Table of Contents
Contraction Types & Definition
What is Contraction?
Speed-Tension Curve
Eccentric Contraction- Benefits
Why So Slow?

Contraction Types & Definition

Eccentric- The part of the exercise in which the outside weight or resistance factor (Body weight in relative exercises) is overpowering the muscle newton strength.
The muscle lengthens as it contracts by having the weight drop the ligament or body part in a controlled timing period.

Concentric- The part of the exercise in which the muscle newton strength is overpowering the outside weight or resistance factor.
The muscle shortens as it contracts while lifting the weight.

Isometric- The part of the exercise in which both the muscle newton strength and the resistance factor are equal.
The muscle neither shortens nor lengthens, rather contracts in a static manner. This is why these type of exercises may be referred to as "Static exercises".

What is Contraction?

Every muscle fiber (Myofibril) hones a great deal of fiber filaments (Myofilaments), which are divided into two groups:

• Actin Filaments- These are also termed "The Thin Filaments". These filaments are coiled with nebulin filaments.
• Myosin Filaments- These are also termed "The Thick Filaments". These filaments are coiled with titin filaments.

The two groups converge into a complex composition, which is also known as "Actomyosin". A perfect view of that phenomenon can be seen here (0:54-1:11):



Speed-Tension Curve

The elements which affect the muscle's ability to produce strength state:

• Maximal power can be achieved via Eccentric contraction.
• One cannot develop maximal power by performing fast contractions
• The abilities to develop maximal power and maximal speed in the same action are different abilities

Remember:
Concentric-wise, as long as your speed is greater, the muscle will develop less power.
Eccentric-wise, as long as your speed is greater, the muscle will develop more power.

These two statements are true, to an extent. Why? Because we need to remember the 2nd element, which tells us that fast contractions simply don't work efficiently. Having your concentric contraction last more than 10 seconds would be too slow, and having your eccentric contraction last less than 1 second would be too fast.

Eccentric Contraction- Benefits

Applying Motor Units
A motor unit is the smallest operable functional unit for contracting muscles. Its structure is formed of a motoric neuron and all the muscle fibers it is attached to.
Not all motor units are the same. Motor units differentiate in number of muscle fibers. Knowing that, we must remember the following rule: "All or nothing". A motor unit will either operate at 100% muscle fiber contraction, or not at all. A motor unit consisting of 10 muscle fibers will apply 10 muscle fibers when operating, or not at all.
Therefore, the smaller the motor unit, the less power it produces, the more delicate the action is. One could see the difference when looking at an eye and a leg. The leg has motor units that measure in thousands of myofibrils per neuron, whilst the eye has but a few hundreds, or a few dozens in some cases. Hence eye movement is extremely delicate and slow in comparison to leg movements.

Fact: While Concentric contractions use X muscle fibers to apply muscle strength, Eccentric contractions use only 40% of those muscle fibers to apply the same muscle strength. Isometric contractions use 60%, and even those are more efficient than Concentric contractions.

Therefore, it stands to reason that comparing the developing power in these different contractions shows that during Eccentric contraction, the muscle is able to develop the same power using a smaller amount of motor units and by doing that, becoming more effective, more economic in terms of ATP/CrP usage, and should we load extra weight during the eccentric part of the exercise, we could be able to apply all of the motor units and eventually develop greater strength.

One of the most effective training methods is the 'Super Maximal Eccentric Workout'.
In this method, the trainee will operate against weight which is 30% larger than his RM1. The concentric contraction, which is obviously unable to be performed due to 130% of maximal strength being applied, is performed by a 2nd party (Another trainee or a trainer), while the eccentric contractions will be performed solely by the trainee, in a slow and controlled manner. This method is designated to the power development of strong and proficient athletes.

DOMS
Delayed Onset Muscle Soreness, the phenomenon which the trainee receives a day or two days after the workout. The muscles are damaged, torn, constantly in repairs during that period, and are extremely sensitive to further contractions due to their periodic weakness.

Fact: Eccentric contractions hurt more than Concentric or Isometric contractions. Meaning, they cause even greater DOMS and provide with an overall greater and more efficient workout outcome.

Why So Slow?

As we've learned, muscle contraction works best when during Concentric contraction, the movement needs to be slow and fast when during Eccentric contraction.
What are the recommended time periods?

In every possible exercise or routine, the most recommended time period of Concentric contraction is 2 seconds. The recommended time period of Eccentric contraction is 4 seconds. Indeed, 4 seconds - 200% the time of Concentric contraction.

so do dem neg reps, ja?

interesting

but for an example if i were to try and apply this to bb flat bench when the weight is at the highest point thats is where im contracting...

that said, it should take me up to 4 seconds (ofc with my spoter helping since the 130%) for me to fully extend?

so if its 4 seconds up, how slow would i need to go down? or is it as slow as possible since they weight would be "pushing" me down?

can you use examples for the eccentric concentric and isocentric stuff
examples of exercises etc

inb4burnsseesthisandtearsthisthreadapart

Going down is the eccentric contraction, which should take 4 seconds. Going up with a spotter while performing an eccentric exercise should take 2 seconds just to put the bar up again, without you even helping to raise it (0% involvement while the concentric movement is being made via outside party / helpers).

Your entire involvement is the eccentric movement, a.k.a Going down at BB Flat. Nothing else.



Waiting for someone else or qualifying someone else to make opposing opinions shows you yourself do not even know what was written to begin with. If you wish to understand what was actually written, trying doing so in a more polite manner than spamming.
That said, burns is actually someone who knows what he's talking about (Rare in this subforum) and therefore I am positive he has nothing to say against this purely fact-based topic. If anything, he would add to it.


My idea of posting this small notice is from having myself exposed to so many posts and topics regarding weight stacking and seeing videos of others in this forum simply lifting too much weight to handle it properly.
The proper timing for 100% efficiency in both muscle strength gains and muscle hypertrophy is 2 seconds Concentric contraction / 4 seconds Eccentric contraction.
Putting on excess weight just to "Lift more" than others is just silly.

Person A using 30lbs DBs performing a 10 repetition set of elbow curls in an overall of 60 seconds (2 seconds Concentric/4 seconds Eccentric = 6*10 = 60) would do a far better job and would stimulate his muscles at a far greater tension rate than person B using 55lbs DBs performing a 10 repetition set in an overall of 25-30 seconds.

I wouldn't be surprised to see people being shocked at how their true weights at lifting in various exercises are actually 60% lower than what they do currently, simply because they do not offer the muscle enough stimulation by having their eccentric contractions last no more than 0.5-1 seconds.

This post was edited by Synonym on Jan 14 2011 10:36am

negative pull ups is eccentric

plank is isometric

the concentric action of a BB curl is when u bring it up, the eccentric action of that BB curl is when your letting it come down

isometric is when the same force is applied an no movement occurs.


more muscle tare occurs when preforming an eccentric movement then opposed to a concentric movement, also stated above you are able to produce more force when lifting eccentrically. this is one reason why some indivuals prefer only training eccentrically as opposed to doing the full movement (concentric/eccentric)


@ Synonym thanks for posting good stuff lucky for me i already learned this in school

This post was edited by staysictonkpils on Jan 14 2011 10:45am

good info..basic stuff, but good nonetheless

so training strictly with negatives more or less is more benficial for muscle tear?

This post was edited by Tear on Jan 14 2011 01:54pm

It is better, yes, since you are indeed applying 130% of your RM1, at a controlled rate.