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Fiber Type Fatigue

I have a question for the experts on this site.

Which fiber type fatigue first during a set? the type 1 or the type 2?

From reading this, it seems that the type 1 cannot really be fatigued…

http://www.biophysj.org/cgi/content/full/82/5/2344

If they can be fatigued, can a drop set be used for that - the first set fatigues the type 1 and the second targets the type 2?

Thanks a lot for your help! :slight_smile:

[quote]Shotgun wrote:
Which fiber type fatigue first during a set? the type 1 or the type 2?
[/quote]

i believe this all depends on the intensity level of force output that is used. If you start with a really high, near maximal force output, whether by using heavy weight or accelerating a given weight really fast, then you will need to uses all three muscle fiber types I, IIa, IIb. and the force output will last until the type IIb can hold out, which is not very long considering that they run on the creatine-phosphate atp cycle. Now if you start with a light force production then you will not be recruiting all the muscle fibers and thus will just go on until the typeI fibers are unable to produce atp from the glycolysis and then oxidative cycle. too much lactic acid and not enough resources to shuttle it out. The type IIs would not play a major role since you would deplete their atp stores very fast once your typeI got tired. laters pk

[quote]Shotgun wrote:
If they can be fatigued, can a drop set be used for that - the first set fatigues the type 1 and the second targets the type 2?
:)[/quote]

the purpose of a drop set is to fatigue all the muscles. It is very intense if done properly and will allow great growth and adaptation of all three muscle types. Ideally you would want to start with a high force production to hit the typeIIb. then you go for a lighter weight and do this weight for 60-90 seconds to really hit the glycolis atp production. Depending on the intensity the type IIa and the type I will be getting worked. Once this time period is over then you go to even lighter weight for the oxidative atp phase and try to work through the lactic acid accumulation. This is a killer.

I remember CT had a type of program where you would do something like: 1 rep near your max, 3 fast reps at 80%, 3 slow reps at 80%, 5 reps at 60% fast, and then till failure with 60% slow. Sorry if i got the numbers wrong. I can’t dig up the routine but i know it was awesome and hard. Something like this would definitely give you strength, size and muscle endurance strength. laters pk

[quote]pkradgreek wrote:
Shotgun wrote:
Which fiber type fatigue first during a set? the type 1 or the type 2?

i believe this all depends on the intensity level of force output that is used. If you start with a really high, near maximal force output, whether by using heavy weight or accelerating a given weight really fast, then you will need to uses all three muscle fiber types I, IIa, IIb. and the force output will last until the type IIb can hold out, which is not very long considering that they run on the creatine-phosphate atp cycle. Now if you start with a light force production then you will not be recruiting all the muscle fibers and thus will just go on until the typeI fibers are unable to produce atp from the glycolysis and then oxidative cycle. too much lactic acid and not enough resources to shuttle it out. The type IIs would not play a major role since you would deplete their atp stores very fast once your typeI got tired. laters pk[/quote]

I see what you mean.

So you think that it is possible to fatigue the type 1. What I don’t understand is that in the link I posted before it says that the type 1 don’t fatigue or very little.

Concerning the lactic acid production, is it only the type 1 which produce it? From what I know all fiber types are able to use the different enery systems.

[quote]pkradgreek wrote:
Shotgun wrote:
If they can be fatigued, can a drop set be used for that - the first set fatigues the type 1 and the second targets the type 2?
:slight_smile:

the purpose of a drop set is to fatigue all the muscles. It is very intense if done properly and will allow great growth and adaptation of all three muscle types. Ideally you would want to start with a high force production to hit the typeIIb. then you go for a lighter weight and do this weight for 60-90 seconds to really hit the glycolis atp production. Depending on the intensity the type IIa and the type I will be getting worked. Once this time period is over then you go to even lighter weight for the oxidative atp phase and try to work through the lactic acid accumulation. This is a killer.

I remember CT had a type of program where you would do something like: 1 rep near your max, 3 fast reps at 80%, 3 slow reps at 80%, 5 reps at 60% fast, and then till failure with 60% slow. Sorry if i got the numbers wrong. I can’t dig up the routine but i know it was awesome and hard. Something like this would definitely give you strength, size and muscle endurance strength. laters pk
[/quote]

But wouldn’t it make more sense to fatigue the type 1 first? that would leave the type 2 alone for the subsequent sets. That would increase the tension they receive, wouldn’t it?

Let’s say you do a 3RM set. All the fibers are recruited, and the type 1 may take half of the load.

An another hand, if the type 1 are prefatigued, most of the load would be taken by the type 2, thus increasing the tension per fiber on them, which is what we want since it’s them really which can grow.

the reason why you do not want to hit a fatigue or failure state while you are warming up is because it would cause you to be too tired for your real sets. Understand that with each subsequent set your body gets more and more tired depending on how hard you hit it. If you don’t have the ability to shuttle out the waste product then your performance will drop. This is one of the important things about being “in shape”, and why short rest periods of 60 seconds are recommended for this.

If you fatigue the typeI first you will not be able to use them to their maximum ability when you are trying to produce high force production.

Why don’t you try a controlled experiment. Figure out your 1 rep max. Take 85% and go to failure. rest 3 minutes, take 60% and go to failure, rest 3 minutes and then take 33% and go to failure. Count the number of reps you did on each set. Repeat this after 72 hours in the reverse order though, first 33% then 60% then 85%. Count the number of reps you do in each set and analyze. Make sure to keep the same controlled rythym for each rep so that force production is the same on both days. Obviously if you are getting tired towards the end of your set it will be difficult to keep the proper rythym going so at that point in time just worry about getting as many reps.
laters pk

There is some evidence that eccentric training can increase fast twitch recruitment.

These include slow “accentuated” eccentrics as well as “shock” or plyos and overspeed eccentrics

There is a principle that states that fibers are recruited in order of size. Small fibers (i.e., type 1) are recruited first REGARDLESS OF THE WEIGHT LIFTED.

If you lift a 5RM weight you will recruit your Type 1 fibers (obviously because they are the first to be recruited) AND your Type 2 fibers. If you lift a 15RM your Type 1 fibers will, of course, be recruited first and as they fatigue the Type 2 fibers will kick in.

I think that in the effort to make a name for themselves in the industry trainers and strength coaches have “over-scienced” the art of training. As mentioned, you can preferentially recruit the Type 2 fibers by doing eccentric contractions. However, it is important to remember that you can lower ~40% more than you can lift so you’ll need a damn strong partner. Rapid eccentrics are also better for hypertrophy, but these are less practical in the gym. To do them effectively you’d have to load the bar up with a weight that you would not “lower” to your chest. A true maximum eccentric would be loading a bar up with a weight that you could not prevent from coming down. You try, but it still comes down. That is a true max eccentric. Not very practical.

Don’t over-science it. Just lift heavy and grow.