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. 

Saturday, April 29, 2017

Reality Check: Accelerometer Systems Aren't Useless

I feel obliged to talk about why I don't discount the accelerometer systems in all cases. Firstly, I will remind you that the intent of this blog is to provide a powerlifting perspective on velocity based training. For perspectives other than that sport, I suggest seeking out other experts that will flesh out their opinions beyond 3 main lifts. In very simple terms, I'm interested in velocity based training as it pertains to fairly slow velocities, often emphasizing velocities above 80% 1RM. Secondly, I should also remind you that my first sensor comparison article is not a definitive study. The sample size is 1 (me). And lastly, there are practical reasons for using accelerometer systems. Axes measured is an important part of that, as well as different training modalities. There's always room for growth in these devices.

Anyone that thinks I'm trying to throw a manufacturer under the bus doesn't understand that I've kind of spread it around on all parties. The last thing I want is someone to look at the sensor comparison article or any article and use it as an argument to disparage a company. All of the companies out there are bringing something unique to the table and should be recognized for that. I'm not throwing shade. I'm not trying to hamper their efforts. Each of these devices has advantages and disadvantages.

Of the three companies I've included in my original comparison, I've spoken to a representative from each (PUSH, Beast, and OpenBarbell). At one point in time, I was even a blog contributor for PUSH. If I was indeed bashing accelerometer systems, why would I ever work for PUSH?


This is the most important part of VBT for strength training. This is not the most important part for all training. Even in strength training, VBT is not the most essential way to monitor, augment, or otherwise manage your training. I've said it before:
If VBT is the most important part of your training plan, your training plan probably isn't good.
That said, if you want to use VBT for strength training, then you will certainly need a device that measures reliably at slow velocities. It does not need to measure accurately, but it must be done reliably.  Accelerometer systems seem to work best above 0.40 m/s or around 80-85% 1RM on many lifts for average folks. Tethered systems (or linear position traducers - LPT's, optical rotary encoders, etc) tend to work reliably around this range for barbell movements. That does not mean they are without fault.

I'm not an engineer, so I can't really talk with great confidence about the full range of capability of accelerometer systems. That said, I have seen systems that use hardware that plausibly should be capable of measuring velocity below 0.40 m/s. If the hardware could measure it but isn't actually returning reliable measures below that, I would surmise this could be an issue of how the signal is processed or broadcasted. All of these devices work through Bluetooth and all seem to perform better on iOS (Apple) devices because of how Bluetooth low energy works on Android (protip: at least buy an iPod if you want less Bluetooth frustration). Additionally, it seems plausible that data can be bottlenecked by the constraints of Bluetooth, limiting their full capability. If Bluetooth was the limiting factor, that's truly a sad state of affairs because 1) the manufacturers are limited by developments on the smartphone end and/or 2) future iterations of the devices must be developed to keep pace with signal broadcast if Bluetooth is the limiting factor. The upside of this is manufacturers could alter the way the signal is broadcast, providing real-time information in short bursts and transmitting extraneous detail after completion of the recording period (after your set).

The other limiting factor could be related to how frequently data is sampled and processed. If this is the limiting factor, the great hope is that manufacturers can update the software end to mitigate this. Anyone that's an early adopter knows this experience. Most devices within the first year of the commercial release act buggy. It isn't until after some time that these issues fall by the wayside. You should keep this in mind when you're looking at accelerometer device reviews on youtube from over a year ago, or even the comparison data I provided in future time.

When I fault devices for not performing well with deadlifts, the common response is some people CAN get deadlifts to work with the device. It usually involves performing the movement in a special way that is arguably too far away from the mode of training to make it feasible.  And just to be clear, I haven't talked to a single manufacturer that was satisfied with how their device was assessed for deadlifts. Maybe there isn't a good solution, maybe deadlifts behave erratically, maybe my consistency in deadlifts suck, or maybe my attempts to measure deadlifts objectively are flawed. Could be any single one, or it could be all of them.


Powerlifting barbell movements are predominantly in 1 axis, but you could argue that all movements happen in three axes enough for it to warrant attention. Even the bench press, which moves in two axes more than the others, doesn't seem to be hampered by measurement in one axis alone. Different devices measure in a different number of axes. Most devices allow for a change in configuration so you can measure in an axis/axes of your choice (floor/ceiling/horizontal mounting). S

That said, depending on what you're doing for assistance/accessories and how much VBT integration you intend to have, it might be advantageous to choose a purpose driven implementation of a VBT device. In particular, lunging in general (side, traveling, and possibly forward/reverse lunging), some types of landmine work, step ups, glute-ham raises, pull ups/chin ups, could be limited by your device selection. 


Consider how much a GymAware cost. At a price tag of $2200, that's not including a subscription. Next, pricecheck a Fitrodyne Tendo or a T-Force unit - don't forget to consider how convenient these set ups are. Last check on the tethered-unit supremacists: tell me the next estimated ship date for OpenBarbell V2. Compare this to the availability of accelerometer systems and they obviously have a leg up. Accelerometer systems have a more favorable equilibrium on both supply and demand.

Just as much as I recommend using some form of autoregulation training before jumping into VBT, I would also recommend incremental implementation of VBT devices. I would recommend trying a product out that has a solid return policy or using one from a friend/facility that already has one. Alternatively, you could minimize your losses by buying at the lower end in terms of price if you weren't sure if you wanted to take the $2200 dollar dive.


