48 hours following training than going to failure (13). In reality, the above examples are really variations of RPE stops, but as this is a concept review, I wanted to clearly explain every possible RPE load assignment strategy.

Tracking Progress and Predicting a 1RM

Something I’ve hit on before in MASS is that even if you don’t use RPE to program load, you should still track it. Tracking RPE would itself be scored as an RPE 1, meaning it takes little to no effort to do, and it provides you with a gauge of progress over time. From one week to the next, one block to the next, or even year after year, you can look back and say “I did 175kg for a single at 9 RPE and now I can do it at 5 RPE.” This is clearly progress and you can track it without having to consistently do fatiguing 1RM tests. If you perform some sort of fatiguing test after every training block, then you might have to take a deload or elongated intro week following the test. However, tracking RPE gives you a metric of how successful the block was from a strength (or volume performance) perspective and even allows you to gauge progress during the middle of a training block by comparing RPEs at a given load to RPEs at similar loads during previous weeks. Table 8 gives specific examples of how to track progress and predict a 1RM with RPE. The first two columns of Table 8 originally appeared in an article from Volume 2, Issue 11, and the third row was newly created for this article.

Progression Schemes with RPE

Another often overlooked aspect of RPE is achieving progressive overload. We are oftentimes fixated on saying we are going to increase 2.5kg each week on a main lift; however, that is just not typically feasible. If you are programming load prescription with RPE like the basic RPE loading example (Table 4), then progressive overload takes care of itself; over time, you should be able to load more on the bar to meet the prescribed RPE. However, if you have a predetermined load and you simply track RPE (Table 8) in a percentage-based program, then you can use your RPE scores from each session or each week to progress load, sets, or reps for the following week. The most basic way to use RPE to progress load is creating an inverse relationship between RPE and progress (i.e. the lower the RPE, the greater the increase in load). Additionally, if you bench 100kg for 3 sets of 10 reps at an average RPE of 9, then you can repeat this until your average RPE is 8, and then add load or add a set. In the previous example, you could continue adding sets until you complete 5 X 10 at an average RPE of 8 and then increase the load on the bar and go back to 3 sets (i.e. 3 X 10 at 102.5kg). There are many other ways to do this, which could be an article in and of itself.  The good news is that we already have it in video form. You can watch the detailed presentation of using RPE to achieve progressive overload, and remember that strategies laid out in the video are not mutually exclusive.

To Implement a Flexible Template in the Warm-Up

Using RPE to assess readiness is not as popular as the strategies discussed above, but it still has merit. A foundational principle of using RPE for load prescription is that it can take into account low daily readiness and high fatigue. So, why not use RPE to account for readiness in the warm-up? Specifically, if you are going through a busy time, then it might make sense to implement a flexible training template. In short, you might have three training sessions per week in which you have a heavy training day, a moderate day, and a light day, but the order in which you do them is flexible to meet your readiness levels. You then need to have a metric that you use to decide which training day to do. The most common readiness metric is the perceived recovery status scale, which is essentially a 1-10 Likert scale with 1 being “poorly recovered and expecting declined performance” and 10 being “well-recovered and expecting improved performance.” In short, a high rating on this scale suggests you should do the heavy session that day, while a low recovery rating indicates you should do the light session. However, data have shown that pre-training recovery ratings do not always correlate with performance in that day’s session; rather, RPE during the warm-up might be a better indicator (14). Thus, if you are using a flexible template, you could simply warm up to a decent load (i.e. 80%-85% of 1RM) and take an RPE. If your normal RPE at an 85% bench press is 6 (4 RIR), and you record an 8 RPE or higher, then you might opt for the light day. If your RPE is 5-7, you might opt for the moderate session, and if your RPE is <5, you might opt for the heavy session. I don’t think you have to be that strict with it, and RPE is only going to fluctuate so much, but – in general – it’s probably better to decide which workout you are going to do in a flexible template after you start warming up rather than before the warm-up. Table 9 presents a “less-strict” version of using RPE during the warm-up to choose session-type.

