Taking part in exercise can effectively enhance students' physique.
First, life lies in exercise.
Animals and humans are always in motion in the process of life. From apes to humans, it has gone through about two or three million years of development and change. The differentiation of human organism from a single fertilized cell to the most advanced and complex organism in nature is the result of the continuous movement of cells. It can be seen that there is no life without exercise.
When it comes to "sports", it is inseparable from "muscles". From the statue of ancient Roman athletes to the strong physique in modern arena, all kinds of physical labor and sports activities that human beings engage in are the result of muscle movement (skeletal muscle movement). There is also a smooth muscle movement, such as gastrointestinal peristalsis, which is also necessary to maintain internal environment balance and metabolism, and is also one of the sources of life activities.
From the microscopic world, the basic unit cells of the human body are also moving all the time. Leukocyte elimination bacteria are moving; Red blood cells transport oxygen and carbon dioxide during exercise; Osteoblasts in the bone marrow cavity constantly destroy and absorb bone, expanding the bone cavity; Osteoblasts in periosteum constantly produce bone, which makes bone thicken and move; The epiphyseal cartilage at the end of long bone is constantly proliferating and ossifying, which makes the bone grow bigger and bigger and move freely. All cells are self-renewing and moving? Modern science has proved that the human body consists of nearly 60 elements, of which about 25 are necessary for human life activities. Among these twenty elements, the most are hydrogen, oxygen, carbon and nitrogen, which together account for more than 99% of the total number of atoms in human body.
It is precisely because of these elements that all kinds of living substances in our bodies are formed. Among the substances in human life activities, the most important are two kinds of high molecular substances: protein and nucleic acid. Protein is composed of nitrogen-containing organic compounds-amino acids. It is the most important component of all cells, the basic substance of cell movement and change, and the most important substance of life. Nucleic acids can be divided into two categories: deoxyribonucleic acid and ribonucleic acid. The former brings genetic genes from parents' fertilized eggs, which is the material basis of inheritance. Therefore, having children is often like the genetic phenomenon of parents. But under some conditions, DNA is variable in quantity, sequence and arrangement, which causes children to develop and mutate like their parents, but not exactly the same. And RNA is related to the synthesis of protein. Understanding the life phenomenon of human body from the structure and function of biopolymers, especially protein and nucleic acid, makes us have a further understanding of the development and changes of human body, especially the basic performance of human body, and also provides biological basis for how to effectively develop human body and enhance human physique through physical exercise.
It can be seen that life lies in movement, and the evolution of human organisms also lies in movement. As the old saying goes, "running water does not rot", and the organs and systems of the human body "flourish when moving, and retreat when not moving". Physical exercise can make individual motor organs, auxiliary motor organs and other organs develop, which fully conforms to the principle of "putting them into use and discarding them" in biology. Some famous people in human history live long. For example, Socrates (469 ~ 399 BC) in the golden age of ancient Greece lived a simple life and insisted on exercising all his life. At that time, the average life expectancy of people was only in their twenties, and he actually lived to seventy! Plato (427 ~ 347 BC), a student of Socrates, was born in a noble family and received a good education (including sports). He is an athlete. He didn't know what was wrong all his life and insisted on physical exercise. He is 80 years old.
Confucius, a great educator in China, lived until he was seventy-two years old. He hasn't heard that he is in poor health. Sun Simiao, a famous pharmacologist and health care scientist in Sui and Tang Dynasties, put forward the theories of "seeking quietness in motion and seeking motion in quietness" and "People want to behave in form, but illness cannot succeed", and put them into practice, thus completing two famous medical works, Qian Jin Fang Yao and Qian Jin Fang Yi, in his life. The former was written at the age of 70 and the latter was finalized at the age of 100. He died on 10. Emperor Kangxi of the Qing Dynasty insisted on riding, shooting, hunting and practicing martial arts for a long time, so he maintained a strong body all his life and lived to the age of 70, becoming the birthday star among emperors of all ages. Physical exercise can improve human health. The main reason is that the human body is a highly plastic organism, and its adaptability to environmental changes is extremely strong within the limits. Physical exercise increases the load of human stimulation by changing the environment, and adapts to this stimulation, and the function of the body is improved, as is the health status.
