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Last rep velocity & RPE: Autoregulated strength training with VBT

In the world of strength training, more than many others, two methodologies have proven themselves to be practical and valid ways for coaches and lifters to create and autoregulate highly effective strength training programs: Rate of Perceived Exertion (RPE) and Velocity-Based Training (VBT).

Both RPE and VBT are powerful frameworks for helping maximise strength gains, improving training quality and results, and minimising overtraining and burnout risk in strength programming - particularly for barbell sports such as powerlifting.

In this article, let’s explore how you can leverage both velocity tracking and RPE in your training and programming to get the most out of both subjective and objective data in your training — giving you a true edge on your competition to make sustained strength gains.

What’s the difference between RPE and RIR?

Throughout this article, I will be using the acronym RPE in a very specific way.

RPE was first used as a measure of training effort in the endurance and teams sports worlds and was quite open and subjective in its interpretation. In strength training, RPE has taken on its own meaning having been popularised and refined as a way to measure and control strength programming, much of this work was pioneered by Mike Tuscherer of Reactive Strength Training.

Mike along with the majority of the powerlifting world uses this Rate of Perceived Exertion (RPE) system, however, some lifters may prefer the Reps in Reserve (RIR) model. I will leave the debate of which is a better scoring system for another time, but both systems require an athlete to match their subjective assessment of how close a set was to the point of failure and give it a ranking. RPE uses 10/10 as the score for a max effort set, with 0.5 point steps down to a warm-up set being 5.5/10, the half point scores allow for those in-between sets where a lifter might not be confident on a whole number ranking. Meanwhile, RIR uses 0 as the score for a max effort set. A 0 in RIR speak suggests that the lifter has 0 reps in reserve, with the score going up (down?) in 1 point steps until a 5 reps in reserve score meaning the lifter had 5 reps remaining before they might have failed, like in RPE, scores beyond a 5 are really arbitrary and all just mean the same thing “warm up set”.

An RPE to RIR conversion chart
An RPE to RIR conversion chart

As is is more popular and widely used, I will stick with RPE for this article, but all the same rules apply for RIR based programs, just convert the RPE to the equivalent RIR and the same rules would apply (rounding any half RPE measures up to the nearest whole number first.

Measuring exertion with VBT

While RPE is a system for subjectively assessing the effort in your training sets, velocity based training (VBT) provides a number of ways to objectively measure training effort and proximity to failure. VBT involves the use of some form of technology, such as the Metric VBT app to track the velocity of barbell movements, providing quantifiable and precise data about performance (velocity, range of motion, bar path, power output etc) on every rep in a set.

Once velocity data is collected for a training set, there are two common ways to measure how fatiguing that set was and how close the set came to the point of failure, velocity loss percentage, and last rep velocity.

Velocity loss percentage - a general measure of exertion

Velocity loss quantifies the drop in bar speed from the fastest rep in a set to the last rep. The higher your velocity loss %, the harder the set was and more fatiguing it was. Typically a velocity loss of 40% is considered the point of failure for most lower body lifts, while 45-50% is not uncommon for upper body exercises.

Last rep velocity (LRV)

LRV is the speed of the last rep in a set, typically the slowest.

The slower this final rep is, the closer you went to an all-out maximum effort set. The slowest speed you can physically still move the barbell at and complete the repetition is known as the minimum velocity threshold (MVT).

Chart showing the load velocity profile - with a single rep at your minimum velocity threshold would be a 1RM.
Performing a single rep at your minimum velocity threshold would be a 1RM.

*Both of these calculations of proximity to failure assume that you are lifting with a good level of intent to move across the set — trying to lift each rep with a high amount of force and effort. Artificially slowing down the reps in a set makes this application of velocity based training less effective.

Limitations of velocity loss measurement for powerlifters

Across strength and conditioning and athletic development settings velocity loss is the more widely adopted and understood approach to measuring exertion in a training set. However, it has limitations, which, as we will soon see, is where last rep velocity can be helpful.