Don't assume I chose the best design method. I didn't. I went with what was practical and tolerable in order to develop a rationale for my case to implement VBT. The target was the consumer market. The only other comparison of multiple devices I've seen talk about them in generality, occurred long before the devices were well-established (IE: before they worked out the major bugs), or simply stood as opinion pieces. I don't think any of these really helped people determine which unit to buy.

If you think I'm going to toss out my PUSH now that I have an OpenBarbell, you're wrong. Depending on what I mean to do, the PUSH still comes out.

This isn't a validation study. At best, the comparisons are akin to what DC Rainmaker for cycling power meters or NotebookCheck does for laptops. At worst, it's little better than Men's Health reviews or Gizmodo.


Accelerometer systems aren't garbage in all things lifting. Accelerometer systems may not even be the worst option in all things. In the end, it's almost like asking what's a better motor vehicle: a Prius, an F150 truck, or a Formula 1 racing car? Depends. Are you focus on commuting, hauling cargo, or getting from point A to B in the least amount of time?

Friday, April 7, 2017

A Powerlifter's Guide to VBT Pt 6: Personal Preferences and Personality (or lack thereof)


I currently make no money off this blog, so there's no incentive to make regular updates. Recently my internet's been out. I live in a rural area where getting an internet technician out to fix things takes about 2 weeks. That sounds like a fine excuse, but congratulations to the North Carolina Tar Heels on their 2017 championship run #Redemption


I've nailed the point that VBT is not the best way for every given individual to train. It's my personal preference. I think there are certain ways and particular individuals that can excel at training with VBT in part or as a whole. So far as I know, I happen to be one of them. I don't think you need to be as inquisitive about your training as I have, track extraneous details of your lifts, or even be bound to a laptop and device to make your training effective. This will lay out the types of individuals who could benefit from training, based on responses to training, attitudes about training, or based who they picked in their bracket for the final four in the 2017 NCAA tournament.

The Grinder

In a phrase: suck it up, buttercup.

Good day or bad day, the bar speed doesn't lie. Just buck up and do the damn work. It helps to be passionate about your training, but it also reminds me of some Army leadership principles. Army leadership is defined dogmatically as providing purpose, direction and motivation. Apparently, motivation is really important. In a very cold manner of thinking, it also defines motivation as "getting others to do what you need them to do." At the end of the day, it doesn't matter if you enjoy your volume or intensity, but rather that you get it done. I like to think about this as being an adult about your training - not to demean other attitudes. Having your own place is nice. Paying your own bills is not. 

Greek myth toiling without end, or
strongman that sucks with atlas stones?

When we use objective measures, it's helpful to keep yourself accountable to your capabilities. You might not have slept well last night, might have personal issues at home, but if you stop feeling sorry for yourself you might be able to get under the bar and do some productive work. After working with VBT for long enough, I've found the effect size of how poorly I feel from whatever stressors have little impact in my training performance. Then again, maybe the Army made me dead inside and the only thing that phases me is not getting enough food a day.

It's easy to get into your own head and convince yourself you are ill-prepared or better prepared than you are on a normal day. Every piece of feedback helps paint a picture of your readiness. These can be objective/subjective and internal/external. No feedback system is infallible, but it helps to have more than one check on readiness and performance. 

The Breadwinner

In a phrase: earn your keep.

A coach I know had this maxim that some athletes have to train good to feel good. This has sort of a breadwinner attitude: do work, make dividends. It's hard to see what those dividends are when your progress is slow, but you can see glimmers of it through your training with velocity. If you perform well, you get to/have to do more work. If you perform poorly, you get to/have to do less work. This cuts both ways with volume and intensity. That part of getting to or having to do work more with volume or intensity depends on your perspective. You're held to a standard, and you are rewarded/punished for your performance, again depending on your perspective.

This idea can cut any which way along intensity and volume tolerance. If 80% of 1RM moves faster today than it usually does: you've earned more intensity. Maybe only somewhere near 5% more, but strike the iron while it's hot. If you keep knocking down set after set without any major declines in opening velocity, you likely have a better tolerance for volume.

The Failure Adverse

In a phrase: don't be effort adverse, just be failure adverse. Try trying.

I largely disagree with this point in general with auto-regulation training. Auto-regulation doesn't remove the potential for failing a lift. It doesn't remove the possibility of injury. Those things are still there, but auto-regulation training puts sign posts along the way. You may recognize them and avoid disaster, but you may not.

Firstly, I disagree with the common assertion that injuries in powerlifting are from max lifts and acute trauma. Anecdotally, most injuries are from cumulative stress over time, training and non-training. In many cases when you see injuries from singular events, it tends to be the straw that broke the camel's back rather than the crossing the injury rubicon.

That said, here's the sign posts I read that bad times are coming...

One thing I notice is inconsistent velocity with a lift that is usually predictable. Misgrooves are often represented in your velocity output. In a higher rep set, you'll often see a few outlier velocities. Sometimes you can chalk it up to re-taking your air for longer sets, but sometimes it's very obviously just sloppiness in your movement.

