Monday, October 22, 2018

Programming a Training Cycle with Velocity

I kind of put this thing on the backburner while life got crazy. Life is a little less crazy now and I'm noticing I'm still generating hits, so it seems there are at least a couple people that find these useful. This is one is going to be a little less involved than other articles. No crazy scientific citations because honestly, programming is largely opinion.

Niche Programming

The problem with programming with velocity is there are a million ways to implement it, but really no working examples of how to put it all together. That's not the case with percent based programming. There's plenty of templates that use percent based programming to progress and peak for a meet. There's periodized models, cyclical progression models, undulating models, and concurrent training protocols.
Special note: when I say "concurrent training" I mean training for strength and hypertrophy at the same time. Or I mean doing high rep work and low rep work at the same time. Some people might say that's the same thing as "conjugate training," but that's kind've a loaded term that tends to imply speed work, max effort days, and a bunch of other things I'm not trying to convey. 
I guess the first question is whether we need to re-invent the wheel or we can just modify something already out there? I'd say it's better to start from a known area and slowly venture into the unknown. Or better yet, how did Mike Tuscherer start when he made RPE? I'd guess it's no different than the process he began when developing RPE to prescribe load.

I think percent based training is the easiest place to start, so let's start there.

Parallels with Percent Based Training

This seems easy enough because all you have to do is sub out a percent of 1RM with a corresponding velocity. If 65% is 0.84 m/s and 95% 1RM is 0.32 m/s, then all you have to do is substitute the two. Once you have that, you can generally follow normal percent based training approaches. Maybe the most ubiquitous way to implement this is block periodization.

With block periodization, you see dedicated blocks of volume and intensity. Early on you generally see lower intensity and higher volume. Late into the cycle, you see higher intensity and lower volume. You could just straight out "translate" from intensity to velocity with some success in this case. But this is only one example of how to implement velocity into a percent based training program. One issue with this programming style is 1RM is assumed to be constant through a whole training cycle, so velocity alleviates that. If you get 3% stronger before you update your 1RM, it doesn't matter because we assume velocity scales with intensity. So if 65% moves at 0.84 m/s, then we can assume whatever weight is moving at 0.84 m/s is your current 65%. Having certainty that a given weight is 65% is also assuring because you also know what 100% 1RM is. 
This is 8 weeks of training using Renaissance Periodization's powerlifting remplates. This is just data from their hypertrophy and strength templates, not including the deloads of each cycle or the peaking phase. Columns represent the number of lifts per type of lift (SQ/BP/DL), solid lines represent their average intensity expreseed as percent of 1RM, and dashed lines (which all overlap) represent relative intensity. Relative intensity is essentially the same as RPE, exertion, or proximity to failure. It's also worth noting that deadlifts average intensity is a little misleading because peak intensities show a linear increase over time.

Here's the same data represented as tonnage, along with acute:chronic workload ratios. 
That same data represented at sets. If you're familiar with RP's approach to volume in their templates, the number of sets are sort of autoregulated. You have an option to increase, decrease, or maintain set counts. In this example, I have always opted to maintain set count for every movement and let the program add sets as part of the normal progression.

There's also cyclical type programs, daily undulating programs, and concurrent programs.

A cyclical program would be something like 5/3/1 or the Juggernaut Method. These are kind of like really, really short linear or block periodization programs. Instead of taking 3 or 6 months to get to higher intensity work, you just progress to that within a shorter span of time. Much the same, you can substitute the percentages for velocities. The problem with many of these types of programs is they rely on AMRAP (as many reps as possible) sets to set increase a training max, but velocity functions in the same way. These AMRAPs empower the program to give you volume commensurate to your progress and a method to increase your working weights. Unfortunately, they're also a training obstacle. Without velocity, we have no way to gauge progress and no way to increase training load except through AMRAPs. With velocity, we can still follow the program as written, update training max in real time, and swap AMRAP sets for more training volume since the AMRAP sets offer nothing that velocity isn't already giving us. But maybe AMRAP sets are fun, so maybe you want to keep them in anyway. The point being is that there's no reason to go for an AMRAP if you have another metric to guide progression, like velocity. Doing an AMRAP is likely more training stress, so you could choose to do it as originally intended for no additional benefit (since velocity is driving progression), or do something else in lieu of it to ensure you have somewhat comparable training volume without the extraneous fatigue associated with an AMRAP set. And that's important, because high exertion work has limited and circumstancial utility. 

Then there are programs that essentially train strength and hypertrophy concurrently. The first example of which is daily undulating periodization (DUP). This works kind of like a "heavy, light, medium" training cycle (HLM), where you're doing a mix of intensities and volumes throughout a week, given that intensity is inversely related to volume. So if it's higher intensity, there are fewer reps per set. If it's lower intensity, there are more reps per set, and so on. Both of these can be set up in a percent based program, but recently there have been RPE versions. In both cases (HLM and DUP), you can have designated intensities to hit for a prescribed number of reps. Just take the velocity equivalent of that intensity and hit it for the target repetitions. 

It seems like HLM is gaining traction again, but it's essentially re-branded DUP. Updating DUP with RPE seemed like it essentially killed the training model's popularity, but it's still a valid training idea. For a while, DUP seemed like it was flirting with the idea of "daily 1RM" training. This seems like the opposite approach to augmenting 1RM as cyclical programs seem to take. Rather than setting rep PRs and updating your training max, you're updating 1RM and attempting to hit them for higher volume sets. Both methods impose a training obstacle that's really only essential because you don't know the current status of your 1RM. RPE seemed to integrate into this seamlessly and I could argue that it's become central to RTS's "top set" method.
It's also worth noting you can have linear periodization with a DUP program. Instead of having something like a week of 12/8/4 throughout you can have a block of 12/10/8, then linearly reduce that to 10/8/6, 8/6/4, and peak with 6/4/2 rep schemes. The overall net effect is a linear decrease in volume and a linear increase in intensity. Not to diminish what DUP is, but it's value is in it's versatility and simplicity. 
Another system that uses a concurrent training approach is GZCL (here's a link to when MegSquats was doing GZCL and a link to Cody Lefever's/GZCL's website). This seems to be only popular on the internet though. Much like 5/3/1, there are a hundred versions, so I'm only going to talk about what it generally does. The main idea is to complete high-intensity work, moderate intensity work, and low-intensity work all within the same session. Usually, the low-intensity work is an accessory, the moderate intensity work is a close variation, and the high-intensity work is a main lift like a competition squat, bench press, or deadlift. Many people also throw in overhead press, but otherwise, it's a quintessential "powerbuilding" program. And once again, AMRAP sets are used to update your training max. 
Let's just throw it out there that overhead press is only popular among powerlifters because of Wendler and Rippetoe. For most people, it actually doesn't help the bench press. So I guess my question is: why the hell are you training the overhead press in a powerlifting program? You don't need to have the overhead press unless you want it in your program. Having bench press as the tested event in powerlifting competitions is completely arbitrary, but it's not changing any time soon. I don't know why people came to value the overhead press more than something like a row or a pull up, but it did. Pulls are damn cool. Why do people neglect their pulls? It actually helps out your deadlift and bench press. I have nothing to support that, but I'm pretty sure it's true. Any case... the overhead press is a stupid, garbage person lift. Also, Mark Rippetoe is a dinosaur that doesn't know how to train anyone except novices, and arguably he doesn't even know how to train them well.
In all of these methods, you are eliminating the need for SOMETHING that previously served as a metric for progress. We no longer need those because we have velocity - at least in theory. With linear and block periodization programs, we need to update 1RM somewhat regularly, maybe at the end of "blocks," monthly, or whatever interval. With DUP or cyclical programs, you're also relying on some other metric. The problem is these methods rely on a singular performance. If that day was good, your training max is inflated beyond your training capabilities. If that day was bad, then you're suppressing your training max until you have another opportunity to update it. Largely, this isn't an issue to begin with because the reps assigned normally allow with some leeway so you're never hitting a 5RM for 5 reps. You're always leaving something in the tank by artificially reducing your training max or underprescribing reps so there are some reps left in the tank. In my opinion, both of these are just workarounds and do come to the detriment of training. If you could just prescribe the right weight on the bar for the right number of reps to begin with, you could do away with a lot of these if you had some way to figure out what the right weight and reps were to begin with.

Actually, isn't that exactly what velocity is supposed to do anyways? My first attempt at making an actual program with velocity was with a concurrent program. I used a GZCL ultra high-frequency template and just replaced the percentages with velocities. Because there wasn't any need for the AMRAP sets. It carried me along well enough to increase my total by 60 kg, so I can't say it was a bad training decision. The main problem I had with this is percent based training assumes proximity to failure is always the result of the intensity and reps. There's nothing to account for a rapid onset of fatigue. In those situations, you have to just figure out how to make decisions on the fly.

