Can I grow taller?

Section 1 Growth and Development of Children and Adolescents

In the past 20 years, the average height of countries around the world has increased by 1 cm every 10 years. There has been a trend in human stature that one generation is getting taller than the next. According to records: In the United States more than 200 years ago, the national average height was 170 cm, and now it has reached 180 cm, an increase of 10 cm; in the past 30 years, the average height of 14-year-old teenagers in Japan has increased by 8.2 cm; in Sweden from 1851 to 1931 In the 1980s, the height of recruits increased from 166.6 cm to 174.1 cm, an increase of 7.5 cm. The former Soviet Union measured the bones of soldiers in the 18th century and found that the average height of soldiers increased by 20 cm in the past 250 years. In the past 20 years in my country, the average height of urban youth aged 18 to 25 has increased by 2.3 cm for men and 2.15 cm for women.

1. Measuring height

1. Benefits of measuring height

People generally believe that weight changes quickly, so weight increase or decrease is often used as an objective standard for assessing health. . In fact, using height growth to assess growth, health, and fatigue is as accurate as weight.

Measuring the height of children and adolescents 1 to 2 times a year (preferably once a quarter) is one of the important means of keeping track of growth and development. If the height growth is normal, it means good growth and development; if the height growth is slow, basically not long, or even stops growing, the reasons must be analyzed and corresponding measures should be taken for targeted remedies.

Middle-aged and elderly people often measure their height, which can also assess the degree of aging to a certain extent. Height decreases with age. For normal people, the peak peak is between 20 and 30 years old. Starting from the age of 40, for every 10 years of age, the height decreases by 1 to 2 cm. The height of elderly men will decrease by an average of 2.25%, and that of women will decrease by an average of 2.5%. Someone abroad reported that from the age of 40 to 90, the height of the human body can drop by 7 to 9 centimeters, and even an obvious hunchback appears. This physiological change in the human body is commonly known as "aging".

Height changes within a day are also one of the important methods to evaluate physiological load and fatigue level. For an individual, it is highest when getting up in the morning and lowest before going to bed at night. This change in height is directly related to occupational characteristics. Those heavy manual laborers and athletes, especially weightlifters, who carry heavy loads on their shoulders and backs, especially weightlifters, will have more obvious changes in height within a day. They will be taller when they get up in the morning than when they go to bed at night. The front is 2 to 5 cm higher. There are two main reasons for this change: First, the intervertebral discs of the spine are compressed. The intervertebral disc is a cartilage tissue with an elastic nucleus pulposus in the middle that acts as a buffer and allows the spine to have a certain ability to stretch. Due to the load on the spine, the elasticity of the cartilage between the vertebrae is temporarily "weakened" and the spine is shortened. Second, the muscles of the neck, back, and chest that maintain the normal physiological curvature of the human spine gradually become fatigued under load throughout the day. The supporting force of the spine decreases, the curvature increases, and the height also decreases accordingly. The physiological increase or decrease of the spine is only a change in one day. After a night of sleep, the muscles are fully rested and the height is restored after the fatigue is eliminated.

2. Methods and requirements for measuring height

1) Measurement method: The person being measured is barefoot, standing on the base of the stadiometer in an "attention" posture, with the heel, sacrum and two Between the shoulder blades is close to the height meter column. The measurer can stand on the left or right side of the person being measured, adjust his or her head until the upper edge of the tragus is flush with the lowest point of the lower edge of the eye socket, and then move the horizontal plate of the stadiometer to the top of the person's head to make it tight. If appropriate, birth height can be measured.

2) Measurement requirements: Each height measurement should be done barefoot, at the same time (more accurate in the morning), with the same height meter. The body posture should be consistent before and after. The height meter should be placed flat on the ground and leaned against. At the base of the wall. It is best to measure your height twice in a row, with an interval of 30 seconds. The results of both measurements should be approximately the same. The error of the height gauge shall not exceed 0.5 cm.

