New Advanced Functions in kMeter 2.3

The latest version of the kMeter App has now rolled out, including several new features solely based on user request. Fredrik Correa explains:

Summary of new functions:

  • Discard reps before saving
  • Import users
  • Delete users

This release is special since all new features are solely based on user feedback and suggestions. After talking to different users I came across various interesting questions such as:

– “My athlete stopped one rep short of the set so the last rep was spoiled, how can I edit that?”

– “I want to do a unilateral drill but work both sides in one set but during the switch I loose a couple of reps, is there a setting for this?”

– “Our facility has multiple kBoxes and we would like to spread the user data (not the training data) over multiple iOS devices, how can we do this?”

Given that my answers would have normally been either “there’s no such feature” or “this would need to be done manually”, these questions made me realise our app’s limitations and how it could be improved.

Before you continue reading and start pulling your hair. We understand these new features are slightly more complicated than previous ones, so we compiled a .zip file containing instruction and templates for importing users here if you need it.


After completing your set and viewing your summary you can now press ‘EDIT’ and you will get a list over every rep (not the pre-reps) in a list. Here you can select the reps you want to discard and they will be taken out of the summary and your metrics will be re-calculated based on the data without those reps.

So if your athlete stopped one rep too short or lost balance in the 2nd rep you can easily just click that one away and save the data like before.

As for the second question, if you want to do 10 single arm rows on each side, you can set up the app with two pre reps and 22 training reps. You start with your two pre-reps followed by 10 training reps and then you switch over and do two (pre-)reps with the another arm and the following 10 training reps. Before saving you will have to discard those two extra reps in the middle of the set (rep 11 and 12) after you switched arms. Watch video.


If you are using the kBox with a whole athletic department of a bigger team and use multiple kBoxes and iOS units, the user data would have been quite difficult to set up. Not anymore.

Now you can set up a .csv file with all you users and import it from an email, google drive or iCloud. You still have to approve every user but it’s much faster and you can send out the .csv to the other coaches for them to add in their devices. When doing this we also added the function to delete users to clean up your user list. Here is a step-by-step guide how to set up the .csv file (or download our templates) and how to import them. Watch video.


We had our multisystem users in mind when we added the import function but sooner or later deleting users would be required too, so we added that feature in the Set Up > User menu. Just select the users you no longer need to track and press delete. Watch video.

Existing kMeter 2.2 Features

These improvements come on top of the current kMeter features that were already available before today’s release:

  • Real time data of average power, peak concentric and eccentric power.
  • Graphic, numerical and voice feedback.
  • Set limit based on reps, time or power drop-off% for traditional, metabolic or VBT based training.
  • Set summary with power, force, displacement, average and peak speed, relative peak power (W/kg BW), rep time, kcal expenditure and more.
  • Multi user, create different users with DOB, gender, height, weight and switch easily from the front screen.
  • Editable data, change drill, user, VAS score from previously saved data.
  • Landscape mode in device or on TV via AppleTV.
  • Share screen of summery to camera roll.
  • Database with possibility to share all or selected data in a CSV compatible file.
  • Filter data in the database based on user.
  • Research mode (send raw data from a set).
  • Edit exercises (change the order they appear in, insert new exercises or delete existing ones).

For a quick demo of the new features check the full video below.


Wrapping Up

Thank you for your feedback, keep it coming! Now, go download version 2.3 of the kMeter now on iTunes.

Happy DOMS!

/Fredrik Correa, Co-Founder


Exxentric Ups Its Product Development Game

Earlier this year Exxentric started a search for a product development engineer. The response from a broad range of highly competent candidates was overwhelming and an intense interview period followed. Now, a couple of months later it’s time for Erik Lindberg to present a new team member.

Exxentric may be known as a flywheel training company, but in our vision for the future we think much more freely than that. In order to extend our technological lead we will continue to work closely with external consultants, subcontractors and trusted suppliers in order to leverage cutting-edge expertise wherever it can be found.