Adapting RPE Training

RPE is much easier to adapt. One of the recurring themes with percent based training is there needs to be some evaluation metric in order to update your training max. With RPE, your max is assumed to be fluid, so training and testing tend to be ever-present. Another great factor in this is you have two things to reference. 

Let's just start with a prescription of 10 reps @ 7 RPE. This means you need to find your 13 RM and do it for 10 reps. Put another way, you need to find a weight that you can do for 10 reps and feel like you have 3 more in the tank. A final way to express it: do ~65% for 10 reps and you will probably have 3 reps left in the tank. 

I know that 65% has an initial velocity of 0.84 m/s, and I know that 7 RPE has a final velocity of 0.32 m/s. This way I can do singles at an ever-increasing weight until I find something that moves at 0.84 m/s. Once I do that, I just do reps at that weight until I reach 0.32 m/s. If I get more than 10 reps to get to that point, this is likely a lift that requires a custom RPE chart. In all actuality, I'm probably just going to take a guess, hit 10 reps, and if it's faster than 0.32 m/s I'm going to add weight until I'm in the ballpark. 

In any case, with RPE programs, in general, they aren't uniquely different than percent based programs other than how they prescribe load. It's perfectly possible to build out a linear periodization program with RPE. In fact, I believe this is the approach The Strength Athlete and Calgary Barbell's generalized intermediate programs take. Both approaches seem to be hybrid percent based and RPE programs. I've done my best to represent how those programs appear based on some basic deductive reasoning, but I think the output of Calgary Barbell's program looks something like this:
This is the first 13 weeks of Calgary Barbell's 16-week program. The template I used to plot these only allows 13 weeks, and I think you get the general idea with 80% of the program represented This is presented with some minor differences than how RP's program was presented. Columns are still the number of lifts, solid lines are still the average intensity (averaged sets), but dashed lines are peak intensities.

This busy graph is the number of sets plotted alongside both peak and average relative intensity. Again, relative intensity is proximity to failure, exertion, or RPE. Calgary BB uses both RPE and percents, so it's easier to unify the language as relative intensity. 

And here's the tonnage along with the acute:chronic workload ratio. It's quite funny to see this because you can see the bias Byrce has towards his favorite lift, the deadlift. He seems to prioritize deadlift volume, whereas I tend to believe the squat develops the deadlift but not the other way around. 
This seems like intensity linearly increases over time, but volume and relative intensity undulate across the weeks. Generally, most percent based programs tend to increase relative intensity in parallel to absolute intensity, but Bryce interesting attenuates relative intensity to allow for undulating volume. This process seems interesting since the outcome is meant to drive strength, whereas most classical periodization models tend to assume strength is meant to lead into power development. Most people developing strength from a classical periodization perspective tend to just lengthen the classical model and exclude the power development phase. 

But you can generally get even something more akin to a linear or block periodization model using RPE. RPE is just the prescription method so the overall program can reflect whatever progression scheme you want. Barbell Medicine tends to program close to what a linear periodization model or block periodization model tends to prescribe. People tend to assume BBM is derivative of Reactive Training Systems, but hearing RTS's progression system described makes it sound much unlike traditional periodization models. I wish I could describe how this is likely a result of Bondarchuk's periodization influence, but like most others, I can't understand Bondarchuk's ideas even after reading and re-reading his books. Any case, here's a data dump of BBM's periodization.
This is much like the previous graphs, but you also see overhead press classified as its own lift. I'm not sure if Jordan Feigenbaum is treating the OHP and bench press separately or combining them, but I've chosen to plot them separately. In this, I've reverted back to plotting relative intensity alongside the number of lifts. Keep in mind this template treats the OHP as a competition lift, not the bench press. This is meant to prep someone for a strengthlifting meet where OHP is the contested upper body lift.
A brief aside: strengthlifting as a competition is a lower body strength competition. Say whatever you want about whether the bench press or overhead press being the best demonstration of upper body strength, but strengthlifting has a huge issue of bias towards lower body strength. In a typical powerlifting competition, the squat makes up 35% of your total, the bench press 25%, and the deadlift 40%. Advantages in morphology, like having short or long arms, kind of give advantage to one lift (like bench) and take away from another (like deadlifts). Take that vs strengthlifting: the squat is 38% on average, the OHP is 17%, and deadlift is 45%. The overhead press has such a dimished effect on your total that morphological advantages in the deadlift have less to lose in the OHP. So that's the secret to strengthlifting: just have a strong lower body and do the minimum to develop pressing strength. Sounds pretty typical for Starting Strength's faults: favors lower body over the upper body. If it hasn't become obvious, I hate Starting Strength. 

Because adding a fourth lift makes volume harder to visualize, here's what total tonnage of all lifts combined looks like. This also includes acute:chronic workload ratio. If you couldn't see a distinct high volume phase, a deload, and a strength phase before, you can definately see it now. Average intensity seemes to take stepwise increases over time until a peak on week 13. Week 13 tends to be more of a "test week" eventually working up to 1RM on the squat, OHP, and deadlift. 

And here's the tonnage and A:CWR by lift. If you know anything about A:CWRs, then you know the squat is a little high on tonnage progression. I'm not sure if that's a huge concern with autoregulation, but it might be.
Adapting to RPE models of training really isn't that different. The only problem is when there's a disconnect between the relationship between intensity, the number of lifts in the set, and the proximity to failure. In those cases, it tends to be the case that volume and intensity don't appear like they follow a clean sequence as they do to traditional periodization models of any kind.
However, it's worth mentioning that most of the ideas on periodization are very generalized. They don't empirically work for all modes of training and they attempt to generalize how to organize and progress training for field sports, also in general terms. In such cases, volume, intensity, and exertion are very generalized terms that sometimes refer to completely different metrics, like distance ran, speed which it was run at, and perceptual feeling of how hard the effort was. 
And that's maybe one of the harder things to deal with if you're going to be dogmatic. You can only generally apply training theory from one sport to another. Like generally applying track and field to powerlifting (Verkhoshansky). Or generally apply training theory from rowing to powerlifting (Issurin). Or weightlifting to powerlifting (Prilepin, Laputin, and Medvedyev). 
The great exception here is RPE program structure seems to adopting an Emerging Strategies approach. So what does an emerging strategies template look like? It's probably impossible to make a generalized emerging strategies template. That's like saying you want a generalized template that's individualized. It doesn't work like that. And if you've ever heard a coach tell you about their case studies with athletes, you'll often here them explain why they depart from textbook periodization approaches to better fit their plan to their athletes. They're essentially interpreting the athlete response to the dose of training, making inferences on what the next best step in the progression is. That sounds much like how adaptive emerging strategies attempts to be except with a lot less reliance on an initial plan. Are these differences consequential? In my opinion, no. But then again I have no allegiance to any programming style and I make fun of everything.

So what was the point of this whole section? Basically to show you it's mostly a distinction without a difference. All it is is another way to prescribe load and another metric to collect. I think that metric is important, but that's just me.

Getting to the point

So then what does RPE offer that percent based training doesn't programming wise? With percent based training, intensity (%1RM or % of training max) and volume (reps and sets) are prescribed with exertion (RIR, RPE, or relative intensity) largely assumed. With RPE, volume (reps and sets) and exertion (RPE) are prescribed and intensity is assumed. Generally, we can assume that intensity is a valid inference before acute fatigue sets in. Let's take something like 8 sets of 4 reps at 8 RPE. Initially, intensity is likely going to be near 84% 1RM. The problem is that keeping weight the same is it takes a lot of work capacity, so you're eventually going to drop the weight. Does that mean intensity is always 84% in the moment, or do you base intensity off the original weight and corresponding 1RM?

Let's take the opposite with percent based training. Let's do 84% for 8 sets of 4. Or 8x4 @ 84% in short. Let's never change that weight. Initial sets at probably going to feel like 8 RPE, or 94% relative intensity. As time goes on, that exertion (or RPE, or RIR, or relative intensity) is going to feel like it's increasing - because that's how acute fatigue works. 

In either case, you have real-life circumstances failing to represent the training. The problem is most percent based programs only present the dose of training and ignore the response. RPE programs actually measure the response with the RPE system but requires you to interpret the data circumstantially.

So let's just get to the point of what two different programs look like. One was more like a percent based program. I would hit an initial velocity and use it's assumed equivalent intensity to do a number of reps. It was concurrent training (trained for both strength and hypertrophy), but both "training zones" or whatever increased linearly. My first lift started at 80% and increased linearly, and my rep work started at 60% and increased linearly. If I couldn't hit all the reps required, I just increased the number of sets. It was pretty gruelling. Here are some graphs that show you what it looked like. They were pulled from MyStrengthBook.