To sum up, physical exercise can enhance immunity; Can prolong life; Can promote health; It can also promote the evolution of the human body.
Second, physical exercise can promote the normal growth and development of teenagers' bodies.
Biological growth mainly refers to the physical changes caused by the proliferation of cells and the increase of intercellular substances; Development includes morphological, structural and functional changes of various organs and systems of organisms.
The growth of bones determines the height. It is very important to promote the healthy growth and development of primary and secondary school students' bones through physical exercise.
The growth of height is mainly due to the continuous elongation of long bones of limbs. There is epiphyseal cartilage between the osteoplasty of long bones of limbs and epiphysis (the swollen parts at both ends of long bones). This layer of cartilage constantly becomes hard bone, generating new cartilage. In this way, the bones are constantly elongated, and this growth process is very vigorous in children and adolescents. Generally, the epiphyseal cartilage is completely ossified into an epiphyseal line until the age of 20 ~ 25, when the bone is no longer elongated. In the vigorous period of bone growth, reasonable physical exercise can promote blood circulation, increase the blood supply of bone, and make the bone tissue in the vigorous period of bone formation get more raw materials, thus accelerating the process of bone formation; In the process of participating in various sports activities, it is very beneficial to stimulate the growth of bones. According to the investigation and study, 10- 14-year-old students who often take part in physical exercise are 4-8 cm taller than their peers who don't exercise regularly.
Physical exercise not only contributes to the growth of bones, but also helps bones to become harder and better support and protect the human body. Generally speaking, the compressive capacity of bones is 25 times greater than that of granite and 30 times greater than that of bricks. When a person weighing 70-80 kg stands, the tibia (calf bone) can bear the weight of 1.5-3 tons without breaking. During physical exercise, due to the traction and gravity of muscles, the bony processes of muscles attached to bones increase. The mechanical stimulation of exercise on bones increases, which makes the cellular metabolism of bones more vigorous. In addition, exercise can also accelerate blood circulation and supply nutrients more quickly, thus making bones thicker and the density of the outer layer of bones thicker. The release of cancellous bone adapts to muscle tension and human gravity, and the arrangement of trabecular bone is more reasonable. Over time, the firmness, fracture resistance and torsion resistance of bones have been improved. Outdoor physical exercise, physical contact with the sun, contributes to the production of vitamin D and the absorption of calcium and phosphorus in the body, making the bones harder and able to withstand greater pressure.
The connection between bones is called joint, which consists of articular cartilage, articular capsule and articular cavity. There are muscles and ligaments around the joints, which strengthen them. The joints can rotate in various ways, so the human body can realize various actions. Although the joint has a wide range of motion and good flexibility in adolescence, the joint capsule and ligament are thin and loose, with poor firmness, and dislocation or sprain often occurs. Regular physical exercise can thicken the joint capsule and ligament and strengthen the firmness and pressure of the joint. Because the joint runs for a long time during exercise, its flexibility and range of motion will gradually improve. This is very important for people's normal activities in life, work and study.
Physical exercise is also of great benefit to the growth of teenagers' muscles. It can be seen from the appearance that people who often take part in physical exercise have strong muscles and great strength. This is because during physical exercise, a large number of muscle capillaries are opened, the number of which can reach 20-50 times that at rest (there are about 4,000 capillaries per square millimeter of muscle at ordinary times, and only about 30-270 are opened), so that muscles get much more oxygen and nutrition than usual, so muscle fibers become thicker, the cross-sectional area of muscles increases, and the weight of muscles can reach 35-40% of ordinary people's weight. People who often take part in physical exercise have stronger muscle fatigue resistance and pain tolerance than those who don't exercise. Muscles are innervated by nerves, and motor nerves and their innervated muscle fibers are called motor units.
The intensity of muscle contraction is related to the number of exercise units involved in contraction. Generally speaking, only 60 ~ 70% of each muscle participates in the work, while athletes can reach 80 ~ 90%. Physical exercise can improve the ability of nervous system to control muscles, greatly improve the speed and accuracy of muscle response to nerve stimulation and the coordination ability between muscle groups, thus exerting the maximum exercise effect and making the action more labor-saving.
