First of all, the motion system
1, skeleton
Features: The bones of children and adolescents are rich in inorganic substances, with little organic matter, high elasticity and low hardness, and are not easy to completely fracture but easy to bend and deform.
Precautions in training: In physical training and children's daily life, children must develop correct body posture. Nowadays, many people's bad postures such as hunchback, scoliosis, high and low shoulders, X-shaped legs and O-shaped legs are mostly caused by bad habits in childhood and adolescence.
2. Joint
Features: The articular cartilage of children and adolescents is thick, and the articular capsule and ligament are thin, loose and extensible. Therefore, children and adolescents have a wide range of joint activities, good flexibility and flexibility, but poor firmness and stability, and are prone to dislocation.
Matters needing attention in training: In addition to routine training, proper strength exercises are also carried out according to the child's physical condition to increase the stability of joints.
3. Muscles
Characteristics: The sequence of muscle development: trunk muscle precedes limb muscle, flexor muscle precedes extensor muscle, upper limb muscle precedes lower limb muscle, and major muscle precedes minor muscle. The physiological cross section of muscle is small, and the effective components of muscle contraction are few. Therefore, children and adolescents have weak contractility, poor endurance and easy fatigue, but they recover faster than adults.
Training notes: high-frequency and low-intensity training can be carried out during training, and each group of training can arrange rest directly and reasonably.
Second, the respiratory system
The respiratory system of children and adolescents is characterized by small lung volume and few elastic fibers and alveoli. Respiratory muscle strength is weak, airway is narrow, and elastic resistance and airway resistance are high when breathing.
Breathing depth is small, breathing frequency is fast, and lung ventilation and vital capacity are small (with the increase of age, breathing depth increases, breathing frequency decreases and vital capacity increases).
Training notes: strengthen the training of respiratory muscles and improve the depth of breathing (use deep slow breathing instead of shallow fast breathing). Pay attention to the coordination of breathing and action (when to do what action, when to do what action, when to exhale, etc.). ).
Third, the cardiovascular system
The cardiovascular system of children and adolescents is characterized by small heart volume, weak contractility, low blood pressure and small absolute value of cardiac output, but the cardiac output per kilogram of body weight is large, which is mainly increased by increasing heart rate during exercise.
The total amount of blood is less than that of adults, but the percentage of blood in body weight is higher than that of adults, and the hemoglobin content is lower.
Matters needing attention in training: arrange the exercise load reasonably, don't hold your breath for too long, and do more long-term moderate-intensity exercise to promote the growth and development of blood circulation system and improve the functional level.
Fourth, the nervous system
The characteristics of children and adolescents' nervous system: the earliest and fastest development of nervous system, unstable neural activity process, low working ability of cerebral cortex neurons and easy fatigue, but flexible neural process.
Training notes: training time should not be too long, pay attention to arrange a short rest; Adopt intuitive image teaching, and use imitation practice method more; The training content should be vivid and diverse; Strengthen the ideological education of will quality and organizational discipline.