3. Methods and requirements for measuring the length of the upper body

1) Measurement method: The person being measured sits on the seat of the height and height meter, with the head pillow and between the shoulder blades The three points of the spine and sacrum should be attached to the upright column of the stadiometer. When sitting, keep your head upright, eyes level, torso straight, legs together, keeping a 90-degree angle between the upper and lower legs, feet on the ground or the pad of the stadiometer, and arms hanging naturally by your sides. The measurer's position and operation are the same as measuring height.

2) Measurement requirements: The occipital part of the head of the person being measured, the ridge between the two shoulder blades and the sacral part should be attached to the upright column of the stadiometer. The rest is the same as measuring height.

4. Methods and requirements for measuring the length of the lower limbs

1) Measurement method: The person being measured stands on a flat ground with his feet shoulder-width apart. Measure the vertical distance from the upper edge of the greater trochanter of the left lower limb femur to the ground, which is the length of the lower limb.

2) Measurement requirements: The person measuring must accurately touch the upper edge of the greater trochanter of the person being measured. When touching, first place the index finger, middle finger and ring finger on the greater trochanter bone of the person being measured, ask the person being measured to bend the knees and lift the thigh, and then straighten the leg and swing the leg back and forth a few times. The person being measured can accurately judge the greater trochanter bone (the upper end of the femur). The upper edge position of the part that rotates with the movement). The measurement error of the steel tape shall not exceed 0.2 cm.

Ordinary families do not have a stadiometer. You can use a small tape measure to straighten it and fix it on the door. Use a book instead of the horizontal plate of the stadiometer. Measure according to the operation method. You can also accurately measure your height.

As mentioned earlier, height depends on two factors: genetics and acquired environment. Among these two factors, although heredity plays an extremely important role, the positive effects of acquired environmental factors, especially during the two critical periods of height growth, of ensuring adequate and balanced nutrition and regular physical activity cannot be underestimated. .

Many people want to be taller, and some young women also pay special attention to the height of men when looking for a partner. Once upon a time, there were jokes circulating in society that compared young men of medium build to some degree of "cripple". It is inappropriate to place one-sided emphasis on height when choosing a mate. Being tall has advantages, and being short also has its advantages. Comparing the two groups of tall and short, short people are smarter, smarter, healthier and live longer than tall people. Chinese medical experts surveyed Hunan, Hubei, Guangxi, Guizhou and other provinces and found that the height of people over 90 years old is mostly between 128 and 158 centimeters, and their weight is about 40 kilograms. American scholar Marlows surveyed celebrities and athletes from all walks of life in the United States using a height of 173 centimeters as a cutoff. The result was that 11% of short people lived 9 years longer than tall people. Among 750 men, 13 of the 15 who lived past 90 were short. Eight of the nine accomplished celebrities who have lived past the age of 90 are short. Giants over 230 centimeters only lived an average of 39.8 years. Short people in the United States have lived to an average of 80.2 years, while tall people have lived to an average of 66.6 years.

The trend of human beings getting taller from generation to generation will continue. Taking my country as an example, the current average height of men in my country is 170.3 cm and that of women is 159 cm. It is predicted that in a hundred years, the average height of men in my country will exceed 183 centimeters and that of women will exceed 169 centimeters. For this reason, some scientists believe that in the future it may be possible to control the continuous growth of human beings in the same way that we control population growth today.

So what is the ideal height? With the development of science and technology, people expect that growing taller and controlling their height will become a reality. If so, humans are happier.

2. Factors affecting height

Height and weight indicators not only reflect the growth and development of children and adolescents, but also coincide with the development of various tissues and organs of the body. Height refers to the length and proportion of each longitudinal part of the human body. It originates from the longitudinal growth of the human body and is greatly affected by genetic factors. When men are 20 to 24 years old and women are 19 to 23 years old, the long bones of the limbs and vertebrae have completed ossification, and the height stops growing.

There are many factors that affect height, such as heredity, nutrition, sports, environment, living habits, race, endocrine, sexual maturity (menarche age at 18 years old is on average 5 cm higher than that at 11 years old), distance Inbreeding, medical advances, and more.