Another inconsistency in velocity loss across the set is a rapid deflation of velocity. If your set starts at 0.52 m/s, drops to 0.48 m/s on the next rep, then nose dives to 0.30 m/s, you have a number that shows your proximity to grindtown - population: you. Sometimes you know that 85% (or today's 85%) should give you X reps, but sometimes your fuel tank leaks. You'll find you don't have as many reps to carry you on as you normally do. These two examples can be measured and might prevent injury, but they're not the most likely or most useful way to prevent injury in an athlete monitoring sort of way. Chances are, you're going to get obvious, subjective indicators that tell you what's happening without velocity telling you what's what.
This reminds me of a period of time after I had a slap tear. I thought I could train around it, but it was pretty obvious it was a persistent injury. Inside of the first 3 reps of my working weight my bar velocity really dropped off. There's probably a mechanistic reason for this (something about the Golgi tendon organ inhibiting contraction, I guess), but the utility in getting that granular is meaningless if you're not willing to accept there is an issue and you need to do something about it besides work around it. Often, outcomes are easier to act upon than diagnostic criteria.
I think the better utility is in finding whether fatigue is chronic or acute. Chronic fatigue is built up over time and can be a sign of over-reaching and over-training. There are many signs to this, but many misdiagnose subjective feedback (how you feel, mostly) as the sole indicator. Many people chalk about their feelings as a sign of overtraining, which is not the case 9 times out of 10. This is probably why many people scoff at the implication of overtraining, because most only diagnose it based on internal, subjective feedback (feelings). I would think it's more helpful to have at least one objective indicator to back up the claim. If you're consistently downregulating intensity or volume with velocity, it could be a sign of a necessary deload week to allow better recovery and improvement in training quality. I guess you could use other things, like feeling tired throughout the day, sleeplessness, elevated blood pressure, or whatever criteria that varies from person to person. My preference is to again rely on outcomes, letting outcomes serve as diagnosis.

If you really wanted to understand whether your fatigue is chronic or acute, I would check standardized load velocity. In a previous article, I advised starting a session with a squat or a bench at a given load every time. Usually, I try to keep it at a light to moderate load, something I know I normally hit for 0.5 m/s on a bench press or 0.65 m/s for a squat. It's even better if you make this pinned movements (pin squat or pin press), since that removes a lot of the variability that could comes from mis-grooving or other performance confounders. You can compare your velocity against short term or long term averages (somewhere in the neighborhood of the last 10 measurements and the last 4 month's worth of measurements) and see the magnitude of difference. You could wrap this into a larger athlete monitoring program, but that's beyond the scope of this. For a cheat sheet on this, check out TRAC at Reactive Training Systems.

The Masochist

In a question: how can I drown my lifts in volume and frequency without killing myself?

Two things I love are volume and frequency. They work for me. The issue with having fluctuations in volume is the fatigue can be unpredictable depending on how your structure your program. I also love high-frequency training, especially for bench press. The great part about auto-regulation is you can scale according to how each lift is responding to adaptation. Of course, the long-term goal is to find out the right combination and amount of training variables (volume, frequency, intensity, etc), but short of having that you can just auto-regulate as necessary. 

The argument here is pretty much the same as the grinder, but the personality type is more suited to the person that looks forward to inducing fatigue. 

The Accountant

In a phrase: you're so numbers driven, you're double majoring in statistics and exercise science.

Playing with volume and intensity gets your rocks off. You have your own scheme to weight values appropriately and periodize to some statistical model. Subjective feedback is cool, but you if it's not quantitative it's not good enough for you. You won't do a workout without filming your top sets, measuring velocity, and updating your worksheet. Before you go to sleep, you think about new ways to quantify your training data and lose sleep if you don't get it started right away - unless that means you'll miss your training readiness quotas by undersleeping according to your baseline of hours slept in the last 10 days. You know all these factors has an effect size of only 2% increase in performance, but you're convinced that changing enough factors will give you the advantage you need in your next meet in the 22 kg class. 

You really don't need much more to add to your paralysis by analysis, but I know talking you out of it won't work. You don't need VBT to make gains, but you also don't need a premium google analytics account and you have that too. I'm pretty sure even your dog hates you.


There's a number of personalities and attitudes that mesh well with VBT. I don't think it makes much sense to shop around for auto-regulation methods based on personality. Chances are you can be one of Mike T's controlled-aggressive archetypes and still find success in VBT. Chances are, one of the above can describe you and you might not get much out of it. I really don't think personally factors into VBT auto-regulation that much, but I do think it's a factor for RPE.

Some people tend to emphasize the importance of increasing training arousal (getting hyped), while others tend to emphasize stimulation avoidance. I don't think being hardline on either one is important, realistically sustainable, or influences the training process significantly to any degree. In the end, I think attitudes about your training don't matter as long as you can make some use out of objective feedback.

We're nearing the end of this series. This one is mostly fluff that responds to criticisms about VBT that I think are erroneous or over-emphasize the importance of personality and mood in training. The next one will be a case study of programming with VBT in comparison to percent based/nRM based programming. I only plan on doing an RPE themed one after that, and this will slip into irregular updates. 

Monday, March 20, 2017

A Powerlifter's Guide to VBT Pt 5: Future Directions for Auto-Regulation Training

[Update 5/9/2017] The manufacturers have responded pretty robustly and directly. Some features I say manufacturers didn't have they actually did have - either on their premium account features or through some other way. Other features were already in the development pipeline.

Most notably, Beast reached out and told me they do provide some velocity-time graph features for the first rep of every set - which is useful for analyzing opening attempts or 1RMs. You can export on Beast - again possibly with a trainer account which I don't have. OpenBarbell also debuted a new export to CSV option. Who even knows that OB is coming out with in their version 3 release, if any changes at all.

