John Odgers M.Sc. - March 23, 2021
Although "percent 1- Rep Max" (1RM) is the most popular form of load prescription (8), it has some major shortcomings.
Fortunately, some of these flaws can be corrected by implementing some form of autoregulation, from Velocity Based Training to Rate of Perceived Exertion.
Autoregulation allows intensity to be individualized on a day-to-day basis based on athlete readiness and performance.
While VBT has utility at high velocities for the development of speed and power, this article will solely look at the utility of VBT to dictate load when training for strength and hypertrophy. Firstly, let's review the flaws with percentage-based loading.
In recent research, a large inter-individual difference in the number of repetitions an individual can perform at a given percentage of 1RM has been observed. Cook et al. found a range of 7-26 repetitions performed at 70% 1RM on the back squat (2). In my research, we found a range of 6-14 repetitions on the front squat and hex bar deadlift at 80% 1RM in males and females (15).
Meaning, if 3x8 at 80% 1RM is prescribed, one athlete may finish and have 5-6 repetitions in reserve (RIR), and some may be failing on repetitions 6-8.
Furthermore, an athlete's strength levels can change on a day-to-day basis and have been shown to vary up to 18% above and below their previously tested 1RM, equating to 36% variance (12).
Overview of RPE and VBT
One way to account for these inter-individual differences is to implement some type of autoregulation. Two main forms of autoregulation are VBT and using the RPE scale based on RIR. Most often, VBT devices are accompanied by a user manual with the following velocity zones based on what adaptation and percentage of 1RM a coach wants to train at on that day (Figure 1).
The Gym Aware linear position transducer (LPT) is one of the more popular VBT devices on the market and has been validated against the gold standard 3D Motion Capture (13). While the Gym Aware runs at $2,000 USD, there are much more affordable options available.
Gym Aware recently launched the FLEX unit that runs at $495 and has also been validated against 3D motion capture (20). Squats and Science has the RepOne unit that is also validated (5) and runs at $395. For individuals who want to use VBT on a budget, these are also viable options.
When utilizing VBT, athletes and coaches can use the zones listed above, or they can create an individual load velocity profile (LVP) or group LVP. Research has shown that the LVP is reliable on a session-to-session basis at submaximal loads (1) and stays the same after gaining strength (6). Thus, once an LVP is created, it can be used reliably throughout the week and in subsequent training blocks as athletes gain strength without needing to re-create the LVP after every training block.
The RPE scale was first published and validated in 2016 by Dr. Zourdos where an RPE of 10 corresponds to 0 RIR, 9 RPE corresponds to 1 RIR and so on (Figure 2; 21). In my research, well-trained individuals were able to predict their RIR within approximately +/- 1 repetition at RPE 6 and approximately +/- 0.20 repetitions at RPE 9 on the front squat and hex bar deadlift (15).
(Zourdos et al., 2016)
A very strong inverse relationship exists between percentage of 1RM and average concentric velocity (ACV). Helms et al. found r values of -0.91 on the squat, -0.90 on the bench press and -0.92 on the deadlift (10). In my research, we found r values of -0.98 on the front squat and -1.00 on the hex bar deadlift between RPE and ACV (15). This strong relationship allows us to use velocity to predict what an athlete's RPE is based on the ACV of the bar.
Longitudinal Research
Dr. Harry Dorrell was the first to use the term velocity-based loading (VBL) vs. VBT (4). He views VBT to be how velocity was originally used and researched, where the goal of the training session was to move the bar at maximal speeds.
VBL differs as it uses the ACV values to dictate the load on the bar.
Historically, the goal of VBT was to move light loads at high velocities. This has its place in strength and conditioning programs, but the utility of velocity to help autoregulate the load on the bar at lower velocities, such as in a strength phase, has often been overlooked. Thus, Dorrell deemed VBL to be a better representation of the use of velocity to dictate load.
Expanding on this, Dr. Dorrell led a study that evaluated the effectiveness of percentage 1RM vs. VBT to prescribe intensity over a 6-week training program.
They found significant increases in countermovement jump height and bench press strength in the VBT group over the percentage-based group (4). Surprisingly, these increases, accompanied by equal increases in strength on the back squat and overhead press by both groups, were accompanied by a significant decrease in total volume lifted by the VBT group. This means the VBT group was able to get stronger and jump higher while doing less total work over the 6-week study.