1. Heredity

Growth and development are affected by innate heredity and acquired nutrition, physical exercise and various living conditions. But among the many factors that affect height, genetics is more important. The human body develops from a single-celled fertilized egg into a complex multi-cellular individual, and from a young fetus into a strong individual, all of which are controlled by genetic genes. The heritability of body length is as high as 0.75-0.92, and it especially affects daughters, with the heritability as high as 0.85-0.92. That is to say, 75% to 92% of male height and 85% to 92% of female height are affected by genetic variation. The maximum is only 25% for men and 15% for women, depending on other factors. It is proved that heredity plays an extremely important role in the height of children.

Relatively speaking, weight is less affected by genetic genes, with 63% of men and 42% of women affected by genetics. 37% of men and 58% of women depend on acquired environmental factors. It can be seen that the acquired environment has a greater impact on body weight.

2. Nutrition

Nutrition is the indispensable material basis for human survival, that is, to maintain normal life, develop the body, and engage in activities, especially the two growth and development of the human body. During the peak period, it is very important to ensure the supply of high-quality and sufficient nutrition and to balance vitamins and minerals (calcium, phosphorus, zinc, etc.). my country's urban children and adolescents are on average 2 to 4 centimeters taller than their rural counterparts. One of the reasons is that nutrition in cities is better than in rural areas. Just take protein as an example. The nutrition for height is especially "stacked" by protein. There are about 20 kinds of amino acids known to exist in the human body or in nature. The amino acids that make up proteins must be provided by nutrition. Food can provide enough 8 kinds of necessary amino acids, which is helpful to accelerate protein synthesis, thereby promoting the growth and development of various tissues and organs of the human body, especially the growth and development of bones and epiphyseal cartilage. Taking lysine as an example, Japan divided six pairs of twin babies into two groups for an experiment. The first group was supplied with normal nutrition, and the second group was supplemented with lysine in normal nutrition. After 13,200 hours of experiment, it was found that the infants in the second group were The first group is 1.7 cm taller and weighs 1 kg more. Experiments on school-age children have shown that the height and weight of the experimental group with 0.5 grams of lysine added to each meal of bread were significantly higher than those of other school-age children. Some countries also add 25 grams of soy flour and appropriate amounts of calcium, iron, and vitamins to the lunch bread for children and adolescents. After half a year, these children and adolescents are 2.62 kilograms heavier, 0.9 centimeters taller, and have 3.4 grams more hemoglobin than those who eat a normal diet. The reason is that protein is not only the "building material" of the human body, but also an important substance that participates in enzymes, hormones, hemoglobin, myofibrin, and collagen that constitute the human body's scaffolding and participates in important physiological activities of the human body. Similarly, the nutritional status of the mother also restricts the normal development of the fetus to a certain extent. If the diet lacks certain nutrients, it will cause fetal malformations.

Malnutrition will not only affect growth and development, but also affect the quantity and quality of brain cells; on the contrary, overnutrition can lead to obesity, which is also detrimental to the physical and mental health of children and adolescents.

3. Sports

Among the many acquired factors that affect height, the most positive and effective factor is sports. What affects the physical development of children and adolescents is muscle weakness. More exercise is the physiological need for children and teenagers to grow taller. Therefore, sports are an important driving force for the healthy growth of children and adolescents. A large number of survey data at home and abroad have proven that children and adolescents who insist on exercising have an increase in chest circumference, vital capacity, and grip strength of 5 to 8 cm, 500 to 1500 ml, and 4.6 to 5.7 kg respectively compared with children and adolescents of the same age who do not exercise or lack exercise. Helps the growth and development of children and adolescents. According to survey data from a primary school in Liaoning, students who regularly participate in school or junior sports training are on average 4 centimeters taller, 2 kilograms heavier, and 200 milliliters larger in vital capacity than ordinary students. Children in the far north of the former Soviet Union are less active in activities during the polar nights when there is no daylight. Although they are tall and have a large frame, their physical strength and endurance are weak. Compared with southern children of the same age, their grip strength is 8 kilograms less and their long jump performance is 9 kilograms less. cm, and the high jump score was 3 cm less. All these prove that sports can not only promote height growth, but also affect the improvement of physical functions and athletic ability.