I'm not going to edit this as every advance in the technology or science happens. I'm hella lazy. So just keep that in mind. I also apologize for the horrible formatting I did. I've tried to correct that.

[Update 5/17/2017] Both PUSH and OpenBarbell seem to have developed through different avenues. PUSH with seemingly more outreach/education and OB with a new build and promise of an updated app. OB is exporting to CSV after a few hiccups with the initial rollout, and it very clearly stores the information on a linked Google Drive account upon successful export.


There are two avenues I'd like to see developed. The first if the most practically oriented, and that's things manufacturers and practitioners can do to bring the technology forward. The second is possible future directions for the research. For the folks on the front line, the obviously more actionable one is on the manufacturer and practitioner end. Without the research to validate our experiences though, we're essentially working by trial and error. I don't mean to fetishize what the academics are doing, but if we were limited to exactly what the practitioners were doing, VBT would probably be limited to the secret strength and conditioning manual of Missouri Football (jokes). There is some overlap between the manufacturers, practitioners, and the research. This is obvious with folks like Dan Baker working with PUSH, Bryan Mann working with GymAware, and Kabuki teaming up with OpenBarbell.


This is probably the easiest part to sort out. The private sector tends to be rapid about sorting out solutions fairly quickly. The main issue is holding some of these things back due to novelty and propriety. One of the most interesting recent advances in VBT devices that I expected more out of was Open Barbell being open source. This was different than previous devices that tried to meet the demands of the loudest and highest paying voices in the industry. These were namely strength and conditioning in sports, mostly money sports (which powerlifting is not). My original hope was that Open Barbell would have diverse application development that would run awry, much like the Google App store. This has not been the case. Meanwhile, other manufacturers seem to be porting out features that have no direct application to powerlifting and pertain more to speed and power sports.

So what do I hope to see/expect?

Possible Hardware Configuration Changes or Methods of Measurement

This section is full on nerd. You might not appreciate it, so skip to the next subheading.

This is possibly more pertinent to accelerometer systems, but it would make sense to me that additional sensors could increase the accuracy of accelerometer VBT devices. Form Lifting seems to be beating down the right track by incorporating a barometric altimeter. PUSH, on the other hand, tries to navigate the measurement by using accelerometers and gyroscopes. Using this approach, if you can get a signal on the orientation and the acceleration of the sensor, you can derive velocity data by normalizing to individuals with some simple inputs (height, weight, etc) following a basic template that teaches the data processor how to interpret the information. I haven't had hands-on experience with Form Lifting, but it would seem to me their sensor has an advantage that PUSH doesn't: movements where the rate of change in orientation of the sensor and velocity is very low. This is most pronounced in the deadlift, where the rate of displacement of the sensor is slow and orientation does not change to a significant degree. A sensor like Beast struggles with deadlifts for one common reason that many accelerometer systems do: the jostling of the bar after dropping and vibrations. The difference with Beast is it allows the user to purge repetitions. This solution is easier with faster movements like the squat and straight guesswork with a heavy deadlift.

Accelerometer systems only have so many ways to navigate this issue. One potential fix is to change sensor location. This seems to be an area where Beast has the most versatility, advertising itself as both a magnet mounted unit and a wrist-mounted unit. PUSH also uses this method by relocating the sensor for jumps (waist belt mount) and pull-ups (upper arm). Another sensor, BarSensei, seems to build their units to be more purpose driven, with accelerometer systems that are both bar mounted and medicine ball internal. 

The next solution ties into the following to some extent. One issue with the systems tends to be that they are unable to tell their position relative to the whole system that's moving (the body and the barbell). One possible fix is to give it more inputs specific to the user. For example, if the system understands orientation about the human body and how it accelerates at different angles, it could be pertinent to teach it the exact position of those pesky joints. For example, a system that assumes your trunk is 30% of your height, leg is 23%, and arm is 32% could gain from knowing what the actual lengths are so as to know how they are supposed to accelerate about the y component when functioning as a whole system. Form gets to sidestep that issue by utilizing their altimeter, but other systems have the advantage of additional inputs, like asking users to calibrate the system through measuring body segments. This is in contrast to using generalized proportions. This is most important when anthropometrics can garner an advantage in a sport, like long arms aiding deadlift mechanics.

Now that we're headed down the path of calibration, we should talk about calibration. If anyone remembers early GPS systems, they required you to do a calibration process whereby the user spun the unit across two planes and raised and lower the device. The counter-quip to this is to build a product that's fully calibrated and holds it to begin with. This might be a sound philosophy when it comes to smartphones becoming outdated every year, but I generally expect my gym equipment to last longer than that. If I had to replace my iron every year, I'd rent it through a commercial gym rather than owning a home gym. An ancillary issue is the price and/or supply can fluctuate wildly. In particular, Beast has taken forever to create an American distribution location, the price of PUSH has only increased due to increased features and development, Open Barbell sells out of stock inside of a day, and GymAware cost roughly the same as a cycle of steroids so why not go that route anyways (kidding, USAPL). Long story, short: it might be helpful to have a calibration feature built-in on the operator end.

Load-Velocity Mapping Built In

PUSH essentially has this built in, but it doesn't really make it useful. For whatever reason, you're perfectly able to run a 1RM-VBT estimate through an app feature, but that information just stays in your dashboard being as useless as calf raises for your bench press. Instead, you just get this feature that lets you dictate a really broad range of velocities for a specific training quality (strength, speed-strength, etc). Below is an example of PUSH's built in 1RM estimate test.

