Getting stronger without moving: how to do isometric training with the kBox to improve your weak spots and potentiate your performance in dynamic work.
Isometric contraction means that no movement is performed during a muscle contraction, which is most often done by pulling or pushing against an immovable object. The reason for doing isometric contractions could be to work around a sticking point or prime your muscles, tendons and ligaments for heavier loads but in a safe way. There are theories that this training can desensitize the Golgi tendon organ (GTO) and reduce the self-inhibitory signals evoked by GTO on the agonist’s muscles during heavy loads.
#1 Unassisted. Set the belt length to your desired isometric position when all the belt is unwinded from the shaft. Pull or push, no motion is done. An obvious benefit is that you can do this unassisted. For strong athletes, you can pull the belt out from the belt locking mechanism and then you just have to re-attach it. For athletes or maximal efforts look at #2 if you are experiencing this. Watch video.
#2 Spotter assisted. Set whatever belt length you want, let’s say enough for a full concentric action. Spotter retracts some belt on the shaft to put an athlete in the desired position. Spotter holds flywheel as athletes push/pull without moving. The benefit here is less strain on belt attachment pin and the preferred option for stronger subjects or maximal efforts. It’s not that much effort for the spotter as you might think and any spotter can hold back a decent squatter. A spotter can use gloves for safety. Try it! Watch video.
The spotter assisted method is interesting since it allows you to easily prime the concentric action with an isometric max and give you a PAP effect (Post-Activation Potentiation), probably since you recruit more muscle fibres during an ISO max and can benefit from this in the following CON action.
Push all out (isometric) for at least 1 second to reach your max force and then the let the spotter release you by letting go of the flywheel and you will fly away.
If the preceding isometric contraction is too long it will add fatigue and lower output. Adjust individually, and use kMeter for assessment and evaluation. In tests, we have seen up to 10% higher peak and average power in the following dynamic set. Watch video.
- Introducing the kBox Methods for Isometric Training, by Fredrik Correa
- Isometrics for Mass, by Christian Thibaudeau on T-nation