Describe the general requirements for a rational technique. Front crawl swimming technique The main working movement that ensures the advancement of the swimmer
Current page: 1 (total book has 9 pages) [accessible reading excerpt: 7 pages]
A. S. Kazyzaeva, O. B. Galeeva
Fundamentals of sports swimming techniques. Tutorial
INTRODUCTION
The modern level of achievements in sports swimming is characterized by a very high density of results at major competitions. There were original ways to increase the speed of swimming (the use of special wetsuits that reduce resistance and improve the quality of gliding), approaches to training methods have changed. So, according to N. Zh. Bulgakova, since the 80s of the XX century, there has been a continuous decrease in the total volume of navigation. Further growth of results occurs by improving the quality level of the training process at various stages of training.
In the 1990s, a fundamental change in swimming philosophy began. So far, coaches have focused on a large number of hard work, now there is a qualitative turn to competitive swimming. We have witnessed the emergence of swimmers who advanced due to perfect swimming technique, and not just because of high physical indicators and talent. The famous coach, sports scientist G. Turetsky notes that it is necessary to base on the priority of perfect technique over speed and strength.
Currently, the strongest swimmers in the world, achieving high sports results, demonstrate more and more advanced swimming techniques, which are highly efficient and expedient. According to the definition of L.P. Makarenko, an effective swimming technique is characterized by an optimal combination of applied efforts and body position at every moment of the stroke. Knowledge of general principles and characteristic features inherent in rational variants of swimming technique, will allow the future specialist to analyze in detail the swimming technique of his pupils and correct mistakes.
In the existing textbooks and manuals on swimming, the features of the technique of sports methods of swimming are not fully described, which cannot satisfy the increased requirements of students specializing in this sport. The proposed manual partially compensates for this shortcoming, it summarizes the current knowledge on the technique of sports swimming methods based on the achievements of modern science and the practice of training athletes.
The proposed manual is intended primarily for students of the "swimming" specialization, and can also be used by athletes and coaches during training sessions in swimming.
TOPIC 1. FUNDAMENTALS OF SWIMMING TECHNIQUE
Every day, the coach has to evaluate the effectiveness of one or another element or technique variant. He, as a specialist, needs knowledge of the laws of biomechanics and hydrodynamics, the correct interpretation of special terms and concepts. Before talking about sports swimming, you should define some concepts.
Swimming - is the ability of a person to move in water without the help of supporting means.
Swimming technique - this is a rational system of movements that allows you to achieve the highest result in competitions.
Movement cycle - a complete system of movements that is repeated many times. For the beginning of the cycle, it is conditionally taken: with a crawl on the chest, swimming on the back, with a dolphin - the moment the hand enters the water, with the breaststroke - the extreme moment when the hands are brought forward before spreading them to the sides.
Step - the distance covered by a swimmer in one cycle of movements.
where L is the step, S is the distance, N is the number of cycles.
Tempo - number of completed cycles per unit of time.
where T is the rate, N is the number of cycles, t is the time.
Rhythm - the ratio of the time of individual parts (phases) of an integral cycle of movements. It determines the distribution of efforts in the cycle, the emphasis on the execution of phases and the moments of the stroke.
The working phase of the cycle - the phase in which the swimmer performs a movement that generates a forward thrust.
The preparatory phase of the cycle - a movement that does not create a traction force that moves the swimmer forward, while it ensures the return of the body links to their original position to complete the working phase.
Traction force - the maximum application of force in the water when performing a rowing movement in place.
Attack angle - the angle formed by the longitudinal axis of the swimmer's body and the direction of movement. If the swimmer's shoulder girdle is located above the pelvis, then the angle of attack is positive, and if it is below the pelvis, then it is negative.
Trajectory- a trace of the movement of a point in space. The trajectory of the rowing movement characterizes the direction and magnitude of the path of the hand or foot throughout the cycle.
Amplitude- distance between extreme points trajectories.
Speed is the distance traveled per unit of time.
Intracycle speed - change in instantaneous values of speed in a cycle of movements (usually fixed in separate phases).
Midel - area of the frontal projection of the body.
There are the following main axes and planes of motion:
Longitudinal axis of the body- an axis passing through the center of the pelvis and shoulder girdle upright.
Sagittal axis of the body- an axis passing through the center of gravity from front to back in a vertical position.
Frontal axis of the body- an axis passing through the center of gravity from right to left. When changing the position of the body in space, the name of the axes is preserved regardless of their orientation to the horizon.
1.1. The concept of swimming technique
Swimming technique, as the most rational system of movements in the water, is essentially determined by the characteristics of the environment in which the swimmer's movements occur. The concept of "technique" covers the form, characteristic movements, their internal structure. It includes the swimmer's ability to best coordinate and use all internal and external forces acting on the body for propulsion. Such a rational system, according to L.P. Makarenko, is inextricably linked with the individual characteristics of the organism, with the level of development of its motor qualities and functionality.
V. N. Platonov notes that the effectiveness of technology is determined by its efficiency, stability, variability, and economy.
An effective swimming technique must correspond to the tasks to be solved and a high end result and implies not only the external correctness of movements, but also a high level of development of a sense of water, rhythm, time, pace, developed efforts, optimal coordination of activities nervous system and muscular apparatus, etc.
The stability of technology is associated with its noise immunity, independence from external conditions, functional state athlete. It should be taken into account that modern training and competitive activity characterized by a large number of confounding factors.
Technique variability is determined by the swimmer's ability to prompt correction of motor actions depending on the conditions of the competitive struggle, the functional state of the body at each specific moment of swimming the distance, which is based on the presence of a labile skill. Modern swimming technique is extremely variable.
It is constantly evolving and improving. at the European, World and Olympic Games athletes constantly demonstrate a variety of styles and options, new elements of swimming technique.
As an example, we can cite the varieties of front crawl swimming techniques that are successfully used at various distances. As the observations of a number of authors show, highly skilled swimmers have their own style: different positions of the head, body, different amplitudes of movements of the arms and legs, characteristic coordination, and so on. But, according to L.P. Makarenko, it would be a delusion behind the individual characteristics of the movements of swimmers not to see the general patterns and characteristics inherent in rational variants of swimming technique. For many decades, coaches have been experimenting, selecting the most effective elements of movements and their coordination, clarifying views on swimming technique in accordance with the laws of hydrodynamics, biomechanics and data from objective research methods. These include the optimal directions and trajectories of the working movements of swimmers, the positions of the working planes of the arms and legs relative to the water, as well as rational elements in coordinating movements, etc.
The technique of sports swimming methods (front crawl, breaststroke, back crawl, butterfly), despite its complexity, is extremely expedient and is subject to the same requirements:
1) the swimmer is in the water in a position close to horizontal in order to experience less resistance from the flow around;
2) some minor fluctuations of the body, and especially the shoulder girdle, may be appropriate when the effect obtained from this fully compensates for the costs of additional resistance and wave formation;
3) the movements of the arms and legs must be complete, that is, it is possible to contribute to the advancement of the athlete to a greater extent;
4) coordination of movements in each of the methods of swimming should ensure: a) uniform advance; b) deep and possibly freer breathing; c) beneficial alternation of tension and relaxation of the working limbs; d) such coordination of stresses, in which the movements of the legs would not reduce the effectiveness of the movements of the hands, or vice versa;
5) the swimming technique of any athlete must meet his individual characteristics.
The efficiency of technology is characterized by the rational use of the energy of time and space when performing movements. All other things being equal, the best is the variant of motor actions, which is accompanied by minimal energy consumption, the least stress of the athlete's mental capabilities. The effectiveness of a technique is determined by its compliance with the tasks to be solved, the level of physical, tactical, psychological readiness and a high end result. The formation of a flexible labile skill, the improvement of intermuscular and intramuscular coordination and breathing techniques contribute to an increase in the efficiency of technology.
The analysis of theoretical and experimental works in the field of sports made it possible to identify the main factors influencing the effectiveness of swimming technique. These include:
1) optimal trajectory and amplitude of stroke movements;
2) the creation of a “fixed” support on the water during the stroke. For more skilled swimmers, the brush travels only 0.4 m during the stroke, instead of 0.6–0.7 m for less skilled swimmers;
3) the use of zones of maximum force angles in working movements, which is achieved by bending the arm at the elbow joint in the phases of gripping and pulling and by extending the forearm in the repulsion phase. This corresponds to two peaks of effort during the stroke;
4) reduction in the duration of inactive phases and periods (drift and influx), which ensures continuous maintenance of a high working effort;
5) coordination of the work of the muscles serving different joints allows achieving the greatest working effort, ensuring its transfer from one link to another;
6) minimizing changes in intra-cycle speed;
7) the optimal ratio between the pace and step of swimming movements;
8) reduction of hydrodynamic resistance during swimming by choosing the optimal position of the body in the water and improving the balance of the body;
9) the use of inertial and reactive forces for promotion.