I would like to see a feature that allows you to map Load-Velocity. Ideally, I would like to see the app conduct a reverse lookup on a build-up set (as you're trying to find your working weight) and return an approximate estimate of your %1RM. Even better would be the ability to set a %1RM and have the device alert you when you're within acceptable tolerances of the corresponding velocity. With this one feature, half the reason to use templates like I do disappears. Chances are, if it's something I do in MS Excel, there's a really easy way to make it happen in an app.

I don't shame people often, but the industry deserves to be shamed on this fact. Some VBT devices have been on the market for years now. The research and practitioners have been pretty clear on the need for L-V tables to make it individually actionable. Instead, manufacturers have sidelined this simple implementation for others. This is a letdown, especially for manufacturers that have had e1RM features since day one. Failing to capitalize on this relegates some VBT devices to cocktail party tricks that have little to no effect further down the road.

Update 8/28/2017: Even though I've railed against video analysis systems in the past, the Apple app Powerlift actually does this. Furthermore, it has been validated by Carlos Balsalobre-Fern├índez. There are some limitations, but it's still good in a limited way. To set up your load-velocity profile, you have to know the length of the movement. To get this, I cheated and used the readouts from Open Barbell's ROM measurement (btw: my squat is 666 mm). You can build out your load-velocity profile and then measure the velocity of individual reps. If I were using it in real time, I would probably just ramp up to 80% actual 1RM, measure the velocity, and use the estimate + basic algebra to figure out the day's 1RM and the working weight for the day. This might not be optimal given recent findings, but I could see this working it's way into the app shortly.

Also, I wouldn't get hung up on the fact that Powerlift's velocity differ from another device if you use one. What's important is reliability, not so much accuracy. The key part is to try to conduct your 1RM predictions from the same camera angle, height, and distance as your load-velocity mapping session.

Load-Exertion Mapping Built In

Likewise, a Load-Exertion (L-E) or built in rep to failure (RtF) table would be just as useful. While I tend to follow velocity loss, there are practical limitations to this simplistic approach. A built in L-E table would give you a good indicator to follow in real time, alerting you to when you're 1-3 reps away from failure. A L-E table establishes what your last rep in the tank, 1-3 reps left in the tank, and so on. Rather than working based on velocity loss, which gives us a very rough guideline, we can dial it into alerts based on how far away from failure we want to be: 1-4 reps depending on the training goal. Granted, RPE ratings essentially do this for us, but this feature alone could increase the cross talk between RPE and VBT. This provides a very clear objective read on reps in reserve that can be used in real-time for VBT users or to validate RPE's assertions on their ratings.

To make L-E feature built in, all that would be required would be RtF sets at two intensities, like 75% and 85%. Those RtF sets could also feed forward into e1RM tests to establish MVT and a more accurate estimate of 1RM.

How about this for a really easy feature: any time you set a new record low velocity, ask if the user wants to designate that as their MVT. Make it something that can opted in or out of, just in case it wasn't a full rep, it didn't meet the criteria for a technically proficient lift, or was purposely moved slow according to tempo prescription.

The "Velocity Zones" Sucks

This one thing is the most important factor IMO to make VBT data fluid and actionable.

Firstly, the velocity zones for are very dependent on the exercise and athlete, depending on the training outcome. You could probably find ideal zones for different exercises for different training qualities for different types (most specifically heights) of athletes. This sounds very time-consuming though and doesn't really help the user. KISS: keep it simple, stupid. That, or I guess you can exploit the fact you have a user database with self-selected data, do a database analysis controlling for height and exercise classification, and multiply it by the squared cosine of making a simple solution harder than it needs to be.

This one thing is the most important factor IMO to make VBT data fluid and actionable.

Granted, there is a way to do this through program creation with some apps and webportals, if you can get over the fact that every system that has a program creation guide as rigid as frozen dog poop. Here's an idea: let me designate the velocity zone myself while using the app. Specifically, let me choose a velocity, plus or minus a given percentage of that velocity for an initial target, and an acceptable stopping point (either a specific velocity or a certain percentage of velocity loss).

Surprisingly, Beast for all it's
lackluster does have this simple
feature. Not exactly on the mark, but
why is this not common to all?

It seems pointless, but when you consider that rows and pull ups have a high MVT, according to the velocity zones, you can hit a 1RM without ever really working within the "absolute strength" zone. If we had this one feature, you wouldn't have to see the screen for real-time feedback. This one thing is the most important factor IMO to make VBT data fluid and actionable. I'll keep saying that in hopes that some manufacturers pick up on the point that this needs to be a basic feature.

Athlete Monitoring - Daily Readiness Testing

Take for example a traditional Sheiko program. Something that has you squat for a certain number of reps, gives you a brief reprieve by benching, then has you do an assistance version of the squat. If you have a very, very clear training priority in the day (squat, in this example), you want to know how beat up you are. One of the more popular ways of checking your daily readiness is by doing a squat at a standardized load. I usually use 60% of my last official 1RM (not my daily 1RM). I call this my "cold start" since I do it first without any warm up or practice reps (maybe air squats or some body weight variant). If that weight moves slower than my L-V tabled velocity, I know I'm carrying a bit of fatigue around. This doesn't stop me from training, but it prepares me for what to expect. If it moves faster, I can probably stack more plates on the bar that day.

