Not sure whether you should buy a GymAware RS or GymAware FLEX? Here’s the comparison you’re looking for. We dive into the hardware, software suite, pricing and look at the scientific validation and user reviews. But before we get started: why choose if you can have both? Check out the GymAware RS x FLEX integration pack.

You might also be interested in the GymAware RS product page or GymAware validation page or FLEX product page or FLEX validation page.

The GymAware RS uses a direct measurement technology. It works like a stopwatch and measuring tape, measuring time and distance. Together, these two measurements determine velocity.

The RS contains a spool and a tether. The tether works like a ruler/measuring tape, which you attach to the barbell or free weight. This system is called a Linear Position Transducer (LPT).

Unlike many other LPTs, GymAware RS considers the angle of the lift. This allows you to focus solely on vertical displacement, by correcting any horizontal movement. LPTs that don’t do this x-axis correction underestimate the movement distance.

Take for example a hang clean exercise. Many athletes put the barbell 3 feet (i.e.) behind the LPT device, so they don’t drop the bar on it. This creates a situation similar to the image below, with the LPT on the ground and the tether attached to the bar in the starting position (bar pos. A).

In the end position of your hang clean, the bar is in a new position (bar pos. B). You would like to know the displacement of the bar to calculate the speed (dashed orange line). However, an LPT measures the change in tether length of the tether in position A compared to the length of the tether in position B.

Without x-axis correction, you’re not measuring the displacement of the bar (orange dotted line). Instead, you measure the change in tether length of the tether in position A compared to the length of the tether in position B. This results in highly inaccurate velocity data. GymAware RS uses x-axis correction by considering the (orange) angle of the lift.

This change in tether length is significantly shorter than your bar displacement. As a result, your measurements are way off, getting lower velocity data.

There are two ways to solve this problem. You can make sure your bar goes up in a 100% vertical line and your LPT is placed straight underneath the bar (virtually impossible). The alternative is x-axis correction, by considering the angle of the lift. This is exactly what GymAware RS automatically does.

This makes GymAware RS a unique and incredibly versatile VBT device. Some example exercises you can use it for:

• Barbell exercises
• Pin loaded exercises
• Kettlebell swings
• Chin ups, jumps, dips, leg press, landmine press, nordic hamstring curls…

The FLEX device uses laser optic technology that measures vertical and horizontal bar position relative to the ground. By differentiating this position data you get highly accurate velocity measures.

The FLEX unit is attached at the end of a barbell. The system requires a reflective mat underneath the laser to increase accuracy.

The app for the GymAware RS is built for teams. It is the culmination of more than 20 years of industry experience and it is uniquely designed to meet the needs of coaches and other industry professionals.

You can unlock many advanced features by upgrading through your online portal which is created when you register for the free account.

The GymAware iPad app only runs on iOS (iPad only). For more information about the app, go to our app information page. There you will also find the link to download the app.

GymAware iPad app

The FLEX Stronger app is built for the needs of individual athletes, remote coaches and personal trainers. You can add other lifters into your session for group training with up to three people.

The FLEX Stronger app is available on iOS and Android.

FLEX Stronger app

If you want to take your training and coaching to a next level, GymAware Cloud is here to help. Note that this is optional, not necessary.

Both the GymAware RS and the GymAware FLEX can connect to the (same) GymAware cloud.

The GymAware Cloud opens up a whole new set of opportunities. It allows you to gain full access to powerful reporting functions, training boards, cloud-based leaderboards and online analytics with a secure login via GymAware.com.

With the GymAware Cloud Premium, you can connect seamlessly with Athlete Management Systems to integrate strength training data.

Learn more about the GymAware Cloud solutions via the button:

Integration: hardware, app, cloud.

Accuracy and reliability are crucial in velocity based training. Here’s why inaccurate and unreliable VBT devices are useless at best and dangerous at worst.

There’s an almost never ending list of scientific publications showing the accuracy and reliability of GymAware RS. In fact, it is so accurate that scientists use it to validate other VBT sensors.

But how about the validation of the FLEX unit?

The first independent validation study on FLEX was published in 2020. It concluded that:

“The FLEX provides valid and reliable mean concentric velocity outputs across a range of velocities. Thus, practitioners can confidently implement this device for the monitoring and prescription of resistance training loads.”

Learn more about the GymAware RS validation and the FLEX validation.

The GymAware RS and GymAware FLEX are both designed for Velocity-Based Training (VBT), but they cater to different user profiles and have some key differences.

GymAware RS has been the gold standard in VBT for more than 20 years. It offers the highest level of accuracy, which is crucial when the stakes are high. As a result, the GymAware RS is recommended for professional and elite-level athletes and coaches.

Compared to the FLEX unit, the GymAware RS can be used for a wide range of exercises beyond just barbell movements. Moreover, it does not require removal when changing weights.

GymAware FLEX has undergone independent scientific validation and is considered to be close to the gold standard in terms of accuracy. Additionally, it’s a more budget-friendly option. As a result, the GymAware FLEX is recommended for a wider range of users: individuals, high school athletes, personal trainers, etc. When combined with the GymAware iPad app and GymAware Cloud, it’s a good solution for teams as well.

Compared to GymAware RS, the GymAware FLEX is wireless, but it does rely on proper mat placement to ensure reps are not missed so it comes down to your preference of technology as well.

Still need some support in choosing your most suitable option? Contact our product expert! Ultimately, the key factors that should influence your decision of buying GymAware RS or FLEX are budget, technology preference, exercises you need to measure, type of users and the need for highest accuracy levels.