In sports swimming, the main condition that determines the swimming technique is the rules of the competition. They determine the size of the distances, the methods of swimming, the rules for starting and turning, the rules for swimming the distance, the finish line, and so on. The technique of sports swimming methods is a structural unity of five elements. These are leg movements, arm movements, torso movements, head movements and respiratory movements.
Sports technique, as a system of movements, has a certain structure. The structure of movements is a natural connection of the constituent parts of the movement as a whole. There are kinematic, dynamic, rhythmic, informational and other structures of movements.
The kinematic structure of the movement technique is made up of spatial, temporal and space-time characteristics. Kinematic characteristics reflect the geometry of movements in time.
The spatial characteristics include: the position of the body in space, the step of the swimmer, the trajectory of its links.
Temporal characteristics: the duration of the movement (the difference between the moment of the end and the moment of the beginning of the movement); pace of movement. The rhythm of movements is closely related to temporal characteristics (characterized by the ratio of the duration of individual parts of the complete cycle of movements).
Spatio-temporal characteristics: speed - characterizes the speed of change in the position of a body point in space over time; acceleration - the rate of change of the velocity vector over a period of time (linear or angular).
The dynamic structure of motion is made up of power, energy and inertial characteristics. It reflects the interaction of external and internal forces acting on the athlete.
Internal forces:
Active forces of muscular traction;
Passive powers locomotive system(elastic-viscous properties of muscles, ligaments and tendons);
Reactive forces of recoil links;
Forces of inertia.
External Forces:
Gravity;
Forces of resistance of the environment;
Support reaction force;
Hydrostatic buoyancy;
Traction force;
lift force;
inertial forces;
Forces of friction.
The rhythmic structure of the technique of movement reflects the ratio of the duration of the parts of the movement, the coordination of articular movements and the change in the nature of the developed effort over time.
The information structure of technology is made up of bioelectrical processes occurring in the brain and muscles. It reflects the order of inclusion and the nature of the participation of certain muscle groups in the work.
1.2. Physical properties of water
The main feature of swimming is that this species muscle activity is carried out in aquatic environment, which differs significantly from air in its physical properties. The main physical properties of water are: density, specific gravity, viscosity, compressibility, thermal conductivity, sound conductivity and refraction.
The density of water is its mass per unit volume. Density is denoted by the Greek letter (rho) and is measured in kilograms per cubic meter (kg/m3):
where m is the mass of liquid, kg; V is the volume of liquid, m 3.
The density of fresh water at 4C is 1000 kg/m 3 . The density of water is 775 times greater than the density of air (1.29 kg / m 3), so movement is difficult in water. In comparison with athletics running in swimming, the speed of movement is much less. Its specific gravity depends on the density of water.
The specific gravity of water is the weight of a unit of its volume. It is denoted by the Greek letter γ and is measured in the MKGSS technical system of units in kilogram-force per cubic meter (kg / m3):
where G is the weight (gravity) of water, kg; V is the volume of liquid, m 3.
The specific gravity of distilled water at a temperature of 4C is 1000 kg/m 3 (1 kg/l). An increase or decrease in water temperature leads to a decrease in specific gravity. The presence of salts or other impurities in water leads to an increase in specific gravity. Sea water, in which many salts are dissolved, has a specific gravity greater than 1 (1.03). Therefore, in sea water it is easier for a person to stay on the surface than in fresh water. Bodies with a specific gravity greater than one sink. Bodies with a specific gravity less than one float.
The substances that make up the human body have different specific gravity. Thus, the specific gravity of the bones is 1.04–1.07 fat - 0.9–0.93, air contained in the lungs - 0.0013. In general, the specific gravity of the human body is slightly less than one - 0.96–0.98.
Different people have different builds and proportions of the ratios of the weight of muscles, bones, body fat, lung volume, etc. Therefore, the specific body weight of different people is not the same. Individuals with large lung capacity, thin bones, and significant body fat may have a specific gravity of less than 0.95. There are people with low lung capacity, heavy massive bones and minimal body fat, whose average body weight is greater than one (1.01–1.05).
Specific body weight varies in the same person. When you inhale it decreases, when you exhale it increases. In addition, the specific gravity of the human body changes with age. Calcification (an increase in the proportion of calcium in the bones) and an increase in the specific gravity of bones, a decrease in the vital capacity of the lungs and other processes can cause an increase in the specific weight of the body.
Knowing the specific gravity of water makes it possible to judge the buoyancy of a person. Studies conducted by a number of scientists have shown that children have better buoyancy than adults. Particularly good buoyancy is in children aged 10–13, which is associated with an increase in the relative proportion of adipose tissue at this age. Females tend to have better buoyancy than males. The study of buoyancy among swimmers in our country indicates that sprinters have worse buoyancy than stayers.
Viscosity of water - is the property of resisting shear forces. Due to the fact that water has mobility, its particles and layers can move by sliding relative to each other. In this case, internal friction forces arise between the layers of the liquid, which impede the movement. These forces cause the appearance of viscosity.
The viscosity of water is low. With an increase in water temperature from 20 to 30 ° C, the viscosity decreases by about 20%, which accordingly leads to a deterioration in the support. The viscosity of the water is also related to the fact that athletes swimming along the central lanes are in a more favorable position than those swimming along the outer lanes. The fact is that when an athlete moves, the layers of water begin to move and partially move after him. Layers of water in contact with the edge have a velocity close to zero, as they "stick" to the edge. The closer the athlete swims to the side, the stronger he feels this “sticking”, the more difficult it is for him to disperse the layers of water moving with him.
The same “sticking” is felt by divers when diving. If the athlete swims too close to the bottom, then he cannot develop a higher speed.
Compressibility - ability to decrease in volume when compressed. The compressibility of water is extremely insignificant, but as a result of compression, hydrostatic pressure forces arise in it, although it does not decrease in volume.
Under normal conditions, a liquid is compressed by gravity (the liquid's own weight and atmospheric pressure). Immersion in water for each meter gives an increase in pressure by 0.1 kg / cm 2 (i.e., at a depth of 10 m, the pressure will be 1 kg / cm 2 or 1 technical atmosphere). Diving into depth increases pressure and may cause pain in the ears. In order to avoid rupture of the tympanic membrane of the ear, it is necessary to carry out “blowing” in a timely manner (in case of pain in the ears) (approximately every meter of immersion). In order to make a "blowing" you need to pinch your nose with your fingers and exhale. In this case, the air through the Eustachian tubes will increase the internal pressure on the eardrum. This exercise is repeated several times until the pain in the ears goes away. If the “blowing” is not done, then the eardrum can burst, which, in turn, can lead to bleeding, and in extreme cases, to loss of consciousness.
Thermal conductivity - property that characterizes the process of heat transfer. The thermal conductivity of water is 5 times and the heat capacity is 25 times that of air. This property explains the rapid cooling of the swimmer's body and the additional loss of energy. At an air temperature of +25C, a person can stay on the surface for any amount of time. At the same temperature in water, a safe stay for human health is limited to 12 hours. At a water temperature of 0 to +4, a person can stay in the water for 10 to 30 minutes, after which he dies.
Sudden cooling in water can lead to sad consequences. The thermal conductivity of water can have a shock effect. For example, if a person basked in the sun for a long time, and then abruptly jumped into cold water, then due to the rapid narrowing of blood vessels, including the brain (a reaction to cold), a person can lose consciousness and drown. Therefore, in hot weather, it is necessary to enter the water gradually and very carefully.
Resistance to the cooling effect of water varies widely. It is higher in people with a pronounced layer subcutaneous fat and is especially high in people trained in swimming in cold water.
Sound conductivity - the ability to conduct sound. Due to the high density of water compared to air, sound travels faster in water than in air. The speed of sound propagation in water is 1400–1500 m/s, which is 4.5 times faster than in the atmosphere. Despite the good conductivity of sound, it is very difficult to navigate underwater. This is explained by the fact that there is no clear spatial perception of sound in water. Therefore, it is very difficult for a person to establish the direction of a sound source under water. Sounds underwater are perceived primarily through bone conduction. Bone conduction is 40% lower than air conduction. Therefore, audibility under water deteriorates. The range of hearing with bone conduction depends not so much on the strength as on the tone of the sound: the higher the tone, the better the distant sound is heard.
Refraction - ratio of the speed of light in air and in water. The speed of light in water is 1.33 times slower than in air, so all objects in water appear 1.33 times closer and larger. This property should be taken into account when observing swimming technique, when diving, when ascending to the surface and during initial swimming training. When diving and initial training, it should be remembered that the observed object at the bottom and the bottom itself seem closer than they really are. The same thing happens when you ascend, when the surface of the water seems closer than it really is.
