Overloaded Concentric Action ­‒ Self Assisted

Overloaded Concentric Action ­‒ Self Assisted is one of Exxentric’s methods for eccentric overload using flywheel training on the kBox.


By adding energy in the concentric (CON) phase using accessory muscles or a stronger movement pattern but only the primary muscle(s) or a weaker movement pattern in the eccentric (ECC) phase you can get a high eccentric overload that can be done at a fast and more athletic specific pace or an eccentric loading without doing much CON work at all if you want.


How to do it

On the kBox use for example legs to push off in an upper-body drill or use the arms (pulling you up using a bar in a squat rack) in the CON phase of a drill. In the ECC phase, you only use the primary muscle that then has to decelerate the energy created by primary and accessory muscle groups. You can also push off with legs in an upper-body drill and then just follow through until the turning point and then use the upper body muscle in the ECC phase only. With this last variation, you rest the primary muscle(s) through CON and get an ECC loading only if you want that. You can also use a stronger movement pattern in CON (for example Deadlift) and a weaker pattern in ECC (RDL) to overload in ECC.


When you can use it

Basically with all upper body drills and also most leg exercises if you have rings, a squat rack or something to push off from. Compare the spotter-assisted variant, when a spotter is available.


Good for

Fast, dynamic, heavy-overloaded consecutive eccentric actions.



Really taxing. Higher speed gives higher demands on technique and form, which is thought in some of our courses.

Proceed to learn more about our courses and equipment, or go back to the methods.


kBox4 Active

The Newest model, the kBox4 Active is built on proven, reliable technology. The perfect tool in strength and rehabilitation at our lowest price point.

  • Newest Model
  • Holds 1-2 Flywheels
  • kMeter Compatible
  • Weighs 15 kg
  • Starting at €1 410 / $1 585
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kBox4 Lite

Often chosen for its smaller foot-print, the kBox4 Lite model is of a lower weight, portability and not to mention its competitive entry cost level.

  • Portability
  • Holds 1-4 Flywheels
  • Built in kMeter
  • Weighs 9.5 kg
  • Starting at €2 300 / $2 575
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kBox4 Pro

The kBox4 Pro is our premium model with the greatest versatility. It’s ideal for sports teams and larger training and physiotherapy facilities.

  • Largest Floor Space
  • Holds 1-4 Flywheels
  • Built in kMeter
  • Weighs 15.5 kg
  • Starting at €2 990 / $3 345
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The kPulley2 is the ideal horizontal solution for improving strength by offering flywheel training for rotational and pull exercises.

  • Horizontal Model
  • Holds 1-2 Flywheels
  • Built in kMeter
  • Easy to assemble
  • Starting at €1 890 / $2 9110
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