Final Thoughts

Before we finish up, we should address the common critique of using RPE, which is that the rating is subjective and may be inaccurate. Some people’s ratings may indeed be inaccurate, but how much does that matter? Well, it can matter a lot if someone is attempting to use RPE to autoregulate a heavy double or single. In this case, if someone records a 200kg squat at an 8 RPE while working up to a single at 9 RPE, that would translate to about a 220kg max. However, if the 200kg X 1 was actually a 9 RPE, this calculation may erroneously cause the lifter to attempt 210kg on the next set, and it could be a true max or the lifter could even fail the attempt. While there would be fatigue consequences to overshooting the RPE at such a high intensity, it is highly unlikely that someone experienced is that inaccurate with RPEs during low-rep sets at heavy loads. It’s more likely that some personality types don’t lend well to programming something like “singles at 9 RPE.” Some lifters might simply rationalize a way to max out when heavy singles are programmed using RPE. In this case, as a coach, I would just prescribe a heavy load for a single that I know the lifter can hit at an 8 RPE and give them an option for a second rep to ensure failure doesn’t occur. On the other hand, a lifter might be too cautious when working up and end up only working to an 8 RPE; however, that is less consequential than overshooting the RPE.

While RPEs are typically quite accurate during low-rep/high-intensity sets, RPEs can indeed be inaccurate during high-rep sets. In fact, well-trained lifters were on average 5.15 ± 2.92 reps off when asked to verbally call out an intra-set RPE when they believed they were at a 5 RPE (5 RIR), a 7 RPE (3 RIR), and 9 RPE (1 RIR), and then continue to failure during a set at 70% of 1RM on squats in which the average reps performed were 16 ± 4 (11). That is a considerable amount of error; however, that was also overrating RPE, meaning subjects actually had about 10 reps left, which is far less consequential than underrating RPE. Further, if using RPE during moderate- to high-rep sets, the point isn’t to be perfectly precise. Rather, the purpose is to simply be within a range (i.e. 5-8) to ensure you are an appropriate proximity from failure. Overall, as previously mentioned, RPE ratings tend to be strikingly accurate in well-trained lifters during low-rep sets (15), and there is no evidence that velocity provides a better gauge of RIR in this case. During high-rep sets intended to be shy of failure, I don’t see some degree of inaccuracy to be too much of a problem, especially if you are overrating RPE. Besides, if you consider the large variance of reps performed at moderate intensities mentioned earlier (i.e. 6-28 at 70%), then a percentage program could lead a lifter to a much greater programming error than an RPE rating inaccurately predicting RIR by just a few reps.

If you are unsure if your RPEs are accurate, try rating an RPE after a few reps and then continuing to failure to see how precise you are. I would recommend doing this with a weight ≥80% of 1RM on a compound movement when you perceive you are at about a 7 RPE. If you are a coach and a client is unsure that there RPEs are accurate, you can advise them to also gauge an intra-set RPE before continuing a set to failure. Additionally, as a coach, I would still have a client rate RPE, even if you aren’t using it to program or progress load, and have them send you videos of those lifts. Then, you can evaluate, although not perfectly, if you think those RPEs are accurate. Of course, you can always validate RPE with velocity, but we do not all have access to accurate velocity devices. If you do have access to an accurate velocity device, then just about everything written in this article can also be accomplished with velocity.

Over the past year, I’ve seen some people prefer to simply rate RIR as opposed to rating RPE. If you are at a 5 RPE or higher (1-5 RIR), then that is perfectly fine. Terminology is just terminology; it’s the intent and implementation that matters. So, if someone prefers to just use the right side of the scale in Table 3 (i.e. RIR), then that will work just fine, as the terms are interchangeable when the RPE is at least 5. However, in the literature, even the RIR-based scale uses RPE on the low end of the scale, as scores ≤4 RPE quantify effort and are not associated with an RIR. It is difficult to determine a precise RIR when so far from failure. It is also possible that even though RPE and RIR are intended to be interchangeable when close to failure, the term RIR simply resonates more with some. So, whichever terminology someone prefers is fine. They are the same thing in the context of this specific scale.

Application and Takeaways

1. RPE is just one of many tools to implement the concept of autoregulation. In its most basic form, RPE can be utilized to prescribe daily training load, which takes into account the limitations of percentages such as daily readiness and the large between-lifter variation in reps that can be performed at a given percentage of 1RM.
2. Although RPE is most commonly used to prescribe load (i.e. 3 sets of 5 at 7-9 RPE) it can also be used to autoregulate volume (RPE Stops), program assistance work, progress weekly load, sets, or reps, and simply be used to track progress over time. The utility of RPE is widespread and not limited to the narrow box we usually put it in.
3. The common critique that RPE is subjective, and thus not perfectly accurate, is correct. However, the point isn’t to always be perfectly accurate. Further, using RPE to predict RIR is quite accurate, based upon the existing literature, during low-rep and high-intensity sets, which is when accuracy is most important.