State University
Physical culture and sports
Swimming test
Topic: Technique and methodology for teaching breaststroke swimming technique
Course 3, group No. 2
Moscow 2009
1 Position of the swimmer's body in the water 3
1.2 Hand movements 4
1.3 Coordination of movements 5
2 Breaststroke technique 7
2.1 Foot movements 8
2.2 Hand movements 10
2.3 Body position and breathing 12
2.4 General coordination of movements 13
3 Methodology for teaching breaststroke swimming technique 16
3.1 General requirements for the methodology of teaching swimming 16
3.2 Exercises for learning breaststroke technique 19
3.3 Pedagogical model of breaststroke technique 28
4. List of used literature 31
^
1 General requirements for swimming technique
Biomechanical analysis of swimming technique, summarizing the experience of coaches and high-class athletes working on technique allow us to formulate requirements for swimming technique. Compliance with these requirements provides a rational technique. These requirements relate, first of all, to the position of the body in the water, rowing movements of the hands as the main source of driving forces, coordination of movements.
^
Technique sports swimming
- this is a rational system of movements that allows the swimmer to realize his motor abilities in the best possible way in a high result in competitions. This concept includes the form, nature of movements, their internal structure (the regular relationship of movements). It includes, and the ability of a swimmer to feel well,
Be aware of and use to move forward all the internal and external forces acting on the body.
^
1.1 Position of the swimmer's body in the water
The body of an athlete when swimming at a competitive speed should take a well-streamlined, elongated, relatively high and balanced position in the water with an optimal angle of attack. For the technique of qualified athletes, the minimum values of the angle of attack of the body (3-5 °) are characteristic. For the swimming technique, which is mastered by beginners, a slightly larger angle of attack (8-10 °) is characteristic, which makes it possible to give the body a “planing” position, which facilitates the preparatory movements of the arms and breathing. Significant impact on general position The swimmer's body in the water is rendered by the position of the head and hips. For most of the full cycle of movements, the head is almost on the longitudinal axis of the body, the neck muscles are relaxed, the swimmer looks forward - down (when swimming on the chest) or up - back (when swimming on the back). In all methods, with the exception of swimming on the back, the head participates in auxiliary movements in the rhythm of arm movements and breathing. For most of the full cycle of movement, the swimmer's hips should be positioned close to the surface of the water. To do this, for example, when swimming in a crawl, the hips perform movements with a small scope, actively sending upwards during a downward strike with the foot. When swimming with a breaststroke, the hips at the end of the push-off with the legs back also go to the very surface of the water and maintain a well-streamlined position throughout the stroke with the hands. A gross mistake when swimming with a front crawl and a dolphin is the “hanging” of the hips - lowering them too deep down and moving the legs not from the pelvis, but from the knees. The body of the swimmer should be a sufficiently rigid structure (due to the optimal degree of tension in the muscles of the abdomen and lower back) so that the driving forces from strokes with arms and legs would be directed without loss along the line of advance of the swimmer forward. The rest of the muscles of the body, especially the muscles of the back,
Should be as relaxed as possible. Powerful muscle groups of the body serve as the basis of the swimmer's motor mechanism. These muscles, on the one hand, provide a streamlined and balanced position of the body, and on the other hand, they take an active part in all working movements of the legs and arms.
If in the swimming technique of beginners it is acceptable, and in some cases even desirable, a stable somewhat fixed position of the body, then in the swimming technique of highly qualified athletes the body should be actively involved in rowing movements. When swimming crawl on the chest and on the back, it turns rhythmically to the left and right relative to the longitudinal axis of the body (an average of 30-35 ° in each direction). These rolls reinforce the stroke with the arms, help to execute it along the optimal trajectory, take the arm out of the water with minimal resistance and carry it over the water. When swimming in a front crawl, turning the torso makes it possible to inhale with minimal tension in the neck muscles and maintain the position of the head almost on the longitudinal axis of the body during inhalation. The degree of body roll depends on the variant of the technique, individual characteristics
Athlete and swimming pace. With an increase in the rate of hand movements, the degree of roll decreases relative to the direction of the swimmer's advance. When swimming breaststroke and dolphin top part the athlete's torso performs active movements up and down along a gentle wavy trajectory. These accessory trunk movements are also aimed at increasing the efficiency of the movements of the arms, legs and inhalation.
^
1.2 Hand movements
Hands are the main mover when swimming in sports ways. Even in the breaststroke, where the movements of the arms and legs approximately equally create traction, the technique of arm movements to a greater extent affects the overall coordination of movements, determines the pace and rhythm of swimming, and is closely related to breathing. This means that arm movements are of decisive importance for increasing the speed of swimming in this method as well. As noted above, the hand should be considered as one of the main elements of the mover, its main working plane. The main function of the hand during the stroke is to provide continuous support on the water. During the stroke, the hand must move continuously, at high speed relative to the water, along an optimal curved trajectory, with an optimal orientation relative to the direction of the swimmer's advance. As already mentioned, the optimal orientation of the hand in the main part of the stroke is its position close to the front. During the entry into the water and in the initial phase of the stroke, the hand should be oriented in such a way as to cut through the water with the fingertips with minimal resistance. After the stroke is completed, it should assume a position that provides minimal water resistance during the preparatory phase of the movements. When swimming in front crawl, dolphin and backstroke, the hand at the very end of the stroke is turned with the palm inward (i.e., towards the thigh). In the first two ways
Swimming, she leaves the water with her little finger, in the latter - with her thumb up. The arm begins the stroke completely (or almost completely) straightened at the elbow joint. The main part of the stroke should be performed with the optimal degree of flexion and extension of the arm in this joint. The specific values of the degree of flexion of the arm in the elbow joint are given below (when analyzing the swimming technique in separate ways). It should be noted that in the swimming technique of junior athletes, the degree of arm flexion in the elbow joint is less pronounced than in highly skilled swimmers. The first half of the stroke in all swimming methods should be performed with the so-called high elbow position. This requirement includes: 1) advancing movement of the hand in relation to the elbow; 2) turning the elbow to the side (but not back or down); 3) slight internal rotation of the shoulder and forearm; 4) the optimal degree of rigidity of the arm in the elbow joint. The stroke technique with a high position of the elbow allows you to lean on the water with your hand and forearm at an effective angle, without losing the forces of the support reaction to the shoulder and torso.
^
1.3 Coordination of movements
For a more productive analysis of the technique and its improvement in the integral system of the swimmer's movements, it is advisable to single out the elements: the phases of the movements of the arms and legs, the generalized phases of the cycle. The generalized phases of the cycle include the movements of all parts of the body. There are three such phases: preliminary, main, final. They flow together, causing each other and continuously repeating in a single stream of swimmer's movements.
The main phase is that part of the general cycle of movements in which the largest number movement, a high intracycle speed is achieved. The beginning of this phase is the moment of significant acceleration of the main working movement with the arms - adduction and extension of the shoulder (determined by the change in the angular velocity of rotation of the shoulder), the end is the moment of a significant decrease in the speed of this movement. The athlete at this time performs the most powerful part of the stroke, leaning on the water with his hand and forearm. All auxiliary movements and breathing are strictly subordinated in this phase of the cycle to the rhythm of the working movements of the hands. The main phase is performed while holding the breath or exhaling. By the beginning of the main phase, the swimmer's body should be accelerated (have a relatively high intracycle speed), and the working planes of the arms should reach the optimal position for support on the water. For example, the plane of the forearm should be inclined to the water surface at an angle of at least 45. The plane of the hand should be 50 - 60 °, while the arm should be bent at the elbow joint at about half of its maximum working angle and have sufficient rigidity.
This task is solved in the preliminary phase of the cycle immediately preceding the main one. During the preliminary phase, the swimmer communicates the necessary acceleration to his body due to working movements with his arms and legs, while maintaining a well-streamlined position. The initial part of the arm stroke in this phase is always performed with a high position of the elbow and mainly due to the contraction of the muscles that flex the forearm and hand and rotate the arm inward (powerful extension and adduction of the shoulder, as it were, is reserved for the next, main, phase of the cycle).
The main phase is followed by the final phase of the complete cycle of movements. Here the task for the athlete is the following: maintaining a high speed of moving the body forward (not allowing a significant drop in speed) and a relatively high position of the body, not allowing a noticeable lowering of the shoulder girdle), with minimal resistance, direct the arm (arms) and shoulder girdle along the optimal trajectory forward to capture water for the next stroke; stretch the muscles of the back and chest during this movement in order to use the energy of muscle stretching in the next, preliminary, phase of the cycle. The swimmer performs the final phase of the cycle due to the final rowing movement with the hand and forearm of one hand (in the freestyle on the chest and on the back) or both hands (in the dolphin) and part of the working movement with the legs (in all methods, except for the breaststroke method). By the end of the final phase of the full cycle, the athlete's body should reach the most streamlined position. This will allow in the subsequent phase of the cycle to again report positive acceleration to the body with the optimal expenditure of forces. When analyzing the full cycle of movements, the swimmer's boundary postures (instantaneous positions of his body links) at the moment of phase change are also distinguished. Boundary poses serve as good reference points in the study of technique (for example, from film records), visual pedagogical control technology, its practical development.
