Part I:

1.)What is the true meaning of Intensity?

Over the years now the word intensity has changed. Although we have many different interpretations of the world now, the true meaning has stood for over a 100 years. Back in the early 1900's late 1800's Russian coaches described the word Intensity as the percentage of their one rep maximal. In weight training do not get the word 'Intensive' mixed up with the word 'Intensity'. Intensiveness would best be described as emotional motivation or aggressiveness carried out.

2.) Is Weight Training safe for children?

Many times we hear people say that young children should not perform heavy weight training in the fact that it stunt's their growth. Many scientist have done research disproving this theory. The Soviet Union published a book known as "The School of Height" debunking the myths that children should not do heavy weight training. Great Britain published a journal study supporting outlining test they performed on young power lifters showing they had better bone density and their bones where much more durable then that of children not subjected to heavy weight training or any other form of impact loading. It is also relevant to note that athletes subjected to heavy loading and resistance are relatively free from osteoarthritis in old age and the subjects that were not exposed to heavy loading and resistance show a much greater incidence of osteoarthritis and cartilage fibrillation. There has also never been a reported and documented case that has had claims of weightlifting stunting the growth of a child.( Bullough et al, 1973, Kempson et al 1975, Seedhorn & Swann 1985, Seedhorn & Wright 1988, Seedhorn et al 1977)

3.)What is hyperplasia?

Very little is known about hyperplasia. Hyperplasia is the splitting of muscle fibers. There has been testing done with animals such as cats(and rats) that have shown muscle fiber splitting. These cats where subjected to heavy resistance training for a prolong period of time. It has also been noted that many Russian scientist have conclusively came to the finding that muscular mass is not only through hypertrophy of muscle fibers (enlarging) but also as an increase in fiber number by means of splitting into smaller sections. It has also been documented that satellite cells, which can activate new cell formation, has been shown to be associated with muscle hyperplasia, through stretching and dynamic exercises. Many people believe that hyperplasia does exist in humans possibly through heavy intensive training sessions, but lack of human testing cannot conclude this.
(Gudz, 1968,1976;Gonyea, 1980; Hether et al, 1991; Tamaki et al, 1992; Antonio & Gonyea, 1994)

4.) What is a muscle fiber?

Your body contains thousands and thousands of muscle fibers. Several of these fibers are bundled together to make up a fasciculi (fascicles) which are incased in a sheath called a perimysium. Many groups of these fasciculi's form the whole muscle, which is then enclosed in another sheath called the epimysium (or fascia). Each fiber cell has several thousand rod-like structures known as myofibrils. Myofibrils consist of a chain of basic contractile units known as sacromeres. Sacromeres consist of both myosin and actin filaments. There are also small areas of the myosin filaments that are called cross bridges. These cross bridges are temporary connected to certain parts of the action filaments that form the basic components for a muscular contraction.

Myosin plays a special role in determining the contractile of the muscle. The myosin heavy chain (MHC) appears in three different is-forms. They are referred to as I, IIa, and IIx forms. They are also located in the muscle fiber that contains them I-I, IIa-IIa, and IIx-IIx. Ia fibers are referred to as slow twitch muscle fibers (ST/Red), whereas IIa and IIx are referred to as fast twitch muscle fibers(FT/White). Type IIx is the fasting contractile muscle fiber. IIx has a contractile velocity 10 times that of a Ia fiber, where IIa lays between them. I, IIa and IIX fibers also have various other forms as well. These fibers are known as hybird fibers which are scares in young people but rather common in adults.

The difference between person to person vary dramatically according to the person and training history. It has been reveled that the elite track athletes and Olympic styles weightlifters, over 60% FT fibers, have three times the fast twitch muscle fibers then that of a marathon runner, approximately 17% FT, and 50% greater in bodybuilders,40% FT fibers. Sub-maximal and high explosive weight training has also produced great hypertrophy of FT fibers. The potential for the body to generate high power output in Olympic style weightlifting movements and other forms of speed movements is determined highly by the proportion of FT fibers.

In every movement muscle fibers are recruited and fired, depending on the movements velocity, load and duration of the set determents which fiber is the most dominantly recruited and fired. The first fiber is the Ia which is resistance to fatigue and last a prolong period of time. The second fiber recruited is the IIa which is a fast twitch fiber which last and intermediate amount of time. The last fiber to be recruited is the IIX fiber which also has the strongest contractile out-put. Olympic lifters have a higher firing rate of FT fibers then ST fibers, whereas a bodybuilder has a higher firing rate of ST fibers then FT fibers. The reason for the differences is Olympic lifter train with lower repetition sets, where their resistance is heavier and more explosive then that of a bodybuilder who normally trains with moderately heavy weight slowly to failure.(Andersen et al, 2000;Hakkinen, 1985)

5) What is Hypertrophy?

Hypertrophy is the gaining of muscular bulk. There are two causes of hypertrophy and they are:

Hyperplasia which we discussed earlier in this article.
The enlargement of cross-sectional areas of certain fibers. (Sarcoplasmic hypertrophy and Myofibrillar hypertrophy)

Sarcoplasmic hypertrophy the volume increases of non-contractile proteins and semifulid plasma build up or increase between the muscle fibers. Although the cross-sectional area of the muscle increases greatly, the lack of fiber density decrease causing a loss in force production. This form of hypertrophy is greatly found in bodybuilders.

Myofibrillar hypertrophy the myofibrils increase in density and increase in individual numbers. Unlike that of sarcoplasmic hypertrophy the cross-section increases which allows the ability to generate and exert force. This form of hypertrophy is mostly found in elite Olympic weightlifters and power lifters.
It is not unreal, but unlikely, that athletes from different sports such as bodybuilding can exert force to that or greater then a power lifter or its not uncommon to see a power lifter exhibit muscular bulk as great as that of a bodybuilder. Although it is highly doubtful that a bodybuilder could exert a force as great as an elite Olympic weightlifter. Heavy resistance training contributes to both forms of hypertrophy, but the design of the training program and genetic factors play a role in the development of hypertrophy to individuals.