Muscle growth happens by way of 2 mechanisms:
(1) The enlargement of individual muscle cells and muscle fibers via elevated
protein synthesis caused by anabolic substances. This is the first growth mechanism and
its called hypertrophy. Androgens such as testosterone and
all AAS have the greatest effect at this level.
(2) The second is called hyperplasia which involves the formation of new muscle
cells and fibers. Though hyperplasia has not been proven in humans, there is a great deal
of research creating great doubt that it does not. As example…a study involving a group
of college students that were untrained, and a group of competitive bodybuilders that
were. Obviously the bodybuilders had much larger arm measurements, yet when muscle
biopsies were performed on both groups the individual muscle fibers were identical.
Since the bodybuilders had significantly “more” fibers, the researchers theorized that they
must have experienced hyperplasia.
Another study on power lifters told the story much more clearly. Two groups of
highly trained power lifters were divided in two (groups that is). One group had trained
life-long steroid free while the other group had an average of 9 years of steroid use. The
steroid group had cycled Anadrol-50, Winstrol-V, Primobolan, Deca Durabolin,
Masteron, and Proviron off and on in various combinations for that period. The steroid
group showed a significant increase in the “number” of muscle fibers when compared to
the drug free power lifters. In the steroid group, researchers also noted an increase in the
number of muscle cell nuclei and an enhanced proportion of newly formed muscle fibers.
These new fibers with more nuclei were formed from satellite-cells. Satellite cells are
immature muscle cells. That is HYPERPLASIA.
Another finding that is equally amazing is that the satellite-cells were found to
have a higher number of androgen receptors. This means that the new cells/fibers have a
greater capacity to use androgens such as AAS. This study showed that the size of the
muscle cell reflects the number of cell nuclei. This study also showed that there was an
increase in satellite-cell numbers in the steroid group significantly higher when compared
to the drug free group.. So what does this all mean?
Intense training with heavy weights creates a stress on muscle fibers and cells
high enough to cause hyperplasia and cellular growth. Those who utilize AAS as part of
their training protocol accelerate these responses to the training stimuli. The newly
formed muscle cells and fibers have a higher content of androgen receptors so AAS work
better on these new cells. Since AAS cause an increase in muscle cell DNA and therefore increases protein synthesis with no increase in catabolism, (actually AAS decrease the normal rate of catabolism) the formation of new cells and fibers is accelerated. Bigger muscles! An important point to add is that years of training intensely
can pay off for those who do not give up training without AAS. New fibers added to existing fibers means more fibers that can grow. In theory, this suggests AAS, which are highly anabolic, (protein synthesis) would be advantageous over those providing higher androgen qualities for long term gains. This is, in part, why more lean mass has been
retained post-cycle when high anabolic/ low-moderate androgenic steroids were utilized.