^
2 Breaststroke technique
Currently, at the Olympics, distances of 100 and 200 m are played in swimming in this way for both men and women. Breaststroke also swims one of the stages of the combined relay race and the distance of integrated swimming. The practical value of this method is great. So, they can travel long distances in clothes; in great excitement; you can transport various objects (holding in your hands or pushing in front of you); breaststroke is easy to navigate in the water. The rules of the competition quite strictly regulate the technique of breaststroke swimming. The main points of the rules read: 1) when swimming in the breaststroke way, the swimmer lies on his chest, his shoulders are parallel to the surface of the water; 2) both hands perform movements simultaneously and symmetrically. During the stroke, they can move backward under water or on its surface; they also stretch forward under water; 3) the legs perform movements simultaneously and symmetrically. When kicking, the feet should be turned to the sides and move back in arcs (dolphin-like movements of the legs up and down are not allowed); 4) during the passage of the distance, it is forbidden to dive the head under water, with the exception of sliding after the start and turning.
^
2.1 Foot movements
Leg movements are the most important part of breaststroke swimming technique. In modern versions of swimming techniques, this method of hand movement has acquired a decisive role. Leg movements, as well as arms, play the role of the main mover of the swimmer. In terms of their structure, the working movements of the legs when swimming with a breaststroke differ from the movements of the legs when swimming with a front crawl on the chest, on the back. In the freestyle on the chest, freestyle on the back and in the dolphin, wave-like movements are performed, reminiscent of the movements of the flexible tail of a dolphin, in the breaststroke there is an energetic repulsion from the water by the relatively rigid supporting surfaces of the feet and legs.
Rice. 1. Technique of simultaneous movements of the legs when swimming breaststroke.
Leg movements in phases.
Repulsion- working phase of leg movements. By the time the repulsion begins, the legs are bent in hip joints up to an angle of 115-140 °, the shins take a position perpendicular to the surface of the water (the angle of flexion in the knee joints is about 35-45 °), the feet are turned toes to the sides, the knees are separated slightly more than the width of the pelvis. During the repulsion, the feet move in arcs outward - back, and then back - inward, the legs are vigorously straightened and closed together. This single continuous movement is performed powerfully and is of an overwhelming, "explosive" character. During the repulsion, the athlete tends to direct the hips up to the surface of the water, and the feet - almost strictly back, without lowering them deeply down. After the completion of the repulsion of the hips, shins and feet immediately relax and, as it were, float to the very surface of the water. There is a short pause in the movements of the legs, during which they maintain a well-streamlined position.
pull up- preparatory phase of leg movements. It begins by smoothly bending the legs at the knee joints. Relaxed legs and feet move close to the surface of the water, the hips maintain a streamlined position and do not sink down. At the final moment of pulling up (approximately in the last 0.1 s of the phase), the hips and lower legs are brought to the position of their greatest flexion in the hip and knee joints. Pulling up is performed in a single smooth movement and with acceleration to the moment of turning the feet with toes to the sides. The feet turn instantly, and the swimmer immediately switches to repulsion.
^
2.2 Hand movements
As mentioned above, when breaststroke swimming, arms and legs are equally movers. But the hands set the pace and rhythm, determine the overall coordination of movements and are closely related to breathing. Hand movements are crucial in increasing breaststroke speed. During the stroke, the swimmer's hands move along their trajectory at high speed, continuously leaning on the water.
Rice. 2. Trajectory of arm movements
Technique of hand movements in phases.
^ Capture water performed smoothly. The swimmer sends his arms forward and slightly to the sides. The hands move at a depth of about 10-15 cm from the surface of the water and are turned with their palms down and slightly outward. The swimmer, with a gradually increasing effort, presses the water with his palms, smoothly bending the hands in the wrist joints. Hands remain as if fixed in elbow joints, elbows turned to the sides (but not down).
^ Main body the stroke begins with vigorous bending of the arms at the elbow joints and a supporting movement of the hands back. The brushes move with acceleration along the rounded area, first outward and then inward, the elbows are held in a high position. The 2nd half of the stroke is the fastest and most powerful part of the considered phase of movements. At this time, the working planes of the hands and forearms occupy a favorable position for support on the water (they are inclined to the surface of the water at an angle of about 60 °), the hands continue to move rapidly along a rounded trajectory back - inward, and then inward - forward. Following the brushes, the elbows also go inward. Vigorously completing the stroke with his hands, the swimmer directs himself forward and slightly up. By the end of the phase, the hands and elbows come together below, under the swimmer's chin.
^ Bringing hands forward - preparatory phase of movements. The beginning of the withdrawal, as it were, continues a single rapid movement of the hands inward - forward during the end of the stroke. The hands at this time are turned with their palms slightly towards each other. The further path forward hands pass smoothly. The hands turn palms down and almost touch. At the end of the withdrawal, the athlete again actively sends his arms almost straightened in the elbow joints forward, in order to start the next grip of water with his hands.
^
2.3 Body position and breathing
The body of the swimmer must maintain a well-streamlined position for most of the full cycle of movements. During the capture of water by hands, the angle of attack of the body is minimal (about 3 °), the swimmer's head is naturally facing forward - down. 
Rice. 3. Breaststroke technique
During the completion of the stroke with the hands, the shoulder girdle rises above the surface of the water, the athlete brings his chin forward and inhales. In modern versions of the breaststroke swimming technique, the so-called late breath. It is performed after the completion of the stroke with the hands, when the hands and elbows of the bent arms are directed inward. The late inhalation technique helps to keep the body in a well streamlined position during the high elbow stroke, allowing for a more powerful stroke.
At the moment of inhalation, the greatest angle of attack of the body is noted. For some swimmers, it reaches 15-17 °. This will not have a negative effect if the swimmer has time to re-align the body well before the start of working movements with legs and arms. Having completed the breath, the swimmer lowers his face into the water and directs the shoulder girdle following the arms forward.
^
2.4 General coordination of movements
The general coordination of movements should ensure the continuous movement of the swimmer forward with the highest average speed and the optimal expenditure of forces. It is not possible to achieve a uniform intra-cycle speed of advancement when swimming with a breaststroke and should not strive for this. The structure of movements of this method is such that speed drops within a full cycle are inevitable even for highly skilled swimmers (reach 1.5 m/s). The maximum values of intra-cycle speed (exceeding y
For highly qualified athletes, 2 m/s) are noted during the stroke with the hands, the minimum (about 0.5 m/s) - during the joint preparatory movements of the arms and legs and breathing. The task of rational coordination of movements is to increase the speed of body movement as much as possible during stroke movements and lose it as little as possible during preparatory movements with arms and legs. One of the common rational variants of the technique is the consistent coordination of the movements of the arms and legs in the absence of pauses in the movements of the arms. In this variant, the push-off with the legs is immediately replaced by the stroke with the hands. The full cycle of movements consists of phases: 1 - preliminary (it, in turn, is divided into two sub-phases - A and B), II - main, III - final. The preliminary phase of the cycle includes pushing off with the legs and the initial part of the stroke with the hands. This is the runaway phase. Its beginning falls on the moment of the lowest intracycle speed and the least streamlined position of the swimmer. During this phase, the athlete must bring the body into an elongated and well-streamlined position as quickly as possible, give the body a relatively high forward speed to the beginning of the main phase of the cycle.
Table
^ Phases of the arm movement cycle in breaststroke swimming
| Phases | The predominant direction of movement of the brushes | Signs of the beginning of the phase |
| ^ Working movements: Preliminary (Water Capture) | Forward-outward | The beginning of the movement of the brushes outward |
| Home: pull-up repulsion | Out-back-down Inside-back-down | The beginning of the displacement of the brushes back The beginning of the movement of the brushes inside |
| Final (reduction of hands near the chest) | inside-forward | The beginning of the movement of the brushes forward and up |
| ^ Preparatory movements : breeding | Forward-up | The beginning of extension of the arms in the elbow joints |
In subphase A, vigorous repulsion by the legs is combined with sending the arms forward (they must take a streamlined position and, as it were, cut through the oncoming flow of water). An increase in the intracycle speed is facilitated by the use of the POTENTIAL energy of the position of the shoulder girdle and the swimmer's head, which, during inhalation (in the previous phase of movements), are at the highest point of their movement above the water. The sending of the shoulder girdle and head following the hands should be carried out without delay, smoothly, in the direction forward and slightly down. At this moment, the swimmer seems to be trying to catch up with the forward bow wave with his forehead.
In subphase B, the initial part of the stroke is performed with the hands (until the shoulder is actively connected to the stroke). Hand movements are performed with a high position of the elbows and a streamlined position of the body, which it manages to take by this moment: the legs are extended and relaxed, the pelvis and hips are at the very surface of the water, the angle of attack of the body is minimal. While maintaining a streamlined and dynamically balanced position of the body, the athlete seeks to give it additional acceleration in the straight forward direction, to bring the supporting planes of the hands and forearms into the optimal position for the next, main, phase of the cycle. By the end of the phase, the working plane of the hand and forearm should reach a position of inclination to the water surface at an angle of at least 45° with an arm flexion angle in the elbow joint of about 135°.