Because physical exercise has the above-mentioned good effects on the growth of bones, joints and muscles, the comprehensive effects are beneficial to the physical growth and development of primary and secondary school students. According to the following research materials: The first example is a survey of two large classes of children in a kindergarten in Beijing. In two years, the average height and weight of the children who exercised regularly increased by 15.6cm and 4.54 kg, while the average height and weight of the children in the control class who did not exercise regularly increased by 14.9cm (0.7 cm lower than the former) and increased by 3.84 kg (0.7 kg lower than the former). The second example is Shanghai Institute of Sports Science. From1March, 1975 to1March, 1978, we made a comparative observation on more than 400 children aged 3-7 in two kindergartens in Shanghai. It was found that the height of the exercise group increased by more than 1cm and the weight exceeded about 1kg compared with the control group.
Third, physical exercise has a good influence on the cardiovascular system of teenagers.
All human life activities are inseparable from happiness. The heart constantly contracts regularly, and through blood circulation, it transports the oxygen and various nutrients needed by the human body to various tissues and organs of the whole body, and transports the carbon dioxide and waste produced by the human body during metabolism to the lungs, kidneys, skin and other places for excretion. The heart works hard for people, even when sleeping, the burden is heavy. For example, if a person's life span is 70 years old, and his heart beats 60-80 times per minute on average, and each beat discharges 50-70 ml of blood, then in his life, his heart beats more than 2.7 billion times and discharges 2 million liters of blood. The heart discharges about 4.5 ~ 5 liters of blood per minute, about 70 tons a day and night, and 2600 tons a year. The heart is connected with blood vessels, which are divided into three categories: arteries, capillaries and veins, and play different roles in the process of blood circulation. It has been calculated that all kinds of blood vessels in the whole body add up to 654.38+ 10,000 kilometers long. Blood travels very fast in blood vessels. The heart ejects blood at a speed of several meters per second, and the blood circulates for one week. Quiet takes 20-25 seconds, and strenuous exercise takes only 6-8 seconds. Calculated in 60 years, the distance that blood flows through is about 65.438+0.5 billion kilometers, which is equivalent to 375 circles around the earth. The adult's heart is a little bigger than the fist, and its weight is about 1/200, and the average person is about 300 grams. It can be seen that only a healthy heart can be competent.
If you want your heart to be healthy, you should start with children and teenagers. In the first five years of childhood, the myocardium grew rapidly. After entering childhood, the heart volume increased sharply, and elastic fibers gradually spread to the myocardium. In adolescence, the development of the heart reaches the second peak, and its weight can reach 10 times of that at birth, and it can reach 12- 14 times of that at birth in later adolescence. 1 1 year-old girls and 14-year-old boys have the most significant increase in heart volume. At this time, the correct physical exercise can make the child's heart develop well.
The good effects of physical exercise on cardiovascular system are:
(A) the heart has a "healthy hypertrophy" change.
1899 Swedish doctor Hansen found that skiers have big hearts, but they are healthy. In order to distinguish it from pathological myocardial hypertrophy, it is called "healthy hypertrophy". Its plump appearance, strong contractility and high heart reserve are the results of thickening of myocardium and enlargement of heart cavity under the influence of athletes' long-term exercise training. During physical exercise, the blood circulation of the whole body is accelerated, and the blood supply of the heart and the whole body is also improved. Protein and glycogen in myocardial cells increased, myocardial fibers thickened, heart wall thickened and capillaries increased. During exercise, the contractility of the heart is strengthened, and every contraction almost empties the blood in the room. However, the increase of venous blood reflux lengthens myocardial fibers and increases cardiac blood volume. So people who often take part in physical exercise have bigger hearts and heavier weights. The heart of a normal person generally weighs 250-300g, and that of a long-distance runner weighs about 500g, which is larger than the average person 1/3.
(2) Increased cardiac output.
The amount of blood injected into the heart every beat is called stroke output. The blood output per minute depends on heart rate and stroke output, but the maximum heart rate of each person during exercise is limited, so increasing stroke output is a very important factor. Regular physical exercise can increase the stroke output: the average person's stroke output is 50 ~ 70 ml, and it can reach about 1 10 ml during strenuous exercise; People who exercise regularly have a stroke volume of about 90 ~ 100 ml when they are quiet, and it can reach about 180 ml when they exercise.
(3) When quiet, the heart rate is slow.