4. Environment

Environment includes natural environment, social environment and psychological environment. The environment also affects human growth and development to varying degrees. Among the basic environmental factors, the natural environment (the sum of various natural factors surrounding humans in the human ecosystem), climatic conditions, and geographical environment have an impact on height as an example. Generally speaking, , Children and adolescents in tropical and temperate zones mature sexually earlier and have slightly worse physical development levels; after a 1975 survey by the Institute of Pediatrics, Chinese Academy of Sciences, the average height (cm) of the 17-year-old age group was analyzed: males, Beijing 168.7, Wuhan 167.8, Guangzhou 164.7; women, Beijing 157.7, Wuhan 157.3, Guangzhou 155.3. my country's 1982 survey on the body shape, physiological functions and physical fitness of children and adolescents has shown that children and adolescents aged 7 to 17 in Beijing are 2.5 to 4.6 centimeters taller than children and adolescents of the same age group in Hunan.

The above two surveys both prove that the height of children and adolescents in my country has a trend of being higher in the north and lower in the south. This trend is not only related to food varieties, but also has a direct relationship with climate environment, geographical location, sunlight time and other factors.

Psychological factors can also affect growth and development. Psychological factors can be said to be the sum of emotions, and the seven emotions of joy, anger, sadness, joy, sadness, fear, and surprise are the expressions of emotions. The emotional world is diverse. Objective things give the human body feelings of joy, happiness, happiness, sadness, pain, and disappointment, which directly affect all human activities. Sudden, strong, and long-lasting emotional stimulation will affect the body's internal organs, the activity of qi and blood, and the functions of the brain and endocrine system. Sadness, depression, sulking, etc. can easily cause children and adolescents to suffer from various diseases and affect their growth and development. Clinical observations have proven that children who have been severely mentally stimulated are not only prone to various diseases, but their growth and development are retarded or even stagnant, leading to premature aging. This is the result of adverse psychological factors affecting brain and endocrine functions. Therefore, to create a good psychological environment for children and adolescents, especially families should provide warmth, care and care to children under the premise of positive inspiration and guidance, so that they can obtain necessary and normal psychological satisfaction, spiritual enrichment and good mood. Happy, healthy physical and mental growth.

5. Living habits

The contents of living habits include a wide range of things, such as diet, exercise, hygiene, sleep, work and rest system, work-rest balance, etc. Improving certain lifestyle habits can also help you grow taller. According to relevant reports, the average height of Japanese citizens increased by 2.23 centimeters in the 34 years from 1892 to 1926. The main reason is that in the past, most people had the habit of sitting cross-legged. As the times progress, sitting cross-legged is gradually replaced by sitting on chairs, which promotes the growth of lower limb bones. Body posture also affects height. When the human body enters the second peak period of growth and development (the pubertal growth spurt period), the muscle growth rate lags behind the growth of height. Therefore, the muscle fibers are thin, the cross-section and volume are small, and the muscle strength is poor. Some children and adolescents do not pay much attention to the correct postures of standing, sitting, walking, reading, and writing in their daily lives. They always lower their heads, lift their shoulders, hold their chests, and hunch their backs habitually, resulting in spinal deformation, which will affect their height by 1 to 5 centimeters.

In addition, medical advances can also promote height growth. For example, taking zinc sulfate and lysine preparations can increase appetite and promote growth and development. The former Soviet Union was very successful in using traction surgery to increase height. A patient with dwarfism named Peter Penkus, who was only 130 centimeters tall, reached 160 centimeters after three years of treatment by Professor Ilishalov. Professor Yi's treatment method is: use a small hammer and fine chisel to pierce both ends of the long bones of the limbs, use steel wires as thick as sweater needles to pass through the muscles and bones to fix them on the metal frame, and use a screwdriver to stretch the metal frame three days later. 1 mm, new bone cells will fill this small gap in just 24 hours, and blood vessels, muscles, and tendons will also grow accordingly. Peter has grown 30 centimeters in three years, and his calves alone have grown 19 centimeters. Professor Yi has stretched the bones of 300,000 people.