The main phase of the cycle consists of the most powerful part of the arm stroke, performed by accelerated extension and adduction of the shoulders. The brushes move at high speed along a loop-like section of the trajectory, creating a continuous support on the water. In the first half of the phase (moving outwards - backwards), they seem to slightly cover the flow with the outer edge of the palm, in the second (moving mainly inward) - with its inner edge.
In the 2nd half of the phase, the rowing movement of the hands is combined with the auxiliary movement of the shoulder girdle and head forward - slightly upward. This kind of shoulder girdle and head strengthens the final part of the stroke with the hands, helps to direct the elbows inward (and then forward), gives the shoulder girdle the necessary momentum for the subsequent forward-upward movement (for inhalation). Throughout the main phase of the cycle, the legs do not interfere with the stroke with the hands, continuing to maintain a well-streamlined position of the hips - smooth pulling up of the legs begins due to involuntary flexion in the knee joints of the relaxed shins. The phase is pumped up at the moment when the elbows go down - inward to the frontal plane, conventionally drawn through the shoulder joints.
The final phase of the cycle includes sending the shoulder girdle and head to inhale with the beginning of bringing the arms forward and pulling the legs to the initial position for repulsion with the completion of bringing the arms forward. In this phase, two parts can also be conditionally distinguished - before the end of inspiration and after it. The first part (the sending of the shoulder girdle to inhale) is characterized by the preservation of a streamlined position by the hips, while the angle of flexion of the legs in the hip joints does not exceed 150 - 155 °. The second part of the final phase of the cycle is characterized by a rapid (within 0.10 - 0.12 s) removal of the lower leg, feet and hips to their original position for repulsion, i.e. to the position of their greatest flexion at the knees and
Hip joints.
The final phase of the cycle is unsupported, it is completely driven by preparatory movements of the arms and legs and inhalation. In addition, the athlete inevitably finds himself in the least streamlined position. Nevertheless, he must strive to maintain the intracycle speed at the level necessary for moving forward, to prevent a significant decrease in speed, due to the smooth, fast, rational execution of movements with arms, legs and breathing. The solution of this problem is facilitated by the optimal message of the shoulder girdle and head forward, following the hands.
^
3 Methods for teaching breaststroke swimming technique
3.1 General requirements for the methodology of teaching swimming
The study of the technique of the sports method of swimming is carried out in a strict methodological sequence.
Technique is studied separately in the following order: 1) body position, 2) breathing, 3) leg movements, 4) arm movements, 5) general coordination of movements. At the same time, the development of each element of the technique is carried out in gradually becoming more difficult conditions, which ultimately provide for the implementation of exercises in a horizontal unsupported position, which is the working position of a swimmer.
Each element of swimming technique is studied in the following order:
familiarization with the movement on land - carried out in in general terms, without working out the details, since the conditions for performing the same movement on land and in water are different;
the study of movements in water with a fixed support. When studying leg movements, the side of the pool, the bottom or the shore of the reservoir are used as a support; hand movements are studied while standing at the bottom chest-deep or waist-deep in water;
study of movements in water with a movable support. When studying leg movements, swimming boards are widely used; hand movements are studied during slow walking along the bottom or while lying on the water with the support of a partner;
the study of movements in water without support. All exercises in this group are performed in gliding or swimming.
leg movements with breathing;
hand movements with breathing;
movements of the legs and arms with breathing;
swimming in perfect coordination.
At the stage of fixing and improving the swimming technique, the method of holistic execution of the technique acquires leading importance. Therefore, in each lesson, the ratio of swimming in full coordination and swimming by elements with the help of movements of the arms and legs should be 1:1. Improving the swimming technique is carried out with a mandatory change in the conditions for performing movements. For this purpose, the following navigation options are used:
alternating swimming of long and short segments (for example, swimming along and across the pool);
swimming segments for the least number of strokes;
alternating swimming in easier and more difficult conditions at a given pace (for example, swimming in elements and in full coordination; swimming in elements with and without support; swimming with breath holding and in full coordination).
a variety of options for performing exercises, which allows you to maintain interest in classes, which is especially important in swimming;
ability to apply various options swimming techniques in changing conditions;
formation of individual swimming technique in accordance with the characteristics of the physique and the level of physical fitness.
Errors that occur when teaching swimming technique are divided into:
typical - the most common in primary education;
rough - distorting the basic structure of movements;
minor - reducing the effectiveness of movements, but not reflected in other elements of the technique;
interconnected - arising from one another.
For a warning possible errors it is necessary to know the causes of their occurrence. The main reasons are:
inconsistency of the educational task with the level of preparedness of the students (violation of the pedagogical principles of accessibility and consistency);
misunderstanding by those involved in the form and nature of the movements performed;
incorrect starting positions when performing exercises.
1) systematic repetition of educational material;
2) the use of leading and preparatory exercises in the classroom;
3) changing the initial positions and conditions for performing exercises;
4) understanding by those involved in the reasons for their mistakes;
5) consistent correction of the mistakes made (at first gross, then minor).
^
3.2 Exercises for learning the breaststroke technique
The breaststroke technique does not impose such strict requirements on mobility in shoulder joints as in freestyle, but requires high mobility in the ankle (dorsal extension), knee and hip joints. For breaststrokers, muscle strength is important not only in the shoulder girdle, but also in lower extremities that create effective progress.
^ General developmental, special and imitation exercises (Fig. 4).
Before starting a set of exercises, walking, jumping, tilting, squats, push-ups are performed.
I.p. – O.S. hands up. Squats.
I.p. - gray on the heels (socks pulled back). Lean back as low as possible; return to the SP, resting your hands on the floor.
I.p. - emphasis lying on the hips. Bending over and grabbing the feet of the legs bent at the knees (socks turned outward to failure), roll from the hips to the stomach and back.
I.p. - semi-squat, brushes rest on the knees. Rotation of the knees to the right and left.
I.p. - standing in an inclination forward, feet shoulder-width apart. Hand movements, as in breaststroke swimming.
In a standing position sideways to the support, bend one leg at the knee joint and, grabbing the foot with inside, pull the lower leg and heel to the buttock. Lower your leg and perform a breaststroke movement with it.
Rice. 4. An approximate set of exercises on land for breaststroke.
In the prone position on the chest, the movements of the legs, as when swimming with a breaststroke.
In the emphasis lying, the maximum deflection and arching of the body.
I.p. - standing facing the gymnastic wall. Hand support on the crossbar gymnastic wall at the beginning and in the middle of the stroke. During the exercise, strongly strain the muscles of the shoulder girdle and arms.
I.p. - standing at the gymnastic wall, leaning on it with your hands. Alternate swings with a straight leg back and forth.
Hand movements, as in breaststroke swimming, with stretching of rubber shock absorbers.
"Starting jump" up.
I.p. standing sideways to the wall, resting his hand on it. Bend one leg at the knee joint, take the lower leg to the side and grab the foot from the inside with the same hand; lower your leg and push it until it connects with the other - as in breaststroke swimming. The same with the other leg.
I.p. - sitting on the floor, emphasis with hands behind. Leg movements, as in breaststroke swimming: slowly pull up your legs, turning your knees to the sides and dragging your feet along the floor; turn the socks to the sides; perform a push, connect your legs and stretch them on the floor. Pause, slowly and gently pull your legs towards you.
In the lying position on the bench, leg movements, as in breaststroke swimming, with the help of a partner (standing from the side of the legs). Pulling up the legs is done independently, but at the moment of spreading the socks to the sides, the partner takes the feet with his hands and helps to take the desired position before the push. Then, without releasing the swimmer's legs, he helps him perform the movement correctly and connect his legs.
Rice. 5. Exercises to learn leg movements
6. I.p. - sitting on the side of the pool, emphasis with your hands behind. Breaststroke leg movements.
7. I.p. - standing sideways to the wall of the pool, holding the side with your hand. Bend the leg at the knee joint, take the lower leg to the side and grab the foot with the same hand. Lower the leg, performing an imitation movement with it, as when swimming with a breaststroke. The same with the other leg.
8. I.p. - lying on his chest at the side, holding on to him with his hands. Leg movements, as in breaststroke swimming.
^ Typical mistakes. Lowering the pelvis; too wide spreading of the knees before pushing with the legs; socks and shins do not turn to the sides before the push.
Methodical instructions. Do not spread your knees to the sides when pulling your legs more than shoulder width apart. Before pushing with your feet, make a stop, fixing the position of “socks to the sides”. Do not start pulling up the legs after the push until they have floated to the surface. Push with the legs to perform a single continuous movement; after the push, maintain a long pause (time for “sliding”), straining the buttocks and muscles of the back of the thigh so as not to sink.
9. Swimming on the back with the help of leg movements, holding the board with straight arms and pressing it to the stomach and hips.
