-“How Training Hasn’t Changed in
-“Slow-twitch or Fast-twitch: Am I One or
the Other, or Both?”
-“Is muscle damage necessary for muscle
growth?”1 – IS THERE ANYTHING NEW IN TRAINING?
How Training Hasn't Changed In 20 Years
years ago, and likely much longer before that, coaches were
already instructing athletes to “shock” the neuromuscular
system by changing workouts every 3 weeks or less! A lack
of variety can kill the momentum and minimize the adaptations
of a hard working individual regardless of their effort
in the gym or their diligence at the training table in their
nutrition. If you continue to demand the same effort from
your body each and every training session then it will adapt
to deliver with the least effort, and therefore the least
adaptation. The human body is very efficient, thus it likely
does require “shock” training.
coaches have always known that the legs are the “engines”
behind power production and athletic performance. Program
design based on this focus was evident in the 70’s and has
persisted into the millennium. As well, it has long been
recognized that there is more to performance than just leg
strength. Athletes must be able to convert their strength
into power, so they must be able to apply the force quickly.
Even in the early 80’s this was recognized and Plyometrics
were incorporated into the training programs. Don’t be fooled
into thinking that Plyometrics are at all a new technique.
– IF MY QUADS ARE FAST-TWITCH, ARE MY BICEPS AS WELL?
athletes succeed based on the characteristics of their muscles.
For example, sprinters are often labeled as having a high
percentage of fast-twitch fibers in their leg muscles, allowing
them to be both fast and strong. By fast-twitch muscle,
it means that the majority of muscle fibers, or at least
more than the average, in a certain muscle are fast-twitch.
In humans, no muscle group is composed of strictly fast-
or slow-twitch fibers. For a review of fiber types and physiology,
see ISSUES #50-52.
if the sprinter has predominantly fast-twitch fibers in
their legs, does this go without saying for the remainder
of the muscles in the body? While at first glance this may
not seem a pertinent issue to the sprinter (after all, they
run on their legs, not with their biceps) it has relevance
to designing strength-training programs.
all, for those with an advanced interest in strength training
and bodybuilding, they will recognize that some strength
coaches and personal training experts have based entire
workouts and training programs on their beliefs of the client’s
predominant fiber type. Thus they are making the assumption
that if my quads are fast-twitch, then my biceps are as
what better way to solve the problem than to go to an expert
for the answer? Well, who better to ask than an expert in
neuro-muscular physiology, Dr. Digby Sale at McMaster University.
what Dr. Sale had to say, “It's a good question that, to
my knowledge, has not been systematically examined. The
only study that I am aware of is one by Tesch and colleagues,
which showed that trained cyclists had an above average
% of slow-twitch fibers in their legs but had an average
% of slow-twitch fibers in their deltoid muscles. In contrast,
for kayakers it was the reverse (higher % slow-twitch in
the deltoid and average % of slow-twitch in the legs).
data could be interpreted in two ways: 1) inherited extremes
in fiber type distribution are muscle specific; 2) years
of endurance training caused a fast-twitch to slow-twitch
conversion in the trained muscles, but not the untrained
muscles of the athletes were unaffected.” Basically Dr.
Sale has outlined the cause of an age-old debate, “Athletes
are born, not made.” or vice-versa.
There may be cadaver studies available in a medical journal
that has addressed this question indirectly, but those studies
likely don’t address our issue specifically. Because cadaver
biopsy studies generally use “average” individuals as subjects,
we still don’t know if athletes in particular have a variance
in their fiber type proportions between muscles.
Hypothetically, in obvious contrast of the data provided
by Dr. Sale, one should expect to see the same fiber proportions
in all muscles of an individual (disregarding any influence
of activity). For example, if you do have a higher than
normal % of fast-twitch fibers in your quadriceps, you should
expect to see a higher % of fast-twitch fibers in your deltoid.
Unfortunately, our daily activity levels may be a confounding
factor (as seen in the data mentioned by Dr. Sale).
Why should all muscles be the same? If you are familiar with human biology,
and more specifically human embryology, you know that the
mesoderm differentiates into muscle tissue. Thus all the
muscles come from the same “germ” layer of cells, therefore
an individual may genetically have a “fast-twitch” germ
layer from which all muscles will develop with a fast-twitch
bias. Is this the determining step? Unfortunately, this
argument is beyond the scope of my expertise and probably
requires a Ph.D. to answer with merit, but it does give
you something to think about before following a program
designed for “fast-twitch” muscles…
– MATCHING MUSCLE GROWTH WITH MUSCLE DAMAGE
Freddie wondered that if a trainee attempted to reduce or
prevent muscle damage from weight training, would this subsequently
impair muscle growth? Freddie is certainly not out in left
field, but rather he is definitely on the right track. However,
there must be a threshold that your muscle damage can return
from. The difficulty is in training and causing the optimal
amount of muscle damage that you inflict.
studies have correlated muscle breakdown to the amount of
muscle synthesis, but you can go too far. After extreme
eccentric exercise, muscle fibers (cells) can breakdown
to a point that they die, but on the other hand, you want
to damage the muscle to the level that will provide maximal
adaptation. Some excellent muscle damage research by Nicole
Stupka, Stuart Lowther and others has come out of the prestigious
lab of Dr. Mark Tarnopolsky at McMaster University. These
researchers induced muscle damage with eccentric training
and found that this routine could stimulate the expression
of proteins involved in apoptosis (cell death) in skeletal
is a fine line between effective training and overtraining
(for lack of a better word). Put simply, you must train
& induce an optimal level of damage (stimulus) -->
then you must provide rest so that adaptation (repair) can
occur in the muscle cell (repair) --> and by the provision
of nutrients you can further promote optimal adaptation.
you reduce damage and still grow? Likely, but one estimate
the magnitude of impairment. In fact, by providing excess
calories or by taking steroids you can add muscle without
even training! But practically, with respect to training,
how does one reduce damage yet still provide an optimal
stimulus to the muscle? Perhaps by providing immediate post-workout
nutrition you can prevent further protein breakdown, but
the mechanical damage from training has already been done,
therefore the nutritional intervention will not prevent
muscle damage or soreness.
agreed that some muscle damage must occur, but the damage
should occur only in response to training, and even that
should not be excessive. Furthermore, proper post-workout
nutrition should be incorporated to prevent further breakdown
of proteins. Unfortunately, determining the optimal amount
of damage (and thus the optimal training program) is an
elusive goal and is what separates the best from the rest.
N. et al. Gender differences in muscle inflammation after
eccentric exercise. J. Appl. Physiol. December, 2000.