Dorrell also led another study that looked at the use of individual LVPs vs. group LVPs over the course of the same 6-week training study. They found no significant strength and power differences between the groups – only a greater potential magnitude of change in favor of the individual LVP group (3).
This is good news for coaches who are working with 20+ athletes at once as it is not realistic to use individual LVPs for each athlete and make set-by-set load adjustments based on them.
For time's sake, and practicality for those larger groups, creating a group LVP is much more realistic and applicable in team sport strength and conditioning.
Additionally, when using a group LVP, we are only missing out on a potential very small benefit compared to using individual LVPs.
Dr. Helms compared percentage-based load prescription vs RPE-based load prescription and found that both loading schemes are effective for increasing strength (11). However, the RPE-based loading may have a slight advantage. This was also supported by Grahm and Cleather who found a greater magnitude of change in squat strength when using an autoregulated loading scheme vs. percentage-based loading (7).
Finally, a study was recently published comparing RPE vs. VBT. They found the VBT group increased squat and bench press strength twice as much as the RPE group (18). While these results show that VBT may be superior, this is the only study to directly compare them against each other. So, until further research is published, these results should be taken with caution.
Misapplication of VBT
While VBT has become very popular over the past 10-15 years, I believe it is being misapplied in several ways. Firstly, simply using the manufacturer's velocity zones (see Figure 1) could cause certain athletes to undershoot or overshoot their desired training load.
Since these are only general zones, strength and conditioning coaches are much better off using a group LVP that is specific to the group they are training, or, when dealing with smaller groups, creating individual LVPs for each athlete. This will also allow coaches to make more specific load adjustments on a set-to-set basis using velocity to dictate load.
Secondly, velocity loss should be used with caution. Velocity loss is a type of autoregulation that has an athlete stop doing repetitions once a certain percentage of velocity loss is achieved based on the speed of their 1st repetition (16).
For example, if velocity loss is set to 40% at 70% 1RM and the first repetition of that set is 0.70m/s, the athlete would continue doing repetitions until a velocity of 0.42m/s is achieved (40% below .70m/s). While this has been shown to be an effective way of achieving different amounts of training volume (16), velocity loss still falls short in a couple of practical ways. In the previous example, the set would be terminated when the athlete reached 0.42m/s, corresponding to approximately 2-3 RIR in the squat. If the same velocity loss was prescribed on the bench press, the first repetition at 70% may be 0.55m/s meaning the set would be terminated at 0.33m/s. This would have the athlete only reach approximately 5-6 RIR. A similar issue arises when we use the same exercise and velocity loss at different percentages of 1RM.
Finally, every exercise has its own RPE/velocity profile. In my research, we created RPE/velocity profiles for the front squat and hex bar deadlift. At an RPE of 8, the front squat had an ACV of 0.46m/s and the hex bar had an AVC of 0.32m/s (15). Using the same RPE/velocity profile for both of these exercises would grossly undershoot or overshoot the desired training stress for that day.
Practical Implementations
Below are 2 examples of how these methods can be implemented to autoregulate training. Both of these methods make up for the shortcomings of percentage-based loading and velocity loss reviewed earlier.
1. RPE and Velocity Ranges
When prescribing intensity for multiple sets of a given exercise, an RPE or velocity range can be given to allow the athlete to select a load so they fall within those ranges.
Ex: Trap Bar Deadlift 4x3 @ RPE 7-9 and/or ACV 0.33-0.30m/s
As the athlete is warming up for this exercise, depending on their RPE and velocity, they can self-select a load that will make their first working set fall within these guidelines. This also allows the athlete to make set-to-set adjustments if they under/overshoot their targets. If their first set is an RPE 6, they will add 5% to their next set which should bring their RPE in the 7-9 Range. Likewise, if the last repetition of their first set is 0.38m/s, they will add 5% so their next set falls within 0.33-0.30 m/s. RPE and velocity can be used together and should not be seen as mutually exclusive.
2. Absolute RPE/Velocity Stops
In this method, an absolute RPE/velocity value is given to the athlete to terminate their set when reached.