10. Swimming on the back with the help of leg movements, holding the board in the arms extended forward.
11. Swimming on the chest with the help of leg movements with the board. After the push, be sure to pause, trying to slide as long as possible.
Exercises without support
12. Swimming on the back with breaststroke leg movements, hands at the hips.
13. Swimming on the chest, arms extended forward.
14. The same, with the help of leg movements, arms along the body.
15. The same, but the arms are extended forward.
Typical mistakes. During the pause, the legs sink. Pull-ups and push-offs are performed at the same speed. After the push, the legs do not join together.
^ Methodical instructions. After pushing with your feet, strain the muscles of the buttocks and the back of the thigh so that the legs do not sink while sliding. Pull up slowly and gently. Spread your toes out to the sides quickly and vigorously. Push with the legs to perform strongly, but gently, until the legs close. When swimming on your back, your knees should not show out of the water.
^ Exercises to study the coordination of leg movements and breathing
To study the movements of the legs in coordination with breathing, the previous set of exercises (from 1st to 11th) is performed, with an emphasis on breathing. Inhalation in the breaststroke is performed while pulling the legs to the starting position, exhalation - simultaneously with repulsion by the legs.
Attention should be paid to the coordination of leg movements and breathing when performing simulation exercises on land: inhalation and exhalation must be forced so that the teacher sees and hears the duration of their performance by the trainee.
^ Hand Movement Exercises (Fig. 6)
Simulation exercises on land
16. I.p. Standing in an inclination forward, feet shoulder-width apart, arms extended forward. Simultaneous rowing movements of the hands, as in breaststroke swimming.
Exercises in water with a fixed support
17. I.p. - standing on the bottom in an inclination forward, legs shoulder-width apart, arms extended forward; shoulders and chin lie on the water. Strokes with hands (first with a raised head, then lowering your face into the water) while holding your breath.
Exercises in water with a movable support
18. Same as ex. 17, with movement along the bottom of the pool.
^ Typical mistakes. Too wide stroke; stopping the hands at the end of the stroke in the “elbows to the sides” position; the absence of a pause during the slide - at the moment when the arms are extended forward.
^ Methodical instructions. When performing a stroke, the angle between the hands should be no more than 90 per cent. Do not lift your shoulders and chin from the surface of the water. Pause in the "hands in front" position. At the end of the stroke, quickly “remove” the elbows - lower them down and press them to the body, then stretch your arms forward.
19. Sliding with rowing movements of the hands while holding the breath.
20. Swimming with the help of movements of the hands with a float between the legs (with the head held high); breathing is voluntary.
21. The same with holding the breath.
^ Exercises to study the coordination of hand movements and breathing
To study the movements of the hands in coordination with the breath, the previous set of exercises (from the 12th to the 17th) is performed with an emphasis on coordinating the breath with the stroke of the hands. Inhalation in the breaststroke is performed during the completion of the stroke with the hands (“late” breath), exhalation - while bringing the hands forward and sliding.
Rice. 6. Exercises for learning hand movements
Exercises for general coordination of movements(Fig. 7)
Simulation exercises on land
22. I.p. - o.s., arms stretched up. Perform a “stroke” with your hands and return your hands to their original position; then perform pull-up and repulsion with one leg, imitating separate coordination of movements.
Rice. 7. Exercises for general coordination of movements
23. The same in accordance with breathing: inhalation is performed simultaneously with the start of the “stroke” with the hands, exhalation - while moving the arms forward and pushing with the legs.
24. The same in full coordination. During the spreading of the arms to the sides, the leg begins to be pulled up, then a breath is taken; at the moment the hands are brought forward, a repulsion is performed with the foot.
Exercises in water with a fixed support
25. Exercise in pairs. The first numbers hold the second from the side by the belt in a position on the chest. The second numbers perform movements in full coordination. Then the partners change places.
Exercises in water with a movable support
26. Breaststroke arm movements in coordination with breathing, moving along the bottom.
Exercises in water without support
27. Swimming in full coordination while holding your breath.
28. Swimming with separate coordination of movements (when the arms finish the stroke and stretch forward, the legs begin to pull up and push); breathing through 1 - 2 cycles of movements.
29. Swimming with short strokes of the arms in coordination with the breath.
30. Swimming in full coordination (the legs are pulled up at the end of the stroke with the hands and perform a push at the same time as moving the arms forward and sliding), with voluntary breathing and exhalation into the water after 1-2 cycles of movements.
31. The same with the "late" exhalation.
^
3.3 Pedagogical model of breaststroke technique
The cycle of movements during breaststroke swimming is conditionally divided into four generalized phases.
First phase - kick(beginning - extension of the legs in the knee joints). Basic actions: legs perform a blow, arms are extended and sent forward; the body assumes a horizontal position, the head is immersed in water; breathing is delayed.
Target: increase forward speed by passing the stroke from foot to hand.
^ Body position at the beginning of the phase : legs in the starting position for a strike, arms in front with palms down and slightly bent at the elbow joints, the shoulder girdle is above the pelvis at an angle of 4 - 6., the head is facing forward - down, the face is immersed in water.
^ Basic settings : 1) perform a sharp kick, fix the pelvis well and direct the force through the back to the hands; 2) complete the straightening of the arms and send them forward, the body in a streamlined position, the head between the arms; 3) during the blow, do not lower the feet deeply; complete the stroke, relax the hips, shins and feet, direct the hips to the surface of the water.
^ Second phase - stroke with hands (beginning - completion of straightening the legs in the knee joints during the impact). Basic actions: the arms perform the stroke, the legs maintain a streamlined position, and the torso is almost horizontal, at the end of the phase the head is raised facing forward.
Target: increase the forward speed to the maximum due to the arm stroke.
^ Body position at the beginning of the phase : arms extended forward parallel to the surface of the water, hands turned palms down - outward, head between hands; legs are relaxed and extended; the body is horizontal and well streamlined.
^ Basic settings : 1) perform a stroke with the hands along the optimal helical trajectory and with acceleration - the capture of water; energetic and relatively long pull-up, fast and powerful repulsion; follow the rigid position and rational orientation of the planes of the hand forearm; 2) until the end of the stroke, keep the head in a relaxed position with the face lowered into the water, at the final moment of repulsion, send the shoulder girdle and head up to inhale; 3) keep your legs relaxed; 4) due to high-quality stroke with hands, bring the body to a relatively high position; do not lower the pelvis; 5) at the end of the repulsion with the hands, it is accentuated to complete the exhalation.
^ The third phase - bringing the hands near the chest and inhaling (beginning - the movement of the hands forward - up). Basic actions: hands and forearms are brought together with a quick and sliding movement inward - forward - up - hands under the chin, elbows near the chest; hands continue to go up - forward; inhalation begins; legs smoothly bend at the knee joints.
Target: keep the speed of advance as far as possible relatively high level due to inertial forces and rational support movement of the hands.
^ Body position at the beginning of the phase : the arms are bent at the elbow joints and are below in front of the chest, the hands are slightly in front of the shoulder girdle and approximately shoulder width apart, the palms look back and slightly inward; head above the water facing forward; legs in a streamlined position and slightly bent at the knee joints; the angle of attack of the body is expressed (12 - 15 .).
^ Basic settings : 1) simultaneously with a quick, but with a smooth reduction of the hands and forearms inward - forward - up, take a breath; 2) do not stop the movements of the hands, do not press the elbows to the body; 3) continue to move with the shoulder girdle and chin up; 4) start smooth bending of the relaxed legs in the knee joints; 5) maintain a streamlined position.
^ Fourth phase - extension of the arms and bending of the legs (beginning - extension of the arms in the elbow joints; ending - extension of the legs in the knee joints to strike back). Basic actions: arms are brought forward, legs perform the main part of the pull-up - flexion in the hip and knee joints; the shoulder girdle and head move forward down, the position of the body is leveled, the head is again immersed in the water.
Target: Lose forward speed as little as possible.
^ Body position at the beginning of the phase : arms bent at the elbows, hands almost together under the chin, elbows near the chest; legs slightly bent at the knee joints, feet and knees about the width of the pelvis, hips in a well-streamlined position; the angle of attack of the body is pronounced, the shoulder girdle and head are above the surface of the water, the swimmer looks forward.
^ Main stops : 1) finish the breath and send the chin and shoulder girdle following the arms forward; smoothly but quickly bring your hands out, turning your hands with your palms down to the starting position for the next stroke; perform the final part of the stroke; perform the final part of pulling up the legs with acceleration; 2) bending the legs at the hip and knee joints and spreading the knees of the side at the end of the phase, instantly spread the feet with toes to the sides; 3) move forward with the shoulder girdle following the arms forward, align the body to the beginning of the kick; do not lower the pelvis.