Here you have bracketed intensity. I believe "max" is anything about 90% of that current 1RM. "Heavy" is 80-90% and so on. I only updated my maxes once every 4 months, so there's some trouble interpreting what this stuff really means. For example, if I updated my 1RM on week 10 I probably would have fewer lifts that would be considered "max." The line also represents "baseline volume" which is just an average of the previous 3 month's volume. However, that only considers volume in the main lifts, so accessories are ignored. I'm very heavy on accessories early cycle.

If it's not obvious, I really do use miniscule deadlift volume. I'm no Bryce Krawczyk. Squats are bae

And then here's everything together. Again, the accessory volume is calculated separately using this system. Again, 1RM wasn't updated regularly, so things look a little different.
This all led into my first powerlifting meet as a 74 kg class lifter. My next prep I decided to take a different approach because ignoring RPE/RIR/relative intensity was grueling. Rather than planning off intensity (based on initial velocity), I decided to plan my training off of exertion (based on final velocity). This allowed me to plan more along the lines of someone who used RPE.

For this I didn't have an accessory heavy period of training, so this is probably more directly understandable.

Here's the number of lifts represented again. As you can see, I continue to keep deadlift lifts on the lower end.

And this is the grand scheme of things. It might look like volume flattens out, but late cycle I also removed all accessories. Generally, the intent with both cycles was to have a really long linear periodization approach while concurrently training for strength and hypertrophy.
This meet qualified me for 2018 USAPL raw nationals. This essentially my only claim to fame other than talking shit and rambling on a blog that doesn't get many hits.

Wrapping it all Up

So does anything meaningfully change when you program with velocity based training? Not really. If you're having crazy fluctuations in 1RM or work capacity, maybe, but generally no. Velocity does 100% of what percent based training can do. RPE does 100% of what percent based training does. Velocity does 80% of what RPE does. And RPE does 80% of what velocity does. The only real difference is that last 20% of what velocity can do that RPE can't, which has only circumstantial utility. That 20% of what RPE does that velocity can't? Just add it on top of what RPE is doing.

So what's the point? It's kinda just that nothing makes any difference, nothing matters, and do whatever you want. Just stay away from Rippetoe and Starting Strength, because they straight garbage.

Sunday, November 5, 2017

Powerlifters Aren't Powerful, They're Forceful: a note on what we're measuring with velocity based training (spoiler: it's velocity)

  • This whole article is esoteric. This is probably as far in depth I'm going to get with power because it really isn't a huge factor for powerlifting
  • Even though there are strong correlations between barbell velocity and several other variables (load, intensity, exertion, your favorite skittles flavor, etc), you're not a Doctorate of all the Strong Things for using VBT. You're just another dude that collects numbers
  • There is no gold standard of velocity based training's metrics. It's still kind of up for debate, especially if you're using it for things like estimating power, force, work, and capacitive magnetic reactance. Please don't use your VBT device for capacitive magnetic reactance
  • Basically, the information we get from VBT, while potentially powerful, really isn't that large of a step forward than quantifying our understanding there's an inverse relationship between %1RM and the volume (sets X reps X weight). It's better than the traditional programming model (opinion), but not that much
  • There are known knowns. Things that we know that we know. There are known unknowns. Things that we know that we don't know. But there are also unknown unknowns. Things that we don't know that we don't know. And ultimately: the absence of evidence is not the evidence of absence prolly means we're guessing
  • I really don't follow up on the things that I plan to do, but here's a page worth of shit posting based on the things I've been reading. No more planned posts.


In the first post of this series, I did several comparisons of 3 different sensors for variations of the squat, bench press, and deadlift. In that post, my comparison measure was 2D video analysis. The obvious red flag here is that of all the comparison measures - 2D video analysis sucks. But this brings into question as to what's an appropriate criterion measure, or gold standard of comparison, when we talk about velocity based training devices. Also, what about the other metrics most units pull besides velocity? How about force, power, and work?

Having these criterion measures is important. For sake of explanation, hydrostatic weighing is the gold standard for body composition (technically it's potassium counting, but we fucked that up with the nuclear age). Bioelectrical impedance, waist-neck approximations (the "Navy equation"), DXA, and BodPod are all compared to underwater weighing typically when evaluating them for accuracy and reliability. You can compare one of these methods to another besides hydrostatic weighing (IE: the navy equation vs bod pod), but the comparison always relates back to the criterion measure - underwater weighing. A good criterion measure will be highly accurate and reliable. Accurate meaning it measures close to the actual value and reliable meaning it will reproduce that value with relatively low variance.

Think of it like three weather men. One is always 10 degrees warmer than he forecasts, but it's consistent. The other one is usually within 5 degrees of the actual temperature, but could be lower or higher. The last one is always 5 degrees above. While he's as accuracte as the 2nd weatherman, he's also more consistant. Actually this is a horrible analogy. No one gets their weather forecast from the nightly news anymore. Moving along
It's a common remark that all you need to know about lifting you can learn in a physics textbook. Yet the same people that say these sorts of things have "power" days in their routine that aren't necessarily powerful or are basically flying in the face of some basic mechanics. Volume is a shorthand metric we use, as is intensity. The underlying variable for volume is work, and intensity is force relative to a maximum. These things aren't necessarily intuitive though, so we shorthand volume with the number of reps by weight, distance, laps, whatever.  Likewise, peak force isn't easily quantifiable, so we just use a ratio relative to our 1 repetition maximum. There's really nothing wrong with that until you start implying that variable resistance (bands, I'm talking about bands) accelerated as fast as possible has a meaningful difference from doing a 1RM. You really wouldn't know that any more than you would you know your altitude just by feel. It might sounds like I'm taking shots at the usual suspects, but really every coach needs to make some assumptions about mechanics as they relate to training because measuring all these things aren't meaningful. And ultimately, the body's response to training isn't exactly required to make sense. Sometimes it just works, albeit sometimes in spite of and not because of the training method. We need to be honest about our instruments' and methods' limitations. I do this all the time with VBT when I talk about deadlifts. Mean concentric velocity has less meaning with deadlifts.

So this will highlight the insufficiency of certain velocity based methods.

Video Analysis as a Criterion Measure of Velocity and Power

Video analysis is probably one of the old school reliables for velocity. Not the best, but has been the mainstay since before VHS. You can record something with a ruler in the frame and use the frame rate and distance of that scale to get a general idea of the rough edges of the movement. Folks have been doing this for sprinters, weightlifters, and all sorts of olympic sports for years. Nowadays, we've opened that up to the masses through things like Dartfish, Coach's Eye, Kinovea, and Tracker. These are all entry-level tools and very valuable.

What you lose in 2D video analysis is essentially depth. You can get horizontal and vertical distance, but getting a measurement outside of your initial measurement is sketchy. An easy way of thinking about this is weight plates. An Olympic weight plate is supposed to be 0.45 meters in diameter. So when analyzing bar speed, it's a pretty easy measure to use. Here's the information lost with 2D video though:
Ian Wilson courtesy of the Hook Grip instagram account.
Both of these plates are the same size when viewed in the same depth,
but it obviously fails when viewed in this objective
The key takeaways are to analyze objects in the same plane, film horizontally and vertically perpendicular to the plane you plan to measure, and have a known unit of measure (a ruler within frame, standardized disc sizes, etc). Some other issues come up concerning video quality and frames per second. Thirty frames per second are going to lose a lot of information from frame to frame, whereas 120 is going to capture a large amount. Likewise, better video quality is going to give you clearer edges to measure. Some phones that film in slow motion are capable of capturing 240 frames per second at a lower quality, so you have to manage clarity of the video against the number of frames you need. The right way to go about this would be to buy something that puts GoPro cameras to shame, but that's not a realistic solution for coaches living in the real world.

Now it's important to note that programs like Kinovea have been validated when it comes to simple movements, and we can describe powerlifting as simple movements. We can postulate about how the bench press is a full body movement and how all three lifts hit all of the things and yada yada. It's simple. There's an upward motion and a downward motion. That's simple. We only make it complicated by focusing on the minutia. Powerlifting is stupid simple, stupid.

A step up would be 3D motion analysis. Using an array of cameras about a stage, we can track movement in three dimensions. This helps understand more complicated movements as well as sort out the axes that affect rather simple movements. Much like with 2D video analysis, you're going to have a known unit of measure within the frame during initial calibration. This helps the software understand position, length, and movement reliably. The great advantage of 3D video analysis is you can track multiple points of interest. If you're solely interested in barbell velocity, you can place a reflective marker at different points along the barbell and body to track that. So not only can you track velocity of the barbell, but you can see the angular acceleration of each joint during phases of the movement. That angular acceleration of all the joints in the movement translates to vertical and horizontal movement by the bar.

