Exercise science is the study of how exercise and physical activity alter a person’s physiology, defined as the body’s structure and function. Early research in exercise science focused on the effects of different types of exercise and environments on the body. Today, the wealth of information about exercise science has motivated manufacturers and fitness specialists to formulate optimal nutrition and exercise regimens for their clients. Information about exercise routines and nutrition plans allow individuals to tailor their daily regimens to their specific goals. Certain types of exercise are best for weight loss while others promote muscle growth.
There are three types of muscle: smooth, cardiac, and skeletal. In order to build skeletal muscle, it is helpful to know the basic science behind this seemingly daunting task. Such details are crucial in professional sports and competitive bodybuilding, leading both bodybuilders and professional athletes to plan their training routines around these uncovered scientific facts.
The key is an exercise technique called progressive overload, wherein one overloads, or stresses, the muscles with each workout.
By putting muscles through challenging tasks, such as sets with increased weights, or through new tasks, such as entirely new exercise routines, progressive overload can allow hypertrophy, or increase in muscle cell size,
There are two well-defined types of muscle hypertrophy:
While sarcoplasmic hypertrophy increases diameter and decreases density of muscle, sarcomere hypertrophy leads to a greater increase in density and will lead to greater muscle strength and athletic performance Sarcomere hypertrophy allows growth of the muscle contractile machinery, composed of actin and myosin filaments, which make up about 80% of each muscle cell..This increases the muscle strength but not the endurance
Sarcoplasmic allows growth of the ATP-producing cell components that can provide energy to the muscle; these components make up the other 20% of muscle cells (Butt).While sarcoplasmic hypertrophy increases diameter and decreases density of muscle, sarcomere hypertrophy leads to a greater increase in density and will lead to greater muscle strength and athletic performance (Starr).Sarcoplasmic hypertrophy occurs when muscle fiber cells experience an increase in their number of mitochondria, or ATP-producing cellular organelles, and in their concentrations of enzymes involved in cellular respiration. The muscle cells also have an increased volume of cytoplasm, known as sarcoplasm in muscle cells; glycogen, an energy storage carbohydrate. All of these changes allow the cells to produce a greater amount of ATP, an energy-rich molecule containing three phosphate groups. Muscle contraction involves removal of a phosphate molecule from ATP, releasing ADP and energy. Thus, since muscle contraction requires replenishment of ATP, sarcoplasmic hypertrophy increases the ATP supply. Even though this does not allow the muscles to improve their strength, it enhances their endurance by increasing the energy supply available to the muscle cells (But People can achieve sarcoplasmic hypertrophy by lifting moderately heavy weights with a large number of repetitions
The rupture of the sarcolemma also causes muscle cells near the site of damage to produce and release growth factors. Sarcomere hypertrophy can be accomplished by lifting heavy weights with a low number of repetitions (Strength Training).
The removal of the damaged fiber cells activates myogenic stem cells known as satellite cells, allowing them to repair the damaged muscle fibers and promote muscular growth. The released growth factors can also stimulate the satellite cells to proliferate (Butt). Located on the outer surface of muscle fibers, satellite cells contain only one nucleus. Once muscle damage activates satellite cells, these stem cells differentiate into myoblasts, which further differentiate into skeletal muscle cells that can then fuse to existing muscle fibers in the damaged site .
Natural Ergogenic Supplements
Bodybuilders and others trying to gain muscle mass commonly take certain natural, ergogenic (muscle building) supplements for muscle growth, Two of the most important supplements are creatine monohydrate and glutamine.
Creatine is a nutrient that is found naturally in our bodies and is composed of the three amino acids arginine, glycine, and methionine.About 95% of our body’s creatine is in skeletal muscle, and about 60 to 70% of this muscular supply is phosphorylated, or bound to phosphate groups. As muscle contraction releases ADP molecules, phosphorylated creatine, or phosphocreatine, donates phosphate groups to ADP to replenish the ATP supply. The efficacy or safety is not been established
In times of protein deficiency, the body may actually break down muscle tissue to provide amino acids to other protein-building biochemical processes in the body. In order to maintain their supply of protein, many bodybuilders and athletes take the amino acid glutamine as a supplement. The most abundant amino acid in the body, Glutamine is also found naturally in most protein and dairy products. By preventing breakdown of muscle over time, glutamine acts as an anti-catabolic agent that increases the effectiveness of workouts.