- ^
Bibliography
Swimming. Textbook. Ed. N. Zh. Bulgakova
Health, medical and adaptive swimming. Tutorial. Ed. N. Zh. Bulgakova
Sports swimming technique. Teaching aid. T.L. Mukhtarova
Sports swimming. James E. Councillmer
Sports swimming. Karl-Heinz Stichert
Coaches, swimmers and triathletes use specific terms for each component of swimming technique and conventions for concepts such as speed or stroke length. Don't be alarmed, the jargon is quite simple and you will master it with success. The good news is that most of the terminology used in this book is globally accepted, which means that after reading this chapter, you should be able to understand most of the swimming and training material on the internet.
Feeling the water
Feeling the water- this term is used to describe the feeling of water on the hands and arms of a swimmer, which appears during a swim. When a swimmer has a good “feel for the water”, he better calculates his movements in it and, due to this, achieves the most effective progress.
We use special exercises supported by illustrative examples that help develop this quality.
First, let's look at the parts of the freestyle stroke cycle and the terminology we'll be using in this regard. In general terms, the stroke cycle can be divided into two components:
1) working movements under water (the phases of "capture", "pulling up" and "repulsing", ensuring the movement of the swimmer's body forward);
2) preparatory movements above the water (“carrying”, when the hand passes over the surface of the water, after which it returns to its initial position, where the “hand enters the water” and “pulls forward”).
body rotation, or body roll as shown in the figure below. This is a rotational movement of the swimmer's body relative to the longitudinal axis of the spine, such a picture is a bit like the rotation of a barbecue on a skewer (yes, that's right!). Rotation of the body helps the swimmer generate more force, reduces water resistance, and helps the swimmer to carry.
Body position is related to how close the swimmer is to the surface of the water, especially their hips and legs. The low position creates additional resistance because it increases the frontal surface of the body.
A wave that is formed at the moment the swimmer's body moves in the water; this term is borrowed from rowing, in this sport such a wave is formed when water breaks against the bow of the boat. The front wave is formed at the moment when the swimmer's head, cutting through the water, raises the water surface in front. At the same time, a depression is formed around the head and neck area, called the "funnel".
At the moment when the head and body of the swimmer move forward,
a forward wave is formed.
It is the occurrence of a forward wave that gives an advantage to a swimmer with correct technique breathing, since he can breathe inside the resulting vortex funnel and, thanks to this, keep his head as low as possible. This method is called " breath inside the funnel».
Bilateral, unilateral and hypoxic respiration
Bilateral breathing means breathing in water on both sides, in which there is, if not alternate, then at least a regular change of side for inspiration.
Unilateral breathing means that the swimmer periodically inhales only from one side he prefers: right or left. We strongly recommend that you learn the double-sided breathing technique, the benefits of which are described in Chapter 7, Part III, on adapting to open water.
Hypoxic respiration- the process of passing the distance with the restriction of inhaled oxygen. In this case, the swimmer breathes less often than usual (usually every five, seven or nine strokes). Many trainers claim that this helps increase lung capacity and aerobic endurance, but this has not yet been confirmed by research.
In our training, we use breath limiting exercises to give swimmers the opportunity to focus on exhaling deeper into the water, less distracted by holding their breath. With rarer breaths, you need to achieve inner calm and take your time, concentrating all your attention on the symmetry of movements.
Stroke length
Stroke length- this is one of the most actively discussed topics in swimming, as you can see from this book. Typically, this length is measured by counting the number of strokes needed to swim through the pool (double-handed strokes are counted). Fewer strokes means a longer stride. When referring to stroke numbers, always consider the length of the pool - it can vary: 25 yards, 25 meters, 33 meters, 50 yards, 50 meters. A typical figure measured in a 25m pool would be 11 to 30 strokes per pool. To denote this indicator, the abbreviation DG is often used - “ stroke length».
stroke rate
stroke rate(not to be confused with stroke length!) is the number of strokes that you manage to do per minute, again including strokes with both hands. This can be compared to cadence on a bicycle, with the only difference being that when you pedal, you only count the movement of one foot, not both. The higher these figures, the more strokes you make in a certain amount of time. The abbreviation for this indicator is G / min - the number of strokes per minute. Standard strokes per minute range from 35 to 110; swimmers who do not belong to the elite group - from 50 to 65.
It so happened that until recently it was difficult for swimmers to control the number of strokes per minute, but with the invention of special audio metronomes, such as the Wetronome or the Finis Tempo Trainer Pro (detailed in chapter 3), this has become much easier to do. The metronome can be set to a predetermined number of beats per minute - then you can coordinate the number of strokes and control the pace in the swim. Considering the number of strokes and their frequency can be extremely useful for improving swimming technique.
In open water, stroke rate, as opposed to stroke length, is fairly easy to measure, and swimmers tend to prefer it there. In general, compared to pool swimmers, their open water counterparts perform more strokes per minute with shorter stride lengths. This technique helps them to cut through the waves more efficiently, cutting through them, and keep other swimmers in the field of view at all times. In Chapters 14 and 39, we'll go into more detail about how to change your technique when swimming in open water.
In some publications, you can also find such an indicator as "the number of cycles completed per minute." A cycle is a combination of strokes with both hands. In other words, 30 cycles per minute is the same as 60 strokes per minute. Some sources also indicate the frequency of the cycle in seconds (one cycle lasts up to 2 s and equates to 60 G/min). Personally, we prefer to measure the frequency in minutes. Because: a) we are always dealing with integers, not decimal numbers, and b) by measuring the frequency with an audio metronome, the swimmer can match each entry of the hand into the water with an audio signal - this helps to constantly control the symmetry of the movements of the right and left hands .
Swimming speed
Swimming speed usually regarded as the time spent on the passage of a certain distance. It can be a 400m or 1000m time, but generally the speed is determined by the time (in minutes and seconds) needed to cover the 100m. Thus, a result of 1:30/100m means that each 100m segment takes the swimmer one and a half minutes.
Elite swimmers can sprint 0:50/100m and slow down to 1:00-1:05/100m over longer distances (if you can call that slow!). The indicators of swimmers that we classify as a group sports improvement, will fluctuate within 1:10-1:30/100 m in long swims. The figures for swimmers of the intermediate level group will be 1:30-2:10/100 m, and the time required for beginners will be up to 3:00/100 m.
This is a special clock for swimming pools, which is really worth learning how to use. They do not have a minute hand, only a double seconds hand, one part of which is colored red and the other part black. Elite swimmers don't use wristwatches to time their swims, instead they rely on a centralized watch placed on the wall of the pool. You, too, sooner or later will learn to calculate the time of passage of any distance, using only the second hands of the "general" clock.
The key to mastering this skill lies in the fact that you know approximately how long you can swim a particular distance. For example, you know that you can swim 400 meters in about eight minutes. If you start at the moment when the red arrow is at 12 (or, as the English say, "reaches the red limit"), you should finish when it is at the top again. Thus, if you finish the distance when the red arrow is at the “10” mark, then you swam it in 8:10, and if at the “45” mark, then in 7:45.
A swimming pool wall clock is a very useful tool, as many believe that wristwatches break the "feel of the water" due to the reduced streamlining of the hand. Moreover, after training, you will be able to use the common clock during the start. For example, if you swim 100-meter segments, each time starting at 2:15, then the first start will be on the black mark in the middle, the second on the black mark "15", the third on the black mark "30", etc. e. This is an easy way to control time during training, when you do not have to constantly look at the clock, filling your head with unnecessary arithmetic!
Torpedo push and slide
Torpedo push and slide- these are the positions that the swimmer's body occupies when pushing off the wall of the pool. This glide is accompanied by a lower water resistance than when swimming in normal mode.
The clock in the pool has two multidirectional second hands. Over time, they will help you calculate the time of swims at various distances.
The fastest way to start the race is to push off the wall and keep sliding through the water until your speed slows down to normal. average speed swimming, after which you need to perform a full stroke. The length of such a "torpedo" push is usually around 5 meters (15 ft), but under the rules set by FINA ( International Federation swimming), elite swimmers can perform a 15-meter (45-foot) glide. We'll talk more about the benefits of pushing hard in Chapters 9 and 10.
Short water and long water
"Short water" and "long water" in pools are technical terms for 25m and 50m pools (same goes for pools measured in yards). At the Olympic Games, competitions are held in 50-meter pools, in which the speed of passing distances is somewhat lower than in short water. This is due to the fact that the swimmer performs fewer turns and does not have the opportunity to maximize the speed advantages that the ability to push off the wall of the pool gives him well. FINA holds world championships in both long and short courses. Accordingly, there are world records separately for competitions in 25- and 50-meter pools. Wikipedia has a separate page that provides a complete table of world records, including the most recent ones. We believe that it will be interesting for you to get acquainted with them, and at the same time compare them with your own results.
review
review: during an open water swim, the swimmer raises his head above the surface to look around and adjust the trajectory of his movement. As soon as the swimmer raises his head, his legs begin to go down, and his shoulders continue to rotate about the longitudinal axis. This creates additional water resistance. In Chapter 35, we will analyze how a good looking technique with minimal head elevation minimizes this additional resistance.
