Choosing the best type of workout program that will stimulate the
muscle fiber type that will get you the results you??re looking for
is extremely important.
Unfortunately, all body building
programs are not created equally when speaking in terms of muscle
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.
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
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.
fiber type is mostly utilized in activities that are relatively
short in duration, but are not at an all out pace.
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
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
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.
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, 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
These are also the muscle fibers that will also rely more
on fat as fuel, as opposed to strictly using carbohydrates or
Training The Muscle Fiber
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
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??.
you??re a runner, try and run longer. If you??re a biker, bike longer.
If you??re a swimmer, swim longer ?V you get the point.
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.
time you are trying to sort out your training plan make sure to take
the various muscle fiber types into consideration.
will allow you to make the most out of your training program so you
get the exact results you??re looking for.