Negative Only - Eccentric Training

[Guest guest]

Casler writes:

It is very difficult to make hard fast statements about eccentric elements

in our training applications.

While we speak as if all the contractile actions are distinctly separated,

in fact in application, they are not.

They are all the product of muscular activation, but concentric is pertinent

to sliding filament action (shortening) while static and eccentric are

products of the breaking of actin myosin bonds or " allowing " those bonds to

relax or detach.

That said, in application these elements merge into the dynamics of the

specific action, along with other affecting elements like the use of the

elastic components.

So what we have is a transitioning complex of muscle actions that are

modulated and initiated by the CNS via feedback and sensory components, as

well as command components.

So when we view or discuss the properties of eccentric loadings to create

the stimulus we need be totally aware of the combination of how these

" loads " and " muscle tension " against them will create them.

So that end, it is clearly significant to know that the eccentric action, in

normal training is always " underloaded " to its capacity. That is, we are

always limited to the load which we can used in the sliding filament

(weaker) muscle action.

Muscle action could have evolved no other way, or else we would be damaging

muscles on a regular basis. As it is, it is rare to have muscle damage from

tension/force training of any significance from concentric action since the

muscle cells are not normally able to commit suicide by sliding filament

action.

Of additional significance, is the fact that the " recruitment " of MU's

during the eccentric action is " adjusted " to suit the force load presented.

This however is far different than the recruitment during concentric sliding

filament action. In sliding filament action, a greater number of MU's are

activated until the load is overcome.

In eccentric actions, the MU activation distribution is far less, due to the

greater efficiency of the act of braking compared to the motor act of

shortening. This difference produces a lower Motor Signal, and fewer MU's

are used to control the load/force. This then is why the muscle damage

occurs until the (SAID) stimulus had caused the adaptive response to that

load.

So what do we learn from this? Well some would suggest a " slower " lowering

of the eccentric load, to somehow capitalize on the aspect of fewer MU's

handling the load, but in fact, that then has a tendency to " reduce " the

tension, by reducing the " load " seen by the muscle.

In a perfect world, (for some applications) the load would automatically

increase to close to eccentric capability, and the ultimate load and speed

would be that which allows us to produce the greatest force against the

load.

This is but an impossible task under mass/weight based loads for many

reasons, and again because we are underloaded to the eccentric to begin

with.

Dynamic weight loads to the rescue. In the science of Strength Training,

there are many parameters to which some swear and others wave away.

As you or your trainee " learn " the proprioceptive abilities you might have,

you quickly find that creating accelerations (both negative and positive)

have a function to the actual load experience. This means " if " we are

looking to load the eccentric with loads that move closer to the

capabilities of the action, and also those which can create the right speed

of the action to cause a more effective SSC (Stretch Shortening Cycle) then

" allowing " a controlled acceleration to acheive that force in the desired

ROM of the eccentric action will provide significant result.

This is the primary principle in " plyo or mio " metrics.

So as athletes, coaches and trainers, we need to understand how and when to

implement these training elements toward the goal, and in a safe controlled

manner.

If I have to make a blanket statement that might sound a little outrageous

initially, I might state that great strength and speed are totally limited

to the proper used and safe implementation of eccentric loadings. Given the

fact that concentric strength is simply governed by the strength of the

motor impulse, the benefits of progressively strengthening the muscle tissue

itself will be enhanced by more accurately loading and training the

eccentric component.

All that said, we have the task of discovering methods to train this

component, as well as how to adjust for the increased severity of the

stimulus so as to not create over-reaching or overtraining, or even worse,

injury.

But to close, it is valuable for those who are interested, to know that to

create the greatest stimulus to the concentric action, the actions MUST be

performed in a way that maximizes the creation of the greatest MU

recruitment, and CNS motor signal during the action. This will normally

involve (with well selected loads) the implementation of speed/load

combinations that allow maximum efforts against the load (accelerations)

while not exceeding terminal velocity (that velocity where the speed exceeds

the speed at which a muscle can shorten via sliding filament action)

In the eccentric, we want a load and speed that will allow the maximum

tension also, but this will be based on a speed force relationship that does

not cause the actin/myosin forced detachments to not be able to create the

maximum (or desired) muscular tensions.

And one final point. I have done much eccentric training a work. I find

little use for " Eccentric Only " training for most purposes. The strength of

the eccentric action lies in its contribution to the concentric/eccentric -

eccentric/concentric cycle, and how it contributes force creation and MMMT

(Momentary Maximum Muscle Tensions) that are then applied to the elastic

components and harvested during the transition to concentric action. By

training the eccentric only, (except for specific and limited goals) I find

that " breaking that link/transition " reduces the functional effectiveness of

the training.

It must be recognized that there are NO HARD FAST RULES that cover all

training goals. You must apply the above information to create the REP or

REPS of your training sets.

Regards,

Casler

TRI-VECTOR 3-D Force Systems

Century City, CA