Inertia in Flywheel Training

Understanding the concept of inertia is key to reaping the benefits of flywheel training. Instead of using weights, the resistance in flywheel training is created through the inertia of a flyweel  which is rotated with muscle force.

Gravity vs Inertia

Traditional strength training is generally done by lifting some sort of weight – such as a barbell, dumbbell and weight stack machines – against gravity to create resistance.

In flywheel training or isoinertial training, resistance is created through the inertia of a flywheel, which is accelerated or decelerated with muscle force. The level of inertia of the flywheel rather than the weight determines the force needed. The principle is equivalent to that of a traditional yoyo device.

The resulting force in a flywheel training exercise depends on a combination of the inertia and the intensity you work with. With a higher inertia, the motion will be slower and more controlled, and your muscle will be able to produce a higher force. With a lower inertia, the motion will be faster which also puts higher demands on skill, balance and technique.

Inertia on the kBox and kPulley

The Exxentric flywheel training devices kBox and kPulley can be equipped with up to four flywheels with inertia ranging from 0.005 kgm² to 0.070 kgm². This facilitates an inertia range of 0.005 kgm² to 0.100 kgm² on the smallest model kBox4 Active, and up to 0.280 kgm² for the largest model kBox4 Pro.

  • Extra Large: 0.070 kgm²
  • Large: 0.050 kgm²
  • Medium: 0.025 kgm²
  • Small: 0.010 kgm²
  • Extra Small: 0.005 kgm²

Choosing Inertia

In flywheel training, choosing inertia means more than deciding between light and heavy. The inertia resulting from the size and number of flywheels impacts the training adaption you get.

Together with your workout intensity, the the ideal choice of inertia depends on your exercise purpose, also coined the Flywheel Workout Zones.

Learn more

 

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Active

kBox4 Active

Kickstart your Flywheel Training with our entry-level model. The perfect device for strength training, rehabilitation, injury prevention, and training in general. Available with our free Flywheel Training app to design all your kBox workouts.

  • Ideal for...
  • • Home Gyms
  • • Personal Trainers
  • • Group Classes
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Lite

kBox4 Lite

Broader range of resistance provided by the lightest kBox model, practical to pack and bring with you on the move. Its built-in kMeter feedback system allows you to monitor your progress in real-time.

  • Ideal for...
  • • Travelling Athletes
  • • Fitness Studios
  • • Physiotherapy Rooms
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Pro

kBox4 Pro

The premium and best-selling kBox model with the largest performance area. Made for intense workouts and serious strength building exercises. Its built-in kMeter feedback system allows you to monitor your progress in real-time.

  • Ideal for...
  • • Professional Teams
  • • Performance Centers
  • • Physiotherapy Clinics
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kPulley2

The kPulley unlocks a variety of horizontal movements, creating limitless training possibilities especially when combined with the kBox. Its built-in kMeter feedback system allows you to monitor your progress in real-time.

  • Ideal for...
  • • Professional Teams
  • • Performance Centers
  • • Physiotherapy Clinics
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LegExx

Our specialized-exercise device, optimized for leg extension training sessions. The LegExx aims to isolate and strengthen the quadriceps muscles. Comes with a built-in kMeter feedback system.

  • Ideal for...
  • • Professional Teams
  • • Health Clubs
  • • Physiotherapy Clinics
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