For more than 20 years, GymAware has been the Gold Standard in the world of velocity based training (VBT). In this article we list how the GymAware RS works and why it’s unique. We also share how valid and reliable this VBT device is, according to independent scientific validation studies. Spoiler: it is so accurate that scientists use it to validate other VBT sensors.

By Loek Vossen

An inaccurate (not valid) and unreliable VBT device is useless at best and dangerous at worst. While you think you’re making informed decisions, those decisions are actually based on wrong data. 

Although the importance of accuracy and reliability may sound like a no brainer, not all VBT devices meet these criteria. 

Here’s what could happen: you set a velocity stop target of 0.75 m/s and your athlete reaches this velocity after 10 reps. However, if you would be using a scientifically validated VBT device like GymAware RS, then the system would have detected that your athlete actually already failed to reach the velocity target at rep 6.

Now imagine this would happen every set and every workout.

VBT is about accurately dosing load, preventing fatigue and injury, tracking progress. All these benefits fade when using inaccurate and unreliable technology. In fact, you would probably be better off with traditional percentage based training instead of velocity based training.

If your VBT device is not valid (not accurate) and not reliable, it is useless at best and dangerous at worst. Blue line: example of reps and their velocity. Red dots: example of invalid, unreliable measurements.

If your VBT device is not valid nor reliable, you probably notice this sooner or later. Your athletes will notice it too. Soon they start second guessing the system and training methodology that you implemented. They lose motivation and you lose trust. Accurate technology does exactly the opposite.

What might be more challenging to notice is a reliable VBT device that is not valid. It shows wrong data, but because it does so consistently, it’s less obvious.

An invalid (not accurate) VBT device that is reliable, is consistently wrong. This is less easy to notice, but equally useless. Blue line: example of reps and their velocity. Orange dots: example of invalid but reliable measurements.

You might think this is not a huge problem and indeed – contrary to our previous example of an invalid and unreliable device – this device does allow you to detect things like progress.

However, all the knowledge gained from scientific research or colleague coaches is not applicable to your VBT device. You can’t apply the widely known velocity training zones, velocity stops or 1RM prediction tests.

Even worse: presumed that you don’t know that your device is consistently wrong, you are most likely consistently overtraining or undertraining your athletes.

This should emphasize the importance of accuracy and reliability. The best way to learn whether a VBT device meets these criteria is to read an independent scientific validation study. Before we share these validation studies of GymAware, we first dive a bit deeper into how GymAware hardware works, because this direct measurement technology is the foundation of our highly accurate measurements.

Independent scientific validation studies show that GymAware is valid (accurate) and reliable.

GymAware RS works like a stopwatch and measuring tape: it measures time and distance. Together, these two measurements determine velocity.

The VBT device contains a spool and a tether. The tether works like a ruler/measuring tape, which you attach to the barbell or free weight.

In more technical terms, the encoder of the GymAware RS is a so-called Linear Position Transducer (LPT). The GymAware LPT is a linear optical encoder.

It’s a unique LPT though, because unlike many other LPTs, it considers the angle of the lift. This is possible due to a sensor near the bottom of the tether, where it leaves the spool. Measuring the angle of the lift is super important, because it allows you to only measure vertical displacement, by correcting any horizontal movement. If you don’t do this x-axis correction, you overestimate the movement distance.

Watch our VBT webinar if you want to learn more about how the GymAware RS works and why it’s important to do x-axis corrections.

Strength coach, Dr. Bryan Mann explaining the importance of x-axis correction in his Velocity Based Training webinar.

Good to know: the GymAware RS technology allows for bar path measurements.

Let’s finish with some technical specs:

• The sample rate of the GymAware RS is 100Hz.
• The tether is super strong (250lb) and long (12ft, 3.65m).
• The battery capacity is for months on a single charge, and user replaceable.
• The housing is super robust, thick-walled, shock absorbing and includes integrated magnets to mount it on the floor or overhead rack.
• The tether contains a magnetic clip for super fast attachment.

Technical specifications GymAware RS

Got a specific product question that we did not answer? Let us know!

In 2010 the Australian Institute of Sports (AIS) compared three GymAware LPTs to a robotic calibrated rig, which was specifically designed to calibrate LPT sensors. Their pilot study looked at the reliability (consistency) and validity (accuracy) of GymAware. This is what they found:

The reliability of GymAware is scientifically proven to be high, showing little variation between sets or sensors. In other words: the data is consistent (high repeatability). In fact, another more recent scientific publication called GymAware “the most reliable velocity device”.

Consistent data with only little variation between sets and sensors is one thing, but does it actually measure what it should? Is GymAware valid?

The validity of GymAware is scientifically proven to be high, showing low errors for distance, mean- and peak velocities. In other words: the accuracy of GymAware is high. It measures what it should measure. Again, a more recent scientific publication also called GymAware “the most valid velocity device”.

