Metric VBT: The revolutionary barbell velocity tracking app

I have been obsessed with velocity based training for as long as I have been coaching.

We had a linear positional transducer (tethered string device, LPT for short) in our gym very early on and would have our athletes compete on relative power output. Whenever an athlete started to hit a plateau for weight, we would shift focus and chase watts relative to bodyweight as a way to create a new training goal, making sessions competitive and motivating.

We knew we were on to something, because every time we brought out the LPT device for a few weeks, athletes started telling us about how much higher they were jumping. Chasing power was giving their lifting intent a boost and that translated into improvements in rate of force development and athletic power output.

Unfortunately, we only had one device and with over 100 athletes we couldn't warrant bringing it out every session. The slow software, bluetooth issues and cost of getting more devices meant we had to treat velocity tracking as a novelty and not a staple of our training.

Despite these limitations, our great results showed just how valuable even this simple application of VBT could be. It makes so much sense that we should put as much attention into the velocity and intent of our lifting as we do into the load, reps, and sets we complete.

The problem with tracking velocity

If velocity based training is so useful and versatile, why isn't it more widely adopted? Why didn't we spend the money and get more LPT units all those years ago?

As of writing, VBT is quite popular in the college training environment and at the professional level but it hasn't really filtered down to the wider training community. I think there are a few reasons for this:

  • The notion that velocity tracking should be complex and sophisticated. Many VBT advocates portray the method as if it were a dark art. They reel off velocities, ratios, charts, and data in rapid fire, creating an intimidating knowledge hurdle for people to overcome in order to start using VBT.
  • Expensive, cumbersome hardware. Legacy solutions require an additional piece of specialised hardware to be purchased, sometimes costing thousands of dollars. Price is an obvious barrier here, and while prices have certainly come down in recent years, equipping a medium sized private gym with multiple units is still not cheap. Beyond price, hardware comes with another set of logistical burdens: batteries to keep charged, swapping from bar to bar, connecting to the right tablet, and switching profiles all add to the friction of velocity tracking.
  • Poor software experience. As inconvenient as hardware can be, having a poor software experience can be twice as frustrating. The data that can be gleaned from velocity tracking is incredibly valuable, but often times the effort and friction involved in accessing and interpreting the data significantly impedes the training and coaching flow. Unless you have a team of interns transposing the data into Excel it can be incredibly hard to action the velocity data in real time, and that is where the benefit is.

Making VBT accessible

This is why we are building Metric VBT.

Metric is the world's first fully automatic phone-based computer vision VBT solution.

No strings. No additional hardware, just point your camera, hit record and lift.

Metric completed it's Beta testing phase in April 2022 and is now available on the Apple iOS app store for iPhone and iPad. The app is free to download and you can record unlimited sets with a free Metric account. Accurate and easy to use velocity based training can be done for $0.

Metric is now available on the iOS App Store, you can download it for free at this link!

With Metric we are completely rethinking how velocity based training is done in the weight-room. Our goal is to address the pain points with VBT by making it effortlessly usable, providing rich contextual data, seamless video integration, and actionable real-time training improvements. We have gone back to the absolute foundations on everything velocity to reimagine how athletes train with velocity and how coaches program. From how you measure velocity, the metrics that matter, scoring and profiling progress, through to app design, training flow, and what data you see and when.

We aren't making a slightly better option, we are completely changing the VBT game.

This is the most important section of any article on this website, but it's also one of the shortest. When you spend two years fixated on a problem your thoughts tend to become incredibly focused. We cannot wait to share MetricVBT with the world.

How we made MetricVBT

But the Metric vision hasn't always been this clear. wWe need to go back to the very beginning to understand how we got here. It all started when my brother Davey started coming to Core Advantage to workout.

Davey is proper smart. A computer scientist and electrical engineer by training, Davey is the kind of person who 3D prints a puzzle to hide your birthday money in.

David Tober - Head Engineer at Metric VBT
Davey Tober - Lead engineer and inventor - MetricVBT

He has been working at Core Advantage since 2016 and has built so many incredible things to streamline our high performance and rehabilitation coaching services, including simple admin integrations, the Core Advantage Interval App, and our custom timing gates system and athlete testing database.