Video analysis of this scale isn't practitioner friendly. It's cost prohibitive, technically demanding, and largely just more trouble than it's worth unless you're doing research. On the research front, Lake et al have heralded the use of a force plate and video analysis as a criterion measure to determine power. The force plate measures force and the video analysis measure velocity, so you get the all the components you need. Sort of.

Let's bring it back to barbells though, since that's the sort of thing powerlifting does. The issue with barbell based VBT is that bar speed isn't necessarily the velocity of the center of mass. There's debate on how you determine that, but this shows that divergence:

Lake et al's article gets straight to the business with the title: Barbell kinematics should not be used to estimate power output applied to the Barbell-and-body system center of mass during lower-body resistance exercise. I'll refer back to this later.

But how consequential is that? Volume isn't a true measure of work and intensity isn't a true measure of force, but they have been good enough to be usable. Especially when it comes to powerlifting, the difference between system center of mass (the barbell and body system) becomes less consequential the heavier you lift. As a male, your center of mass is near your belly button, and the more plates you stack on, the closer it will move towards the position of the bar. And that center of mass is going to change not just with load, but the position of your body. When this is consequential is when we're dealing with light loads: such as those done to develop power. It's a good thing the objective of powerlifting isn't about demonstrating the most power. You're really getting a metric of barbell power with most units and rough approximations of system (bar and body) for others.

One of my favorite past-times is meme-ing fitness industry stills from YouTube

Bar Tethers

Linear position transducers (what I keep calling tethered VBT devices), are the most common measurement of bar speed. Most device validations are in comparison to other, older LPTs. Some of the most common comparisons seem to be to Optitrak, Tendo, and T-Force. Just because it's the most common doesn't necessarily mean it's the most valid though. We're essentially comparing one device's yardstick to another's and seeing how close they are to one another and the frequency that the difference is the same. As long as we can keep comparing to that same yardstick, it doesn't matter. Ideally, you want accuracy and reliability, but short of that reliability across all your feasible working intensities is most important. So if a device sucks at measuring slow things, heavy things move slow, and you lift heavy things - don't do it.

Some proponents of VBT have heralded tethering devices as the gold standard. Anyone that says that is probably trying to sell a product or obfuscate what their device is measuring. As I demonstrated in the first article, it seems to be the case that tethered devices are more accurate and reliable for measuring velocity. It does not measure power or force though. To measure those things, you need force plates. You can calculate it with known masses (bar weight, body weight, etc), but it's essentially best for velocity. Everything else is approximation and calculation, and there is certainly some drift across different ranges.

I don't know how to say this better than the original author, so here it is:
"Other studies have indicated that methods that depend only on kinematic and kinetic results have limitations when used to determine power output (Cormie et al., 2007b; Hori et al. 2007). It seems that the linear position transducer technique overestimates power due to increased force output production derived from double differentiation of bar displacement. When this technique is applied also to the mass of the subject, standard biomechanical procedures are rejected in that force is determined without considering the acceleration produced through a movement (Dugan et al., 2004). Despite this limitation, our results indicate that monitoring bar velocity is a useful procedure to control load intensity in resistance exercises, as observed by other authors (Hori et al., 2007; McBride et al., 2011)" - Garnacho-Castaño
The Cormie et al paper from 2007 cited has an interesting experimental method shown here:

The key part here is the use of a force plate. The tethers are inverse mounted and it just does trigonometry to determine position across time. Both this method and the method demonstrated by Lake involved force plates. There's really no getting around actual measures of force. To put it another way, trying to use VBT devices to measure force or power is like using a thermometer to measure rainfall. Ok, not that bad, but sort of.

Another point worth mentioning is that the trigonometry used with two tethers is achieved all the same using GymAware's technology. Rather than measuring the lengths of the side of the triangle (with one unchanging known side length) determining the angles within, GymAware measures one side and an angle which gives you a measure of vertical and horizontal position (the other two sides of the triangle). All that shade you been throwing on social about trig, and now it's actually kinda useful ain't it? Trig is useful folks. Build a staircase.

It's important to point out that Cormie et al and Lake et al's method do stand in conflict to one another. To some extent, Lake is probably right that center of mass is the "real" variable we should be measuring (kind of like how work is the "real" variable for volume). At the same time, Lake does not sufficiently explain how they determine the center of mass. This isn't necessarily impossible either if you apply something like segmental densitometry (for example, DEXA gives limb weights). Without taking sides here (Lake vs Cormie), the important parts are 1) both of them point out the necessity of a direct measure with a force plate 2) both research groups have authors that have done a lot of research on powerlifters, so they're pretty damn rad.


Accelerometers seem to bridge this gap to some extent, when the right inputs are used. The issue is Force. Force is a product of mass and acceleration. If we return to the issue as mentioned by Garnacho-Castaño et al, inertial sensors would seem a likely solution. If I haven't hammered the point home yet, while accelerometer technology has failed to perform on some fronts, it could be the missing link we're looking for. This is especially pronounced with power movements.

I've talked before about how you could theoretically determine velocity when an accelerometer is attached to a fixed point if you know the lifter's height. It's a rough approximation and relies on relatively normal proportions of limb length according to height and the mechanics of exercises being relatively comparable across a broad population. That method would require a certain amount of machine learning or constants and manual inputs of the lifter. At a minimum, I would think height and weight would be important to determine force and power. That said, if tethered devices clearly excel at measuring bar velocity, then they're probably the right tool for the right job.

Banyard et al down at Edith Cowan Uni used the same method that Cormie et al used and took GymAware and PUSH head to head in one of the most comprehensive comparisons. Again, these comparisons are made with a dual tether and force plate system:
Notice this is only figure 3 and 8. You should see the rest of them. Some have insisted that the difference between actual power and GymAware's power is only 10 watts. I'm seeing 100 watts. Follow the link.
If your main take away from this is that PUSH is hot garbage and GymAware is overpriced because it measures what it says it does, you're missing the point. The point here is that I'm not sure why these are currently two separate products. A combined approach using both a tether and an accelerometer could still be affordable (assuming GymAware doesn't set the price), you'd likely see additive value. Force plates are almost out of the question.  In order to cover the size you'd need for a simple movement like a squat, you're talking about an upfront investment of $600 minimum.
Just do the math. If the cheapest tether device is $200, and a force plate set up would cost $600, that's like 4 red competition plates you can't buy.

I haven't been paying terribly close attention to PUSH, but it would appear they're actually serving their market pretty well. They've implemented a new system that uses some video processing in combination with the sensor to collect different metrics. Again, this really doesn't matter for our purposes because, well, barbells. If you are using the PUSH as a powerlifter, one great feature they've implemented is velocity cut off notification. That makes it decent for hypertrophy work (because lighter=faster), but maybe not a strength. The only other VBT device I can think of that has attempted to add another input (IE: video, displacement, etc) is the Form Sensor. However, Form's altimeter really only helps to improve vertical velocity as far as I know.

Approximations aren't all that bad

Some accelerometer systems are getting their estimates of power based on the combined input of load and body weight. This sort of works, but we have to recognize it is an approximation. The issue with most accelerometers in the end is that they tend to be thrown off by sudden changes in direction, jarring not related to the movement, and Germanic talismen inscribed with the correct order of runic scripture. Ignoring some of the inadequacies there, approximations aren't too bad. 

A good example of combined measurement and constant (manual input) measures is the Powerlift App. When you break it down, the app functions as a video stop watch. It takes a video that you use as a visual reference point, you input a range of motion for that movement (which hopefully you measure appropriately), and choose start+end points for the concentric part of a movement. It's actually pretty good at it and has been validated in a lab. All the app does is convert the start+end point frame count to determine time, dividing the ROM by that time to determine mean velocity. You're not going to get peak velocity.
Side note: Powerlift is unlike many devices in that it actually stores correlations of load and velocity, as well as many other useful funtions. Most device manufacturers could take some tips from Carlos. Technically some do this, but is a sort of way that can only be reference manually - far from optimal. 
Again, with combined measures and inputs, you can improve this further. For example, if you were to take the average of your ROM from all loads over 90%, you could improve reliability near 1RM distance. You could also manually input your MVT in advanced options, but for sake of fidelity it's probably better to only use ROM input from another device you trust and video an MVT rep to keep it relative. 

Why it Matters: Science, Theory, and Methods

When I say the science, I really mean more of the mechanics - the sort of rules that things obey. There is something troublesome about scientific training. Firstly there's the fact the science does sort of exist in a vacuum. The protocols employed by science are commonly used to elicit a response, to tease out a marked difference or similarity of one treatment versus another. It really doesn't matter if it's a realistic training program (let's pretend that's the only kind of sports science for this), but one that emulates enough elements of real training protocols but has a magnitude large enough to elicit a response. Basically, most of these programs don't have ecological validity - they aren't programs that would be optimal.

