Nearly every sport requires strength, but what each sport really calls for is sport - specific - strength. Mxs plays an important, if not the determinant, role in creating sport - specific strength. An athletes ability to generate MxS depends to a great extend on the diameter or cross-sectional area of the muscle involved, more specifically, the diameter of the myosin filaments, including their cross bridges; the capacity to recruit FT muscle fibres; and the ability to synchronize all the muscles involved in an action.

Muscles size depends greatly on the duration of the hypertrophy phase, where the diameter of myosin/actin and the increase in protein content in the form of cross bridges depends on the volume and duration of the Mx S phase.

STRUCTURE OF THE MUSCLE Celle

A muscle consist of special fibers of a few inches long to more then 3feet that extend the entire length of the muscle. This fibers are grouped in bundles called FASCICULI, held together by a sheath called the PERIMYSIUM. Each fiber contains many threadlike protein strands called MYOFIBRILS, which hold the contractile units, the SARCOMERES. Each sarcomere contains a specific arrangement of the contractile protein’s myosin(thick filaments) and actin(thin filaments), whose actions are important in muscle contraction. The ability of a muscle to contract and exert force is determined by its design, the cross-sectional area, the fibers length, and the number of fibers within the muscle. The number of fibers is genetically determined and is not affected by training; however, the other variables can be. Dedicated training increases the thickness of muscle filaments, increasing both muscle size and force of contraction.