Your DNA determines how many muscle fibers a person is born with. This
number never changes cause one can't make more muscle fibers during
their lifetime. With more muscle fibers, one has the potential to be
stronger. It is an acquired trait because you could train your
muscles to become bigger. When you train, for example resistance
training, your muscle produces more myofilaments which increases their
diameter. This is why you develop large muscles when you train.
The size of the muscle is partly dependent on the DNA and exercise.
This is because DNA traits is actually responsible for how a muscle formed in the body. This trait is usually gotten from the parents of the offspring.
In the same vein, exercises can also be responsible for the size of an individual’s muscle. Exercises help in the expansion and building of muscle tissues which makes it bigger.