You can download the full AIS (2010) study here.

Reading all scientific publications about velocity based training devices would take several days if not weeks. Luckily there’s a summary.

In 2021 J. Weakley and his colleagues published a scientific review, using 82 scientific publications, talking about 22 velocity based training devices.

Not interested in reading 82 scientific publications? Here’s a review about those papers, talking about 22 VBT devices.

This is what they said about GymAware:

Of all linear transducer devices, the GymAware PowerTool has been the most investigated, with nine independent validity studies.

(…)

When these devices have been directly compared to each other during free-weight exercises, it appears that the GymAware provides the greatest accuracy. This accuracy may be due to the device’s ability to account for horizontal displacement and variable rate sampling which is distinct to this device.

(…)

During free-weight exercises, the within-device reliability of the GymAware PowerTool has been shown to be of a high standard. During the free-weight back squat, typical errors of 0.03–0.05 m/s across loads of 20–90% of 1RM have been shown.

You can find the full article via this link: The Validity and Reliability of Commercially Available Resistance Training Monitoring Devices: A Systematic Review.

If you do want to read more, then here’s an (incomplete) list of scientific papers talking about GymAware. You can also ask your personal question to our product expert:

Scientists agree on the value of GymAware, but how about coaches and practitioners in the field? Some stats we are proud of:

For more than 20 years GymAware has been trusted by World Champions, Olympians and Pro Athletes — and those who prepare them to win.

At the time of writing, Trustpilot shows a rating of 4.6 stars (out of 5), based on 27 GymAware reviews. This gives GymAware the status of Excellent.

GymAware Trustpilot reviews

The famous Garage Gym Reviews give GymAware a 4.33 star rating (out of 5).

For sure Bryan is one of the most knowledgeable experts when it comes to velocity based training. In fact, he was the first to come up with the name velocity based training.

Bryan uses VBT as a practitioner, researcher and educator. Many have seen his famous VBT webinars. His opinion on GymAware?

Co-founder of Kabuki Strength, Chris Duffin, chose GymAware to provide real-time feedback and use additional metrics for benchmarking. He says:

Sport scientist and Strength & Conditioning coach Mladen is the brains behind Complementary Training. He has been using GymAware since 2012.

Ryan is the head of strength and power at Brumbies – the Australian professional rugby union. In a Q&A session, he shared some unique insights on how he works with GymAware. He mentions:

Theo is the Lead Strength and Conditioning Coach for the Dutch National Rowing Team, where he introduced velocity based training using GymAware.

We were fortunate enough to learn how he uses GymAware.

Now that you know how scientists and coaches in the field think about GymAware, it’s time to experience it yourself! Learn more about the GymAware hardware and software and the GymAware pricing, or ask your questions to our product expert.

We now finish with a (non complete) GymAware literature list.

“It appears that the GymAware provides the greatest accuracy”

• Weakley, J., Morrison, M., García-Ramos, A., Johnston, R., James, L., & Cole, M. H. (2021). The Validity and Reliability of Commercially Available Resistance Training Monitoring Devices: A Systematic Review. Sports medicine (Auckland, N.Z.), 51(3), 443–502.

“It is a reliable tool for tracking changes in jump height to measure performance improvement and monitor fatigue.”

• Wadhi, T., Rauch, J. T., Tamulevicius, N., Andersen, J. C., & De Souza, E. O. (2018). Validity and Reliability of the GymAware Linear Position Transducer for Squat Jump and Counter-Movement Jump Height. Sports (Basel, Switzerland), 6(4), 177.

“Sport professionals should not use Push Band 2 devices when the aim is to accurately monitor velocity variables during HBD exercise because of a low within-unit agreement and a high fixed and proportional bias and RSE compared with GymAware devices, which may compromise the utility of the collected data.”

• Jovanovic, M., & Jukic, I. (2020). Within-Unit Reliability and Between-Units Agreement of the Commercially Available Linear Position Transducer and Barbell-Mounted Inertial Sensor to Measure Movement Velocity. Journal of strength and conditioning research, 10.1519/JSC.0000000000003776. Advance online publication.

“PUSH accuracy for determining MV, PV, MF, MP, and PP across all 6 relative intensities was questionable for the back squat, yet GymAware was highly valid at assessing all criterion variables”

• Banyard, H. G., Nosaka, K., Sato, K., & Haff, G. G. (2017). Validity of Various Methods for Determining Velocity, Force, and Power in the Back Squat. International journal of sports physiology and performance, 12(9), 1170–1176.

“The data provides evidence that the GymAware can be used to measure kinetic and kinematic outputs”

• Dorrell, H. F., Moore, J. M., Smith, M. F., & Gee, T. I. (2019). Validity and reliability of a linear positional transducer across commonly practised resistance training exercises. Journal of sports sciences, 37(1), 67–73.

