I had my first workout the day before yesterday (GMT +8 pacific time zone) since my spinal, lower back & right lats injuries end of August. In total, I rested 2 months and absolute nothing except frequent visits to traditional chinese medical treatments. It was a leg workout.
Obviously, I was excited to be back the gym. The sound of the weights cling clang each other is very familiar to me. I am disappointed that I was a lot of muscle mass, muscle hardness. My lifting stamina sucked big time and it is understandable. I am not ashame at tall to say my strength dropped by at least 50%.
I will have to change my workout by focusing ways to intensify the liftings rather than lifting heavy, which I try to do for most part of 2007. One way to do is eccentric movements (negatives), which I have tried them before. I used the tempo of 6-0-2(3)-0 for all the exercises I did, namely leg press, hack squats, leg extensions, seated leg curls and lying hamstring curls.
6 : 6 seconds for eccentric motions. 0 : 0 seconds for pause at the bottom. 2(3) : 2 ~ 3 seconds for contraction and 0 : 0 seconds for pause at the top motion.
I read a post at the another forum referring to negatives training and decided to use the negative training principle again. Just some knowledge to refresh my training and myself. 
Obviously, my muscles are sored now. DOMS, DOMS, DOMS!!! 
It was a familiar feeling and I am feeling better. Hope the muscle memory comes back soon.
============================================
=============
Understanding The Unique Movement, Eccentric
<strong />
The power of Eccentrics was first realized around 188? ( question mark represents an unknown number). The original name was Excentric, where the prefix ex means "from/away" and Centric meaning Center, hence Excentric can be understood to be moving away from the center. Its effects were tested by various scientists using various exercises from squats, curls down to back to back cycling, downhill running, uphill running and level running.
From those research it was found that eccentrics are superior for strength gains and size gains compared to concentrics or isometrics. Many studies have proved that eccentric actions induce more muscle damage than the other movements due to higher tension on the active muscles, the muscles used during this movement. Though active muscles produce more force during yielding movement, it is also noted that less fibers are recruited than the other actions.
While all the researchers are agreed on the abovementioned facts, there are disagreements between them. Some researchers say that during eccentric portion, more large motor units are recruited ( note that less MUs are recruited during this movement, hence, it would means that smaller MUs are dismissed and large MUs are mainly used during this action ). So, our question is " What? Size principle does not hold true here? " Fortunately there are some studies on the motor unit recruitments of this lengthening action. Lets see.
Researchers found that the recruitment pattern during this movement follows Size Principle. *** This research was done to find out about the motor unit recruitments of eccentric actions and was funded by Natural Sciences and Engineering Research Council of Canada***
Lets move on to .. " wait a sec! what the heck is size principle actually?" You ask.
Well, when you lift a weight, small MUs are recruited first. But it does not necessarily means larger MUs, Type IIa and Type IIb, are recruited only later on. Depending on the demand, how much force you need to exert, larger MUs will come into play while also recruiting small MUs. As the demand get greater, more and more Larg MUs will be recruited. So, it means that if the load is light enough for ur small MUs to handle, larger ones wont be recruited. But what if the load get a lot heavier?? Well, then, larger Mus are recruited while still activating the ones, either small ones or both small and some large MUs used according to the demand. And what about firing rate? muscles also produce more force by increasing its firing rate? Yes, but firing rate increases only after you have recruit as much motor units as possible. ( do more read up to know more about these)
Ok, lets get back to previous studies we talked about. So, you are saying that fibers follows size principle while lengthening? Would it means that the other researchers who say " larger MUs are recruited and smaller ones are dismissed ruing eccentric actions " are wrong? Before I give my answer, lets take a look at the reason why they say so.
There is another fact that every scientists or researchers have found about yielding action, which shows that fast twitch fibers receives most damage from this movement while the damage slow twitch fibers receive withing this action is no different from other movements.
Some of the references;
*** Cope, T. C, and M. J. Pinter. The size principle: still working after all these years. News Physiol. Sci. 10: 280-286, 1995
Hortobagyi T, Hill JP, Houmard JA, Fraser DD, & colleagues. Adaptive responses to muscle lengthening and shortening in humans. J. Appl. Physiol. 80(3): 765-772, 1996 ***
The findings show this fact. But, would it be the right thing to say more large MUs are recruited and smaller ones are dismissed, thus, breaking size principle? No, it is not right to assume so just because large MUs receive most damage! Why? you ask.
We will review the facts about eccentric actions first!
1. During lenghting actions, less MUs are recruited
2. Each fibers used in this movement induce greater force ( greater force from a fiber = increased firing rate = greater tension ) compared to the other movements
3. Large MUs receive most damage in this action
Wow! now is time for neurology class!
Q. Why less MUs are recruited?
A. Lets assume that you are curling 120 lbs. When you are doing concentric portion, lifting phase, your body recruit a large number of motor unit ( re-read, it is large numberof mus not large/er mus ). Assume that you recruit 10 MUs. This combined force is greater than the load of 120 lbs, hence, the load is lifted up. When you hold this load half way, it is known as isometric contraction, where some of the motor units are turned off ( lets assume it is 8 mus you are using now ). At this point, the load is not moving as the force your mus produce is the same as the load. When you lower this load, the number of MUs you recruit decreases ( assume it is now 5 mus ), thus, the force of ur mus are weaker than that of the load and the load go down at a controlled rate.
