As mentioned previously, the amount of force produced by a muscle is linked directly to the number of actin and myosin fibers in a muscle. This explains why the larger muscles which contain a greater number of actin and myosin, produce a greater force. Resistance training can cause the muscle size to grow in two ways, hypertrophy or hyperplasia (Powers, 2015). Hyperplasia is an increase in the total number of muscle fibers in a single muscle. However, there is not much evidence that muscle actually increases in size because of this method. There are many studies that confirm and deny this method. Most of muscle size increase, 90%-95%, occurs due to hypertrophy. Hypertrophy is an increase in the cross-sectional area of a muscle fiber, or the increase in the actual size of the current fibers (Powers, 2015). It is the primary method of muscle size increase in long-term strength training. This increase in the size of filaments is due to an increase in myofibrillar proteins, for example actin and myosin. The increase in these actin and myosin filaments occurs because additional sarcomeres are added to the current sarcomeres. Additions of these proteins increase the number of myosin cross-bridges, which increases the ability to create force. Resistance training increases the size of both type I and type II muscle fibers, but there is greater amount of hypertrophy in the …show more content…
It is the main component that generates the force to move the body. Skeletal muscle comprises much of the body’s weight, 40% (Frontera, 2015). The skeletal muscle works by contracting. This is explained in the sliding filament theory where myosin binds to actin and pulls the actin past it. This causes the contraction and the generation of force (Frontera, 2015). Skeletal muscle is unique in the fact that it can adapt to specific types of training. The two main types of training are endurance and resistance. Endurance training causes the skeletal muscle to switch from fast to slow muscle fiber type. It also results in an increase in the total mitochondrial content (Hawley, 2014). Resistance training causes an adaptation in the nervous system and in the increase of skeletal muscle size. This is shown mostly by hypertrophy, or an increase in the size of the current fibers in a muscle. Resistance training, like endurance, also shifts fiber type from fast to slow (Powers, 2015). The adaptations that occur to these types of training are overall beneficial to the human body and can help increase the performance of an