The number of times a person's heart beats per minute is the heart rate, which is about 60 ~ 80 times a minute when a normal person is quiet. People who often take part in physical exercise have a lower heart rate than those who don't exercise. According to the heart rate measurement of 260 athletes who participated in the Olympic Games, it was found that their average heart rate was 50 beats/min, and the lowest was 30 beats/min. This is because taking part in physical exercise can improve the level of heart function, make myocardial fibers thicker and contract more forcefully, and inject more blood every time, so even if the heart rate drops, it can meet the blood volume needed by the human body. Slow heart rate and strong pulse make the heart rest for a long time after each contraction, which is not easy to cause fatigue. Prolonged atrial diastolic period can fill more blood to return to the heart, and prepare the blood volume and function for the next ventricular ejection, which is the performance of saving heart function.
For example, when the heart is quiet, 4.5 liters of blood per minute can meet the metabolic needs of the whole body. If the average person's heart stroke output is about 60 ml, it needs to beat 75 times per minute; The athlete's stroke output is about 90 ml, so only 50 beats per minute is enough. In intense physical activity, people with sports foundation will not feel uncomfortable when their heart rate reaches 200 beats per minute, while people without sports foundation will often be unbearable. In addition, people who often take part in physical exercise have better elasticity of blood vessel wall and fewer vascular obstacles, and well-developed and plump muscles play the role of "second heart function", indicating that the function of cardiovascular system has improved.
(4) The improvement of the regulation function of cardiovascular system is mainly manifested in:
1, rapid mobilization. In the early stage of exercise, the function of circulatory system can be quickly mobilized to meet the needs of exercise quickly.
2. Great potential. Exercise can exert the maximum functional ability and fully mobilize the mental reserve.
3. Quick recovery. The timing of exercise can vary greatly, and once the exercise stops, it can quickly return to a quiet level.
(5) Other effects of physical exercise on cardiovascular system.
1. Exercise can increase the diameter and elasticity of coronary artery, which has a positive effect on preventing coronary heart disease.
2, exercise can consume a lot of fat in the body, not only can lose weight, but also can reduce the pressure on the heart and reduce the incidence of heart disease.
3. Physical exercise can increase the elasticity of arterial blood vessels and reduce the incidence of hypertension.
Fourthly, physical exercise has a good effect on the respiratory system of teenagers.
People can't live without oxygen all the time. In the case of complete hypoxia, human life can only last for a few minutes. From this point of view, oxygen is more urgent and important than food for life-sustaining activities. At the same time, carbon dioxide and other waste gases produced during metabolism in the body need to be discharged out of the body in time, which requires a strong respiratory system function. Regular exercise is helpful to improve and improve the function of respiratory system.
(1) The function of respiratory muscles is enhanced.
The human spine, sternum and ribs form the thoracic cavity, and two lung lobes are in the thoracic cavity. Respiratory muscles mainly include intercostal muscles and diaphragm. In the process of exercise, due to the strengthening of breathing, the respiratory muscles gradually developed and became strong and powerful. People's chest circumference increases, and the range of breathing action increases. When inhaling, under the action of respiratory muscles, the lungs expand with the expansion of the chest cavity, increasing the amount of inhaled air. When exhaling, muscle contraction can exhale more carbon dioxide. The improvement of respiratory muscle function makes it difficult to get tired when breathing and can work for a long time. The influence of exercise on respiratory muscles can be seen from the change of breathing difference (the difference of chest circumference when trying to inhale and exhale, called breathing difference), which is only 5 ~ 8 cm for ordinary people and 9 ~ 16 cm for athletes.
(2) Increased vital capacity.
People exhale all the air after taking the maximum deep inhalation, and the amount of exhaled air is vital capacity. The average adult is 2500 ~ 4000 ml, and the number of people who often engage in long-distance running exercise can reach more than 4500 ~ 6500 ml. Teenagers who often take part in physical exercise also have larger lung capacity than ordinary teenagers. This is mainly because childhood and adolescence is also a period when hundreds of millions of lung cells gradually mature and develop rapidly. Physical exercise can fully open alveoli, which is very beneficial to the growth, development and elasticity of alveoli.
(3) When quiet, the breathing frequency is slow and the breathing depth is deepened.