Not terribly recently, Dan Baker suggested a standardized load of 80% 1RM IRC. The smallest worthwhile difference in determining deviation from readiness was 0.04 m/s difference from baseline. If you can move that faster, you're stronger (at least that point in time). More than 0.04 m/s difference in terms of drop in velocity means fatigue is inhibiting your readiness. This seems to come from his coaching experience and possibly data from his previous studies (the Oceania strength and conditioning community is awesome like that). YMMV

With enough measurements, you should have a baseline reading (think of it like a rolling average). With that baseline, you'll also have a gauge of what is abnormally above or below your baseline. This is the same kind of principle that Heart Rate Variability uses on a global level, but this gives you a direct read on local neuromuscular readiness. Again, this is something you can do through Excel using something like basic Z-scores or percent difference from baseline. Here's a fictional example:

Standard traffic light system. Green means increase training
load, yellow means normal training load, red means decrease
training load. Arbitrarily set at a difference of 10%

The hardest part of athlete monitoring is finding a way to make it unobtrusive and have additive value to the training process. It's already a bother to make an excel sheet to accompany an app to accompany a device to accompany a barbell. How is this not a thing? Manufacturers that want to sell their product like it pertains athlete monitoring should put something in the fine print that says, "but you figure that part out on your own, hoss." 

Graphs Against Time

Given the amount of samples most of these devices collect per second, it would be really helpful and plausible to have velocity-time graphs or displacement-times graphs much like what is shown here:

These seem minor, but in powerlifting it really helps validate struggling areas of your lift. For example, a change in the slope of displacement over time can show you the slow parts of your lift. That slow part of your lift is likely going to be a weak point or sticking point. Depending on the location and your development, you can overcome that sticking point by "strengthening the zone" by focusing work directly in that weak range of motion. Another way to breaking past it is by developing acceleration before that point so more acceleration can be developed to "power through" that sticking point through inertia. 

Granted, this is something you should see during the course of training but gives you a ruler to measure it by. Objective feedback is one of the selling points of VBT. There are likely some practical limitations here like the throughput of information that can be sustained through Bluetooth, but I see this information be utilized more after the fact during set review. This does not need to be a real-time feature, making this still a plausible feature.

Added Value: Tandem Video Recording with Data Overlay for Coaches

I have to admit this is something GymAware already does to the best of my understanding, along with graph overlays. It seems like online coaching with set review is fairly common. Advances in the internet and mobile devices have facilitated the process. I'm all for it, within reason. For coaches that see added value in the velocity data, this helps centralize all the important information by giving the mean velocity of each lift as the lifts are performed. This would be especially helpful for 1RM attempts, RtF sets, and L-V mapping sessions. I highlight those because those three things could throw off the whole accuracy of V-%1RM plots and potentially over/underload future training sessions. Below is an example of video synced with mean power from Dan Baker:

Even on the individual level, this allows the athlete to understand potential causes of velocity inconsistency, such as intervals in which they brace, range of motion contributions to velocity, the magnitude of simple form breakdowns, etc. Unless GymAware has copyrighted this specific tool, it seems easy to implement. This is something people commonly do through two different applications and the feature would merge the process and consolidate the information.

Cut the Fat: Microcycle Management for Coaches

No, I don't think this being able to create and push training plans to athletes is worth a damn. It seems like everyone except for the barebones manufacturers want to provide this. However, it's limiting to the point of being useless. A good example is one manufacturer automatically prompting you to follow the training plan as soon as it starts. Needed a build-up set to figure out what load is appropriate for your working sets? Too bad, that single plate warm-up just counted as one of your 6 working sets. There are plenty of scenarios where this level of inflexible management just performs poorly. Any workout program that's so rigid that it doesn't allow you to take a dump mid-workout to prevent pooping your pants during your squats is a bad workout program - I don't care what it adds to your total.

One example of program creation from Beast

Part of the whole point of auto-regulation is that you're not following a play by play script. These program features attempt to constrain the training process that is meant to be boundless. So I'll make it simple: you don't need to remove this feature, but there are zero reasons to buff it out. If there are recreational users that think it's useful, freeze it's development because it's a waste of time and resources. 

The market is already glutted with program creation and distribution products without VBT. No one's buying the product strictly for this point alone. Recognize it for what it is: fluff. I rate this feature a flat out zero fucks given. Here's a shorthand program that will get me through a session with VBT:

Comp Squat: 6+/2@0.42 m/s, stop @ 0.32 m/s
Close Grip Bench:  @0.54, stop @ 0.30 m/s
Pin Squat: @ 0.6 m/s, stop @ 0.33 m/s
(4x10 follows)
Ab rollout, shoulder external rotation, pull ups

That alone gives me 90% of what I need to know and the other 10% I want isn't supported by any program management tool I've seen.

Air Cast and Mirracast

[Edit 8/8/2017: If it works with Apple, you can cast it. Just make sure you change your screen time out. That said, this actually hasn't been super helpful now that I've taken it for a test drive. I much rather prefer to have some sort of mounting system. Especially when it comes to bench press and I'm staring straight up.]

This is not really a feature that needs direct support. As far as I know, you can do this on both systems, possibly with a little bit of ingenuity. Screen-casting (Air Casting on Apple and Mirracast on Android) solves the simple problem of using the information in real-time. This might seem ridiculous, but it is quite an obstacle to finding a clear way to suspend your iPod in plain view during your squats and bench presses. Granted, a Perchmount makes this easier, but the only way I've gotten this to work with squats has been good ole 2x4" ingenuity. This is probably limited to users that lift in home gyms, but it's something to consider for people that struggle with using real-time feedback to regulate their sets. 

