Review: Beast Sensor – take the guesswork out of your lifting

Beast Sensor




Ease of use


Use of information





  • Gives your training a scientific dimension
  • Discreet form factor
  • Information is very detailed
  • Allows you to understand optimal weight and number of reps
  • Does not slow down your workout


  • You need to educate yourself on the concept of velocity based training
  • You may find yourself overwhelmed with the amount of data provided
  • There is a learning curve involved on how to interpret the data


While there are plenty of activity trackers to choose from if you are interested in tracking steps, distance and calories, there are only a handful that have been designed for weightlifters.

Beast Sensor is one of them. Being magnetic, the device attaches a number of different ways and shows you in real time how much you are pushing, rep by rep, whether you are lifting weights, using a machine or performing bodyweight exercises.

Essential reading: Boost your gym session with these devices

You can chose to visualize speed, power or strength and monitor your performance live while working out. Use the time while resting between each set to understand how to make your training more effective. For example the information in the Beast app will allow you to determine the optimal weight to lift and the number of reps to perform to reach your training goal faster.

The innovative wearable comes from an Italian based company. The team is made of aerospace engineers, strength and conditioning coaches and sport enthusiasts who are passionate about technology and its applications to sport and fitness. They ran an Indiegogo campaign back in 2014 to fund product development and have been going from strength to strength since.

I’ve been testing the Beast Sensor for a couple of weeks now. Read on for my in-depth review.

Ease of use
Use of information


The Beast Sensor is a small little yellow rectangle that measures 20x19x40 millimeters and weighs only 38 grams. It comes in a smart box containing a wrist strap, micro-USB charging cable and instruction booklet.

The sensor is designed to magnetically slap on to barbells, dumbbells and kettle bells, and you can also attach it directly to gym machines.

The other alternative is to slot it into the wrist strap. The magnet and velcro will keep it in place. It does feel a little awkward having this small square device strapped to your wrist, but it in no way inhibits you from performing your exercises.

What I really liked about it is the fact that it is discreet. I’ve worked out in the gym multiple times now with the sensor, but because of its small form-factor, no-one has commented or even noticed that I am using the wearable.

Finally, you also have the option of purchasing the Beast Vest, which will allow you to attach the sensor directly to your body for tracking bodyweight exercises such as pull ups or push ups. The vest has multiple attachment points for the Beast Sensor to allow perfect positioning and measurement precision. I actually found out that just popping the device into your pocket is sufficient enough for tracking certain body weight exercises, so the vest is an option to consider, but by no means a necessity.

If you were to open up the sensor, you would find three accelerometers, gyroscopes and compasses. They do the clever work of capturing your motion in 3d space and translating this into data, which is then transferred via Bluetooth to your smartphone for analysis. The patented algorithm is specifically designed to calculate force, speed, power and explosiveness of every exercise in realtime and to automatically count every repetition you make.

The Li-ion fast charge battery lasts about 8 hours. Which means, with normal use (3-4 visits to the gym per week), you only need to recharge it about once every 7-10 days.

Ease of use

Setup is easy. Charge your Beast Sensor via the micro USB cable. To correctly charge the sensor without damaging it, make sure the device is powered on. Download the app from the app store or Google play, install it on your smartphone, and set up an account by answering a few basic questions. The bluetooth pairing of the sensor is done inside the Beast app. The app will indicate when a successful connection has been made.

Before delving into the detail, I should explain a bit about velocity based training (VBT). This type of training can be a key component in taking the guesswork out of exercising once you get your head around the basics.

Review: Beast Sensor – take the guesswork out of your liftingThe term has been around for some time now and actually dates back to the Soviet era. Researchers at the time were trying to understand the optimal weight to be used for a variety of training exercises of shot putters and Olympic weightlifters. They concluded that the velocity (or the speed) of the lift can be used to determine the best weight-load for optimal training.

This means, instead of simply using the percentage of your best lift (which is what is typically done), the weight-load is determined by the speed of the lift on a particular day for each exercise. After all, some days you may be on top of your game, other days you may not be sufficiently recovered to perform at your best.

Professional strength coaches have been using VBT for years. Why? Because it’s a form of auto-regulation. Instead of sticking to a prescribed rep and set scheme you adjust loads, reps, and sets on a daily basis.

