Training with the kBox has a very simple premise. The primary aim is to maximise strength gains through the load acceptance/braking phase of key movement patterns and muscle actions – the eccentric phase. The eccentric phase of a movement requires significantly greater force production, and therefore strength, than a typical comparative concentric action. Eccentric strength is often undertrained, despite being arguably the primary area of need for sports involving deceleration tasks, particularly for injury risk reduction.
Using traditional weight training, the eccentric phase is typically inadequately stressed to elicit optimal strength gains. In contrast, the kBox from Exxentric allows the user to ‘self-select’ the eccentric load in a safe and measurable way by requiring the individual to resist high eccentric force relative to the concentric force they are able to produce. ‘Relative’ is the key word here, and one that gives the kBox an exceptional advantage for specific uses over more traditional methods of strength training for sport with regards to safety, efficiency and efficacy. In basic terms, the highly demanding eccentric force required to resist/’brake’ the flywheel is naturally appropriate for the user due to the self-generated momentum and therefore load applied by the flywheel. This is a unique feature of the kBox and holds great value for use with all populations, from elites to amateurs.
Outside of the more obvious benefits of flywheel training using the kBox we, at Pyramid Performance & Health, value the kBox for a variety of reasons and its versatility for use with individuals of varying ability levels and age ranges.
Physiological strength gains aside, the kBox has proven an invaluable tool for improving muscle coordination and ‘self-organisation’, requiring users to ‘feel’ their way through physically challenging movements and develop self-awareness of posture and body position when under load.
“It has proven a popular and effective piece of kit amongst some of my youth athletes. Some of these athletes, particularly those who are growing quickly, struggle with exercises such as barbell squats, Romanian deadlifts and more due to a lack of proprioception and a tendency to focus more on the bar than their own body position.”
Tom Whitaker, S&C Coach at Pyramid Performance & Health.
For these athletes, the kBox allows them to focus less on the external load and purely focus on their own body position, resulting in better movement mechanics and greater attention on crucial cues for performance improvement.
The kBox is an exceptional tool for use with injured athletes. The ability to self-determine force output means that the athlete can apply as much force as they feel comfortable with and auto-adjust between reps, sets or sessions with little focus on the external exact load. This is especially useful with soft tissue injuries in mind, where appropriate progressive eccentric overload is necessary for rebuilding muscle and tendon tissue tolerance. Additionally, a lack of eccentric control and strength has repeatedly been shown to be a risk factor for serious injuries such as ACL ruptures.
“The eccentric overload from the flywheel allows us to develop strength that not only helps the individual produce more force in a ‘worry-free’ manner, but also directly reduces the risk of reinjury that is often very difficult to replicate with traditional strength training. It can sometimes be hard to introduce higher load strength training as part of an appropriate rehab programme to those inexperienced in the gym, as asking them to control the load to give the necessary stimulus for strength gain is often very unfamiliar/makes them feel uncomfortable. The kBox solves the problem by giving me the ability to simply ask the client to perform exercises at their own comfortable pace with confidence, while I know that they are getting the correct stimulus intended. It keeps things very simple and reduces the intimidating nature of heavy strength training.”
Holly Calver, Sports Therapist and Rehab Specialist at Pyramid Performance & Health.
For clients, the kBox is new, exciting, appears low-risk, and feels positively hard work. Athletes comment on the intensity, physical challenge, and rewarding feeling of pushing themselves on a piece of equipment that feels like nothing else.
“Making use of the kBox ticks so many boxes for me and so many of our athletes at Pyramid. From a performance point of view, I need athletes to build strength efficiently in their key areas of need to support performance goals. Ensuring they feel they can do this safely with confidence is my number one priority, which the kBox allows for without doubt. Achieving this by exposing them to high eccentric load with minimal teaching time needed is ideal, and removes the barrier often run into with heavy barbell work for example. I also find the kBox incredibly effective for improving mobility/range of motion by increasing strength at length in specific muscle groups, for example the hamstrings. We know this is an extremely important for reducing the risk of muscle strains and tears for high-intensity sports.”
Ryan Spencer, Director of Performance & Rehabilitation at Pyramid Performance & Health.
Overall the kBox is a piece of kit that athletes enjoy, allows for highly specific gains in strength, and importantly is efficient in ticking boxes for long term athletic development. The ability to achieve maximal force output through the eccentric phase is arguably the biggest benefit of using flywheel training within an S&C programme, yet we at Pyramid Performance & Health have found the less expected benefits relating to movement competency training and athlete buy-in to be of equal importance.
Pyramid Performance & Health is a performance, fitness and rehabilitation company based in Nottinghamshire. They provide everything needed for optimising human performance under one roof, including:
- Performance Training
- Sports Science Support
- Strength & Conditioning
- Injury Rehabilitation
- Sports Therapy
- Sports Nutrition
For more information check them out at www.pyramidperformancehealth.com and on Instagram/Facebook @pyramidperformancehealth
The inertial load/power relationship -The-effects-of-varying-inertial-loadings-on-power-variables-in-the-flywheel-romanian-deadlift-exercise.pdf (researchgate.net) – O’Brien et al. (2020)
The k-Box effectiveness for injury prevention - IJERPH | Free Full-Text | Eccentric-Overload Production during the Flywheel Squat Exercise in Young Soccer Players: Implications for Injury Prevention (mdpi.com) - Raya-González et al. (2020)
The implications of using the kBox regularly - Chronic effects of flywheel training on physical capacities in soccer players: a systematic review (tandfonline.com) – Allen et al. (2021)