This whole casting idea means less if manufacturers make initial velocity and end velocity prescription more accessible, but there is some additive value of buffing that up with something like delay video casting with metrics overlay on the video. Video demonstrates a simplistic system:

Data Export (Plus Import) and Cloud Based Syncing

This is something some manufacturers already provide. PUSH exports to CSV, which functions the same way as Excel. This seems like a minor thing, but depending on what you're using your device for it can be annoying to manually transcribe information. PUSH is unique that it gives the extraneous details, like time spent concentric/eccentric, force, and other things that aren't available in the user interface. As far as I can tell, Beast doesn't do this. OpenBarbell just made an update that uses your Google login to sync, but as far as I can't tell it's not syncing anywhere where a user can retrieve it and the only viewable data is stored locally - a problem across multiple devices.

Export as shown on PUSH - probably the most underrated feature

The most interesting idea would be removing long-term data analysis from the realm of manufacturers' web portals and allowing hand off to others. There are plenty of platforms that currently do this, like and Fusion Sport. Some of these platforms have opened avenues of cross integration to allow automatic syncing (rather than manual inputs) of pertinent athlete monitoring metrics, like heart rate variability. Reactive Training Systems has developed a system that performs according to the metrics Mike T thinks are important, like resting heart rate and subjective questionnaires. It's helpful to note that this service is free to use regardless of whether you work with RTS or not. It does simplify the process. This saves you the trouble of developing your own data collection system and figuring out the analysis yourself. The problem with TRAC is it's developed with RPE in mind. The only other game in town that's powerlifting specific is MyStrengthBook, which is more training analysis than it is athlete monitoring. Regardless, neither currently seem to think of training in VBT terms. If you buffed out your VBT process to include multiple RtF sets alongside referencing velocity to %1RM, you could potentially create a VBT to RIR translator, making TRAC a usable training log.

The truth of the matter is there is no good VBT training tracker for powerlifting. This is to include among the manufacturers of VBT devices. Manufacturers need to abandon the idea of managing their own data when there are plenty of others whose sole attention is managing the training that can do the job better. The first training analysis to take VBT seriously and integrate or import velocity data and provide effective long-term analysis is probably going to a get a lion's share of the VBT consumer's market. The flip-side of that market is it's likely smaller than the RPE market. It would seem to me the easiest way forward would be to exploit the features of MSB/TRAC and translate VBT data into RIR as a proxy for RPE, then release the extensive data under the handle twitter handle Guccifer to satisfy our Russian periodization overlords.

Here's a walkthrough for data export on GymAware's portal:

And finally here's a video demonstrating how you export data on Beast and Open Barbell:

[update: since the original post, Beast and
Open Barbell has added this feature. #TomHanksVBT_Hero]


This isn't nearly as easy. It's easy to find the shortcomings of manufacturer's for current consumer requirements. It's easy to list out the things we don't know. It's hard to list out the things we don't know that we don't know. One of those Donald Rumsfeld known knowns, known unknowns, and unknown unknowns things.

So here are the obvious things we can talk about that we need to pursue on the research side of the house. Most of this is from the interest of strength training and powerlifting, not power development which seems to be better covered in the literature. For the sake of simplicity, this is the short list of things I'm selfishly interested in seeing studied for current needs in powerlifting and strength training.

1) Inter-individual Differences: determine velocity characteristics and differences across heights, limb extremities, anthropometrics, gender, etc

This one seems obvious. Taller folks or people with longer extremities are moving over a longer range of motion. This probably has some influence on their maximum and minimum velocity under load. That part seems easy, but the more complicated part would be examining the effect on sticking points during common movements. 

It'd be interesting to see how well our understanding of the literature holds up for training women and lighter class lifters in terms of velocity. It seems to be internet slapstick to cite that women and lighter lifters have differences in training load and reps at a given %1RM. Given the granular detail VBT provides, it could be helpful to see if we can characterize these training differences in velocity terms (velocity loss, mean velocity, MVT, etc).

2) Intra-Individual Differences: changes in velocity over time from different training modalities

We kind of have a working idea of this through the force-velocity curve, but this doesn't typify the differences in training that any practitioner has seen.

Credit to Haff and Nimphius

Everyone that's worked with a new athlete while running VBT (even if only for observation and not auto-regulation) have typically seen changes in MVT across time, usually corresponding with a change in strength (1RM). I've also seen this difference in speed trained athletes that tend to have higher MVT's than traditionally strength trained athletes. There's probably some interest in finding some middle of the road types of folks, whether that means a type of athlete or a type of training. In that selfish powerlifter way, I wonder how a conjugate method F-V curve compares to other powerlifting training modalities.

Furthermore, a mechanistic view on MVT would be interesting to see. It would seem there are many factors that could contribute to MVT dropping over time, such as changes in form, bar path, and other kinematics, but part of me wonders what the absolute floor to MVT is and whether there is a way we can predict the bottom end of minimum velocity threshold or the absolute minimum that minimum velocity threshold can move. There's probably some energetic or fiber type contribution that would also aid in explaining that, but I feel like that's a far reach and would not significantly impact how I use VBT in training.

