Team photo

Reinventing strength training with Flywheel technology


    Exxentric was founded by Marten Fredriksson and Fredrik Correa in Stockholm in 2011 when the kBox1.0 was launched. After a period of fast growth Exxentric released the third version of its main product the kBox3, it was at this point that flywheel training started to grow and expand globally.

    Perform Better became the UK reseller in 2015. Since then Exxentric has grown it’s reseller network and have now sold devices in 65+ countries worldwide and you see flywheel training being applied in a wide variety of environments: professional sports, rehabilitation and health and fitness. Exxentric is now on the fourth generation of kBox and have added more products to the range.


    The fourth generation of kBox comes in three different models: the Active, Lite and Pro with each model being available in three packages: starter, advanced and advanced plus. In 2019 Exxentric launched two new colours in addition to the standard brown: blue and black.

    In 2018 the kPulley was launched, which uses the same scientifically proven flywheel training benefits to the kBox4. This was updated to the kPulley2 in 2019 and the new portable kPulley Go was released in late 2021.

    The LegExx was launched in 2020 and offers open kinetic chain training ideal for quadriceps strengthening, rehabilitation and increased mobility.

    View Products 

View Products

  • “The kBox system has proven to be an invaluable addition to our training armoury for strength development, rehabilitation and post-game conditioning. Its novel design and versatility lend itself to a schedule comprising high fixture density and foreign travel. A must-have for any high-performance environment..”

    - John Currie, Head of Performance, Celtic FC

  • “Having used kBox at several clubs now, I’d have this kit high on my list of essential equipment for an S&C department. This kit provides coaches with another tool in the toolbox to develop attributes for both fit players and also to create rehab plans for return to play. The versatility of the kBox allows coaches to train athletes at the training facility or on the road.”

    - Andy Johnson, Shrewsbury Town FC

  • “After having used this piece on a consistent basis for several months with my clients, athletes, and myself, I can honestly say that this is one of the most incredible pieces of strength training equipment I’ve ever used.”

    - Dr. Joel Seedman, PhD