Velocity based training buyers guide 2022
The most important thing you must consider when choosing your velocity based training (VBT) device…
By now the world knows that I love velocity based training (VBT). GymAware is the scientifically validated Gold Standard in the world of VBT, so they were the only ones I contacted. My team is the best in the country, so of course I wanted the best products. This article is NOT a sales pitch for GymAware. This can be referred to as a Velocity based training buyers guide for 2022. Whether its 2022 or ten years ago, the most important factor I state in this article is 100% unbiased and independent of any brand or organization – drumroll please… it’s “independent scientific validation”! When purchasing VBT devices, there are so many considerations, and companies make it even harder for you to choose. They love to pick up their most attractive feature and sell it aggressively. With scientific validations, you can be sure you’re not being fooled by phoney sales tactics. Also, its hard to decide based on VBT product reviews, because are so many so-called influencers out there…
Over the last 2 ½ years, I have used the GymAware PowerTool (now upgraded to RS) and the GymAware FLEX (FLEX Stronger) with my own training and that of my team. The GymAware FLEX is newer to the market, but the studies out there also give raving reviews towards the FLEX. Here’s the reason why choosing a VBT Tool that is scientifically reviewed is so important. I am coaching some of the best athletes in the world. Right now, I am the Head Coach of Men and Women’s Weightlifting at Lenoir-Rhyne University where we have 20-year-old Ryan Grimsland, arguably the best male weightlifter in America. He has added a whopping 33kg to his total in just the last year making him the most improved athlete in America by far. I will not trust just any random device to measure Ryan or any of my up and coming athletes. They deserve and expect more from me. Not to mention the studies I am a part of right now regarding VBT. I will never trust somebody’s word or great sales tactics. People believe me when I say something works so my I really value my credibility. This VBT buyers guide is not a specific device review… The intent here is to highlight why scientific validation is the most important consideration. It comes above any VBT product reviews, features or fancy technologies that we usually see out there being broadcasted.
Looking up scientific studies to validate the VBT device that you intend on purchasing takes extra time. However, it doesn’t take that long. If you simply Google ‘scientific studies validating Velocity Based Training devices’, you will witness several recent studies pop up on your screen. You will also notice that Linear Position Transducers or LPTs are at the top of all of them. Don’t worry, I have done with leg work for you, and several of them will be cited at the end of this article.
Right now if you search for VBT tools, there are so many options. I will quickly explain each technology before I go over why it’s important to have scientific validation from scientists outside the organization.
Types of VBT Measurement Tools
- Linear Position Transducers
- Camera-based systems
- Laser-based units
Linear Position Transducers:
LPTs are tools that use a tether. It’s the most accurate and the most precise way to read velocity. Velocity is simply distance divided by time, and the tether makes it easy to measure distance like a ruler as well as calculating the time. The problem is that if LPTs aren’t produced properly with well-designed hardware, then LPTs can deliver incorrect data as well. Once again, I recommend checking out the scientific literature produced on each.
Accelerometers are more scientifically explained as Inertial Measurement Units (IMUs), and are actually a combination of accelerometers, gyroscope, and magnetic sensors that provide information regarding acceleration (change in velocity), orientation, and gravitational force. LPT’s use the first principles of velocity to calculate the distance, vector, and time, or more familiar to all of us velocity equals distance divided by time. That’s why they are so accurate. IMU’s are using a reversed acceleration equation to calculate velocity. By that I mean, IMUs capture the acceleration of an object at specific time intervals. Acceleration can vary greatly during longer time intervals, so this is the first potential problem with an IMU. Let’s say that a particular IMU is using a time frame of 5ms. The equation for motion is v=vo+at, or velocity equals the original velocity plus acceleration multiplied by the interval of time. Therefore, the IMU calculates velocity after every 5ms, giving you the current velocity at each time frame. However, what about the original velocity (Vo)? As you know, in the beginning the initial velocity equals zero because the object isn’t moving, so the first velocity reading is (velocity= 0 + acceleration reading at the point time 5m/s). Then another 5ms takes place and the IMU takes its second measurement reading, the Vo will change to the previous velocity calculated and so forth. This means the initial velocity at each given time interval is actually the velocity calculated in the previous interval. A long story short this leads to a degree of error. The longer the duration will create a bigger error as each time frame adds error on top of error. Put simply, these units are using algorithms and equations that are inherently flawed, some more than others, to give as close of a reading as possible. However, there is always a margin of error for the precision and accuracy with some being better than others. Once again, there’s a need for scientific validation (Clemente FM, et al., 2021).
Camera-based / Optical Systems are high speed cameras that once again are capturing images in space and time using algorithms to predict velocities. Like IMUs, there will always be some sort of margin of error with some systems being fairly extensive. These units are also very expensive, but their marketing budgets are still getting some units sold. Some of these systems are mounted to rack and rendered immobile, and some are able to be moved around with durability being a question for the individual brand. Others are simple apps on the user’s mobile phone. Therefore, I recommend considering all the possible uses. For example, will you ever need to take the unit on the road for away games? I would definitely urge any coach or organization to do their research before spending thousands on something that is unreliable or unable to satisfy all the potential needs.