3. Predicting height

Height is the most important indicator of body shape characteristics and attracts the attention of the world. There are many methods to predict height, such as using bone age prediction method, using foot Longest prediction method, height prediction method using parents, height prediction method using children and adolescents for the current year, height prediction method using height at the beginning of puberty, mathematical prediction method, etc. The information in this volume only introduces prediction methods that have been tested and have scientific basis at home and abroad.

There are many methods for predicting height, which can be roughly divided into two categories. One is to use current bone age and current height to predict adult height: the theoretical basis is that there is a high correlation between height at each age and adult height, R=0.8. Based on your current bone age, can you predict how tall you are likely to grow?

In 1987-88, the National Sports Commission of my country organized a study on Chinese bone age assessment standards and formulated the "Chinese Wrist Bone Development Standard CHN Method". In 1992, it was approved as an industry standard of the People's Republic of China and officially announced and implemented.

When taking an X-ray of the wrist bones, separate the five fingers of the left hand, place the palm of the hand downwards against the X-ray box, straighten the hand in line with the forearm, and aim the X-ray lens at the third metacarpal head, about 90 cm away from the back of the hand. . In addition to all the bones of the hand and wrist, the X-ray should also include 3 to 4 cm of the distal end of the radius.

CHN method *** evaluates the development degree of 14 bones in the radius, metacarpal, phalanges, and carpus. The bone age can be estimated by adding the grade scores of the 14 bones and looking up the table.

After systematic training and repeated practice to accurately grasp the criteria for distinguishing the grades of each bone fragment, the error in film evaluation using the CHN method is not large.

The bone age assessed by the method of assessing the bone age of the wrist bones is also called biological age. It is a sign of human growth, development, maturity, and aging. In children and adolescents, biological age is usually regarded as the degree of growth and development. Biological age is roughly consistent with a person's life age calculated based on their birth year. However, due to the influence of genetics, nutrition, physical exercise, disease and other factors during the growth and development process of each person, the speed of development is not necessarily exactly the same as the calendar age. Some people develop early and their biological age is greater than their chronological age. There are also people whose biological age is smaller than their chronological age. The speed of development is sometimes uneven. A person's development lags behind for a certain period of time, but after a while, the development speed may accelerate and become normal again. It is customary to call development normal if the difference between bone age and living age is within ±1 year. If the difference between bone age and living age is >1 year, it is called premature development (abbreviation: precocious puberty). If the difference between bone age and living age is less than 1 year, it is called developmental delay (abbreviation: late maturity). During the growth and development stages of children and adolescents, regular assessment of their developmental level is of great significance in promoting the healthy growth of children and adolescents.

Among the various bone age prediction methods, after comparison, the TW2Mark2 method is more accurate. During prediction, it is required to enter the current height and bone age, and the girl also needs to enter whether she has had her period. Then different prediction formulas for men and women are used to calculate adult height.

The other type is to predict adult height based on the genetic factors of parents. There are also several prediction formulas. After comparison, foreign formulas have larger errors. The Hubei Provincial Sports Research Institute conducted a survey on the heights of 1,821 young men and women and their parents in 1983 and 1984, and calculated a height prediction formula that was better than the prediction using foreign formulas. The error is small and it has good results in the selection of athletes and the physical assessment of adolescents in my country. The height prediction formula is as follows: (Unit: cm)

Boy’s height=59.699+0.419×Father’s height+0.265×Mother’s height

Girl’s height=43.089+0.306×Father’s height+0.431× Mother's height

The future height predicted by bone age is mainly predicted from the current development level, and the future height predicted by parents' height is predicted from the innate genetic possibility. Therefore, the difference between the two It is entirely possible for the forecast results to be inconsistent.