Ex: Front Squat 1x3@ RPE 8/0.46 m/s, followed by 3 Back-off sets with 5% load drop
In this example, an athlete would warm up until they achieve the top set listed, 3 repetitions at 8 RPE or a final repetition velocity of 0.46 m/s. Following their top set, they will decrease the load and perform 3 back-off sets that are terminated when an RPE of 8 is reached, or their velocity goes below 0.46 m/s. This allows the load to individualized, but also the amount of volume that each athlete is performing to be individualized. Athletes who handle volume proficiently will be able to get more repetitions before hitting the RPE/velocity stop value and athletes who are less proficient with volume will perform less volume – due to the nature of how the autoregulatory method is set up.
A second way to use this method is to autoregulate the number of sets the athlete performs. After they have reached their 1x3 @RPE 8 or 0.46m/s, they decrease the weight by 5% and do between 2-5 back-off sets for sets of 3, stopping when they reach RPE 8 or 0.46m/s again on a set. See Table 1 for an example. This is not an exhaustive list, only examples of the many ways these can be implemented.
Table 1.
|
Set Number |
Method #1 |
Method #2 |
|
1 |
225x3 @ RPE 8 or 0.46m/s |
225x3 @ RPE 8 or 0.46m/s |
|
2 |
215x5 |
215x3 |
|
3 |
215x4 |
215x3 |
|
4 |
215x3 |
215x3 |
|
5 |
|
215x3 |
|
These velocity stop values can be taken from previously published literature, or they can be created based on data from your athletes. This was the goal of my research – to publish RPE/velocity profiles for trained individuals on the front squat and hex bar deadlift (see Figure 3).
Morán-Navarro et al. confirmed that the ACV at RPE 6 and 8 are the same across 65, 75, and 85% 1RM (14), which allows us to create one RPE/velocity profile and apply it to a wide range of intensities with accuracy. This is also very simple to do. If you are doing a 3-5 RM during your fitness testing with your athletes, you can simply use the ACV values at 0-5 RIR to create an individualized RPE/velocity profile for each athlete, and if you decide to, your whole group averaged together.
Finally, the ability to see or receive feedback while performing repetitions on an exercise has been shown to increase athlete motivation and competitiveness when compared with not receiving any feedback (19). Further, when augmented verbal velocity feedback was given to athletes, they performed all exercises with faster velocities, increasing the intent of moving the barbell maximally on each rep (17). This could have benefits in the long term, especially with power-based movements.
Finally, tracking athlete RPE and velocity can also be used as a tool to assess athlete daily readiness and fatigue. Through the process of warming up, both velocity and RPE have the ability to get an estimated 1RM for that day on the exercise at hand. This allows us to track athletes projected 1RM without needing to work up to a true 1RM or even a 3-5 repetition max.
By the nature of how velocity and RPE adjust the training load daily based upon how an athlete performs during their warmups, athlete monitoring is built in to these methods of load prescription. If we bench press once per week, we can use the estimated 1RM from the linear regression line created by the LPT to track those changes week to week. Likewise, we can also do this with RPE. If an athlete front squats 275 for 3 repetitions at RPE 8, we can use the chart in Figure 4 (9) to calculate an estimated 1RM for that day.
Ex: 275lbs / 85% = 323.5 lbs
Figure 4.
(Helms et al., 2016)
Conclusion
Even though percent 1RM has its shortcomings, there are autoregulatory tools available to help us correct for those. While we won't always get the perfect weight on the bar, VBT and RPE can help us get closer than the 18% error associated with using a percentage of a previously tested 1RM. Furthermore, these tools can aid in assessing fatigue and athlete monitoring on a daily and weekly basis. Of the longitudinal research available comparing fixed loading vs. autoregulated loading, all studies lean in favor of using a flexible approach (4, 7, 11, 18). Therefore, I think this type of load prescription can only add value to and improve the quality of strength and conditioning programs.
VIDEO: Autoregulation: VBT and RPE
References
- Banyard HG, Nosaka K, Haff GG. Reliability and validity of the load–velocity relationship to predict the 1RM back squat. The Journal of Strength & Conditioning Research 31: 1897-904, 2017.
- Cooke, DM, Haischer, MH, Carzoli, JP, et al. 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 33: 890-895, 2019.
- Dorrell, H. F., Moore, J. M., & Gee, T. I. Comparison of individual and group-based load-velocity profiling as a means to dictate training load over a 6-week strength and power intervention. Journal of Sports Sciences, 38: 2013-2020, 2020.