Velocity loss is most useful in sets ranging from 4-12 reps where enough reps are completed for fatigue to begin accumulating, but not so many reps that the set becomes a conditioning activity. In this rep range, a velocity loss of 40-50% can be reliably seen as the point of failure (RPE 9.5 +) for most intermediate and above lifters.

Because velocity loss is only really useful for sets of 4 or more repetitions, the first major limit of this can be pretty obvious — most of the work strength athletes need to do is in the 1-3 rep range.

Furthermore, velocity loss, calculated as the difference between the fastest and last rep of a set, can sometimes give a skewed picture of exertion when an athletes readiness and daily strength levels might be fluctuating. Something further exacerbated the more advanced you are along your strength journey (again, think high-level powerlifters).

When an athlete is in a state of residual fatigue — called low readiness — their power and force output is affected due to a fatigued nervous system. This impact is most evident in the fastest and most forceful reps of a set, usually the first 1-3 reps.

The Metric VBT app highlighting the Trends feature for measuring fatigue and readiness
The Metric VBT app's Trends feature is aimed at highlighting this by focusing on this top-end performance to gauge readiness with a single contextual metric.

When a lifter is in a state of low readiness, and force production is suppressed, velocity loss can be deceptively minimal.

Because the the velocity on early reps are lower, athletes will actually see less velocity loss for the same number of repetitions, inadvertently making the set more fatiguing and compounding the issue of low readiness.

Velocity based training used to measure a training set to failure. Looking at high readiness
Example 1: High readiness and a fast best-rep velocity leads to higher velocity loss scores
Velocity based training used to measure a training set to failure.
Example 2: Low readiness and a suppressed best-rep velocity and lower velocity loss scores, despite the residual fatigue

This is a counterproductive way to autoregulate training stress for strength athletes. An alternative is to use last rep velocity to gauge proximity to failure and exertion in each work set. When combined with Trends analysis for tracking readiness and a subjective RPE tracking system, last rep velocity (LRV) becomes a valuable tool for creating and following high-precision programming and periodisation.

The Interplay of RPE and Last rep velocity (LRV)

Blending Rate of Perceived Exertion (RPE) with Velocity-Based Training (VBT) through the last rep velocity (LRV) metric, gives lifters and coaches the best of both worlds; objective real-world data with subjective assessment of training in real-time.

What is particularly awesome about using RPE and LRV together is that they tend to be strongly correlated, the higher the RPE, the lower your last rep velocity. The relationship is unique for each exercise and the specific values will vary between individuals but it holds true for most strength training contexts with loads above 80% of 1RM, and rep ranges from 1-8 repetitions.

A general conversion chart between last rep velocity values and RPE
A general conversion chart between last rep velocity values and RPE. Max out = 10RPE, Tough = 8.5RPE, Moderate = 7RPE. Values are example only, your specific velocities may vary.

This RPE - LRV relationship is less useful on power training (where RPE doesn’t really make sense) and on higher rep or tempo based training where tempo or energy system factors skew both RPE and velocity tracking data.

Taken to its logical conclusion, the slowest last rep velocity you can physically perform a 1RM with is known as your minimum velocity threshold (MVT). The MVT value is effectively a lifters physiological limit for that exercise, the slowest they can maintain their form and grind out the concentric portion of a rep and not get beaten by gravity.

What’s nice about the velocity of your 1RM is it is also a pretty good guess at the velocity of your last rep on a 3RM, 5RM, 8RM and all RMs in between. There might be some drift in this value for some lifters, but it’s a pretty solid guess.

Chart illustrating maximum sets of different reps ranges tend to all have last rep velocities around the same mean velocity value
Maximum sets of different reps ranges tend to all have last rep velocities around the same mean velocity value

How to use last rep velocity in your strength training

The first thing to do to take advantage of the LRV in your training is to create an RPE - LRV conversion chart for each or your main lifts. You can do this by measuring velocity on your sets with Metric VBT and inputting the last rep mean velocity values for each set into this free LRV calculator on the VBTcoach website.