Training theory on the other hand (not "scientific theory") is basically the rationale which we think training follows. This is a blend of what coaches have seen in practice and lab rats have evaluated in a laboratory setting. That connection from A to B isn't always a straight line. For example, the force-velocity curve is more based on the functional characteristics of muscle fibers. It's not necessarily the same thing when we're talking about movement created by multiple muscles and about multiple joints.

Lastly, the methods are how we choose to execute our training theories, hopefully based on the practical applications of the science. Using bands is one such methodology. I've beaten that dead horse long enough though, so let's use Orange Theory Fitness. Orange Theory Fitness markets itself as a science-based weight loss program. It sort of is. If we think of work (joules) as a proxy for energy expenditure (calories), then high volumes of energy expenditure are more obtained at lower intensities. I'm basically saying pure cardio. That's not exactly the Orange Theory Fitness training program. Secondly, there's a significantly greater magnitude of difference obtained through diet. So it's not all bullshit, but science did not divine the right answer to Orange Theory fitness and there's plenty of caveats. But science sells. Even diet programs use that tactic.

Everyone fails at marrying these three elements together, including your gurus, to some degree. With velocity based training, most of that fault comes from the science. I spent this whole article highlighting disagreement. The training theory failing comes from over-expansion of concepts like the force-velocity curve (IE: the training zones). An extension of that carries over into methods. Assuming the force-velocity curve can be made so specific in gross movements could be made even worse with the idea when adding variable resistance.

Putting it All Together

If you own a tether system, stop being so uppity. You have the most appropriate system for measuring velocity, and even that is still subject to error - even more so if it doesn't measure angle of pull. You could probably rig up two single axis system to improve vertical velocity measurement and maybe even track bar position throughout a movement, but there is no consumer level solution yet. Beyond the fact that tethers aren't appropriate for movements in three planes of motion, accelerometers do have additive value to help us better measure simple training metrics - like force, power, and work. We don't have those solutions yet, but that's likely the future. It might seem ridiculous to forecast the future like that, but given the relative utility of Accelerometer-GPS units for field practice, it's not too far off.

Velocity based training is supposed to be a method to quantify things we were making guesses about. Generally, something that's powerful was subjectively fast enough and light enough. I say subjectively because it has to be someone with some authority and experience in developing powerful athletes with movements that best mediate that training quality. That sense of what is powerful is largely a presumption. As much as velocity tells us, there's still plenty we can't nail down. Operating in this unknown area is fine though. We've been operating in the unknown using simple measures for decades. But you should probably stop taking VBT measures of power and force at face value.

#MaybeJustLiftWeights #ButHaveYouReadSUPERTRAINING

Sunday, August 6, 2017

VBT: Deadlifts are not your friend

If you want a how-to-deadlift guide, I suggest my favorite website. That's not what this is.

Edit 8/8/2017 - Since I posted this two days ago, my google scholar news alert pulled up a new article examining the relationship between velocity and prediction of number of reps at a given intensity (XRM)/reps in reserve (RIR). They created generalized equations to predict XRM and RIR, but found that like all things VBT, it truly needs to be individualized. Furthermore, they showed that XRM can be determined from velocity, but RIR does not appear to be identifiable. This seems to say that it is possibly less ideal to use the exertion-velocity relationship identified by practitioners like Mladen Jovanovic than it is to use velocity to determine XRM. On a practitioner level, this seems inconsequential since you can just use the velocity-XRM relationship of that individual to drive exertion. If you want 2 RIR, just perform the velocity XRM plus 2 reps.
In effect, even though I have weakly advocated the exertion velocity-relationship, it is likely more appropriate to use the velocity-XRM relationship using your individualized data. Even though I resolved this solution specifically for the deadlift, it's actually more appropriate for more movements. I'm not going to edit this to reflect this new finding.


The deadlift is a bratty kid in velocity based training. It thinks it's the center of the universe and doesn't play by anyone's rules. If you sort through many of the velocity based training research articles, you will find an overwhelming amount of information on the bench press, bench throws, squat, jumps, squat jumps, pull ups, and prone rows. Likewise, many of the principles established in the one exercise you can often apply to the other. But you don't see much for deadlifts. One possible explanation for this is it's hard to publish negative results.

Key Points:

  • Most exercises in PL have you start at a velocity and slowly bleed that velocity off with each rep. Deadlifts do not do that though.
  • Since velocity loss is a factor in auto-regulation in VBT, there has to be a reason why.
  • Nope. Not a reason I see. Maybe deadlifts just suck?
  • I have an idea of how to solve this by re-working something else Mike T does. I steal from Mike all the time

Velocity Loss Across a Set

If you take a set for the bench press and go until failure, you will see velocity start off fast and slowly drop off to grindtown. You see the same thing with the squat. This has been termed velocity loss and is talked about to at length here.

Mean concentric velocity across multiple intensities of the bench press and half squat from Izquierdo et al.

In a previous article about the future directions in VBT, I alluded to the potential for research in different variations of movements. The research has ventured here in terms of the load-velocity relationship and appears to be continuing that way. For sake of simplicity though, here's how that has looked in the past year of my experience:

A comparison of velocity loss across multiple movement types
You see the general decrease in velocity with successive reps. It appears the deadlift doesn't do that though. You have high coefficients of determination (R2) for everything except the deadlift. Moreover, if you look at the trend line for the deadlift, it's relatively flat. It's like a table that has that one leg that needs a shim. And much like that table, I also get the impression that fixing it isn't on anyone's to-do list and we'll just continue to live with it.

Velocity Across Intensities

Deadlifts aren't entirely useless in VBT. It appears velocity is useful across different intensities, but confusing across a set. Here's an example:

Velocity across different sets in the conventional deadlift. After each set, load is increased. This plotted using only the initial velocity rather than the average of multiple reps  (3 for light, 2 for moderate, and 1 for hard sets) as I have advocated in the past.
As you can see, with each successive increase in load, velocity appears to decline. The coefficient of determination seems high enough (above 0.90 would be optimal). If you were to isolate this into the %1RM that you're most likely to work with in powerlifting (for strength or hypertrophy), most sets will fall between sets four to seven.

So while we can't regulate volume within a set (and therefore exertion), we can obvious regulate load. Likewise, you could be specific about how you regulate fatigue. An example of this would be hitting 80% 1RM for as many sets as possible. Once initial velocity drops below a predetermined velocity threshold, the volume (in sets) has been achieved.

Determining Confounding Factors

There are maybe a few things that could contribute to this phenomenon, and I'm not sure what it is. I tried to identify as many potential candidates as possible and figure out a way to tease out the results.

Sumo vs. Conventional

If you pull your deadlifts sumo: 1) you eat ass 2) you're a goddamn cheater 3) you make that singlet look good. 

For sake of argument, there's nothing that makes this phenomenon unique to deadlift type. The first graph of velocity loss across sets is sumo. The second graph was sets of 3, and in each set you get a rather noisy picture in nearly every set. So that's not it. 

From a motor learning perspective, it makes more sense for me to limit this to the sumo deadlift. It's my competition deadlift. Over the past year, I've done half a dozen different variations of the sumo deadlift. In that same time period, I've only done one type of conventional deadlift. If I was regularly cycling in conventional deadlift variants, it would make sense to prefer this. In the end, the two lifts are more similar than dissimilar. Even if you don't agree with that, take your first world problems and GTFO.

Concentric Only Lift

The common thread that squat and bench share that make them differ from the deadlift is that the lifts are preceded by an eccentric movement. The running idea here is that this eccentric loading transfers some force through the stretch reflex. Even with a pause, the stretch reflex lingers for some time. This was what prompted Louis Simmons to use the box squat and unload the muscle.

There's also the argument that velocity loss across a set could be different with touch and go vs pull and reset. I wasn't seeing such a pronounced difference on a cursory survey. Also, the rationale doesn't make sense to me since I generally see concentric-only lifts (pin presses and pin squats) to be more reliable. To tease this out, I attempted to emphasize the concentric part and start the set with the eccentric portion of the movement. I basically did what all the pull-and-reset Nazis complain about and made it into something they would hate even more. I started the bar an inch below lock on an adjustable height monolift. Then I pulled the bar that final inch as the monolift swung away. At this point, I'm able to start the deadlift by lowering it. 
The natural question is "how do you finish the set?" There's two ways. You can get to lock out and try to duck walk the weight back to the monolift like an idiot or finish by putting the bar back down on the ground. I'd like to tell you I didn't learn which method the hard way. But I did. Yes. I did. I don't think this movement helps develop anything particularly better than normal deadlifts, but if you're going to do them then just end with the bar on the floor.
This emphasizes the eccentric part across the whole set - not just from the second rep and onward. Let's just call it the "sumo droplift." You heard it here first folks.

