[quote]jmwintenn wrote:
Alright I know that some of you are very knowledgeable so I hope you can help me.I’ve read lately that your brain only allows you to use 20% of your total muscle capacity.Supposedly if you use more than this your muscles will tear and rip from the strain.So my question to all of you is:
1.True or False
2.Is there any truth in it(ie. you can only use 80%)
I also have a favor to ask,don’t call me stupid.It kinda sounds like BS but it intrigued me and I havent been able to find a definite answer from anywhere. [/quote]
First, I don’t think its about how much of your muscle you use, but how highly it is activated. I have definitely read that 90%+ of your motor units are activated by lifting a load just 50% of your voluntary max, but that what happens above this load is that the nerves fire progressivley faster (and ideally more synchronously) to raise force output.
Tendon reflexes can supress or enhance the firing rate, but there is a limit to firing rate determined by the refractory period of the nerves.
Also, using compound movemements increases nerve firing rate which is why its impossible to flex maximally in an isolation moevement.
Picking up a car is different though. I think when you are talking about a big complex exercise like the deadlift, there are so many potential weak points that could cause a reflexive inhibition that if you could supress this inhibition, you could definitely pick up more (maybe 150% more even for a trained individual under extreme situations.)
This also proves that training to failure in terms of force production is stupid. If you could really deadlift 500 and you are only doing 375 for a voluntary max, 500 is clearly not necessary or ideal to make improvements and you would probably cause many small injuries throughout the body.
[quote]jmwintenn wrote:
thanks guys,specially snatchandcleanjerk.Alright here’s another one,what do you think would happen if there were no limiters.And what would be needed to cause this.
See this is why I love this,our body is THE ultimate machine.[/quote]
I am stronger when I am mentally drained (but not physically). If I woke up in the middle of the night-semi asleep I could probably set a pr if the movement wasn’t too technical.
Hypnotic state, relaxation. Many top lifters have claimed that they don’t remember anything of the lift itself, just, unracking and racking.
The logical part of your brain will shut you down, so possibly occupying the logical part of your brain with something else during the movement itself-like trying to solve a math problem in your head as you do a deadlift.
[quote]ZEB wrote:
Basically you are referring to the “Golgi Tendon Reflex.”
This prevents you from lifting or stretching a muscle well beyond it’s capability. Which of course prevents you from damaging your body.
Simply google “Golgi Tendon Reflex” and you can read all about it.
Zeb[/quote]
But this reflex also elicits stronger contractions up to a limit-perhaps 20% above voluntary levels, so its a delicate balance.
The thing is, for most heavy lifts, you want to use the reflex to up the force of muscular contractions, but for “hulking out” that requires total supression of reflexes.
[quote]mertdawg wrote:
jmwintenn wrote:
Also, using compound movemements increases nerve firing rate which is why its impossible to flex maximally in an isolation moevement.
…
This also proves that training to failure in terms of force production is stupid. If you could really deadlift 500 and you are only doing 375 for a voluntary max, 500 is clearly not necessary or ideal to make improvements and you would probably cause many small injuries throughout the body.
[/quote]
Excellent points. Getting stronger on compounds movements will make you stronger on isolations a helluva lot faster than the other way around. I’m not even sure the other way around is even possible.
It took me a long time to understand that “training to failure” is a subjective, non-scientific waste of time. Push your limits without burning yourself out and your body will still adapt. I train till I find any extra weight or another rep would be very difficult and I manage to add 5 pounds to the bar or belt every week. Sometimes I just do “practice days” with a weight I know I can handle and that weight will still feel tough. Can’t be at my best all the time, but inbetween my attempts at new weight, I get practice with old weight that may still be close to that particular day’s maximal output.
There is truth to it, to a certain extent. I’ve heard of it being more like “begining lifters use, on average, less muscle capacity; experienced lifters use, on average, more muscle capacity” There’s something called “STRENGTH DEFICIT” and I think you should look into it.
If all this is true imagine what certain animals are capable of doing in situations of extreme stress. Take somthing like a gorilla for example…an animal that is naturally 10 times stronger then any man and think about what it could do under circumstances in which its CNS unlocked the limiting function.
Also…been looking for an article that time magazine wrote a few yrs back. The article basically said that humans are close to reaching our physical potential but I beleive did make mention of what you guys are talking about…be real cool if someone could find it.
somehow i believe that even though a gorilla may be that much stronger, it would be more limited in terms of energy if it were actually able to exert its strength to do work.
think about this scenario:
if a woman can lift a car(1000kg) lets say, 1 foot in the air(.3m) then there is 3000 joules of energy required.