Only one on the market is the FLEX by GymAware (FLEX Stronger). This unit fits on the end of a barbell like a collar using a laser that is reflected on a mat to measure distance with the laser acting the same as a tether. As long as the mat is positioned correctly with nothing between the FLEX device and the mat, these units have worked almost as well as the LPTs. They’re an inexpensive way of bringing VBT to life in your gym or garage. Once again, laser units use the first princi
ple of velocity to calculate readings (velocity=distance/time) with the laser acting as the tether. If you’d like more info on the GymAware FLEX and its features, I recently wrote an article going over common mistakes with FLEX and how to make most of its features, read here.
Most important consideration: Scientific Validation
I believe VBT to be a necessary expense to any organization or individual that wants to maximize athletic development and keep athletes safe. However, there’s an expense to any of these units, so you are going to want them to work. We are also in an era in the high school, collegiate, and professional team weight rooms that mimics the cold war space race. LSU purchased a $1,000,000 weight room, so Texas purchased a $2,000,000 one. The same is happening amongst high schools and professional organizations as a way of recruiting and brand awareness.
I am all for this, but the new equipment needs to do what it says. I have also witnessed the good ‘ole boy system of strength coaches purchasing equipment from a sales rep that happens to be a lifelong friend. I know of one university that spent well over $100,000 on VBT equipment that they now don’t use because the system didn’t work as well, so the strength coach just left the units up on the racks as marketing tools. That breaks my heart. As a coach that loves VBT, that’s the saddest thing I have ever heard.
Another area to consider about each product is the length of time in the industry. Unfortunately, lately there have been a few companies that were fly by night leaving organizations holding expensive units with no support or updates. If you are looking to invest in VBT, I recommend taking a deep dive into the company as you would a potential partner. Technology is constantly changing regarding the hardware of a device as well as the software. If a company has been in business less than a decade, you might take a deeper look at the company and get some references, or look elsewhere to be safe.
No matter however many velocity based training buyers guides or reviews you refer to, nothing beats the authenticity and unbiasedness of independent scientific research. Fortunately, there are a number of scientific research articles out there that validate certain VBT instruments. These are studies performed by scientists outside of the organization of any particular brand with zero conflicting motivations such as money or kick backs. These studies validate some companies, and unfortunately make it quite clear that some instruments aren’t living up to the hype.
These studies look at accuracy, precision, and each individual parameter or feature that coaches can use to improve his or her athletes. For example, there are studies that look at accuracy, repeatability of measurements on multiple reps, and peak velocity compared to mean velocity like this piece of research (Fritschi R, et al., 2021). While other studies look at the different parameters produced by each like power, bar path, and force. These are all amazing tools for improving athlete performance, but those parameters need to work. (Weakley, J, et al., 2021) did a fantastic job with their meta analysis taking a look at all of the research, checking each for validity, and comparing the remaining valid studies. As usual, LPTs appear on top, and the FLEX unit receives positive validation. I use multiple parameters in my own research. I look at individual Reactive Strength Index, power to weight ratio, bar path, and more. However, none of this is useful if it doesn’t work.
Feel free to look over the pieces of research that I have cited below and the research that each of them display. I want each of you to have velocity tools that work. My mission is to provide as many coaches as possible reliable information to create the best possible results for their athletes. I consistently consult with weightlifting coaches that directly compete with my athletes. I love that my athletes win most of the time. However, it’s more important to me that the field of athletic development is positively impacted from the information that I produce. Therefore, go out there and buy the most expensive unit or the cheapest, but make sure that whatever you purchase actually works and provides the data it says that it will. I can say with 100% confidence that the tools I use in my coaching and research do exactly that.
Watch the video presentation on this topic below:
Being a World Champion in powerlifting, Travis competed at a world-class level in Olympic weightlifting and has coached professional Olympic weightlifters alongside Don McCauley and Glenn Pendlay at Team MDUSA. Now Travis coaches the most successful weightlifting team in the USA.
- Clemente FM, Akyildiz Z, Pino-Ortega J, Rico-González M. Validity and Reliability of the Inertial Measurement Unit for Barbell Velocity Assessments: A Systematic Review. Sensors (Basel). 2021 Apr 3;21(7):2511. doi: 10.3390/s21072511. PMID: 33916801; PMCID: PMC8038306. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8038306/
- Weakley, J., Morrison, M., García-Ramos, A. et al. The Validity and Reliability of Commercially Available Resistance Training Monitoring Devices: A Systematic Review.Sports Med 51, 443–502 (2021). https://doi.org/10.1007/s40279-020-01382-w
- Sánchez-Pay, Alejandro & Courel Ibáñez, Javier & Martínez Cava, Alejandro & Conesa-Ros, Elena & Morán-Navarro, Ricardo & Pallarés, Jesús. (2019). Is the high-speed camera-based method a plausible option for bar velocity assessment during resistance training?. Measurement. 137. 10.1016/j.measurement.2019.01.006. https://www.researchgate.net/publication/330295693_Is_the_high-speed_camera-based_method_a_plausible_option_for_bar_velocity_assessment_during_resistance_training
- Wadhi T, Rauch JT, Tamulevicius N, Andersen JC, De Souza EO. Validity and Reliability of the GymAware Linear Position Transducer for Squat Jump and Counter-Movement Jump Height. Sports (Basel). 2018 Dec 19;6(4):177. doi: 10.3390/sports6040177. PMID: 30572577; PMCID: PMC6316460. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6316460/