In order to further improve our product development process, we will now also add a new engineer to our own technical staff. Salli Carlfjord, who is a highly qualified engineer with a degree in Mechanical Engineering and Exercise Physiology from the University of Halmstad, will co-ordinate all activities in this area.

Salli is also a competitive athlete with no less than five wins of the Swedish Waterpolo Championship under her belt. Last week-end, she also won the Engadin swim-run competition in Switzerland (see picture).

In her role as Product Development Engineer, she will report to Fredrik Correa, Head of R&D.

We all welcome Salli to the #exxentricfam!

Erik Lindberg/Erik Lindberg, CEO

Introducing kMeter 2.1 at the CSCCa National Conference

On site today at the National Conference of the Collegiate Strength and Conditioning Coaches Association, we are proud to introduce version 2.1 of the free kMeter app, providing reliable exercise feedback for kBox users. The kMeter now includes editable exercise list, research mode and more:

So, what were we able to add in the new version 2.1? If you are in Orlando this week, just stop by booth 928 at the CSCCa conference for a personal demonstration ? or keep reading:

Edit Exercises

Change name, order of the existing drills or remove or add your own drills. By changing order you can make sure your favorite drills are at the top of the list saving time for you saving data. Create your own drills and no need to write long comments and having to keep track of them.

I think many of you will like this possibility to edit your own exercise list. Let us know if you use it!

Research Mode

By turning this on the share button in the summary turns in to a raw data dump into an Excel-compatible file giving you the rotational data for every 40 ms reading. This is a feature some have asked for, and now you got it.

Minor Fixes

We made a few fixes regarding W/kg in the relative power calculations and file compability when sharing data to Excel.

Existing kMeter 2.0 Features

Before we wrap up, let’s briefly go through the current kMeter features that were already available before today’s release:

  • Real time data of average power, peak concentric and eccentric power.
  • Graphic, numerical and voice feedback.
  • Set limit based on reps, time or power drop-off% for traditional, metabolic or VBT based training.
  • Set summary with power, force, displacement, average and peak speed, relative peak power (W/kg BW), rep time, kcal expenditure and more.
  • Multi user, created different user with birthdate, gender, height, weight and switch easily from the front screen.
  • Editable data, change drill, user, VAS score from previously saved data.
  • Landscape mode in device or on TV via AppleTV.
  • Share screen of summery to photo roll.
  • Database with possibility to share all or selected data in a CSV compatible file.
  • Filter data in the database based on user.

For a run through of the new features, check out the video below.


Wrapping Up

Thank you for your feedback, keep it coming! Now, go download version 2.1 of the kMeter now on iTunes.

Happy DOMS!

/Fredrik Correa, Co-Founder


[Swedish] Kurser i svänghjulsträning med nya kBox4

Nu kan du som tränare få både utbildning och utrustning för svänghjulsträning – från 550 kr per månad.

kBoxSquat with coachCoacher och tränare på fyra kontinenter, från elitidrott till fitness och hälsa har redan börjat använda kBox4, den nya generationens redskap för svänghjulsträning. Men som ett helsvenskt företag är vi inte nöjda förrän träningsformens fördelar fått fullt genomslag även här hemma.

Efter årsskiftet kör vi därför igång de första introduktionskurserna på svenska med kBox4. Datumen är:

  • Fredagen den 27/1 kl. 12–16
  • Lördagen den 25/2 kl. 9–13

Kursavgiften är 990 kr inkl moms, men för deltagare som beställer en kBox efter kursen så drar vi av hela avgiften!

kBox4 Lite with FlywheelKostnaden för instegsmodellen kBox4 Lite är ca 18.800 kr plus moms. Numer har vi dessutom tagit fram ett helt nytt leasingerbjudande för företagare, från ca 550 kr/månad vid ett 36-månadersavtal med 5% restvärde.

Om du har några frågor eller vill se en komplett prislista så kontakta oss gärna, eller gå till bokningsformuläret för att reservera din plats direkt.