Adults breathe about 65,438+04 ~ 65,438+06 times per minute, while people who exercise regularly breathe deeply and slowly, about 8 ~ 65,438+02 times per minute, which is mainly due to the great respiratory muscle strength of athletes, and the amount of air that enters the lungs after each breath (about 300 ~ 500 ml for ordinary people and about 600 for people who exercise regularly)
(4) The ability of negative oxygen debt has been improved.
People need to consume a lot of oxygen during strenuous exercise, but if the maximum oxygen intake of human body can not meet the oxygen needed during exercise, they can only partially supply energy through anaerobic glycolysis, forming an oxygen debt. After exercise, you must repay your oxygen debt, which is also the reason for your rapid panting after exercise. The average person's maximum oxygen debt does not exceed 5 ~ 7 liters, while athletes can reach 20 liters. Muscle ache after exercise is caused by the accumulation of lactic acid produced by glycolysis in the body under the condition of hypoxia. After the movement stops, it must be eliminated by further decomposition of oxygen. People who don't exercise often have poor respiratory function and a slightly lower ability to bear oxygen debts. When they exercise, they will be panting and their muscles will ache all over. Well-trained people can not only exercise for a long time, but also have strong tolerance to acidic substances and eliminate fatigue quickly.
Fifth, physical exercise has a good influence on the nervous system of teenagers.
All human activities are regulated and dominated by the nervous system. On the other hand, all kinds of physical exercise activities have a corresponding good influence on the nervous system, which improves its function. Specific performance in:
(A) enhance the comprehensive ability of memory and analysis.
Memory ability depends on the structure and quality of the brain. Brain tissue is very sensitive to the supply of oxygen, which consumes 1/4 of the total oxygen in human body. If you want to strengthen your memory, you must first ensure that your brain gets enough oxygen. It has been made clear that physical exercise can improve the functions of respiratory system and cardiovascular system, thus providing necessary energy and oxygen for brain development. Human memory and intelligence are also related to the integrity and diversity of communication between the central nervous system and the peripheral nervous system of the brain. Regular physical exercise can sharpen vision and hearing, improve the analysis and comprehensive ability of nervous system, speed up the conduction speed of nerve fibers, increase flexibility and improve the memory information of human brain.
(2) Eliminate brain fatigue and improve study and work efficiency.
Exercise is an active way to rest, because in the process of exercise, the nerve centers related to exercise are excited, and the centers related to cultural learning enter a state of inhibition. With the enhancement of the excitability of the motor center, this inhibition is more in-depth, so that the nerve center related to cultural learning can get a good rest and play a protective role. Physical exercise after study can increase the supply of oxygen and nutrients, and also help to improve the function of the brain.
(3) Improve the regulation ability of the nervous system.
The improvement of this ability can effectively enhance the adaptability and adaptability of the human body. For example, muscles need a lot of oxygen and energy supply during exercise. Under the adjustment of the nervous system, the respiratory system and circulatory system are quickly mobilized to give full play to their functional abilities to meet the needs of sports. When the temperature changes sharply, the human body can adapt to the changes of the external environment more quickly through the adjustment of the nervous system. Taking part in physical exercise, the internal and external environment is changeable, which can effectively improve the adjustment ability of the nervous system and maintain a good relationship between the body and the external environment.
Six, physical exercise can promote the development of physical fitness and sports ability of primary and secondary school students.
Physical fitness is the human body's strength, speed, endurance, agility, toughness and other functional abilities in the process of completing actions. The level of physical fitness is based on physical structure, physiological function and health level, and is also closely related to congenital genetic factors and acquired physical exercise. Sports ability refers to the ability of human body to walk, run, jump, throw, climb, roll, turn, drill, hang, support, push and pull. Primary and secondary school students' physical fitness and sports ability are in the stage of rapid growth, which is the golden period of development and improvement. Therefore, in primary and secondary schools, actively participating in various sports activities is very important for developing physical fitness and sports ability, and also for improving health and strengthening physical fitness.
