Training For Your Body Type

Over the years I've been asked hundreds of times: "How do I gain mass?" The simple answer is always train harder, eat more and get sufficient rest. More often than not though, I find myself delving into the individual's diet and training habits, refusing to take the easy way out. Typically my investigation begins with such questions as: how many days do you train, how many exercises, how many reps until failure, goals, typical daily diet habits, etc. Usually at this point it becomes apparent that most people do not know enough about their own body to make a significant impact on the size of their muscle tissue - which has led me to write this article.
To truly understand your body and achieve your desired goals, you must first determine your body type. Body types, or somatotypes, fall under three different classifications: endomorph, mesomorph and ectomorph. The classic endomorphic physique is characterized by the ability to gain muscle and fat easily, a naturally strong, "stocky" build and the inability to lose fat rapidly due to a very slow metabolic rate. Offensive linemen and strongmen are typically endomorphs. At the opposite end of the spectrum is the ectomorph: your classic "hardgainer." These individuals are typically characterized by a thin build, long, thin limbs with stringy muscles, and a small frame and joints, and are typically extremely lean and struggle to gain any substantial amount of lean muscle mass due to an extremely fast metabolic rate. Examples of ectomorphic physiques are those of distance runners and cyclists. The third and final classification is the mesomorph: the classic athletic physique, the one we all aspire to look like. These individuals possess the ability to gain lean muscle mass quickly, lose body fat rapidly, are naturally strong, and display round, full muscle bellies, ideal for bodybuilding. Now you may be thinking that you don't fit exactly into any one of these three classifications; and it is possible. Due to training, or genetics, you may be a hybrid of two classifications. To make it simple, consider the traits of your physique and align it with the one category that you have the most in common with. From here we can start to develop a plan that best suits your needs.
Now that we have determined your somatotype, we need to talk about fiber types. The striated muscles of the human body are comprised of different fiber types. The term for the balance between the different fiber types is one you may recognize: fiber type distribution. The ratio of slow- to fast-twitch fibers may determine one's ability to gain strength and muscle mass. Before we get into that discussion, let us first determine the differences between the fiber types contained within your skeletal muscles.

The first fiber types that we must talk about are slow-twitch fibers (Type I). These muscle fibers are characterized by a high resistance to fatigue and a slow contraction time (how quickly force is generated). Typically slow-twitch fibers have very low concentrations of creatine phosphate as well as glycogen and glycolytic enzymes. Remember, our muscles use the energy from ATP, made by creatine phosphate, to contract/release, especially during anaerobic training, which uses a glycolytic energy pathway. So these fibers are more beneficial during times of aerobic training, not anaerobic training. Another key feature of slow-twitch fibers is the fact that they contain higher triglyceride stores and oxidative enzymes. Aerobic training uses oxidative energy pathways (oxidative phosphorylation, Krebs cycle), which yield higher amounts of energy and are typically fueled by fat stores.
The next fiber type that we will discuss, fast-twitch fibers, can be divided into two separate categories, Type IIA (a.k.a. fast oxidative) and Type IIB (fast-twitch). Type IIA fibers are in between Type I and TypeIIB fibers, possessing properties of both. These fast oxidative fibers have a moderate resistance to fatigue due to higher creatine phosphate and glycogen stores, as well as moderate triglyceride levels. Within the Type IIA fibers, there is a balance of glycolytic and oxidative enzymes. These characteristics make Type IIA fibers ideal for prolonged anaerobic training - supersets, giant sets, drop sets, or for sprinters who run 400 and 800 meters.
The second of the two fast-twitch fibers, Type IIB, is most valuble in the realm of weight training. These particular muscle fibers have the highest concentration of creatine phosphate, thereby generating ATP quickest, in addition to higher levels of glycogen and glycolytic enzymes. These characteristics are ideal for weight training and strength activities, generating the most force in the shortest period of time, allowing an individual to overload the muscle - all necessary for muscle growth.
When it comes to training for mass and strength, fast-twitch fibers (Type IIB) are probably of more interest to you. We needed to talk about the other two first because fiber recruitment starts from smallest to largest. No matter how heavy a weight you may move, slow-twitch fibers will contract first; they may not generate much force, but they will always contract first. As the intensity escalates, increasing the need to generate force, fibers with the larger motor neurons (Type IIA and IIB) will be activated to generate the necessary force. This leads to my next point: in order to gain muscle mass, it is necessary to train at a high enough level of intensity to activate fast-twitch fibers. Far too often individuals fail to train at a high enough level of intensity, thus failing to recruit and activate fast-twitch muscle fibers. To gain muscle mass, you must place a demand on these fibers. First off, they are the only fibers capable of generating the force needed to move weight heavy enough to cause the microtrauma necessary for muscle growth. Additionally, fast-twitch fibers have much greater surface area than slow-twitch fibers. By training in a manner that targets fast-twitch fibers, your muscles will hypertrophy (grow larger) due to the fact that fast-twitch fibers are bigger and are receiving the most stimulation. Not only will the size of the muscle increase, but so will strength; thus size and strength are related. If muscle hypertrophy (size) is what is most important to you, you will want to train with a weight that brings about muscular failure between 8 and 12 repetitions. You will still gain strength, due to the increase in the size of fast-twitch fibers, but more importantly you will be causing muscle hypertrophy.
You are probably wondering, "How does this all help me with gaining mass, and what does my body type have to do with it all?" When you look at body types, you will see correlations with certain fiber types. Take an ectomorph for example: very lean, stringy muscles. This would lead us to believe there is a larger distribution of slow-twitch fibers, since slow-twitch muscle fibers have a smaller cross-sectional surface area. In order for that individual to gain muscle size, the primary focus must be on stimulating fast-twitch muscle fibers as much as possible. The number of slow- and fast-twitch fibers will not change, but the relative size of each can. As the fast-twitch fibers grow larger and hypertrophy, the slow-twitch fibers may start to decrease in size (atrophy). When this happens, the relative percentage of fast-twitch fibers, in terms of overall muscle size, is increased. This individual may not have the genetic structure to become a professional bodybuilder, as would a mesomorph, but they can definitely manipulate their fiber type distribution to increase the size of the muscle as much as possible. So for an ectomorph, the ideal rep range for stimulating the most fast-twitch fibers would be 4-8 reps per set. In the case of a mesomorph or endomorph, these individuals already have larger amounts of fast-twitch fibers, so when they train these particular fibers, hypertrophy is accelerated, thus putting them at a genetic advantage for gaining lean muscle mass. A mesomorph would see greatest gains in muscle mass training in the 8-12 rep range, while an endomorph may experience better results training in a 12-15 rep range.
No matter what your body type, or fiber type distribution, you will always have the ability to increase the amount of high quality lean muscle mass you carry on your frame; the quantity of your gains is what may vary. If you're like me, you will want to get the greatest gains out of your efforts. By training based on your body type, you will be able to maximize your efforts in gaining lean muscle mass.