References

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2. Borg GA. Psychophysical bases of perceived exertion. Med sci sports exerc. 1982 Jan 1;14(5):377-81.
3. Hackett DA, Johnson NA, Halaki M, Chow CM. A novel scale to assess resistance-exercise effort. Journal of sports sciences. 2012 Sep 1;30(13):1405-13.
4. Tuchscherer M. The Reactive Training Manual: Developing your own custom training program for powerlifting. Reactive Training Systems. 2008;15.
5. Zourdos MC, Klemp A, Dolan C, Quiles JM, Schau KA, Jo E, Helms E, Esgro B, Duncan S, Merino SG, Blanco R. Novel resistance training–specific rating of perceived exertion scale measuring repetitions in reserve. The Journal of Strength & Conditioning Research. 2016 Jan 1;30(1):267-75.
6. Foster C, Florhaug JA, Franklin J, Gottschall L, Hrovatin LA, Parker S, Doleshal P, Dodge C. A new approach to monitoring exercise training. The Journal of Strength & Conditioning Research. 2001 Feb 1;15(1):109-15.
7. Ormsbee MJ, Carzoli JP, Klemp A, Allman BR, Zourdos MC, Kim JS, Panton LB. Efficacy of the repetitions in reserve-based rating of perceived exertion for the bench press in experienced and novice benchers. The Journal of Strength & Conditioning Research. 2019 Feb 1;33(2):337-45.
8. Helms ER, Byrnes RK, Cooke DM, Haischer MH, Carzoli JP, Johnson TK, Cross MR, Cronin JB, Storey AG, Zourdos MC. RPE vs. Percentage 1RM loading in periodized programs matched for sets and repetitions. Frontiers in physiology. 2018 Mar 21;9:247.
9. Graham T, Cleather DJ. Autoregulation by” Repetitions in Reserve” Leads to Greater Improvements in Strength Over a 12-Week Training Program Than Fixed Loading. Journal of strength and conditioning research. 2019 Apr.
10. Cooke DM, Haischer MH, Carzoli JP, Bazyler CD, Johnson TK, Varieur R, Zoeller RF, Whitehurst M, Zourdos MC. Body Mass and Femur Length Are Inversely Related to Repetitions Performed in the Back Squat in Well-Trained Lifters. The Journal of Strength & Conditioning Research. 2019 Mar 1;33(3):890-5.
11. Zourdos MC, Goldsmith JA, Helms ER, Trepeck C, Halle JL, Mendez KM, Cooke DM, Haischer MH, Sousa CA, Klemp A, Byrnes RK. Proximity to Failure and Total Repetitions Performed in a Set Influences Accuracy of Intraset Repetitions in Reserve-Based Rating of Perceived Exertion. Journal of strength and conditioning research. 2019 Feb.
12. Pareja‐Blanco F, Rodríguez‐Rosell D, Sánchez‐Medina L, Sanchis‐Moysi J, Dorado C, Mora‐Custodio R, Yáñez‐García JM, Morales‐Alamo D, Pérez‐Suárez I, Calbet JA, González‐Badillo JJ. Effects of velocity loss during resistance training on athletic performance, strength gains and muscle adaptations. Scandinavian journal of medicine & science in sports. 2017 Jul;27(7):724-35.
13. Pareja-Blanco F, Rodríguez-Rosell D, Aagaard P, Sánchez-Medina L, Ribas-Serna J, Mora-Custodio R, Otero-Esquina C, Yáñez-García JM, González-Badillo JJ. Time Course of Recovery From Resistance Exercise With Different Set Configurations. Journal of strength and conditioning research. 2018 Jul.
14. Zourdos MC, Dolan C, Quiles JM, Klemp A, Jo E, Loenneke JP, Blanco R, Whitehurst M. Efficacy of daily one-repetition maximum training in well-trained powerlifters and weightlifters: a case series. Nutrición Hospitalaria. 2016;33(2):437-43.
15. Sousa CA. Assessment of Accuracy of Intra-set Rating of Perceived Exertion in the Squat, Bench Press, and Deadlift (Doctoral dissertation, Florida Atlantic University).