Q. Why each muscle fiber induce greater force?
A. haha, you will have get back to structural function of ur muscle cells when you make movements. But, i will make it short and simple for those who are not familiar with all these terms and processes. Here we go;
The muscle spindle records the change in length of ur muscles and how fast they are stretching and sends signals to the spine which convey this information. Your CNS then receives this infomation and attempts to prevent the muscles from being injured by sending signals to resist the change in muscle length by causing the stretched muscle to contract more. The more sudden the change in muscle length, the stronger the muscle contractions will be. ( key points to note, "cause the STRETCHED MUSCLES to contract faster".. " The MORE SUDDEN the change in muscle length, The stronger the muscle contractions will be"… ) ( note the second point carefully and remember it since i wil be using this fact to back up something later )
Ok, lets answer your second question. Now, you know from the first answer that less fibers are recruited during this movement and your fibers produce force which is greater than the force they produce in concentric phase. But, according to size principle, more MUs will be recruited if the demand is greater, that is when more force output is needed, why it never happens here but jumps steps and straightaway produce more force by increasing firing rate? hey hey, you are very careless….. did i not tell you to note some points just a few secs ago? CNS attempts to prevent muscles from being injured bcos of the signals sent to it by muscle spindle saying that muscles are being stretched at a certain speed by causing STRETCHED MUSCLES, the less fibers being used now, to contract faster. Wait Wait Wait! what is with contracting faster?? contract faster = twitching faster = firing faster = more force! It is the reason why each fibers here produce greater force!
Q. Why Large MUs receive most damage in this action?
A. From my second answer, you see that these active fibers produce more force by twitching faster compared to other portions, concentri and isometric. While both slow twitch fibers and fast twitch fibers used in this portion twitch faster, due to the contractile and metabolic properties of fast twitch fibers, they receive most damage!
HOLD ON! What the heck is contractile and metabolic properties?
Ah, darn, why do i have to tell you every little thing? Never mind, i will just tell you briefly, contractile means relating to contractions. Fast twitch fibers contract = fire = twitch fast, right? And, they are less used compared with slow twitch fibers, right? Hence, when used, especially when they have to produce more tension by firing even faster, they easily get damaged which is one of its metabolic properties. And which is why everyone is saying fast twitch fibers are easy to grow. Got it? And slow twitch fibers are always used which is why they can not be stimulated, damaged, easily since they have already adapted to being used everyday or most of the time. Now, stop being lazy and asking me everything,,, go google for these properties and read.
So, now, you can see what my answer is, right? my answer is that muscle recruitment pattern during eccentric portion follows size principle, recruiting less fibers, at the same time inducing more force and it is also true that large fibers get most damage.
By now, we are already clear about what really happen during eccentric actions. What is next, then?
Strength gains and size gains!!!
To name a few studies;
1. A study by Komi and Buskirk (1972) show greater strength increases after an eccentric training regimen than after a concentric-only regimen.
2. Higbie conducted a study on negatives in 1996 and found a combined strength increase (concentric strength improvement plus eccentric strength improvement) of 43% with an eccentric-only regimen compared to one of 31.2% with a concentric-only regimen. found a combined strength increase (concentric strength improvement plus eccentric strength improvement) of 43% with an eccentric-only regimen compared to one of 31.2% with a concentric-only regimen.
3. Dudley, in 1991,found that eccentric-only training led to an average muscle size gain of 6.6% over ten weeks while a concentric-only program led to gains of 5%.
4. Another recent study by Farthing and Chilibeck, in 2003 concluded that eccentric training resulted in greater hypertrophy than concentric training.
5. A recent study by LaStayo, in 2003, found accentuated eccentric training to cause 19% more muscle growth than traditional strength training over eleven weeks.
One study shows that Muscle activities during eccentric only regime increases by 22 % in 3 weeks! Means better neural adaptation!
Golgi tendon organs shut down your muscles when it face great stress hence applying the break to stop your muscles from moving as much weight as possible. You can train them to get used to more tension by using eccentrics.
Not only that, since you can handle more weights while using eccentrics it help you build up your confidence when you do other lifts. But, what is so good with building up confidence? you ask. Well, it release your body’s survival mechanism’s break which always try to stop you from lifting as much load as possible by not letting you recruit all the fibers.
The other benefit is that since you are using less fibers during eccentric phase, whereas concentrics and isometrics recruit more fibers, you will need less oxygen to lift the same weights! Means, low metabolic cost! The most bang for your bucks!
So, the benefits are;
1) There’s a greater neural adaptation to eccentric training than to concentric training (Hortobagyi et al. 1996).
2) There’s a more important force output produced during a maximal eccentric action. Means you can use a higher external load.
3) There’s a higher level of stress per motor unit during eccentric work.
4) Most of the muscle microtrauma to the cells occurring during training is a result of the eccentric action performed ( A study by Brown, in 1997, and the other one by Gibala, in 2000). It’s been established that this microtrauma acts as the signal to start the muscle adaptation process ( This one is done by Clarke and Feedback, in 1996).
5) Low metabolic cost.
6) Significant strength gains in untrained limb, for instance, if you do dumbell curls with right arm there will be noticeable strength gains in your left arm ( studies are too numerous to mention that I will just let you look around for yourself )
But, what about the side effect/s?
Oh, yeah. It has side effects! It causes microtrauma as you know, causing DOM. It damages muscle proteins and cause calcium to leak hence activating enzymes which accumulate water around this injury at the same time causing pain.
Another side effect is that while your muscles are recovering, your maximum force output is not available since the fast twitch fibers which are cable of inducing greatest force are under repair. But, during that time you can produce moderate force which can be maintained longer as this force come from smaller fibers which take over damaged fibers.
The other one is this damage ( can be called a small injury since muscle cells + connective tissues are torn ) takes long time to recover. Depending on the damage receive from negative regime, it can take a minimum of a week to 30 days for these fibers ( connective tissues are also made up of fibers ) to fully recovery.
============================================
==============
Leave Comment