MOSCOW, July 9, Vladislav Strekopytov. Special molecular mechanisms help to maintain health for a long time. One of the key factors is the work of the muscles. What happens to them during sports and how it affects life expectancy, told experts — biologists, doctors and professional athletes.
Signal for growth
During training, the muscles are subjected to mechanical stress: they bend and stretch, which causes microtrauma. The body tries to heal the damage. In addition, physical activity triggers the production of certain hormones, enzymes and neurotransmitters.
All this leads to accelerated protein synthesis, muscle tissue growth and changes in its structure. How quickly muscles grow depends on the type of exercise, training and rest regimen, nutrition, hormonal balance and genetics.
“Muscle development is facilitated by regular sports activities with an emphasis on strength exercises,” says Mikhail Kutushov, PhD, doctor of medical sciences. “Such training stimulates molecular processes that lead to muscle growth. Another important aspect is nutrition. muscle tissue material. At the same time, it is important to provide the body with energy. And for this, carbohydrates and fats are needed.»
“Not only those involved in fitness, but also professional athletes often complain that they can’t gain muscle mass,” says neurophysiologist, candidate of biological sciences Yuri Koryukalov. “This may be due to the biochemistry of the body. For muscle growth, it is necessary that in the blood there was enough protein and vitamins — especially C, B and D — trace elements and hormones.
The most important hormones that stimulate protein synthesis are testosterone and somatotropin, which is also called growth hormone. Their optimal level is achieved with proper nutrition and a balance between physical activity and rest.
«During the rest period, molecular processes occur in the muscles that promote growth and recovery. With a lack of rest and overstrain, growth slows down,» — emphasizes Kutushov.
Genetic factors also play a role. Some people are naturally more prone to develop skeletal muscle. But with proper nutrition and training, everyone can build muscle, regardless of genetics, scientists say. -crop-ratio=»1″ data-crop-width=»600″ data-crop-height=»600″ data-source-sid=»rian_infographics» class=»lazyload» lazy=»1″ />
Two energy mechanisms
The human muscle frame consists of skeletal (striated) muscles, and those, in turn, are made of elastic elastic tissue that can contract under the influence of nerve impulses. Their main task is to ensure the mobility of the body.
Muscle fibers are of two types: slow or red, as they are also called because of the high content of myoglobin, a red binding protein, and fast, white. The first are hardy: able to work for a long time, but not very strong. The second are strong, but quickly get tired. Marathon runners have more red fibers, while weightlifters have more white fibers. In bodybuilders, fast fibers make up up to 80 percent of muscle mass.
The energy for the molecular processes that lead to muscle changes is found in carbohydrates in the form of glycogen. Under the influence of enzymes, it breaks down to glucose, which then enters the bloodstream.
Slow fibers get energy more efficiently from glucose, splitting it completely into carbon dioxide and water. But this requires oxygen. Fast ones work anaerobically, without oxygen, but glucose in them is broken down only to lactic acid, which causes muscle pain after active strength training.
In both cases, adenosine triphosphoric acid (ATP) is synthesized — a universal energy source for all biochemical processes, occurring in living organisms.
During physical education and sports, significant changes occur not only in the muscles themselves, but also in other organs and body systems that provide the muscles with energy and oxygen.
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“Cardiac output, heart rate, respiration increase,” explains Maxim Enikeev, head of the orthopedic rehabilitation of the European Medical Center (EMC), Candidate of Medical Sciences Maxim Enikeev. blood flow, improves the supply of muscles and the removal of decay products. The same role is played by nitric oxide NO, which is formed in the muscles during contraction.Insulin is required for glucose to enter muscle cells at rest. But under load, the muscles begin to «pump out» glucose from the blood on their own. Therefore, exercise is especially important for diabetics and those diagnosed with a «pre-diabetic condition.» Scientists have found that in just one hour of exercise, blood glucose levels can be reduced by 1-1, 5 millimoles per litre.
More and better
During physical activity, not only quantitative, but also qualitative changes occur in tissues. Muscles become more flexible and plastic, stretch more strongly. Active protein synthesis and improvement in the structure of sarcomeres — the main structural units of muscles — increase their strength and reduce the risk of damage.
«Muscles increase due to an increase in the number and thickness of fibers,» says boxing coach, master of sports Artur Kalita .- New fibers appear as a result of the splitting of hypertrophied fibers into several thin ones, their thickness depends on the size of the nuclei and myofibrils.
As a result, muscle fibers become larger, and they themselves become stronger. Connective tissues are also strengthened — tendons and ligaments that support the muscles and allow them to work with greater load.
“The growth of muscle mass occurs mainly due to white fibers,” says Enikeev. “In the red ones, the increase in volume is less noticeable, but the number of mitochondria increases in them — small “boilers” in which glucose is burned. This has a positive effect on muscle endurance. It should be noted that the primary strengthening of the muscles during training does not depend on their growth or changes in the muscle structure, but due to the improvement of neuromuscular conduction — the transmission of a signal from the motor nerve to the muscle. the main exercise, just aimed at improving this conductivity and blood circulation in the muscles.
Hidden resource of the body
Those who play sports tend to look younger than their peers. Scientists are finding plenty of evidence that physical activity can actually slow down aging.
“Sports activities have a positive effect on the muscles and the body as a whole,” notes Elena Bogatova, a cosmetologist and nutritionist, a specialist in anti-aging therapy. “Exercise stimulates energy metabolism, protein synthesis, helps strengthen connective tissues and bones, increase endurance, improve metabolism .Exercise produces happiness hormones — endorphins, which improve mood and sleep, reduce anxiety and stress. «
Regular physical activity normalizes blood pressure, reduces the risk of cardiovascular disease, promotes the production of antioxidants that protect cells from oxidative stress DNA damage, has a positive effect on the endocrine system.
We can also talk about the direct effect of rejuvenation. Muscle tissue contains a natural supply of adult stem cells — myosatellites. They are located between the basal layer and the cell membrane (sarcolemma) of muscle fibers. It is from them that growing muscles are formed. Under normal conditions, myosatellites are in a «dormant» state, but in response to tissue damage or exercise, they begin to divide, causing tissue regeneration and renewal.