3kj of energy doesnt sound like much, but considering this feat is done probably within 10-20 seconds or so means that 300-150watts of power are being produced by the muscles involved. THATS HUGE power! i dont think the amount of atp on tap could supply that.
then multiply those power numbers for a gorilla, 3000 -1500watts? thats insane.
[quote]jmwintenn wrote:
i dont think you can convert joules to ATP,ive never seen a formula for that[/quote]
the free energy of hydrolysis of ATP is approximately 30kj per mol.
Within a cell, however 50kilojoules/mol is the energy that can be derived from a mol ATP.
In cells we typically have 3mmol of ATP.
if that were the case then each cell can do 15j of work. But of course we know the energetics are not 100% efficient and that a cell will not utilize all it’s energy for a muscle contraction.
[quote]consumer wrote:
jmwintenn wrote:
i dont think you can convert joules to ATP,ive never seen a formula for that
the free energy of hydrolysis of ATP is approximately 30kj per mol.
Within a cell, however 50kilojoules/mol is the energy that can be derived from a mol ATP.
In cells we typically have 3mmol of ATP.
if that were the case then each cell can do 15j of work. But of course we know the energetics are not 100% efficient and that a cell will not utilize all it’s energy for a muscle contraction.[/quote]
Yes muscular activity is extremely ineffcient, with majority of energy released as heat. If ever a way could be developed to over come this ineffciency and more energy used in mechanical force production, that truely would be superhuman
The total quantity of ATP in the human body is about 0.1 mole. So it never really has ATP on tap hence its consumption must closely follow its synthesis. On a per-hour basis, 1 kilogram of ATP is created, processed and then recycled in the body. A huge amount would need to be generated for the car lift feat. And probably a one shot attempt due too waste accumilation.
[quote]mertdawg wrote:
Wayland wrote:
A huge amount would need to be generated for the car lift feat.
Why? Lifting a 1000 kg car a meter off the ground would only be 10,000 Joules, 240 some calories, or .24 kilocalories with 100% efficiency. [/quote]
man I know that the math says it would only require 24kcals to lift a car, but something about that really bothers me. If this was the case, then things like Cranes, would not require so much power.
[quote]consumer wrote:
mertdawg wrote:
Wayland wrote:
A huge amount would need to be generated for the car lift feat.
Why? Lifting a 1000 kg car a meter off the ground would only be 10,000 Joules, 240 some calories, or .24 kilocalories with 100% efficiency.
man I know that the math says it would only require 24kcals to lift a car, but something about that really bothers me. If this was the case, then things like Cranes, would not require so much power.
[/quote]
[quote]mertdawg wrote:
consumer wrote:
mertdawg wrote:
Wayland wrote:
A huge amount would need to be generated for the car lift feat.
Why? Lifting a 1000 kg car a meter off the ground would only be 10,000 Joules, 240 some calories, or .24 kilocalories with 100% efficiency.
man I know that the math says it would only require 24kcals to lift a car, but something about that really bothers me. If this was the case, then things like Cranes, would not require so much power.
That’s 0.24 kcals not 24!
[/quote]
haha my mistake, even more unbelievable. what are we missing? that accounts for 5 orders of magnitude?
What did they used to “teach” us in high school? Something to the effect that a glass of orange juice had as much potential energy as a quarter stick of dynamite or something?
The point is, just because energy is released more slowly by the body, don’t assume it isn’t dealing with a lot of energy over time.
Your muscles are strong enough to crush your bones.
Example: This passage is from Wikipedia definition of Tetanus: The first sign of tetanus is a mild jaw muscle spasm called lockjaw (trismus), followed by stiffness of the neck and back, risus sardonicus, difficulty swallowing, and muscle rigidity in the abdomen. The stiffness and spasming of muscles expands throughout the body inferiorly, and can be so powerful that they cause muscle tears and even fractures[2]. These muscle contractions are due to tetanospasmin?a chemical released by C. tetani?which inhibits the release of both GABA and glycine, the neurotransmitters that serve to inhibit muscle contraction.
Golgi tendon reflex - This reflex response is dissapated after a few seconds. This is why you hold passive stretches for about 10sec, to dissapate the stretch reflex response in your muscle that is naturally resisting the lengthening of the muscle. And obviously, as most know, this is the reflex you’re using when you bounce weights around, rather than lift slowly. Of course both methods train different aspects of muscle contractions. Explosive movements and any athletic movement rely completely on this golgi tnedon reflex response for explosive power and contractile energy conservation.