Learning The Muscle Fiber Types
One factor that many people overlook when they do all their
research about the best type of muscle building strength
training program to go on is the various types of muscle tissue
and what type of training is best suited to them.
While you can’t differentiate between muscle fibers from your
outside appearance, on the inside of the muscle tissue body,
there are three main different fibers present.
Type A Fast-Twitch Muscle Fibers
The first type of muscle fibers are known
as Type A Fast Twitch and are responsible for the most forceful
contractions generated, however, will fatigue the fastest.
For example, if you were to perform an all out set of 3 reps
for bench press, you would predominately be using these type A
muscle fibers.
They tend to have very large motor neurons and very low
mitochondrial density. They also have a low oxidative capacity,
meaning they will not be able to utilize oxygen very well. It
is for this reason that they are not suited to endurance type
of activities, because during these exercise variations, oxygen
must be present in order to sustain the muscular
contractions.
The major type of fuel that these muscle fibers are going to
rely on is creatine phosphate and stored muscle glycogen
(glucose). They will not utilize stored body fat at all due to
the fact that they are only able to continually contract for
between one and about 20 seconds.
Type B Fast-Twitch Muscle Fibers
The next muscle fiber is also classified as a fast twitch
muscle fiber but not to the extent that type A are.
This muscle fiber type is mostly utilized in activities that
are relatively short in duration, but are not at an all out
pace.
For example, if you were to sprint 100 meters, you’ll be using
mostly type A. If on the other hand, you are to do a running
interval at about 80-90% of your max capacity for 30 seconds,
this would utilize the type 2A more.
Some of the characteristics of the type B are that they still
have a large motor neuron (not as large as Type A though), they
are on the intermediate scale as far as being resistant to
fatigue, and they have a high degree of mitochondrial
density.
These muscle fiber types are also able to use oxygen to a great
extent, as demonstrated by their higher resistance to fatigue
and longer duration of contraction abilities.
Slow Twitch
Finally, the third type of muscle fiber that you have in your
body is classified as slow-twitch.
This is the muscle fiber type you would use if you were to run
a marathon or any other extended duration, medium-to-low
intensity activity.
These muscle fibers have a very high ability to resist fatigue
and have a large oxidative capacity.
They are also relatively slow to contract, therefore you cannot
expect a great deal of force generation from these muscles,
thus, will not be intended for exercises requiring a high
degree of power.
They are very high in terms of mitochondrial density and have a
large number of capillaries running throughout their
bodies. This is to enable sufficient oxygen to get to the
muscle tissues so that they can carry on the extended duration
of muscular work they are intended to do.
These are also the muscle fibers that will also rely more on
fat as fuel, as opposed to strictly using carbohydrates or
creatine phosphate.
Training The Muscle Fiber Types
So, now that you’re familiar with the three major classes of
muscle fiber types, it’s time to recognize how you would train
each effectively.
Since type A are your primary force generators, if you wish to
get a higher performance from them you’ll need to train using
exercises that require you to max out your effort for a short
period of time.
Think sprinting at full speed, 1-5 rep sets for lifting, and
any type of plyometric activities.
Next, to train your type B muscles fibers, you’ll want to
slightly decrease the force with which you are to contract
while simultaneously increasing the time over which you
contract ever so slightly.
For example, perform 30-45 intervals repeated ten times with
about a minute or a minute and a half at a low to moderate
pace. For your weight training activities, aim to target
the 6-10 rep range to utilize the fact these muscle fibers have
a higher oxidation ability.
Finally, to improve your slow twitch muscle fibers, think
endurance. This type of fiber will usually require the greatest
amount of time to train for improvement because you’ll want to
focus on simply going ‘longer’. If you’re a runner, try
and run longer. If you’re a biker, bike longer. If you’re a
swimmer, swim longer - you get the point. This type of muscle
has the ability to go for extended periods of time so this is
exactly what you want to train it to do.
So, next time you are trying to sort out your training plan,
make sure to take the various muscle fiber types into
consideration.
Doing so will allow you to make the most out of your training
program so you get the exact results you’re looking for.
About the
Author:
Vince DelMonte is the author of No
Nonsense Muscle Building: Skinny Guy Secrets To Insane
Muscle Gain found at No
Nonsense Muscle Building
He specializes in teaching skinny guys
No Nonsense Muscle Building
without drugs, supplements and training less than
before.
© 2006-2008, Vince DelMonte Fitness. All
rights in all media reserved.
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