So you want to gain muscle? There are many different programs and methods of training out there that are going to accomplish muscle growth. Add to that the fact that each individual is unique and that what may work for one in acquiring muscle mass may not work for another.
There are, however, general standards and principles that most 'mass gaining' training programs are based upon; and whilst many use traditional methods of training for hypertrophy, there are other ways to achieve the same, if not better, results.
This article will discuss the different types of muscle fibers, the physiology of muscle growth, training parameters that work best for hypertrophy, and provide a sample program for muscle building.
Slow Oxidative Fibers:
Slow oxidative fibers are commonly referred to as Type I muscle fibers. These muscle fibers are recruited first during activity, contracting slowly due to slow Myosin ATPase activity.
Although Type I fibers have a high Myoglobin content, they contain low glycogen levels, using aerobic glycolysis for Adenosine Triphosphate (ATP) (i.e. energy) synthesis.
Myoglobin:
Myoglobin is a single-chain globular protein of 153 or 154 amino acids, containing a haem (iron-containing porphyrin) prosthetic group in the center around which the remaining apoprotein folds. It has eight alpha helices and a hydrophobic core.
A high oxidative capacity, due to the many capillaries and mitochondria that they contain, allows them to have a very slow rate of fatigue, therefore making them best suited for endurance activities such as distance running (Marieb, 2004).
Fast Oxidative Fibers:
Fast oxidative fibers, also called Type IIa muscle fibers, are recruited second during exercise. Like Type I fibers Type IIa fibers have high Myoglobin content and many capillaries and mitochondria.
However, instead of low glycogen stores their glycogen content is moderate, causing them to be moderately fatigue resistant. Alongside this, they have fast contractile speeds and Myosin ATPase activity, therefore making them best suited for activities that use both the anaerobic glycolysis and aerobic glycolysis energy systems, such as sprinting (Marieb, 2004).
Physiology Of Muscle Growth
When muscles are used they adapt and change. Changes are dependent on the type of activity and muscle fiber types used, the load exerted on the muscle, and the velocity and duration of the contraction (Marieb, 2004).
Muscle growth, also referred to as muscle hypertrophy, is an example of muscular adaptations and changes.
Muscle hypertrophy occurs primarily through chronic anaerobic, high-intensity resistance activity, like that which happens during resistance training lifting weights (Brown, McCartney & Sale, 1990; Cureton, Collins, Hill, & McElhannon, 1988; Marieb, 2004; McCall, Byrnes, Dickenson, Pattany, & Fleck, 1996).
Resistance training causes neural adaptations, which result in changes in muscular endurance and muscular strength, and eventually, the size of the muscles (Fleck & Kraemer, 2004).
Resistance training causes an increase in the cross-sectional area (CSA) of all muscle fiber types (Brown, et al., 1990; Cureton, et al., 1988; Holm, et al., 1991; McCall, et al., 1996; Widrick, Stelzer, Shoepe & Garner, 2002), without an increase in muscle fiber numbers (McCall, et al., 1996).