Henrik Petré

Vi ser fram emot att höra av dig!

/Henrik Petré, Head of Education

Now Shipping: The kBox4 – with a New Accessory

Today, we celebrate the great reception of the new kBox4 by presenting a new bag for your flywheels, making any kBox even more portable.

The initial kBox4 batch has been delivered to the first pre-order customers over four continents, and now the second, larger batch is just about to start shipping. Our website is now updated with some nice new photographs of the kBox4.

Meanwhile, excellent feedback (such as the post pictured to the right) has started coming in from users of the new kBox generation, which makes us really happy. Thank you so much!

New Flywheel Bag

Flywheel BagFor all of you as well as for users of all previous kBox models, we now have the pleasure of presenting a brand new accessory: the Flywheel Bag.

Aimed at further improving the portability of the kBox, the Flywheel Bag provides a convenient way to carry your Flywheels and other accessories between clients or training sites, leaving both your hands for carrying the kBox platform itself, weighing only from 11 kg.

The Flywheel Bag is compatible with Exxentric Flywheels in all sizes and for all kBox versions, and it is now available at EUR 50 plus shipping and local tax.

Learn More

Read more about the kBox4 and all new accessories on our updated equipment pages. To get a full price list (starting at EUR 2,190 / USD 2,570) or discuss a kBox4 order for your facility, contact us or reach out to your reseller today.

Revealing the Fourth kBox Generation

As of today, we have started accepting orders for the fourth kBox generation, consisting of the larger, smoother and smarter kBox4 Pro and the compact game changer kBox4 Lite. Here, CEO Erik Lindberg shares the full story and presents a pre-order offering:

kBox4 prototypesSince we launched the kBox3 in December 2014, we have had the pleasure of welcoming many new customers on six continents active in sports, physiotherapy and fitness. The feedback we have received has been overwhelmingly encouraging and creative.

With the suggestions and ideas shared by all of you, we have spent considerable time and energy developing the next generation flywheel training devices. Today, we are excited to share some details of the new models and their features, as we gear up for shipping of the new series.


The appearance of the new generation may be familiar, as you can see from the final prototype version pictured here. However, the kBox4 series has gone through a major overhaul, and for the first time it now features two different models.

The new kBox4 Pro is without doubt the best flywheel training device we have produced to date, catering to the growing demand from professional teams and athletes, successful physiotherapy clinics and top range fitness facilities. At the same time, we now launch the kBox4 Lite, designed to offer an entry level system for teams, clinics, gym owners, personal trainers and private users, opening up the benefits of flywheel training for completely new user segments. Several new product features that we have worked on for a long time will be included in the kBox4 generation, as well as new and redesigned accessories.

On top of all this, we have reviewed the pricing of the whole product line, making our total offering even more attractive. Furthermore, pre-orders placed now will be offered at a discount, with the first kBox4 Pro deliveries estimated for late October and the kBox4 Lite in late November.

The new models

kBox4 Flywheel auto-lock mechanismAmong the many important improvements of the new series is a reduction of rotational friction by over 50% which will facilitate even more pronounced and precise eccentric overload.

Both models feature a brand new quick-lock flywheel system for fast and convenient inertia changes. The new kBoxes are also stackable, making it possible to place several kBoxes on top of each other when stowed away. Another feature shared by both new models is a flat top surface without visible bolts or holes.

In addition, the different models also have unique qualities:

The kBox4 Pro

  • kBox4 Pro prototype…is 22% larger than the kBox3, with a top surface of 55x90cm instead of 45x90cm.
  • …is actually lighter than the kBox3 despite the size increase, at less than 14,5 kg (chassis only, without flywheels).
  • …can be equipped with up to four flywheels including a new 0.070 kgm2 wheel, allowing for a massive total inertia range from 0.010 up to 0.280 kgm2, or 40% more than the kBox3.
  • …has an auto-rewind mechanism for drive belt length adjustment, similar to the kBox3.
  • …can be equipped with re-designed Foot Blocks, offering more convenience and quicker handling.

