I read an article recently that had a little bit on the brain and its impact on strength. It was only a little bit of the article but is fascinated me nonetheless.
Technically I understand the term "failure" to mean the muscles Maximal Voluntary Contraction. If i lift a 12RM load the idea is that i can lift the weight for 12 Repetitions. If i try to lift a thirteenth repetition i will fail because I have reached maximum voluntary contraction. THis is how I see it break down.
12 repetition lift:
In this case the theory is that for the first few reps you don't use all your available muscle fibers. you only used about 60% of available fibers. This is more than enough to lift this load.
After the first 3 reps your muscle fibers get a little fatigued. in order to lift the next 2-3 reps they recruit some more muscle fibers (80%) and you can go on lifting.
for the next 3 you need even more fibers to accomplish the task (90% fiber recruitment).
for the final 3 reps you need to call in all your reserves. You use as close to 100% of your available muscle fibers as you can recruit and have reached failure.
Sorry buddy...no can do. You have no more reserves left to lift this load 100% of your muscle fibers were fatigued. You can be happy that as you used all fibers you can also enjoy growth in 100% of your fibers as opposed to just 80% if you'd stopped lifting before failure. The only way you might continue is forced reps, but on your own your dusted.
One interesting topic is what happens to cause failure. Theoretically failure should indicate that all muscle fibers have been recruited and therefore another rep is not possible as there are no more fresh fibers left to work. Either this or something would have to happen in the muscle that would interfere with the muscles contractile capabilities like a build up of lactic acid, causing failure.
One thing that fascinated me was an article that stated that researches were saying that nothing critical happens in the muscle to cause failure. Think about this...
When a life or death situation exists ordinary people seem to find "superhuman strength" all of a sudden. regular Joeï¿½??s and Janes have lifted massive loads like half a car when someone was trapped underneath yet they never exhibit extraordinary strength before. Why? The body can only do what the muscle is capable of, so if they couldn't do it before something else must be holding them back right?
Researchers attributed this to the "central governor" theory. They think that during an everyday effort like weightlifting the brain is the big daddy of the lift. When it senses that the muscle is starting to work HARD it will fear potential injury. As a result it will send a signal to the muscle to call it quits and cause failure (although technically the muscle may have been able to continue). It's simply a protective mechanism for muscle injury. In a life or death situation however the brain realizes it HAS TO lift the load and all injury prevention mechanisms are put on hold resulting in "superhuman strength".
Even Arnie said "the mind poops out long before the muscle does". So it seems that the brain has the ultimate say in your muscle building potential. Maybe the guy that gets the best results in the gym is simply the guy who's brain doesn't give a rats if he gets injured or not and allows him to lift the larger load. After all, those that are interested in building muscle WANT to damage our muscles. This is our defining goal. All the while our own brains may be screwing with us and calling it quits before the muscle does.
So maybe there is an easy solution to when you've plateaued. If the muscle is technically able you have to screw with your "central governor" protective mechanism. simply have your workout buddy there with a gun to your head and say "if you don't lift this load for thirteen reps its curtains!!" The only way it will work is if your brain actually believes its true. Also recommended is a change of undies if you happen to soil yourself in the process.
Personally I think that knowledge alone of this theory helps me push past some mental barriers to tap into strength i believe is there but i don't use because I Psyche myself out. Hey...whatever works!!