Proudly presented by Zero Sum Gains

Range of Motion and Bar Deceleration

Powerlifting often comes down to the weak range of motion. In the deadlift, that either happens off the floor or at the knees. Typically conventional deadlifts fail due to deceleration near the knees and sumo deadlifts fail to generate enough acceleration off the floor to power the move into lockout. It could be possible that acceleration from the floor to the knees or from the knees to the lockout is the confounding factor. When that irregular behavior gets mixed in with the rest of the movement, that might be what's causing the rather noisy picture of velocity across the set.

The easy way to tease this out is by separating the parts of the movement. Block pulls are a common supporting movement. I'm just going to do them as sumo block pulls, which is less common. To get the range of motion from the floor to the knees, I've decided to use spotter arms upside down. Once both sides contact the safeties, I lower the weight again. 

If the range of motion is the issue, then obviously one of these two should come out significantly cleaner than the other.

Jefferson Deadlifts

Obviously, this will show us everything we need to know about deadlifts. This is really the only deadlift you ever need. Not even in powerlifting. This is the only deadlift you need in life.

SMDH - What it looks like

Normal sumo deadlifts are flat. This particular set has a lower coefficient of determination than the one I showed in a previous graph (0.003 vs 0.3). The sumo droplift is not only flat but has the worst coefficient of determination (R2) out of all of the lifts (translation: no. Dumpster fire). Block pulls have a downward trend and half sumo to the knees have a counterposed upward trend. Just by the look of the trend lines, it would seem like half sumo to the knees are what contributes to the noise with velocity gain across a set. In reality, though, coefficients of determination (R2) of 0.03 and 0.11 are hot garbage.

I'm not sorry you read through all that bullshit just to arrive at the fact that I don't know why deadlifts for reps doesn't work. Maybe God just doesn't want you doing high rep deadlifts. High reps=cardio, right? All I can tell you is that the things I identified as potential confounders don't appear to be it. 

So why bother? Why waste your time? Everyone seems to have this idea that because VBT doesn't work because of a lack of understanding of how to use it. It's still very useful to regulate load/intensity with velocity. Don't let frustration with VBT deadlifts drive you away from VBT.

The Work-Arounds

I've harped on the idea that VBT is only one way to autoregulate training for powerlifting. If you want to blend your methods, that's something you can easily do. If you're experienced with subjective measures like RPE, you can easily integrate that. Alternatively, you could just program your deadlifts via percent of training max. You can even augment that training max at whatever frequency you want with AMRAP sets using the usual calculation Jim Wendler uses or this. Wendler's favorite:

wt. x reps x .0333 + wt.= 1RM

There is an alternative though. Let's take for example the RPE chart from Reactive Training Systems:
Not original content. See source link
We know that the load-velocity relationship works. In that same instance, the %RM-velocity relationship works. The only issue we have is obtaining the MVT. MVT is usually the last rep in the tank whether it is a 1RM or a multiple rep max. In this case, though, MVT is best obtained through testing 1RM and can be updated on occasion with reps slower than MVT that occur in training (because that happens). With that said, we can use the %RM-Velocity slope and intercept (nerd shit, go back to the "How the Sausage Gets Made" article and download the excel files) to do a reverse look up on the velocities. 

So rather than getting %RM value to use, you can use a mock up of this chart to determine what your initial velocity should be. Here's a visual:

Assuming this works, you can better control exertion/proximity to failure. Unlike bench and squat, you can't auto-regulate within a set, using a stop velocity to tell you when to terminate a set. Instead, you're working on delayed feedback. Intensity/load is still real time, but you're basically flying blind and assuming work capacity is fairly stable. If you give up the gas mid set and hit a wall, obviously the only thing determining the end of the set is subjective feedback (IE: feels heavy, bro. I be done). 

This is the streamlined way I've done this. After playing around with how to auto-regulate deadlifts, I've taken to using MyStrengthBook's personal record table screenshot below:

The menu gives you a table of your rep-maxes, which I initially used for programming. Upon realizing I could convert the raw weights into percent 1RM, it became obvious that there is a non-real time alternative to terminate sets to a predetermined exertion level using velocity. I'm not going to say it's perfect since I'm still evaluating it, but it's food for thought.

Continuing Forward

It's been a good three months since my last update. I said from the beginning that this wasn't going to be an indefinite series. Potentials on the horizon: Gym Aware included in the comparisons, Open Barbell V3 included in the comparisons, PUSH evaluated on update sumo deadlift algorithm, an RPE-VBT excel template, and VBT/RIR in typical bro exercises (depending on lit review).

Some of the things I said in the past year have been elucidated by newer research. Not anything refuting things I said (at least none I'll admit to), but I think about half of my future directions have already been knocked off the list if not currently in-process. I'm not going to re-write that. Likewise, some issues on the manufacturer side have been changed. I try to add footnotes at the beginning where appropriate, but for the most part it's hard to keep track since I primarily train with one device.

Wednesday, May 24, 2017

A Powerlifter's Guide to VBT Pt 7: RPE to VBT translator

This entry was meant to be posted quite a bit earlier, but I delayed it. In my part of rural Texas, internet service providers crash with tiny weather upset. I was not about to type this shit out on mobile just to get it done in time.


-RPE and VBT are not competing systems.

-Which system you prefer is entirely dependent on many variables. The most important one is what type of feedback you find valuable: internal subjective feedback or external objective feedback.

-The science shows strong correlations for both, but there's some issue with the noise associated with velocity.

-The exertion-velocity relationship can explain the RPE rating system in velocity measurements, helping bridge the two worlds. Or if you're lazy, and accuracy be damned, there's an equation to level the two.

-Even if you don't care much for bridging the gap between RPE and VBT, doing the exertion-velocity relationship can open a world of programming and planning strategies. 

-Why VBT=awesome-sauce and RPE=face palm. We are competing, VBT is winning, and RPE can suck it.


Most people that tend to be into Velocity Based Training (VBT) are also actively using/interested in Rating of Perceived Exertion (RPE). RPE was popularized by Mike Tuchscherer from Reactive Training Systems. Others have outlined the advantages of RPE vs VBT vs other autoregulation systems better than I have, so I'm not going to attempt to do that. Despite how some tend to put it, VBT and RPE are not mutually exclusive practices, can exist in both harmony and in conflict to one another, and each has key takeaways to aid the other. There are caveats to using both systems.

If anyone thinks VBT is innately juxtaposed against RPE, I steal most of my new ideas from RPE and try to find a way to make them work in VBT. In fact, very, very few of the ideas I've expressed so far are original. I cite most of the ideas I'm stealing. So far, it seems like few are attempting to bridge RPE and VBT. Many tend to favor one method and use the other as a footnote barometer. I tend to favor using them on an "it depends" basis. 


Looking back at my previous writing, I have seriously taken for granted that people understand RPE. Let's alleviate that by inadequately explaining it. RPE attempts to quantify subjective feeling. Here's the infographic:
A more thorough breakdown can be found here. That said, I haven't taken the time to compare and contrast Mike T's current RPE methods against his old ones, The Strength Athlete, or anyone else's. 

There's also Reps in Reserve, which operates more like an abbreviated RPE system with no half steps. I associate this more with Eric Helms' and Zourdos' work, but you could attribute both of these methods to APRE, Borg, or Confucius. You could even argue that Renaissance Periodization/Juggernaut uses an RPE method when saying 3/fail, 2/fail, 1/fail (1-3 reps away from failure). 
The common argument for RPE/RIR is that everyone instinctually uses RPE without realizing it. Everyone uses how they feel to autoregulate their training. This can involving decreasing load when they're having an "off day" or other methods of adjusting training according to perception of readiness. While they're not wrong, that's also like saying just because I pay Social Security that I'm pretty much a Communist. That argument functions as a pidgeon-holing effort that I disagree with. I see the purpose of the argument though. 
I could equally argue that since RPE proponents consider perceived and sometimes measured bar speed, they are closet VBT fetishists. I'm not claiming that.
If I were to inappropriately simplify RPE, it's something like this: say a lifter completes an 8 rep max for 6 reps, they just did 6 @8 RPE or 6 with 2 RIR (reps in reserve). I will switch between all three of those interchangeably because I'm pretty bad at self-editing. 


Obviously, VBT is king. VBT is the absolute king of ding-a-lings. No question. It's science.

Not really, but it depends. Let's start conceptually or by "attitude." If you've been using RPE for an extended period of time, then obviously RPE is better for you, at least short term. The opposite is probably true for VBT. You could argue that VBT relies on reference velocities often in the form of tables, but you could also argue that RPE relies on tables. Both of them rely on previous experience. If you introduce a novel movement someone isn't familiar with, their referent minimum velocity threshold (velocity of last rep in the tank) or RPE rating might be meaningless. 