The kBox4 Lite

  • kBox4 Lite prototype…is more than 25% lighter and also smaller than it’s big brother. Top surface is 45×70 and also slightly lower, making it very compact and easy to stow away.
  • …weighs in at only 10,7 kg, making it the perfect flywheel device for traveling coaches and athletes.
  • …can be equipped with up to two flywheels, for a total inertia range of 0.010 up to 0.100 kgm2.
  • …has a manual system for drive belt length adjustment and easier maintenance and belt change.

The Accessories

HarnessWe also have some important news to share on the accessories:

  • The Harness has been re-designed and now comes in a black fabric, with padded shoulders and a loop in the back of the waist belt. The Harnesses are now also offered in discounted 3-packs (S, M and L) and 5-packs (XS, S, M, L and XL), inviting more customers to acquire the full size range to ensure a perfect fit, regardless of the users’ size.
  • A new model of kGrips will be introduced and sold in pairs.
  • Ankle CuffWe are now also introducing Ankle Cuffs for the first time, also sold in pairs, facilitating exercises such as the kBox Hip Extension.


With the new functional and technical improvements mentioned, we have still managed not to increase the price of the kBox4 Pro as compared to the previous generation. Due to the strengthened dollar, we have also been able to decrease the previously higher USD prices.

A kBox4 Pro starter system and basic accessories costs from EUR 2,920 (USD 3,420) plus shipping and taxes. The kBox4 Lite on the other hand will cost almost 25% less than the Pro model, opening up flywheel training to completely new categories of users. A starter system with the kBox4 Lite and basic accessories costs EUR 2,190 (USD 2,570) plus shipping and taxes.

Prices of the Flywheels and the Harnesses have also been adjusted downwards, making it more affordable for customers to acquire a complete set of accessories with every kBox.

While our customers have grown used to industry-leading delivery times within days from order, we know that there will be lead times during production ramp-up and we need to ask for a bit of extra patience. However, in return we are offering a 10% pre-order discount for customers paying for their orders before October 10th.

If you need your new kBox system soon, please note that shipping will be prioritized based on the payment date for each order.

Wrapping up

We are really excited about this next phase in the development of global flywheel training, and we look forward to welcoming you to the #Exxentricfam.

To get the full price list or discuss a kBox4 investment for your facility, contact us or reach out to your reseller today.

Erik Lindberg/Erik Lindberg, CEO

Should Personal Trainers Use the kBox with Clients?

What would happen if we let four untrained individuals, with completely different age, gender and training background work with a personal trainer with a kBox and body weight as their main loading alternatives for six weeks? To find out, we just launched the new project #kBoxPT16. Exxentric’s Henrik Petré explains:

kBoxPT16 collageA common misconception about flywheel training is that it is adapted for training of well trained performance athletes or in rehabilitation after injury.

This is despite the fact that the majority of studies in the field of flywheel resistance training are conducted on untrained, healthy individuals. These studies have shown very good improvements in both hypertrophy, maximum strength and power for this target group.

The biggest benefits of flywheel training with kBox are the variable resistance in the concentric phase of the movement and that it allows for eccentric training in a safe and efficient manner. The fact that eccentric training breaks down the musculature more than concentric or isometric training suggests that flywheel training is very powerful and time-efficient.

On top of that, the kBox only weighs 14 kg plus the flywheel and is almost totally silent. With this in mind, you will quickly understand the great benefits for health and fitness. Whether you want high quality and safe training at home or group train together with an educated personal trainer at the gym, the kBox is a great loading alternative.

To put flywheel training with the kBox to test with both older and younger adults regardless of their physical state and working with a personal trainer, we have just started #kBoxPT16.

For a period of six weeks, personal trainer Niklas Westblad, B.Sc., will work with four clients of varying age, gender and physical status, training with kBox two times a week. The clients’ strength and balance will be tested before and after the training period using the kMeter and more, to measure the effect of the intervention.