3) Characterize particular movements: DEADLIFTS, rows, overhead presses, pull-ups, and variants of the primary lifts

[Edit 8/8/2017 - The Spaniards covered 4 different bench press types: regular bench, bench throws, bench press from pins, and bench throw from pins. They appear to be doing another article on the subject.]

[Edit 8/28/2017 - This has been fleshed out even more with different squat variations, plenty of stuff on pull-ups, and prone rows. The general trend seems to be that when the eccentric and concentric part of the movement is separated, there's increased accuracy and reliability. For many of these things, it's just a matter of the research catching up to what the practitioners know to be true. There have been circumstances where it appears researchers have really challenged our understanding of VBT.]

First of all, we need to recognize that deadlifts quantifiably behave differently. Deadlifts are noticeably absent from the research when it comes to VBT strength training. I get it. You can't publish an article with no real results to show for. It might be more productive to make comparisons across multiple exercises, both in the context of low-moderate intensity for power development and high-intensity for strength development.

Rows and pull-ups (for devices and methods that support body weight movements) are another confounder. When I did measure pull ups, one thing I found was that the velocity floor seemed higher (MVT around 0.42 m/s, far enough within accelerometer performance limits) for rows than it was other exercises. This seemed to be the case for seal rows without resetting to the floor, Yate's rows, and Pendlay rows. Normally I would contribute this to my lack of emphasis on upper back strength (I know I'm not only PL that seemingly negates upper back in favor of comp lifts), but according to folks like Dan Baker, this tends to be the case with his Rugby players that spend a lot of emphasis doing bench pulls.

I can tell you bench, squat, and deadlift general MVTs. I can't tell you overhead press MVT's and only have a rough understanding of velocity behavior across a set. In particular, the first rep and any "broken" reps (short stops at the bottom on successive reps) tend to be lower velocity. I generally don't care about this too much, but it needs to be said since there's some carry over to WL.

A hypothetical graph of %RM-V behaviors
Having a general understanding of how to treat assistance movements would really helpful. For example, if you knew that close grip bench press and Spoto presses were only mildly different from regular bench press, it would be helpful to characterize the magnitude of difference in the same way we generally say bench/deadlift and squat MVT's are 0.15 m/s and 0.30 m/s. It would seem to me that the main difference in the %RM-Velocity plot could be the slope of the line, the intercept, and the MVT. A picture of this would be appropriate and is shown on the right. This is a simplistic explanation, and it's likely certain factors tends to change different parts of the relationship.

This is generally what I find for me and what I've found with a few clients when using VBT as an observational metric, not an auto-regulation metric.

[Edit 8/28/2017 - Actual graphs of variants of the bench press, pin press, bench throw, and bench throw from pins.]
[Edit 9/5/2017: The same graph as above recreated with overlapping trend lines using Desmos online graphing calculator]

4) How rep count schemes and rep tempo modifiers affect concentric velocity

This is somewhat covered in the non-VBT scheme of research. I mentioned in the past the idea of using cluster sets to maintain velocity at high intensity and increase set volume. Myo-reps are another method which acts roughly the same way but is used to increase volume for hypertrophy/work-capacity appropriate loads. The mechanistic approach is helpful, but a good question would be whether this training modality is meaningful.

One interesting development in VBT was a study that focused on a VBT program vs an eccentric VBT program. Spoiler alert, there were no significant differences in 1RM improvements in the squat or bench press when comparing training modality. The Spanish VBT proponents have also played with rep modifiers, finding that imposing a pause between the eccentric and concentric improved reliability (something I have found useful). Anecdotally, I'm wondering if this utility can be expanded to include other tempo schemes. VBT has one added benefit to traditional methods of controlling tempo that it can give instant feedback as to whether the stated goals of the protocol are being met, and thereby what the practical limitations are.

Until we have a clear understanding of these things, we're shooting in the dark or we're going to need other methods to pick up the slack (like RPE).

[Edit 8/28/2017: We're getting a little of that now. This shows rest time equated cluster sets and traditional sets.]

5) Comparison showing the obvious superiority of VBT to that of traditional percent based training and rating of perceived exertion

Not necessary, but if anyone wants to beat down that path they're welcome to it. Different strokes for different folks.


Most of the things that manufacturers can do to bring the technology and practice forward are very simple. All of the concepts are not new, and many pre-date many of the VBT devices on the market. Bringing VBT to bear in use in the general public necessitates this process. Simple changes like %1RM-Velocity mapping, Load-Exertion mapping, and others would streamline the process and help athlete management. Many of the features that have been fleshed out apply to those that work with "velocity zones" which are too wide to manage the fine processes of strength training. And when it comes to powerlifting we are working with a narrower range of the velocity spectrum than power athletes. This is not because VBT does not lend itself to strength athletics, but because VBT manufacturers have not made their products nearly as accessible to strength sports.

It is my opinion that manufacturers should focus on how to manage the training session, not try to fill the role of presenting ways coaches (or self-coached individuals) should attempt to manage training across time. Rather than attempting to do two jobs poorly, they should focus on auto-regulation mechanisms internal to the system (via the app) and outsource mesocycle data management to those that have the potential to focus on it better. I've linked to multiple places, but for powerlifting specifically, this is best handled through MyStrengthBook or TRAC. 

The science still has a few questions to answer. Most of these relate to how we understand velocity as a marker of intensity, exertion, and fatigue across more movements and variations of movements. Giving us an understanding how this varies across different individuals or across an individual's development would better help us understand VBT beyond specific practitioners' experiences.