An example use of the VBT and RPE conversion calculator
The free VBTcoach RPE and VBT last rep velocity converter. Try it here.

Once you have created a chart for your lift, take a screen or write the velocity values somewhere you can reference during your training, they will come in really handy with making informed real-time training decisions.

Here are some example use cases:

Substitute LRV for RPE on novel training prescriptions

As you go through training blocks the rep-set schemes will be constantly changing. If you start a new training block with an unfamiliar rep scheme it can take a few weeks to calibrate your RPEs to this new rep range.

In this instance, you can refer to your last rep velocity values and use the real-time feedback feature in the Metric app to help you more quickly find the correct training weights, RPE range and proximity to failure. This will help you hit your program targets sooner in the training block and avoid under or over working on those first couple of weeks on the new plan.

Assessing fatigue to autoregulate sessions

Residual fatigue will impact your strength levels on a day-to-day basis. One day 100kg x5 moves at 0.5m/s and feels like a 7RPE the next it is 0.38m/s and feels like a 9RPE.

1RM tested daily shows a wide fluctuation in strength levels = Zourdos, 2016
Daily strength levels fluctuate widely. Athlete 1 1RM values isolated for illustrative purposes

Sometimes its completely appropriate to push straight through this fatigue, train hard, and just do the work, other times making a course correction and autoregulating your session in real-time to avoid overtraining is not only the smart approach, but will also lead to better short and long term progress.

RPE alone is a great system for modulating this, but its hard to deny the psychological limitations inherent in RPE. Humans are subjective beings and even the most disciplined of us are prone to anchoring and bias that might skew our RPE ratings, especially if it might mean a training session gets cut short!

There is even a whole category of memes dedicated to powerlifters blowing out their prescribed RPEs!

Use last rep velocity as an unbiased mediator on these tricky-to-rate sets.

Most of the time you can back RPE and keep to the training plan. However — and this is a big however — Last rep velocity is like the video referee for your lifting, ready to step in when the game is on the line helping you make important load adjustments or program decisions in real-time confidently and objectively.

You might not use this last rep velocity second opinion very often (maybe 10-20% of the time in my experience) but this small number of decisions have an outsized impact on the long term adaptations a lifter will make — They can really make or break a training block and program, especially as you become more experienced and the margin for error gets tighter.

Precise RPE calibration and training intensities

Even the best lifters struggle to gauge RPE from time to time, use LRV as a teaching tool, improve your self-assessment, and calibrate your RPE ratings in real-time.

A nice way to do this is by giving the RPE score blind (without looking at the velocity data) then refer the last rep velocity to see how close your RPE got to your conversion chart scores. Give yourself a range of ±0.03m/s to be considered close, and then watch for trends to see how sharp your RPE skills are.

If you are considerably over reporting on the RPE, rating sets it was harder than they actually are consider what might be biasing your RPE and holding you back when you have more to give.

Alternatively if you under reported RPE, and calling even your max out sets an RPE 8 maybe you can’t trust your internal strain gauge and might need to call on last rep velocity or even velocity loss % as a way to dial in how hard you push your training.

The best way to control this if your RPE system is a bit out is to use real-time feedback and set a velocity target, this way you will receive audible feedback as you train to help calibrate your sets and complete work at the level optimal for making gains.

Dominate the weights with velocity based training

This is far from an exhaustive list, but in sum, anywhere RPE can enhance training, the incorporation of LRV can take this even further, or serve as an objective substitute.

If you are looking for a way to track your workouts, catalogue your training videos, log RPE data and try out velocity based training, check out the Metric VBT app.

You can get it on the iOS app store here →

And to create your own RPE - LRV conversions, check out the VBTcoach calculator here →

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References and resources

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