VBT is external and objective. RPE/RIR are internal and subjective. They're not really opposites since they both serve the same function, but in terms of how the feedback is garnered, they are opposites. Different people will find a meaningful use for both/either.

If you're bad at gauging internal, subjective intensity, then RPE won't work for you. It can be frustrating to get ahold of and in the moment if feels like your navigating with a broken compass. If that sounds familiar, then troubleshoot the situation or move on. Maybe something more objectively based is more appropriate. VBT and AMRAP sets become better options in that case. Each of those has drawbacks though. I'm not going to cover AMRAPs as an autoregulation method much - but GZCL and 5/3/1 are good examples of that.

So how could external, objective feedback be worse than something like RPE? This probably would serve better with illustration. Here's an as-many-reps-as-possible set (AMRAP):

The first rep looks like an honest attempt. I would argue this rep could be a good indicator of intensity - around 80-85% of that day's 1RM. The last rep is equally a good read, and would be a good indicator of minimum velocity threshold (MVT). Again, MVT has been a good indicator of the last rep in the tank, velocity at 1RM, or what we could call RPE 10. 

The issue is reps 3 to 5. Rep 3 takes a massive nose dive, rep 4 attempts to recover that velocity, but it isn't really regained until rep 5. At rep 5, it seems to take the same incremental loss in velocity it had in reps 1-2. There's a certain amount of noise to every measurement. The problem leveled against VBT is often that it is noisy, that its measurement varies too widely from rep to rep. We try to reduce this by choosing appropriate devices (as we've shown, with the device comparisons). You'll subconsciously try to do this if you rely solely on VBT. You'll start forcing yourself to perform sets in a way that data acquisition is more optimal - often in ways conducive to the training process, but possibly in ways that hinder the training process. The upside of VBT is you often have to think less to augment your training. If your measurements are noisy though, you have to put on your coaching cap more often and determine what's a real measurement and what's an artifact of performance. Sometimes you want to work out and not pretend to be a half-decent data scientist.


RPE is king of ding-a-lings. VBT=Communism. 

Not really, but with the limited research we have comparing the two, RPE comes out on top in a few respects. Firstly, velocity is not as good at predicting 1RM based on the levels of confidence. In the tables I've used, there's a point estimate as well as the upper and lower ranges of the estimate based on 95% and 90% confidence intervals. These intervals can be fairly wide, so the point estimate should be taken with a grain of salt.

VBT needs to be individualized and varies by exercise. The general guideline is that 0.30 m/s is MVT (1RM, 10RPE, 0 RIR) velocity for normies in the squat, and 0.15 m/s in the bench and deadlift. Zourdos et al found that experienced squatters hit MVT at a slower velocity than noobs (0.24 m/s vs 0.34). Similarly, Helms et al found the same trend, with squats clocking in at 0.23 m/s, bench at 0.10 m/s, and deadlift at 0.14 m/s. But when it comes down to the nitty-gritty, here's what that looks like in the grand context:

A value of 1 or -1 is a perfect relationship. 

You have to think of this in the context of their use though. It's far easier to gauge a 1RM attempt as a 10RPE than it is completing a 10RM for 7 reps and identifying it as a 7RPE. Much the same, it's easier to determine reps in reserve closer to failure with velocity as the referent measure than it is further from failure. For intermediate lifters, both systems tend to excel closer to failure. Both studies seem to demonstrate the relationships of velocity and RPE at 1RM, but the science is chugging along for loads short of 1RM and the information is still forthcoming. Additionally, there is something to be said about framing a user's understanding in the context of VBT. If you were to anchor velocity training in the same context that you anchor RPE, and furthermore allowed a good period of evaluation of both systems, you would likely see some changes in the results. Maybe even VBT comes out worse, or maybe that RPE is strongly associated with Sovereign wing nuts.

Anchoring is essentially how you "build" your personal RPE tables. With a 1RM and an AMRAP at a given percentage (let's say 85%), you can split the difference and generate a table of best-guesses of %1RM for every given prescription of number of reps and the corresponding RPE. See the link provided earlier in the article.

Much like you really have to force yourself to be honest when using RPE, you have to move with intention with VBT - or attempt to move every rep as fast as possible while maintaining technique. At this point, you could circle back to the common assertion by both parties, that either system performs well enough, requires at least intermediate experience to gain full utility, and either could be more appropriate than the other for different individuals.

Future directions for this could be studies showing whether or not one could accurately predict 1RM based on sub-RPE10 ratings for multiple reps. Likewise, the same sort of study could be used in the VBT realm, showing whether you can predict daily 1RM based on regular fluctuations in velocity at a standardized load. Chris Duffin mentions this in a YouTube round-table about VBT and his experience using OpenBarbell before a meet. Additionally, there is no science in the works to determine reps in reserve to velocity, something termed the exertion-velocity relationship.


AMRAPs are great at getting a submaximal measure of MVT. If you run a VBT-1RM estimation without a known MVT, you're guessing. There's two ways to get that: do an AMRAP or do a 1RM test. Obviously, the second option renders the estimation useless. Also, it shouldn't be surprising if your estimate is off. 

AMRAPs are also great to determine exertion. Exertion could very simply be explained as the proximity to failure. Assuming a MVT of 0.11 m/s, a rep at 0.19 m/s requires more exertion than a rep at 0.26 m/s. But can we take that seriously when we stop short of failure? Especially with how much noise can be in that measurement? Maybe.
Two AMRAPs pictured left, then the velocities averaged across according to the reps in reserve. Notice the change in R2

Here's two sets according to their reps in reserve. One was a 4RM, another was a 6RM. Because this is ordered by RIR, it was essentially performed in reverse (RIR 5 in the 1st graph was the first rep, RIR 3 in the 2nd graph was the first rep). You can see by the data points that there is some noise. According to the regression, the first AMRAP has a higher coefficient of determination at 0.89 than the second at 0.79. A perfect fit would be 1. When we average across, that coefficient of determination kicks up to 0.93. 

A recent exertion-velocity table that helps demonstrate
AMRAP utility in VBT
The above table shows an example of how we can smooth the noise inherent in VBT across a set. Bring your attention to AMRAP set 2, particularly in the middle. The last rep (0.25 m/s) is an honest attempt, and you can see that the first can be taken seriously to (0.36 m/s). The middle two make no sense. However, when we average two sets across, we can smooth that noise out. If we plot this averaged mean velocity across two AMRAPs and correlate it to RIR, we can interpolate how many reps we have left in the tank based on final velocity. The generalized midpoints between each rep become half-steps. A half-step might be noise, so maybe it's more useful to round it, but it could be interpreted as RPE.

Another graph of successive rep velocity decrements
from a published article, not quite as noisy as mine. 

I keep talking about noise. So what's the smallest worthwhile difference to figure out noise? It likely depends person to person. I would guesstimate it's something in the neighborhood of 5% of velocity, generally speaking, but I generally operate off of +/- 0.03 m/s. I came to this conclusion based off of individual experience, so don't hold it against me too seriously. It's a ballpark.
You'd be right to point out that there is some noise in RIR 1-3. The incremental drops in velocity aren't that large, and therefore are questionable. By using the regression, we can use the slope to get an optimal read on exertion. Much like RPE though, you'll have more reliable measures the closer you get to 10 RPE or 0 RIR. Much like we don't worry about anything below 6 RPE to begin with, you do see noise in velocity at 6 RPE or lower. 
If you were to run this against a regression and estimate RPE according to velocities, you sort of force a fit, but it does ball park things for you. The main issue is when you're going for large sets in excess of 10. Larger sets are going to be more noise than they are data, so I try to keep the nRM attempts under 10 reps. It's worth pointing out that half steps in RPE might be truncated due to the size of the incremental velocity losses. Guess what fills in the gaps in this case? Subjective, internal feedback. Just like you can use VBT to spotcheck RPE, you can do the opposite.
Sounds like a bunch of hand-wavy mathemagic. Possibly. If you ask me for a peer-reviewed article that supports this assertion and I can't help you. The best I do is refer you to people that are more qualified than me. To be fair, in a previous article I did mention this as an outstanding issue that researchers need to resolve. 


I've tried to do my due diligence here. A quick search through RTS's forums will find mostly inquiries about how devices compare. One reply in particular from November of 2014 has the following equation from Mike T:
This was back in 2014 though and I'm not sure if Mike has since disregarded this. I also can't verify whether or not this matches up with my experience because I haven't used it extensively.

[Edit 8/8/2017: It would appear from an article in July from IJSSP that generalized equations don't work, however this could be due to the fact they didn't account for MVT. In a follow up article, I advocate using initial velocity to determine XRM and regulating exertion using that relationship. This appears to be back by the research in that same article.

