LEARNING THE MUSCLE FIBER TYPES
By VINCE DELMONTE
Choosing the best workout program, to stimulate the muscle
fiber type you need to get the results you’re looking for, is extremely important.
Unfortunately, all body building programs are not created equally, when speaking
in terms of muscle fiber types.
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, they 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 as 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 muscle
fibers 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 relativelyslow to contract,
therefore you cannot expect a great deal of
force generation from these muscles, and 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.
For a comprehensive training guide that includes information of muscle fiber training click on No Nonsense Musclebuilding.
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