According to an American survey report, genetic factors play a great role in morphology, longevity and mobility. They pointed out: "Comparing the height of 18-year-old son with the average height of parents, it is found that the son of short parents is shorter than the son of high parents 14.8 cm." According to the experimental data, Kalkus, a Czech, put forward the formula of the height relationship between children and their parents as follows:
Son height = (father height+mother height)? 1.08
Daughter height = (father height? 0.923+ female height
Soviet scholars study the relationship between children and parents' height, and think that the correlation coefficient between father and son is (0.45 ~ 0.46), while the correlation coefficient between father and daughter is (0.200 ~ 0.382), which shows that it is more accurate to predict the height of son according to the height of father. On the contrary, it is more accurate to predict the daughter's height according to the mother's height.
In sports ability, the biomechanical structure of walking and running is also greatly influenced by genetic factors.
The development of maximal oxygen uptake is mainly determined by genetic factors (h = 0.200 ~ 0.750). Some people think that 93.6% of maximal oxygen uptake and 85.5% of maximal pulse frequency are affected by heredity. 9%。 Anaerobic metabolic capacity is more influenced by genetic factors than aerobic metabolic capacity (h = 0.70 ~ 0.99).
Seven, physical exercise can improve the ability of primary and secondary school students to adapt to the external environment.
The external environment refers to the natural environment and social environment. The natural environment includes geographical environment, seasonal change and climate change. Social environment includes the influence of urban environment and the stimulation of other social factors to human body. Soviet physiologist Pavlov said: "Health is the balance between human body and nature." This is consistent with the theory of "correspondence between man and nature" in traditional Chinese medicine. The adaptability of human body to the external environment is an important symbol of human function and health.
The natural environment is complex and changeable. Taking part in physical exercise and getting in touch with natural conditions, especially air, sunshine and water, is conducive to enhancing resistance, enhancing the adaptability of blood vessels, nerves, muscles and other tissues, and also helping to improve the working ability of the nerve center that regulates body temperature, so that the body has a strong adaptability to the external environment. Statistics of many units in our country show that the incidence of upper respiratory tract infection and other diseases of children who often participate in physical exercise is obviously lower than that of ordinary children. According to foreign reports, the number of young athletes suffering from colds at school is only 18% of the number of students who do not participate in sports.
Eight, participating in physical exercise can cultivate the sentiment of primary and secondary school students, cultivate good emotions and promote mental health.
Marx once pointed out that a good mood can relieve physical fatigue and pain more than ten drugs. There is a saying in our country called "Laugh, you are ten years old" and "Laugh often and stay young forever", which all show the importance of emotion and spirit to people's health. The Oshner Clinic in New Orleans, USA, found that 74% of the 500 patients with gastrointestinal diseases who were admitted to the hospital for continuous consultation were ill because of their bad mood. There is a similar situation in the report of the outpatient department of Yale University School of Medicine. Among all patients seeking medical treatment, 76% got sick because of emotional stress. Recently, their cardiologist concluded through scientific research that stressful, depressed and troubled lifestyles are important risk factors for people to suffer from heart disease. They believe that this lifestyle will increase the concentration of cholesterol in the blood, promote the formation of blood clots, raise blood pressure and cause arrhythmia.
It is also reported that more than 90% of headache patients suffer from a disease called "tension headache". It can be seen that people's mood and mental state have a great influence on people's health. Everyone has a power that is most beneficial to health, and this is the power of a good mood. A good mood is also a kind of "medicine" to treat diseases. The medical value of this "medicine" is immeasurable, and it usually has two functions: one is to replace the bad emotions that cause tension; Secondly, it can also produce a function similar to pituitary gland and maintain a moderate balance of endocrine function. This balance produces a happy mood, makes people feel comfortable and happy, and regulates some unhealthy emotions and psychology, such as depression and depression.
Driscoll, an American psychologist, found that running can successfully relieve college students' anxiety during exams. It is also found that people who are nervous and irritable will relax after walking 15 minutes. Primary and middle school students have the joy of success, the satisfaction of progress and the joy of victory in sports activities. In addition, the change of environment, the elimination of mental bondage and the stimulation of beautiful natural environment can make primary and secondary school students feel relaxed and happy. This is very important for mental health and even general health.
To sum up, primary and secondary school students often participate in physical exercise, which plays an extremely important role in their normal physical growth and development, the improvement of physiological functions of various organ systems, the development of various physical qualities and basic sports abilities, and the improvement of their ability to adapt to the external environment and mental health. Adolescence is a period of rapid physical development and change, which lays a good foundation for physical growth, development and development and creates very favorable conditions for lifelong health and happiness.