“GymAware displayed excellent reliability and acceptable variability during the jump shrug and hang high pull while the Push Band showed instances of poor-moderate reliability and unacceptable variability at various loads.”

• Suchomel, T. J., Techmanski, B. S., Kissick, C. R., & Comfort, P. (2023). Reliability, Validity, and Comparison of Barbell Velocity Measurement Devices during the Jump Shrug and Hang High Pull. Journal of functional morphology and kinesiology, 8(1), 35.

“These findings support the use of mean velocity and peak velocity from GymAware for resistance training (RT) monitoring and prescription due to their low magnitudes of error; thus, allowing for the detection of meaningful changes in neuromuscular status and functional performance during RT.”

• Jukic, I., King, A., Sousa, C. A., Prnjak, K., & McGuigan, M. R. (2023). Implementing a velocity-based approach to resistance training: the reproducibility and sensitivity of different velocity monitoring technologies. Scientific reports, 13(1), 7152.

“Overall, GymAware was the most reliable and sensitive device for detecting the smallest changes in RT performance, regardless of the velocity metric used.”

• Jukic, Ivan & King, Andrew & Sousa, Colby & Prnjak, Katarina & McGuigan, Michael. (2022). Velocity-based approach to resistance training: the reproducibility and sensitivity of commercially available velocity monitoring technologies. 10.21203/rs.3.rs-2261925/v1.

“GymAware provides practitioners with reliable kinematic information in the back squat and bench press”

• Orange, S. T., Metcalfe, J. W., Marshall, P., Vince, R. V., Madden, L. A., & Liefeith, A. (2020). Test-Retest Reliability of a Commercial Linear Position Transducer (GymAware PowerTool) to Measure Velocity and Power in the Back Squat and Bench Press. Journal of strength and conditioning research, 34(3), 728–737. https://doi.org/10.1519/JSC.0000000000002715

“The test-retest reliability of velocity and power assessed by the GymAware system was moderate-to-excellent for the deadlift and good-to-excellent for the squat.”

• Grgic, J., Scapec, B., Pedisic, Z., & Mikulic, P. (2020). Test-Retest Reliability of Velocity and Power in the Deadlift and Squat Exercises Assessed by the GymAware PowerTool System. Frontiers in physiology, 11, 561682.

“The Gymaware was the most reliable for both exercises”

“The Gymaware was the most valid device, with small systematic bias and no proportional or fixed bias evident across both exercises”

• Thompson, S. W., Rogerson, D., Dorrell, H. F., Ruddock, A., & Barnes, A. (2020). The Reliability and Validity of Current Technologies for Measuring Barbell Velocity in the Free-Weight Back Squat and Power Clean. Sports (Basel, Switzerland), 8(7), 94.

“All the linear position transducers were able to assess squat performance”

• Lorenzetti, S., Lamparter, T., & Lüthy, F. (2017). Validity and reliability of simple measurement device to assess the velocity of the barbell during squats. BMC research notes, 10(1), 707.

“The GymAware estimates of peak force and peak power were moderately to strongly correlated with the force plate measurements”

• Crewther, B. T., Kilduff, L. P., Cunningham, D. J., Cook, C., Owen, N., & Yang, G. Z. (2011). Validating two systems for estimating force and power. International journal of sports medicine, 32(4), 254–258.

“The optical encoder (GymAware) provided valid measures of kinetics during free weight resistance training movements.”

• Drinkwater, E. J., Galna, B., McKenna, M. J., Hunt, P. H., & Pyne, D. B. (2007). Validation of an optical encoder during free weight resistance movements and analysis of bench press sticking point power during fatigue. Journal of strength and conditioning research, 21(2), 510–517.

“These data indicate that the commercially-available LPT (GymAware) is a valid and reliable measure for kinetic and kinematic variables of interest”

• Askow, A. T., Stone, J. D., Arndts, D. J., King, A. C., Goto, S., Hannon, J. P., Garrison, J. C., Bothwell, J. M., Esposito, P. E., Jagim, A. R., Jones, M. T., Jennings, W., & Oliver, J. M. (2018). Validity and Reliability of a Commercially-Available Velocity and Power Testing Device. Sports (Basel, Switzerland), 6(4), 170.

“GymAware provided the most accurate output across exercises”

“Practitioners who require negligible measurement error in their assessment of movement velocity are advised to use linear position transducers over inertial sensors.”

• Mitter, B., Hölbling, D., Bauer, P., Stöckl, M., Baca, A., & Tschan, H. (2021). Concurrent Validity of Field-Based Diagnostic Technology Monitoring Movement Velocity in Powerlifting Exercises. Journal of strength and conditioning research, 35(8), 2170–2178.