With its variable resistance and safety, the kBox is a great tool for strength training in youths for both sports performance and health and fitness.

Coaches, PE teachers or personal trainers working with youth have many aspects they must consider like training age, technique, exercise selection, maturity for example. Considering that training often occurs in a group setting, the loading and safety also become important. Thus, flywheel training on the Exxentric kBox fits in perfectly.

Objectives for Youth

When youths perform strength training, it is important that they can perform:

  • basic movement patterns that involve many muscle groups and joints (i.e. push, pull, squat, hinge and so on).
  • movements where the balance factor (i.e. body centre of gravity) is regularly involved, and
  • individually loaded drills since strength, maturity and training age can differ a lot between individuals in the same age group or team.
  • safe training without excessive load on weak spots where the technique used for regular weights demands loads too low for adaption.
  • fast transitions between users and drills to give enough training volume for a larger group with limited resources in space and time when added as an adjunct to regular team sports training.

Flywheel Applications

The applications of flywheel training for youth are to a large extent similar to the general applications for health & fitness.

Beyond the benefits described on those pages, specific applications for youth include:

Sticking Points

The variable resistance of flywheel training makes it superior to free weights or dumbbells and weight stack machines when it comes to solving the problems with sticking points and the individual load.

An example could be an ice hockey team where the range in a team of 14 yr olds can be 40-75 kg, 30 cm of height difference and, as a result of this, there are different loads and settings on the squat rack when doing squats. With the kBox all team members can be cycled through their squat sets with only having to change the range of motion which is done in a few seconds. The loads are taken care of by the variable resistance where the stronger subjects will accelerate more and hence have to decelerate more than their small or weaker teammates. They could all still be working at the same relative % load without making any adjustments. Even if you would have to change inertia between users this is done very fast and any 14 yr old can handle this if they are instructed correctly.

Eccentric Overload

Another superior benefit with the kBox is that the subject can be ”self-supported” to create eccentric overload which has been proven by science for seniors to efficiently develop e.g. tendon stiffness and power (Onambele 2008, see below). This can prepare the athletes for the eccentric loads seen in sports like landings and change of direction.

Practical advantages

The kBox offers everything from a low force, low-speed training up to high forces, power training and the possibility of everything from pure concentric contractions to eccentric overload. All this provided in a safe and ergonomic way without sound and with no risk of collision. With a small, mobile device like the kBox it also fits easily into the gym, PE area, locker room or why not on the pitch.

Using a computerised feedback system such as the kMeter, you can monitor the subject’s effort and power output if you want to limit them or follow their progression over time. This can also be a great motivational tool for the athletes. With the kMeter W/kg (power output relative to bodyweight) it is also easier to explain why a smaller and weaker athlete might be faster than his bigger counterpart. By tracking relative peak power you can also validate that you put muscle on your athletes that they really use.

Physiological advantages

The kBox uses flywheel technology which offers variable resistance, less need to shift weights and force output is determined by the client, which gives an effective workout that is also safe and has a lower risk of injury. The variable resistance also gives a variable lever offering a smooth resistance all through the exercise which strengthens the muscle over the whole ROM. Also, the ROM is easily adjusted if you want to limit the depth in the squat. For example, you can prevent your client going beyond certain angles (watch video).

The harness is automatically distributing the pressure from the load over both shoulders and also reduces torque on the lower back if the client’s technique isn’t perfect. From the first day in the clinic, you can start doing squats and other functional lower limb exercises even if the client is totally new to the type of lift.

Eccentric load is widely accepted to be the most effective way to treat tendinopathy and it has never been simpler than on the kBox. However, with youth, especially those in team sports, building the eccentric strength is more useful for all the eccentric demands in their sports. Using different types of methods you can get a significant eccentric load in all possible exercises.

Flywheel training has a solid foundation in scientific support. Still, specific studies on youth are lacking but the practical benefits together with the available research on adolescents and adults say that flywheel training can be a safe and efficient tool with youth subjects.

Further reading


Go back to Applications or proceed to flywheel training equipment.

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