Case Study 4
You are teaching a college undergraduate exercise physiology class. One of your students, Bob
Parker just started a resistance training program. He is surprised at his increase in strength (in the
first 6 weeks), but he has not increased his muscle size. He would like to know how this is
possible. Then, 3 months later, Bob feels stronger, but notices that his muscles have not
sufficiently grown larger, and he wonders how he has gotten somewhat stronger without
sufficient muscle growth. Explain to Bob what exactly is going on and why his “genetics,”
training, and other related variables might be hindering his size development (160pts).
For most males that go to the gym, muscle hypertrophy, which is muscle size growth, is
the goal of their workouts. The student, Bob Parker, has noticed his growth in his performance,
but has not seen the same growth in the mirror. While some of his muscles probably have grown,
he may be dealing with the adaptive nature of the body, where the CNS (Central Nervous
System) is inhibiting the immediate muscular hypertrophy response. This inhibiting is due to the
CNS calling for other adaptations to occur prior to the hypertrophy. Those adaptations can
include increased coordination, increased motor unit recruitment, response time, and contraction
rates. For Bob, the strength gain that he is noticing is mainly taking place in the coordination of
his muscular system and his nervous system, which means that these two systems are working
more efficiently together. Another adaptation that is becoming more efficient is the motor unit
contraction rates, which results in an increase force production and an increased level of
maximal tension. These two increases together lead to an increased level of strength, which is the
change that Bob Parker is referring to.
Since Bob Parker is using resistance training to increase his strength and pursuing muscle
hypertrophy, understanding that the muscle growth comes with ligament and tendon growth as
well. These two become more resistant to opposing forces, creating a greater level of strength
and ability for them to complete their task. Specifically speaking, the Golgi Tendon finds its
adaptation through resistance training by allowing more freedom of movement for the muscle,
allowing them to find more ways to produce force and fire more motor units when completing a
movement.
Backtracking to the CNS and the other neural adaptations that the body undergoes when
participating in resistance training, which are determined by the type of contractions the muscles
are being called to utilize. All of these adaptations are controlled through the spinal cord, the
NMJ (neuromuscular junction), and the motor cortex throughout the participation of resistance
training.
For Bob Parker, the growth in his strength that he has noticed in these beginning 6 weeks,
will not be matched with muscular hypertrophy until the following 6 weeks, being that the
resistance training program remains the same. Any level of significant drop off in the program
will result in a lesser amount of hypertrophy. The hypertrophy will not significantly affect the
force production, motor unit recruitment, contraction rate or the coordination. In fact, the
hypertrophy may lead to these adaptations becoming more efficient, now that the muscles that
they are using are not larger and stronger. The only change that one will notice is the lack of
recruitment of Type II motor units, being that the hypertrophy will require a greater level of low
force motor unit recruitment, which is found in the Type I motor units.
As mentioned, after the initial 6 weeks of neural adaptations, the following 6 weeks will
be followed with muscular hypertrophy. However, even though the muscle growth is increasing
along with the motor unit recruitment, not all of the motor units are being recruited. In fact, a
larger muscle that is being produced in the following 6 weeks, may not mean a stronger muscle,
unless that muscle is put under a correct amount of progressing resistance. This lack of increase
in strength is due to the lack of work that has not been place on the nervous system. If one is only
working the muscular system and not the nervous system, one could find themselves only
increasing the muscle size without significantly increasing the muscle force production, which
would lead to a wasted resistance training program.
Being that Bob Parker’s training age is under a year old, the program he is participating
in needs to be assessed. Bob needs to focus in on the reps and the fundamentals of movement.
This requires an increase in volume, to practice the movement, and a lower level of resistance, so
that Bob can control the movement. Beginners will notice progress through adaptations by
completing 2-3 training sessions a week (Haff & Triplett, 2016). Those 2-3 days will be where
Bob Parker can find ways to slowly increase his load, or resistance, over the month, while
consistently attacking the same level of volume within that month.
I would recommend that Bob Parker keeps his reps at amount 8-12 reps per set,
completing about 3-4 sets of each exercise, leaning more towards the higher amount of reps for
the muscle growth that he is pursuing. Bob should increase his resistance from low to moderate
throughout the program, with his goal being that he has a couple reps left “in the tank” after each
set. This will allow for muscular hypertrophy, and being that Bob is new to resistance training,
this will also result in strength increasing, especially early on in his program.