In a nutshell, velocity output helps dictate how much load you should be adding or removing on a particular set. The information on the speed of your lifts tells you if the load is too heavy and needs to be changed. The weight is then adjusted as the training goes on to stay within the desired range, developing the traits you want to see improved.

Review: Beast Sensor – take the guesswork out of your lifting

There are a number of different zones you can focus on. The slower the velocity achieved against a given (absolute) load, the greater the intensity. For example, for maximum strength, your velocity, expressed as metres per second (m/s) is going to be very low, hence the weight-load is going to be high. To develop speed, you are looking at a much higher m/s and lower weight.

In a way, this type of training is similar to heart rate zone training for runners. Each zone reaps specific physiological benefits.

With the science lesson out of the way, we can continue on.

To begin with, the app gives you a simple choice: start training in freestyle, or do a planned workout. Planned workouts are pulled together via the web portal. They are essentially a pre-planned set of exercises.

If you cannot find an exercise you are interested in, the web portal will allow you to design your own. As long as there is a place to stick the magnetic sensor, the workout can be tracked. Which means, you can use the device to track pretty much anything that involves some sort of lifting or body movement.

However, you can only apply VBT to this exercise if there are optimal conditions to measure vertical speed of each lift: it must be performed with Barbell, Dumbbell, kettlebell or bodyweight; each rep must consist in a single movement and not a compound movement.

Once you decide on the exercise, you then need to choose the type of workout for that exercise. This goes back to our VBT lesson. There are five options to choose from:

  • Performance tracking: this training mode displays metrics, stats and tracks the progress of your workout. This workout mode is suitable for all exercises.

The next four modes are applicable only for VBT suitable exercises. VBT will be applied to let you know if you are using the correct weight. In order to make VBT method effective, remember to always push as hard as you can through each set.

  • Hypertrophy: Use to bulk up muscles, gain strength and size with functional hypertrophy. The suggested speed range for this objective is between 0.4 and 1 m/s, and the reps performed should be between 5 and 15.
  • Max strength: To increase the maximum force muscles can produce in a single voluntary effort. The suggested speed range for this is between 0.1 and 0.5 m/s, and the reps performed should be less than 5.
  • Power: This mode will determine the best conditions for strength and speed in order to maximise your Peak Power production. The suggested speed range for this is between 0.7 and 1.4 m/s, and the reps performed should be between 3 and 8.
  • Velocity: Use this mode to increase the maximum speed of your movements. The suggested speed range for this is higher than 1.3 m/s, and the reps performed should be between 3 and 8.

If all this sounds complicated, don’t worry. You can always opt for the performance tracking option which will simply monitor your workout, count the reps – and is a way to train for those who want to set a base line or free train with no specific guidelines. It does take a bit of time to understand the concept of VBT, but it is definitely worth the effort if you want to train smarter.

The countdown timer will then begin, giving you time get in position to perform your exercise. Once the lift is complete you can tap on the grey pencil in the app to get more data. This is a great feature that allows you to drill down for more detailed information. For full analysis, as well as historical data, open up your workouts in the web portal. The smartphone option also gives you the chance to delete any ghost reps (reps which the sensor sometimes adds at the end of the exercise).

All in all, the process is very seamless. I did not encounter any connection problems, the app tracked the reps with no hassle and provided the data in real-time. I did encounter the occasional ‘ghost’ rep at the end of some sets – but its a simple matter of highlighting the rep – and clicking on delete.

Use of information

There are three important variables that are essential for muscle growth. They are: volume, intensity and density. The right combination of these three variables will increase the efficiency of your training thus ensuring optimal muscle growth:

  • Volume is basically the amount of work done. It is usually calculated by multiplying reps, sets and weight; Beast will do the entire math for you, so you’ll have just to concentrate on doing the work in the gym. The web portal shows you how your volume evolves during time. The value is also displayed on your smartphone app at the end of your workout session.
  • Intensity, in training terms, is defined as how heavy is the load with respect to your 1 repetition maximum (1RM). Beast finds your 1RM based on the force expressed on the best repetition ever performed till that day. Intensity is then calculated based on the weight you loaded on the bar. For good hypertrophic work intensity should range between 70%-85% of your 1RM.
  • Density refers to the time to complete a workout, normally you would need to train with a stop watch, but Beast will automatically keep the time from the first rep and display the value as kilograms or pounds lifted for minute (kg/m or lbs/m). The higher this value the better for hypertrophy, by decreasing your rest time you’ll increase density, incomplete recovery will cause faster muscle growth.