Davey is the behind-the-scenes hero of our business, quietly going about building these brilliant sports science solutions with a really good lateral approach to long standing fitness industry problems.

In 2016, not long after he returned from six months studying abroad in Sweden, we started training together. Davey would come to the gym after hours, we would lift some weights, talk nerdy stuff and hang out.

I was lifting with a tethered VBT device and after some back and forth on the benefits of velocity based training Davey was a bit disappointed that we were stuck using a string to measure velocity.

Then he says "What if we used SONAR to measure bar speed?".

"You mean like a bat?"

So he got to work, spending a few days a week developing an accurate wireless solution to track bar speed using SONAR. We made a pendulum style cardboard box with a sensor facing the ground and hung it off the barbell.

In the few tests we ran, it was actually pretty accurate. We got consistently within 85% of an LPT on day one. Not valid, but reliable enough to be an interesting idea.

The tricky thing with research and development is that it is expensive.

Going from an interesting idea that has potential to creating something that will really work is incredibly costly in both hours and dollars. Then to take the next step and go from something that works to an actual product we could sell and ship is twice as hard and expensive again. So as excited as we were with the prototype and potential of our SONAR VBT, Core Advantage in 2016-2017 was still very much a gym first and foremost, we weren't thinking about becoming a technology company.

So the SONAR (we were calling it the bar-bat) went from being an interesting idea, to a dormant project, to being completely shelved.

As interesting as this solution was, we started to realise that the problems with VBT couldn't be solved by building different hardware. The problem was the fact that you needed any hardware in the first place. Having to buy, carry, set up, charge and care for an extra physical device was the key limitation for most people starting with VBT.

The business model and work required to find out whether people would like a SONAR VBT device wasn't worth the gamble, so we returned our focus to building in-house solutions: the testing software, our timing gates, and the Core Advantage Interval App.

But Davey and I continued training together a few times a week, talking technology and getting stronger, all the while complaining about having to use a string whenever we trained with velocity.

Then GymAware launched the Flex unit in October 2019.

Initially we were angry, they had beaten us to the punch with an accurate stringless velocity tracker! But we quickly realised that their idea of an array of optical sensors around the bar was a much smarter idea than our pendulum SONAR sensor. Plus Kinetic performance build beautiful hardware.

Our anger and envy quickly turned to excitement though, because it got us back to thinking about how to solve the velocity tracking problem again.

One day between bench sets Davey says: "We could probably track a barbell with your smartphone camera using computer vision?"

"You mean like Tesla auto-pilot?"

Computer vision in general, and especially phone-based computer vision had come a long way since we first explored velocity tracking in 2017, and augmented reality continues to improve at an accelerating pace, but we probably weren't prepared for how hard it would be to achieve an accurate technology!

Nevertheless we knew that getting accurate velocity data without a device, all while collecting video footage on your phone could revolutionise and democratise velocity based training.

So we got to work, building and validating our computer vision solution over about 18 months. In September 2021 we released the first teaser of Metric VBT, the worlds first automatic velocity based training computer vision app.

We are well on our way in solving the computer vision problem, with the private beta right around the corner, but there is a secondary problem that Metric aims to solve which is ease of use. Velocity tracking should be both easy to implement and beneficial to the training process, something not all existing technologies deliver on. Over the coming months and years we plan to solve that problem building an affordable and friction free velocity tracking solution.

Learn more about Metric

Metric can be downloaded for iPhone via the App Store and directly from this link.

UPDATE: Since publishing this blog we have released the first internal validation of MetricVBT, check it out here.
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References and resources

  • Jovanović M, Flanagan E. 2014. Researched Applications of Velocity Based Strength Training.
  • Zourdo, M, et al. 2016. Efficacy of daily one-repetition maximum training in well-trained powerlifters and weightlifters: a case series

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Elevate Your Training with Metric VBT

Maximise your workout effectiveness by monitoring key metrics like velocity, power, range of motion and tempo with just your smartphone.

Metric VBT automatically calculates your 1RM from bar speed data, along with bar path tracking, RPE logging and a full workout builder.

Metric is the perfect lifting app to refine your technique and enhance your strength.

Download it on iOS today.

App Store download logo for Metric VBT