- Dorrell, H. F., Smith, M. F., & Gee, T. I. Comparison of velocity-based and traditional percentage-based loading methods on maximal strength and power adaptations. The Journal of Strength & Conditioning Research, 34: 46-53, 2020.
- Goldsmith, JA, Trepeck, C, Halle, JL, et al. Validity of the open barbell and tendo weightlifting analyzer systems versus the optotrak certus 3d motion capture system for barbell velocity. International Journal of Sports Physiology and Performance 14: 540-543, 2019.
- González-Badillo, J. J., & Sánchez-Medina, L. Movement velocity as a measure of loading intensity in resistance training. International Journal of Sports Medicine, 31: 347-352, 2010.
- 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.
- Haff, GG, Triplett, NT. Essentials of strength training and conditioning 4th edition. Champaign, IL: Human kinetics, 2015.
- Helms ER, Cronin J, Storey A, et al. Application of the repetitions in reserve-based rating of perceived exertion scale for resistance training. Strength and conditioning journal 38: 42, 2016.
- Helms, E. R., Storey, A., Cross, M. R, et al. RPE and velocity relationships for the back squat, bench press, and deadlift in powerlifters. The Journal of Strength & Conditioning Research, 31: 292-297, 2017.
- Helms, ER, Byrnes, RK, Cooke, DM, et al. RPE vs. percentage 1RM loading in periodized programs matched for sets and repetitions. Frontiers in Physiology 9: 247, 2018.
- Jovanović, M., & Flanagan, E. P. Researched applications of velocity based strength training. J Aust Strength Cond, 22: 58-69, 2014.
- Lorenzetti, S., Lamparter, T., & Lüthy, F. Validity and reliability of simple measurement device to assess the velocity of the barbell during squats. BMC research notes, 10: 1-5, 2017.
- Morán-Navarro, R, Martínez-Cava, A, Sánchez-Medina, L, et al. Movement velocity as a measure of level of effort during resistance exercise. The Journal of Strength & Conditioning Research 33:1496-1504, 2019.
- Odgers, J., Zourdos, M., Helms, E, et al. Rating of perceived exertion and velocity relationships among trained males and females in the front squat and hexagonal bar deadlift. The Journal of Strength & Conditioning Research 35: S23-S30, 2021.
- Parejo-Blanco, F, Rodriguez-Rossell, D, Sanchez-Medina, L, et al. Effects of velocity loss during resistance training on performance, strength gains and muscle adaptations. Scandinavian Journal of Medicine & Science in Sports 27: 724 – 735, 2017.
- Pérez-Castilla, A., Jiménez-Alonso, A., Cepero, M, et al. Velocity Performance Feedback During Ballistic Training: Which Is the Optimal Frequency of Feedback Administration?. Motor Control, 1: 1-14, 2020.
- Shattock, K., & Tee, J. C. Autoregulation in Resistance Training: A Comparison of Subjective Versus Objective Methods. Journal of strength and conditioning research, 2020.
- Weakley, J. J., Wilson, K. M., Till, K, et al. Visual feedback attenuates mean concentric barbell velocity loss and improves motivation, competitiveness, and perceived workload in male adolescent athletes. The Journal of Strength & Conditioning Research 33: 2420-2425, 2019.
- Weakley, J., Chalkley, D., Johnston, R, et al. Criterion validity, and interunit and between-day reliability of the FLEX for measuring barbell velocity during commonly used resistance training exercises. The Journal of Strength & Conditioning Research 34: 1519-1524, 2020.
- Zourdos, MC, Klemp, A, Dolan, C. Novel resistance training–specific rating of perceived exertion scale measuring repetitions in reserve. The Journal of Strength & Conditioning Research 30: 267-275, 2016.
READ John's research (cited in this article) here.
About John
John Odgers is the Assistant Strength and Conditioning Coach of the Los Angeles Kings. Before that, he served as the S&C coach of the Iowa Wild, the AHL affiliate of the Minnesota Wild. Odgers earned his Bachelor of Kinesiology in Human Kinetics with a high-performance specialization in 2016 and his Masters of Kinesiology and Exercise Science in 2019
Prior to entering college, Odgers spent part of four seasons playing for the Yorkton Terriers in the SJHL and spent one season with the Prince George Cougars of the WHL. Odgers won the Royal Bank Cup with the Terriers in 2014.