The selected participants represent a convenience sample in which none of the participants have used flywheel training before:

  • Christer, a 71 year old real estate appraiser with no background in sports. Despite his age he is still working, four days a week. Christer’s goal is to start training regulary, become more mobile and stronger in his legs.
  • Mimmi, a 51 year old physiotherapist with a great passion for running. Mimmi´s goal with this training period is to become stronger in the legs to benefit her running. Mimmi currently has a frozen shoulder which limits her much in her selection of exercises in traditional gravity based training.
  • Louise, a 37 year old mother who loves to play golf in her spare time. She works as a project manager for a large construction company in Stockholm. Louise’s goal with this training period is to be generally stronger in the whole body but especially the legs as she has a skiing holiday planned with her family and wants to be strong enough to have a great time in the slopes.
  • Oskar, a 27 year old guy with a great passion for sports. He played soccer in younger years but since then he has been relatively inactive. He currently works as a sommelier and his goal for this training period is to “kickstart” his training.

You can follow the project through the hashtag #kBoxPT16 on Instagram. We look forward to following the progress of Niklas’ clients and wish them the best of luck!

/Henrik Petré, Head of Education


Launching Exxentric USA

Andreas Ahlström

Following a period of rapid growth, Exxentric has formed a new business division for the American market. As of today, the former independent reseller Flywheel USA will become an integral part of Exxentric under the name Exxentric USA. The CEO and founder of Flywheel USA, Andreas Ahlström, will be promoted to Senior Vice President of Exxentric. As such, he will oversee and supervise all Exxentric business in the United States, based in Portland, Oregon.

We have been extremely pleased with Andreas’ relentless customer focus and his deep experience and understanding of training methodology and technology. We very much look forward to working closely together to secure the ongoing success of Exxentric in the United States.

For more information and contact details, see our new page for Exxentric USA.

/Erik Lindberg, CEO Exxentric

An Expansive Year for Flywheel Training

2014 saw inceasing numbers of professionals using flywheel training around the world and growing scientific support for flywheel methods.

For Exxentric, it has been a successful and eventful year, with more new customers around the world than ever and a successful launch of the kBox 3. Here is a recap of our year and an outlook at 2015, by our co-founder M.D. Fredrik Correa.

Exxentric Summit 20142014 was an intense year. Among our best experiences was starting a new tradition with the Exxentric Summit in Stockholm in May with participants from all over Europe. Our distinguished guests made it a very fruitful couple of days. We made many new friends and got new ideas for coming products and improvements. Afterwards we got a lot of positive feedback and, yes, we aim to make this a recurring event.

We also moved into the US market with a new local distributor as well as a reseller. It feels great to now be able to serve all the US athletes, coaches and institutions interested in flywheel training. In a short time our skilled partners have spread the concept of flywheel training widely in the US and connected with lots of great people in our field. The step to enter the US has also made a big impact as several articles about flywheel training on the kBox have been written by some of the very best strength and conditioning coaches, Chris Korfist and Carl Valle. We were even asked to write an article presenting our story and our concept of training in one of the most influential blogs for track and field coaching.

kBox 3As you might have noticed, at the beginning of December we launched the highly anticipated kBox 3 and started shipping it, initially to partners and key users. We are thrilled that so many of you have appreciated the improvements that we have been working hard with during this year. We believe that the new kBox 3 has set the standard for closed chain, multi-exercise flywheel devices with its increased versatility and ease of use.

During the first weeks after launch, your demand for the kBox 3 even outstripped our production pace. From January 2015 we will be going at full capacity at our new production facility in southern Sweden in order to minimise your wait for delivery.