Edit 9/03/2017: According to unpublished work by Garcia-Ramos, a single repetition to gauge daily 1RM tends to overestimate. A better method is to use 2 points to generate the estimate. That's sort of what many practitioners did anyways without so much evidence and with a bit more intuition. TBH, VBT is just gonna be one of those things where the practitioners are going to be one step ahead of the science at all times.]


Reviewing what we've done so far leading up to this article... that's a load-velocity test (which is just a fancy data-geek warm up) and two AMRAPs. The load-velocity (L-V) table becomes a %1RM-velocity (%1RM-V) relationship. The two AMRAPs give you MVT, turning to L-V into a 1RM estimate. Then the two AMRAPs averaged across gives you the exertion-velocity (E-V) relationship. This E-V relationship is transformed just like the previous relationships to give us the RPE-velocity relationship (RPE-V). Essentially three rounds of data collection to give us five different relationships. And you have to do that for every lift you plan to autoregulate. 

So if you have 15 movements to be used in a macrocycle, that's 15 movements to map out. That initial investment of time is pretty large though. In theory, you should have your competition movements repeat every macrocycle so the data could roll over with very little update. So that's 12 movements, which is still an incredible amount of investment. This is also why I introduce movements into follow-on macrocycles slowly. Rather than having only 3 movements carry over, I usually have three-quarters of my movements from my last macrocycle repeat into the next one, so roughly just 4 movements. Exercise selection is a whole different argument, and I'm neither a huge believer in variety for variety's sake or hyper-specific training. Or you could use deload weeks between cycles much like I do and make them testing days since the volume is fairly low. You could cap intensity for load-velocity testing at 80%, and I doubt a single at 80% is going to be a huge hindrance to your recovery.

But really, one of the great advantages with this is you may only need this one relationship, depending on how you use it. Using just E-V, you can set a rep goal, like 8 reps with 2 RIR (or /2 fail, or a 10RM for 8 reps, or 8 RPE - pick your semantics). You can then get within the 2 reps based on the linear relationship between E-V and RIR. For heavier lifts where fewer reps are possible, it's even easier to determine what the opening velocity should be. But now it just sounds like you're doing exactly what RPE advocates always say: base your autoregulation off RPE, but adjust with external feedback like VBT.

If you're going for straight up training wheels to get you from VBT to RPE, this is probably the way to go. If you also wanted to run an RPE program as a VBT ideologue, you could transliterate the E-V data into RPE. 


Previously I mentioned using INOL to gauge the number of reps per lift in a session. This was generally my attempt to control for training stimulus regardless of intensity used. While I think INOL is quite effective in regulating intensity and volume in proportion, they really don't say much towards your proximity to failure. Three sets of five reps at 60% is regarded the same as one set of fifteen reps. Because of this, it's obvious that INOL somewhat ignores proximity to failure, or exertion.

New reader, what this? INOL attempts to gauge training stress/stimulus through an equation. It takes into account the number of reps and intensity of the lift. This gives you an arbitrary number that you can use to determine if a "volume day" is as taxing as a "heavy day." This is covered and linked to in previous articles.

Furthermore, the blending of INOL and VBT is somewhat dubious at best. INOL is more theory than substance, and any modicum of its substance is relative to percent based training, not VBT per se. This detail may be beside the point, especially if your autoregulation isn't changing load by more than 7.5%. To confound the issue even more, INOL is supposed to be a planning tool, not an autoregulation tool. Maybe you can figure out some sort of system with hand-wavey reverse look ups, but maybe you're over-complicating it. 

Regardless of intensity, I see additive value in regarding each set in the perspective of proximity to failure. RPE does exactly that, where 1x @8 RPE is essentially one rep with two left in the tank, or more concisely a 3RM done for 1 rep. Why does a rating system matter though? Why does it matter to talk in "proximity to failure" terms or RPE terms?

Mike T's recent summit at powerlifting university 2017 shined some light on this that made me take it more seriously. Much like INOL, Mike had created a system of coefficients that weighted the training stress of each set. For example, @9-10 RPE (no reps left in the tank) was 1.33, @8-9 was 1, @7-8 was 0.8, and so on. You can add all weights across a movement within a session or within a week and compare it to some ballpark guidelines. Whereas INOL weights reps according to intensity regardless of proximity to failure, Mike T's training stress index weights exertion by sets. Granted, if you're measuring by a different unit, you should create bounds for those units.

For a single movement, Mike put forth 2.5 for an easy session, 3.5 for a moderate session, and 4.5 for a hard session. Much like INOL, it operates under the "single movement" clause, whereby the training stress of bench vs that of your squat aren't lumped together. It's not clear to me whether something like touch and go bench and feet up bench are arbitrarily separated, but you could argue it either way. For a training week, good planned bounds would be 14, 20, and 26, for the same rating scheme (easy, moderate, hard).

As I said before, this is all in reference to Mike's seminar on 2017 powerlifting university summit. I'd use the pictures or talk more in depth about it, but given that it was paid-for material and it's not my idea to share, I'd rather just give you the jist and refer you to buy access.

Unlike session rating though, this is separated by movement pattern with all squat type movements lumped together, etc. I may have misunderstood this, to be fair. Much like the INOL theory though, these guidelines could vary from individual to individual. This makes sense though given it's a proxy for work capacity, and work capacity is more of a moving target than it is a fixed point.

I like this application because everyone talks about work capacity when there's seems to be little agreed upon measure, normative values, etc. Work capacity is essentially a working theory. Mike Israetel talks about maximum recoverable volume (MRV) and maximum adaptable volume (MAV), which sounds much like work capacity as well. Mike T's training stress index also meshes pretty well with MRV terms of understanding how we manage lifting schemes.


Another good reason to consider RPE methods of the E-V table is the inherent fallacy of velocity loss. I've said before that velocity loss can be misleading. At very high percentages of 1RM, the threshold of 20% velocity loss (or 40% even) is below your minimum velocity threshold, or your last rep in the tank. Following the velocity loss rules to a T guarantees one of two things: 1) blunt force adaptation or 2) getting stapled.

Velocity loss is a VBT concept that strength adaptations occur from training where only 20% velocity is lost. Training with a loss of 40% of opening velocity is better from hypertrophy. It's sort of a minomer since you can perform both 85% of your 1RM to a quarter of velocity loss or 60% of 1RM to a quarter of velocity loss - with one of those better contributing to strength development. What is really hard to do is to get 20% velocity loss at sets at 90% and above - even if you can bang out 5 reps at 90%.

Even if you think E-V tables are too much additional work (when really they can be the only VBT data you record, ignoring all others), you still have to remember your MVT for these situations and have a general sense of how much velocity you usually bleed off in your final reps. If your final rep or 1RM moves at 0.24 m/s and you hit a rep for 0.27 m/s, there might not be another rep in the tank for that set. The next velocity decrement could be below your ability to power through. Alternatively, 0.27 m/s could just be noise - and you should plan around that. The only method you have to rebut this without this information is by going by subjective opinions on whether you can complete the next rep - which sounds exactly like what RPE is trying to accomplish. 

Furthermore, E-V tables allow another programming strategy that ignores percent of 1RM. This might be useful for movements that have no real 1RM as well - like your rear foot elevated split squat or other supporting exercises. 1RM for those lifts may never be tested, may be implausible/unreliable to test, or pointless. Rather than using percentages, you can undulate by number of repetitions if you know your E-V. If you plan to hit sets of 8 with 2 reps before failure, you can use E-V to determine appropriate starting velocity.

Or you can do what I do: not really care about the autoregulation, hit a fixed number of reps and sets, and make sure it's heavy enough to be hard. It's an accessory - not existentialist theory. Just do the damn work and be done with it.

While I've so far been an advocate of autoregulated volume and intensity, you can use this to truncate your autoregulated variables or control for number of lifts (NL). 


I hope after reading through this you've understood that VBT is king of all of the dingle-dangles. Not really, but since this is a VBT-Powerlifting blog, it's sort of becoming of me to suggest it.

Others have shown a strong inverse relationship with velocity and RPE. RPE and AMRAPs are the most common autoregulation techniques. VBT can be used to augment RPE, and is most commonly used that way. Likewise, AMRAPs can be used in conjunction with VBT as well. These three methods tie together on multiple levels, providing more forms of feedback. Brandon Senn explains this process really well in his article about the Autoregulation Book of Methods.

Which system or combination of systems is best is really user dependent. Even a staunch VBT advocate should be able to see some redeeming qualities in RPE. More importantly, autoregulation training methods are more similar than they are dissimilar in their application. Even if it's not your preference to use one system to drive the training process, another system will help analyze the process. The very obvious advantage that RPE or AMRAPs have over VBT is the bar for entry. Neither have price tag implicit to the process. I still do not feel required to win you over, but I hope I've alienated and emasculated all sides in this obvious shit post.