It should be noted that since there are many factors that affect height, no matter which method is used to predict, the prediction formula cannot take all factors into account. Moreover, after prediction within a certain period of time, it will be predicted Many changing factors such as the subject's nutrition, disease, environment, etc. are also unpredictable. Therefore, although we are sure that these forecasting methods are scientifically based, the trends reflected in the forecast results are not wrong. However, errors in height prediction are always inevitable.

4. Sports promote growth.

1. Two critical periods for human body growth

From the perspective of human growth and development, there are two peak periods of height growth and development in a person's life. The first time is in the second trimester to infancy. The fetal height grows fastest during the second trimester (4 to 6 months). During these three months, the fetal height grows approximately 27 centimeters, accounting for one-half of the entire fetal height. It is the fastest growing stage in a person's life. During infancy (from birth to 1 year old), the growth rate slows down slightly, but still grows by 20 to 25 cm, which is 50% of that at birth. Afterwards, the growth rate slows down and remains relatively stable until the second peak of growth and development, which is about 10 years old for girls and 12 years old for boys (puberty). During adolescence, the average height growth is 7 to 8 centimeters, and the maximum increase can be 10 to 12 centimeters; the annual weight gain is 4 to 7 kilograms, and some individuals can reach 8 to 10 kilograms. After about three years, the growth rate slows down again, until the height basically stops growing when the female is about 17 years old and the male is about 22 years old. Since the second growth spurt of girls begins earlier than that of boys, the height development curves of boys and girls cross for the first time around the age of 10. Before the crossover, boys were taller than girls. After the crossover, girls were taller than boys; by the age of 12, The second growth spurt for boys begins around the time when girls' growth rate has begun to slow down, so in turn, boys are taller than girls, and the curves cross for the second time.

Due to the larger growth spurt and longer growth period of boys, most men have higher body shape indicators than women by the time they reach adulthood.

The development pattern is based on the average value, but there are three types of early maturation, normal maturation and late maturation for both men and women. The characteristics of precocious puberty are that they start to develop at an early age and the peak of height growth occurs early, but the growth spurt is often shorter. Therefore, although they appear taller at the beginning, they may not necessarily be higher than those of late maturers in the end. The weight-to-height ratio of early-maturing girls is generally higher than that of late-maturing girls, and they end up with narrow shoulders and a wide pelvis, tending to be short and fat. The characteristic of late-maturing people is that although they start out shorter, their growth spurt lasts longer, and they end up being taller than those who mature earlier. Late-maturing boys have narrow pelvises, broad shoulders, and are tall and thin. Normal development is somewhere in between.

When we know the general rules and growth peaks of height growth, we can make comprehensive adjustments to pregnant women, fetuses, infants, children and adolescents during these two periods. In addition to supplementing comprehensive and balanced nutrition, especially In addition to protein of high quality and sufficient quantity (in the second half of pregnancy, the fetus grows bones and needs to be supplied with calcium. It is advisable to eat more calcium-containing foods, such as soy milk, tofu, eggs, potatoes, cabbage, carrots, etc., fried small fish and shrimp You can eat it with the skin, eat more fresh vegetables, fruits, honey, etc.), and do moderate exercise. During pregnancy, especially in the second trimester (4 to 7 months), the miscarriage rate of pregnant women is greatly reduced, pregnancy reactions are eliminated or reduced, and the mental state is stable. Pregnant women should engage in moderate physical activities, such as aerobics, deep breathing, active games, etc. Walking can also be used to lightly exercise the dorsal and abdominal muscles with small amounts, weak intensity, and slow rhythm. This can not only improve the functions of the nervous system, cardiovascular system, and respiratory system, regulate gastrointestinal function and human metabolism, but also help fetal development and delivery.