You should use Beast to monitor these variables and make the appropriate changes when necessary. If you increase your 1RM, increase the weight trying to keep intensity over 70%. Try to increase both density and volume, increase density by shortening rest time, increase volume by adding more weight or increasing the number of reps. Adapt your training gradually by changing only one variable at a time to see what works better.

The full set of metrics tracked by beast can be seen below.

Review: Beast Sensor – take the guesswork out of your lifting

Much of the data is shown in real time. After each exercise is performed, Beast tells you how much you´ve worked to improve your strength, power, velocity, resistance and explosiveness. As mentioned, the data is also saved in the cloud and is accessible through a personal dashboard, where workouts are visualized on a feed. The dashboard allows to review the workouts, view progress, etc.

It is very interesting and motivating to be able to see details for each rep as and when you are doing it, including information on how the bar travels and finding out how fatigued you are. A good time to review the data is between your exercises. The data is very detailed so for a proper look, set some time after you complete you workout to read through all the statistics. I suggest using the web portal which will provide you with much more detailed info.

Review: Beast Sensor – take the guesswork out of your lifting

It is worth noting, for this review we used the newly released Beast 2.0 version of the smartphone app. The app is still in development and certain features such as 1RM, data about rate of Force Development, like starting strength, index of explosive strength, maximum rate of force development, and explosive Strength Deficit are disabled and are set to be reintroduced in the coming months. The company says, the reintroduction of these data points over the next couple months will include dedicated widget to make the information more accessible, effective and understandable.


The Beast sensor will add extra motivation to your strength workouts as it motivates you to constantly set new goals. And by setting goals and moving the bar, you can also constantly challenge yourself and improve your personal bests.

It takes a bit of time to understand the basics and set everything up. But after that, you can move from one rep to the next without losing any time. In fact, I found that the app actually speeded up my workouts, by counting down 1 minute of rest time between reps.

Also there is a hidden value, a motivating aspect of seeing each individual rep quantified. You essentially feel like there is a coach standing next to you, costing your reps and letting you know how well you are working out. All in real-time.

Or how about challenging a a gym buddy to a bit of friendly competition: Who’s stronger? Who’s more explosive?


The verdict

The idea behind the Beast Sensor is a wearable that can help you optimize your training cycle. The technology is not very intuitive at first, and there is a learning curve involved if you are not familiar with the concept of VBT.

The sensor essentially provides an objective metric to evaluate the effectiveness of an exercise. VBT can optimise your training to target specific qualities that you wish to see developed, whether this is more strength, speed or explosiveness. It can also lead to less injury due to overtraining.

Sleeping, hydration and psychological state change from day to day, and this can greatly influence your performance on any given day. Maybe you are training at 50% of your 1 RM but you feel weak. Using the Sensor you might realise that you are not producing enough power and bar speed to hit your training goals. Or you may be having a good week, you are training in the 60% of your 1 RM, you can see that you are moving the bar faster than the training zone, bump up the weight to around 70%.

It’s a form of auto-regulation. Instead of sticking to a prescribed rep and set plan, you adjust your workout on a daily basis.

Furthermore every training session is recorded on the web portal so that you don’t need to log exercise, repetitions, sets or any other information by yourself.

In a sense, you might find you are a bit overwhelmed by the amount of data provided. But in order to get the most out of the Beast Sensor, you should take some time to review and understand the data so that you can make adjustments to your workouts.

Review: Beast Sensor – take the guesswork out of your lifting
Beast Sensor
Review: Beast Sensor – take the guesswork out of your lifting

This is a tool that trainers and coaches could easily use to track their clients’ progress and make training routines more efficient. I can also see how this could be a very powerful tool for those who frequent the gym regularly.

You will find out more about the quality of your workouts and not just the weight you lifted. The sensor will take the guesswork out of your lifting and give your training a new – scientific – dimension.

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Marko Maslakovic

Marko founded Gadgets & Wearables in 2014, having worked for more than 15 years in the City of London’s financial district. Since then, he has led the company’s charge to become a leading information source on health and fitness gadgets and wearables.

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