Muscles on Muscles

Unfortunately, 99.999% of us humans are not blessed with the genetic abnormality of Myostatin deficiency, like those lucky beasts, the Belgium Blue cattle.
Myostatin is a growth factor which inhibits muscular hypertrophy (or growth) and there is nothing any of us can do about the levels of myostatin in our body. It's down to pure genetics.

What we CAN do is decide on a training methodology to ensure we maximise muscular hypertrophy to the greatest possible extent.
When we exercise our muscles grow. This growth is a result in an increase in the size of the cells of the muscle, NOT as a result of growing more muscle cells (muscular hyperplasia).

The first thing that happens when someone, who has not been active, begins to exercise, is a Neural Response. This is an increase in the neural drive which results in muscle contraction. After just a couple days of training, a previously inactive individual can see noticeable gains in strength just from "learning" to use the muscle.

After a couple of months of training hypertrophy will kick in and muscle growth will occur. Hopefully it's the right type of muscle growth.

In my opinion, you are after myofibrilated hypertrophy - which means you have gained muscle size due to increase in thickness of muscle cell walls, rather then sacroplasmic hypertrophy, which is increase in muscle size due to an increase in volume of cell sarcoplasm (or the fluid which fills the cells)

Myofibrilar hypertrophy is attained by lower rep, lower duration, higher intensity exercise, and is characterised by muscular growth such as sprinters, olympic weightlifters, powerlifters and strength athletes.
Sarcoplasmic hypertrophy is as a result of high rep, lower intensity longer duration exercise and results in muscular hypertrophy characteristic in professional body builders and endurance athletes.

In my opinion, Sarcoplasmic hypertrohy is a waste of time and effort. What's the use of a huge bicep if you cant do one pull up?

How to use this information:
Train to get strong and fit. Not to have a six pack and tiny waist. Lift heavy and hard. Dont waste your time on low effect cardio. Train for conditioning