On the scientific side we have seen growing buzz about flywheel training and eccentric training during 2014. We were overwhelmed by your interest in the article we shared showing the huge increase in start speed for swimmers who made flywheel lunges first (the Post-Activation Protocol). Articles and pods covering the topic of eccentric training are also coming at a steadily increasing pace, and we have started to share the best of them with you on social media (including our Facebook and Twitter profiles). Also, we’ve been really proud about all of you kBox users who are sharing images and stories about your flywheel training. We try to share and pass on as much as possible. If you tag your posts with our name we’re sure to find it (or use hashtags such as #kBox3, #flywheeltraining or #exxentric). Our prediction is that you will read a lot more about flywheel training in 2015, as researchers, coaches, athletes and personal trainers realise its potential when you want to get effective eccentric training in a safe way.

App under developmentAs we look forward to 2015, we have many things to get excited about. For example, in the not too distant future we will present you with an app-based and wireless feed-back system for the kBox! I can’t tell you much more about it but it is being tested right now in real training situations and will be launched in 2015. To the right you can see a preview of an early version of the app. The solution will be backwards compatible, so all earlier kBoxes with a SmartCoach sensor will be compatible with this new app solution. SmartCoach continues to be the tool for the professional coaches among you, while the app is developed to enchance the experience for those of you training on the kBox yourselves.

Also, as some of you already have seen, we’ve started to rework our web site, and there’s more to come. On the product side you have given us lots of ideas for development, and our ambition is serious. I can’t go into specifics but we can tell you that our R&D department has got a heavily increased budget for 2015 thanks to your increased interest in the kBox. This increase is aiming at presenting new products as well as accessories during 2015, so stay tuned!

Wishing you all a Happy New Year!

/Fredrik Correa, M.D., co-founder

Now shipping the kBox 3

Today, we have proudly started shipping the kBox 3, the newest version of our versatile flywheel training device. Here, founder Fredrik Correa explains how the new kBox 3 will improve the experience for our users, based on his background as a professional coach.

Exxentric kBox 3With the kBox 3 we wanted to improve the user experience by making it even smoother to shift between exercises and users. It was already one of the most, if not the most, versatile multi-exercise devices on the market but that was something we wanted to improve even more.

A new automatic strap adjustment mechanism means that the tower is gone and replaced by a small lever the you can press with your foot. When pressed you can either pull out the strap or let it go and it will then be retracted. When the length is adjusted you just let the lever go and you can start working out. You still have the superior strap length compared to other devices and only need the extension strap for overhead exercises.

With the new strap adjustment feature you can shift from leg to upper body exercises in a second creating completely new routines with super-sets, circuit training and other High Intensity Training routines.

In addition, this change reduces the height of the kBox when packed for travel by 26%, resulting in a beneficial improvement of flexibility for coaches and athletes who take advantage of the unique portability of the flywheel training device.

A second big improvement is that the surface area is increased by 12.5%, without being larger in the base. In addition to the removal of the former strap adjustment tower, this change results in even more versatility and flexibility in the training. You can move around, go deeper in the squat or sit on the kBox without interfering with the tower. This will be very welcome not only to our taller users but to anyone that want to use the multi-exercise functionality with the kBox.

The third important change involves the re-designed foot supports to facilitate single legs squats and to give heel support for two-leg squats and patella and achilles tendinosis. These are so new that we haven’t even had time to make proper photos of them to show you yet.

We hope to set a new standard with the kBox 3 when it comes to flywheel multi-exercise devices. Going forward, we believe that coaches and users won’t accept a limited depth or range of motion in the exercises or that you have to bend down to pick up a rope or turn a knob to adjust length.

Today, we start shipping the first kBox 3 directly from our new and larger production facility, to meet the increasing demand in both quality and quantity.

Fredrik CorreaOur research and development section is never at rest, and we are eager to hear your thoughts on the design and functionality. Your feedback is what brought us here and we hope that you will help us to continue to improve. So if you have any thoughts, please contact us, or share them with us on Facebook or Twitter. Thanks in advance!

Eager clients have already pre-ordered the first week of production. If you are interested to get your hands (or feet) on the kBox 3, contact us or your local reseller today to request a demonstration or a trial. We are looking forward to hearing from you.

Happy DOMS,

Fredrik Correa, M.D.