BY LOEK VOSSEN
Human Movement Scientist
Eccentric training improves strength, speed, power and performance-related abilities like jump height and running speed to a greater extend than concentric or traditional training. But what do we mean by eccentric training and eccentric overload?
Lifting a weight with your biceps is a good example of a concentric movement. Your muscles become shorter and therefore lift the weight towards the ceiling.
It is possible to do an eccentric movement without using a lot of strength. For example, by lowering a low-weight dumbbell. However, when we talk about eccentric overload, we don’t talk about these low-weight movements. A movement contains eccentric overload when you produce more force then you are able to produce concentrically. In practice this often means you lower more weight than you could lift (>1RM). Therefore, lowering a weight slowly does not contain an eccentric overload if you were able to lift it. It should come as no surprise that slow eccentric movements (like slow eccentric squats) do not have the same positive results as true eccentric overload movements.
Eccentric overload in Flywheel Training
But how are you going to lower a weight eccentrically when you weren’t able to lift it? That’s a serious practical problem if you don’t have one (or two) personal trainer(s) helping. But not in Flywheel Training. If you don’t do anything special, every flywheel training exercise contains as much concentric force as eccentric force. Action equals reaction. Due to gravity, this is not the case in traditional weight training. But how do you create eccentric overload in Flywheel training? There are 4 easy to perform strategies!
(1) Delayed eccentric overload
First, produce as much force as possible when pulling the cord concentrically. Use the full range of motion to do so. Then, only decelerate the flywheel in 2/3rds of the eccentric movement. Since you absorb all the energy of the concentric phase in only 2/3rds of the eccentric phase, you will experience eccentric overload in these 2/3rds.
Example: perform a squat in the concentric phase, don’t decelerate the flywheel in the first part of the eccentric movement, but fully decelerate it in the last 2/3rds of the movement.
(2) Impulse overload
This strategy looks a lot like the delayed eccentric overload strategy. Again, produce as much force as possible when pulling the cord concentrically. Then position yourself into one position, for example halfway through the eccentric movement. You then “wait” until the flywheel “hits” you while you try to maintain your position. The eccentric overload will by very high in the specific position angle you choose. This is not a beginner strategy!
(3) Add a concentric muscle group
An easy way to create eccentric overload in flywheel training is by using more muscle groups in the concentric movement when pulling the cord, than when eccentrically decelerating the flywheel.
Quadriceps + Biceps = Biceps + Eccentric Biceps Overload
If you want to overload your quadriceps with this strategy, you can use a squat rack to pull yourself up with your arms while performing a squat.
Squat + Pull up = Squat + Eccentric Squat Overload
(4) Unilateral overload
This strategy uses the same principle as the previous strategy. Example: perform a squat with two legs to pull the cord out, decelerate the flywheel by only using one leg.
Quadriceps right + Quadriceps left = Quadriceps right + Eccentric Overload