When a baby is born without disease or other external stimulation, crying a few times is not a bad thing, but a good exercise and good for health. When a baby cries, stretches its limbs, and "dances", it not only accelerates blood circulation and provides sufficient nutrients and oxygen to the brain, bones, and muscles, but also improves cardiopulmonary function and the growth and development of the thorax. Babies aged 6 to 12 months can be appropriately induced to play, turn over, crawl or help them walk according to the situation, which is helpful for physical and mental health and brain development. The nervous system is the earliest, fastest and most mature system in the human body. At the age of 6 to 7 years, the weight of the brain has reached 90% of that of an adult. By the age of 20, the weight of the brain has increased by 10%, weighing about 1,400 grams. However, at this time, the internal structure and function of brain cells are becoming more complex. reached a period of great perfection. Therefore, providing more information stimulation to infants and young children is extremely beneficial to their brain development and physical and mental health.

The pubertal growth spurt is the transition period from children and adolescents to maturity, and is the second peak period of growth and development in life. During this period, the human body's morphology, physiology, psychology, biochemistry, endocrine and intelligence will all undergo mutations. Therefore, moderate physical exercise during adolescence, especially more general stretching exercises, will help grow taller.

2. Why can sports help you grow taller?

There are three main reasons why sports can promote height growth.

(1) Promote the increase in growth hormone secretion. There are three main endocrine hormones that control height, namely growth hormone, luteinizing hormone and sex hormones secreted by the pituitary gland. Among these three hormones, growth hormone has the most significant effect. It is an essential substance to ensure normal growth and development of the human body. Experiments have shown that after 90 minutes of moderate-intensity physical activity, the secretion of growth hormone in the human body increases twice as much as at rest. The good stimulation of sports can also ensure deeper sleep. Scientists have discovered through electroencephalography, electrocardiography and eye flow monitors that when children and adolescents sleep for an hour, the secretion of relevant hormones (growth hormone, luteinizing hormone, sex hormones and prolactin) in the body is extremely strong, especially growth hormone. The amount of secretion reaches a peak, and the content in each milliliter of blood is as high as 20 micrograms, which is 5 to 7 times that during the day. Increased secretion of growth hormone can promote normal growth and development of children and adolescents. According to reports, a 23-year-old woman grew nearly 3 centimeters in height after falling into coma due to illness for two months. If the secretion of growth hormone is insufficient, it will seriously affect the growth and development of children and adolescents, and even cause dwarfism.

(2) It can increase the proliferation ability of epiphyseal cartilage. The key to "tall" is the length of the long bones of the lower limbs and the growth and development of the spine.

From the perspective of human anatomy, the long bones of the limbs are tubular bones, with cartilage between the two ends and the bone body (in infancy, each bone has a growth point or ossification center), called epiphyseal cartilage. As people mature from infancy, their height increases several times, mainly due to the growth of epiphyseal cartilage. When the epiphyseal cartilage completes ossification, people will no longer grow taller. The growth and development of epiphyseal cartilage is controlled by growth hormone. Insisting on physical exercise can not only increase the secretion of growth hormone, but also promote strong metabolism and accelerate blood flow. When a person is at rest, it takes 20 to 25 seconds for blood to circulate throughout the body, which is shortened to 8 to 9 seconds during exercise. Physical exercise can also increase oxygen intake by 7 to 12 times. For teenagers aged 15 to 20 years old, the respiratory rate can be increased from 18 to 20 times/min in quiet state to 30 to 40 times/min, and the lung ventilation volume can be increased to 70 to 120 liters. With sufficient blood oxygen and accelerated flow rate, sufficient raw materials can be supplied to bone cells.

Appropriate exercise can not only provide sufficient raw materials for the proliferation of epiphyseal cartilage and provide beneficial "mechanical massage" to it, but also play a good role in changes in bone morphology, structure and function. For example, bone density thickens, making bones stronger and stronger; the arrangement of bone trabeculae becomes more orderly and regular according to different pressure and tension; the protrusions of muscle attachment on the bone surface become more obvious, etc. These changes can greatly improve the bone's properties of traction, compression, torsion, bending resistance, and fracture resistance.

