How the muscles work
Skeletal muscle ensure that all goal-directed movements of the body and maintaining posture of a person. This “machine” that converts chemical energy into mechanical energy and heat. Motor elements of muscles are composed of proteins — myosin and actin. Muscle contraction and relaxation are regulated by changing the concentration of calcium ions. Therefore, when you deficiency in an athlete’s diet protein muscles are weak and increases the risk of injury, and lack of calcium can cause convulsions.
The only direct source of energy for muscle contraction is special, the phosphorous compound is adenosine triphosphate. It is also called adenozintrifosfornoy acid, is also widely used shrink — ATP. In the
splitting of ATP is produced adenosine diphosphate (ADP) and releases energy, 20-30% of which goes to the Commission of muscular work, 50-60% is converted into heat, and the remainder is expended on the maintenance of metabolism. So phosphorus is essential not only for the brain.
Reserves of ATP in the muscles is very small — enough to maintain their work within fractions of a second. Therefore, to ensure long-term activity of the muscles need constant restoration of ATP. This process is carried out in the muscles of anaerobic (without oxygen) and aerobic (with oxygen) pathways. In the human body can be used three main sources of fuel: creatine-phosphate (ECOP), carbohydrates in the form of glycogen and glucose and fats. These three types of energy differ in the amount of energy that is released when using them, and for the duration of her education. Energy systems for ATP production in the muscle is also three: Postojna, glycols-maceutical and oxidative. They differ in energy capacity, i.e. the maximum number of generated energy and energy capacity, i.e. the maximum amount of energy released per unit time.
The recovery of ATP during muscle contraction occurs almost instantly due to the ECOP. Works Postojna system. It is characterized by the greatest output, but small capacity. Stocks KRF rapidly depleted and can provide employment within not more than 5-6 C. However, this mechanism of producing energy, which is anaerobic, is very important as it acts at the beginning of any work, when have not had time to include other energy systems. In addition, and this fact is of great importance when playing many sports, only Postojna the system is able to restore ATP at a speed necessary to perform the work, which is characterized by a maximum power (e.g., push rod, starting separation, etc.). The increase in the volume and mass of the muscles contributes to the increase of the total content KRF and, consequently, the increase of performance of the athlete when performing explosive work.
The following cascade provide muscles with energy during more prolonged exercise is supported by the glycolytic system. At the heart of its activity is the process of anaerobic breakdown of carbohydrates (glycogen and glucose) to lactate. This process is called glycolysis.
Glycogen is the main reserve carbohydrate, which is stored in the muscles and liver and is very efficient as an energy source. In the future we’ll talk about how you can increase its reserves in the body. Under the influence of training anaerobic glycolysis in humans could be greatly enhanced. For example, there is evidence that trained sprinters activity of glycolysis in the muscles of the legs can be increased to two thousand times. But working with anaerobic glycolysis as the primary energy source can last up to 3 min in cells and tissues accumulate considerable amounts of lactic acid.
If you increase the duration of the energy supply of the muscles is mainly due to the oxidative system and a process called oxidative phosphorylation. This aerobic process, meaning it is carried out with sufficient supply of oxygen to muscles. As energy substrates are carbohydrates (glucose and glycogen) and fats. At work, characterized by large capacity, oxidized mainly carbohydrates, while low-intensity work — fats. Both of these fuels are in the form of reserves in the muscle fibres. The capacity of the oxidative energy system is thousands of times greater than the capacity of phosphagen-Noah and glycolytic systems. It allows to perform muscular work for many hours with sufficient circulation and providing oxygen to the muscles. Those who are engaged in sports in which a crucial component is endurance, it is important to know that a long and intensive work of the muscles is best achieved energy with simultaneous use of carbohydrates and fats. Fats far superior carbohydrates time during which they can support. However, the use of some fats provides up to half the speed of energy production than the simultaneous oxidation of fats and carbohydrates. And from this parameter (speed energy) depends on the intensity of work performed.
And a little more physiology and biochemistry. As you probably noticed, in the description of the mechanisms of muscle energy, we used phrases such as the disintegration of the tissues, the cleavage of ATP, crea-InfoSpace, carbohydrates, etc. The combination of all these processes, enzymatic breakdown of large molecules aimed at ensuring energy and plastic needs of the body, is called catabolism. Catabolic processes lead to the formation of large amounts of energy.
At the same time in the body reactions are the opposite. The synthesis of proteins, fats, carbohydrates, and other compounds, tissue and cellular structures necessary for life. All these processes involve the use of energy, and their set is called anabolism.
Sports activities require huge amount of energy, which is formed by a powerful catabolic reactions. It is necessary due to the rational organization of power to provide an appropriate level reductive anabolic processes. Otherwise, you may not only depletion of carbohydrates and fats, but may start to flow full of muscle proteins for energy needs. This is highly undesirable because strong muscles are the basis of sports achievements.
In the regulation of the processes of catabolism and anabolism critical role played by special chemical substances — hormones, that are secreted by specialized endocrine cells in the body. Reductive anabolic processes in the muscle are stimulated under the influence of hormones such as growth hormone (somatotropin) is produced by the pituitary gland, insulin is a pancreatic hormone, male sex hormone — testosterone. Adrenaline can markedly stimulate the processes of use of glycogen for ATP resynthesis. The adrenal hormone cortisol increases the intensity of catabolic processes, etc. It is therefore necessary to consider not only the caloric content of food substances, but also their impact on the level of hormones in the body.
The energy balance in the body is determined by many factors and depends on diet, physical activity, genetic traits, emotional state, hormonal status, environmental factors, etc.