(3) You can get more vitamin D and "air vitamins". Mass sports activities are mostly carried out outdoors, where there is sufficient sunshine and fresh air, which can enable the human body to obtain more vitamin D and "air vitamins". Physicists have found that sunlight passes through a prism and emits seven colors: red, orange, yellow, green, cyan, indigo, and purple. There are many invisible rays outside the seven-color light, which account for about 50 to 70% of the sunlight. Red light excites nerves and improves the function of the cardiovascular system, respiratory system and muscle tissue. Yellow light and green light have a calming effect, while blue light and purple light have inhibitory effects. In different seasons, the length and intensity of light are also different, so seasons have a greater impact on growth and development. Taking height and weight as an example, among the four seasons of the year, height growth is the fastest in spring. Compared with the three months from September to November, the height growth in the former is 2 to 2.5 times higher. On the contrary, weight increases fastest in autumn, and the three months from September to November is the fastest weight gain period in the whole year. The main reason for rapid height growth in spring is that the sun is getting closer to the earth in spring, so the sunlight contains more infrared and ultraviolet rays. Infrared rays have short wavelengths, strong penetrating power, and contain a large amount of heat energy. They can evenly heat human skin, reflexively promote blood vessel dilation, accelerate blood flow, and provide sufficient blood oxygen for epiphyseal cartilage proliferation. Ultraviolet rays can turn a substance called "ergosterol" in human skin into vitamin D. Vitamin D enters the blood and can promote the gastrointestinal absorption of calcium, phosphorus and other substances, providing more control for the growth of bone cells. Bone material.

Performing physical activities outdoors and breathing fresh air can help you get more "air vitamins." The south is evergreen and colorful all year round, while the north has red flowers and green willows in spring, summer and autumn. In such a natural environment, anions multiply. Anion is an essential "element" to maintain the normal growth and function of human cells. Scientists call it "air vitamin". Someone divided white rats into two groups and fed them (with the same nutrition). Group A was fed in normal air, and group B was fed in cotton-filtered air. Four weeks later, group A had no change and was safe and sound; group B had a high prevalence of disease, and some were facing death. The key reason is that the anions in the air breathed by the white mice in Group B have been completely absorbed by the cotton. It can be seen that the increase in the number of anions in the human body not only helps children and adolescents grow taller, but also helps improve the body's function and health.

3. Which exercises can help you grow taller?

The skeletal system grows rapidly during children and adolescents, and the bones contain a large proportion of organic matter and a small proportion of inorganic matter. The bones are fragile and flexible. The spine of children and adolescents is highly elastic, but the strength of muscles and ligaments is poor, and the strength of fixed joints is weak. The neurological process of children and adolescents is characterized by excitation being more dominant than inhibition. Cerebral cortical nerve cells have poor working ability and are prone to fatigue, but they have fast response, fast recovery and good flexibility. During the period of children and adolescents, especially during the pubertal growth spurt, height growth is rapid, thoracic development is relatively lagging behind, the development speed of the heart cannot keep up with the growth rate of other parts of the body, blood and oxygen supply are relatively insufficient, and the regulatory function of the cardiovascular system is also unstable.

In view of the above characteristics of children and adolescents, when exercising, you should choose those exercises that have a large stretching range, a high frequency, a strong sense of rhythm, and a short duration. You should try to avoid those exercises that are too intense, long in duration, and breath-holding endurance and static exercises. practise.

(1) Whole-body stretching program: There are many whole-body stretching programs, such as freehand exercises, light equipment exercises, aerobics (body) exercises, pull-ups, arm flexion and extension, and arm extension and wave swings. , hanging swing, leg swing, leg press, kick, cheat leg, split leg, "bridge" and so on.

(2) Coordination projects: These projects include ball games, swimming, skating, skiing, dancing, activity games, etc.

(3) Jumping events: These events include single and double jumping on the spot, single and double jumping while moving, stride jump, frog jump, vertical jump, standing long jump, standing Multi-level long jump, rubber band jumping, skipping rope, supported jumps, obstacle jumps and more.

(4) Short-distance competition events: Short-distance competition events include track and field events of 50 meters, 60 meters, 100 meters, 200 meters, 400 meters and 4×100 meters relay races, swimming (butterfly, backstroke) , breaststroke, freestyle) 2