(ability to hold on to the leader) - a maneuver in which you swim immediately behind or next to another swimmer, receiving a certain advantage from this. Drafting is acceptable in open water swimming, including during triathlon competitions, and is regarded as fair play in which the swimmer seeks to improve his position as much as possible. Chapter 36 will explain that there are two basic positions for successful open water drafting: either stick directly behind the leader, or to the side of the leader and slightly behind.
In open water, swimmers can gain an advantage by swimming directly behind or to the side of other swimmers. It's called drafting - sticking with the leader.
Crawl on the chest (freestyle)
When swimming in front crawl, the swimmer moves forward with the help of alternating strokes with his hands and movements of his legs up and down. After the stroke, the swimmer takes his hand out of the water and carries it forward through the air. Arm movements provide the main thrust, leg movements help to maintain a higher position of the body in the water, and also promote propulsion. Inhalation is done by turning the head to the side.
Body and head position
The body is almost horizontal. The longitudinal axis of the body deviates from the horizontal line and makes an angle of 2-6 degrees with it. This slight deviation is caused by the need to keep the head in a position in which it would be possible to breathe without disturbing the coordination of movements of the arms and legs. The muscles of the neck are mostly relaxed, the face is immersed in water. The water level runs across the top of the forehead.
The body of the swimmer should not fluctuate either along the transverse or anteroposterior axis. Some rotation of the body relative to the longitudinal axis is necessary so that the swimmer can take his hand out of the water, carry it forward through the air and turn his head so that his mouth is above the water (for inspiration). In addition, these turns help to strengthen the stroke of the working hand. The amount of oscillation depends on the mobility of the swimmer's joints, but always such that it does not distort the movements of the legs. The deviation of the shoulder girdle from the horizontal position should be higher than the deviation of the pelvis.
Do not arch your back excessively. Excessive lumbar arching increases water resistance and makes it less efficient work feet. The swimmer must give his body the most streamlined shape and reduce the resistance of the water to a minimum.
Hand movements
Hand movements are performed alternately. The whole cycle of movements with one hand can be divided into five phases:
1) stroke;
2) the end of the stroke and the removal of the hand from the water;
3) moving the hand forward over the water;
4) immersion of the hand in water;
5) the influx and the beginning of the stroke.
The main phase is the stroke, with which the swimmer moves forward. Hand movements in other phases are auxiliary, preparatory. They are performed to give the hand a position from which to start the next stroke.
stroke performed in a downward-backward-upward direction. During the stroke, the arm first bends slightly at the elbow joint, and then straightens. In this case, the hand moves along a curve, which in its shape resembles a semicircle, somewhat stretched in length.
To achieve greater speed and uniformity of movement, the stroke should be as long as possible. The length of the stroke from its beginning to end is determined by the distance measured along a horizontal straight line from the point from which the stroke began to the point at which it ended.
It is unprofitable to start the stroke at the moment when the arm is horizontal. A significant part of the energy in this case will be spent on pushing the body up. Therefore, the stroke is preceded by the influx phase, during which the outstretched arm is immersed in the water. When the hand takes a position at an angle of 20-30 degrees relative to the surface of the water, the stroke begins. The hand enters the water first with the hand, and then with the forearm and shoulder, in order to be able to quickly make a stroke. Plunging into the water, the hand goes forward and in depth with the brush so that an angle of 140-150 degrees is formed between the shoulder and forearm; palm facing down and somewhat inward. The beginning of the stroke merges with the end of the influx.
Taking your hand out of the water . At the end of the stroke, the arm straightens, which should coincide with the approach of the arm to the surface of the water. As soon as the shoulder takes a horizontal position, the elbow begins to move up to the side, and the arm bends at the elbow joint. It is taken out of the water quickly, but gently. The relaxed forearm and hand are carried away after the elbow joint, that is, the elbow appears first at the end of the stroke on the surface of the water. Flexion of the arm in the elbow joint occurs mainly under the influence of the heaviness of the forearm and hand. The hand at the moment when it is taken out of the water is turned with the palm up or up-in.
Moving your hand forward over water . This phase of hand movement merges with the previous one. The inertia developed when the arm is taken out of the water is supplemented by some active muscle effort that moves the shoulder forward. The muscles of the forearm and hand are relaxed. By the middle of the movement, the arm in the elbow joint is bent at an angle, the elbow is raised above the water by 25-30 cm, which allows the swimmer to hold the hand and forearm almost perpendicular to the direction of movement. The hand is slightly laid back (in relation to the forearm) and the palm is turned back and slightly inward. From this point on, the movement of the forearm accelerates and it begins to overtake the shoulder. At the same time, the arm unbends at the elbow joint, the hand, overtaking the forearm, turns palm down. The movement of the hand in this phase should be continuous, fast, but not sharp or convulsive. The muscles of the hand that are not involved in the work are relaxed.
Immersion of the hand in water and influx . The hand falls into the water gently, but quickly enough. The hand and forearm are in one straight line. The palm is turned down. In this case, the fingers should be connected in the form of a “boat”, but not tense. First, the hand is immersed in water (fingers forward), and then the forearm. The dive ends when the hand is completely submerged in water. The influx phase begins, which has already been basically described in the analysis of the stroke phase. During the influx, the arm is not tense, straightened, palm down.
Combination of hand movements . The hands work alternately: while one of them performs preparatory movements, the other makes a stroke. Preparatory movements are carried out above the water and partially in the water. As a result, the time spent on preparatory movements is somewhat less than the time required to complete the stroke. Therefore, the hands continuously seem to catch up with one another: on the ending stroke with one hand, the working movement of the other begins. This moment (the so-called grip) is a very important detail of crawl swimming technique.
At the beginning and end of the stroke, its relative inefficiency is noted, so the swimmer most energetically spends the middle of the stroke. The resulting some unevenness in the progress of the swimmer is softened due to the moment of adhesion.
Leg movements contribute to the balance of the swimmer's body in a horizontal position and move it forward. The swimmer's legs, rhythmically bending and unbending at the hip, knee and ankle joints, move alternately up and down (that is, the movements of the foot and lower leg are made from top to bottom). The legs are bent at the ankle joints approximately at an angle of 60-70 degrees, at the knee -
30-50 degrees, and in the hip - 15-20 degrees. The amplitude of the swing is such that the distance between the feet in the extreme lower and extreme upper positions reaches 40 cm.
Swimmers with the most productive footwork have a whipping movement at the beginning of the shin kick from top to bottom. At the same time, the thigh, moving down, slightly overtakes the lower leg, and the lower leg - the foot. The following movement of the foot from the extreme upper position merges with a slight, but very significant flexion of the leg in the hip joint. As a result, the lower leg acquires an additional repulsive backward movement.
The legs of rabbits work somewhat unevenly. They make two enlarged swings, of which the largest is inhalation. A second, slightly smaller swing follows the first and helps turn the swimmer onto the chest. In addition, freestylers loosen up their leg movements somewhat during the second, most efficient part of the arm stroke. The movements of the freestyle legs are variable, they depend on whether the swimmer's legs are “light” or “heavy”, as well as on the degree of leg mobility in the joints.
The main options for leg movements in rabbit swimmers:
With a noticeable accent of shin and foot strikes down (“heavy” legs);
With a lesser emphasis on strikes with the lower leg and foot down (“light” legs);
With a lash up (very “light” legs and great mobility of the knee and ankle joints).
Breath
The respiratory rate is determined by the pace of swimming movements. During one cycle of arm movements, a swimmer can take one breath and one breath. Inhalation is made at the moment when one of the hands finishes the stroke, leaves the water and begins to move forward over the water; this is followed by an exhalation, which continues until this hand again begins to perform the movement of the last stage of the stroke. You can inhale both under the right and under left hand. The technique of movements in both cases is the same. The following is a description of the process of breathing with the head turned to the left.
While the left hand performs the first half of the stroke, the swimmer calmly, slowly, exhales air through the nose or through the mouth. The swimmer's face at this time is immersed in water and turned down.
In the middle of the stroke with the left hand, the swimmer begins to turn his head to the left and at the same time strengthens the exhalation through the mouth so that it is vigorously completed when the mouth is at the surface of the water. This moment should coincide with the end of the stroke. As soon as the mouth is above the water, the swimmer takes a quick, vigorous and full breath, after which he calmly turns his head to face down. The inhalation ends when the hand performs the first half of the movement above the water. Having immersed the face in the water, the swimmer, slowly, begins to exhale.
Further, in the process of training, bilateral breathing is used: after inhaling under the left hand, hold the exhalation a little, skip the moment of the next breath under the left hand and make it under the right, then skip the moment of inhalation with the head turned to the right and again take a breath under the left hand. Thus, one breath is for three strokes (can also be performed for 5, 7, 9 strokes), while usually one breath is performed for two strokes (stroke with the right and stroke with the left hand).
When turning your head to inhale, you do not need to lift it up, as the oncoming wave can enter your mouth. In addition, this movement will greatly tire the muscles of the neck.
You should also not turn your head too hard. When moving forward quickly and turning the head correctly near the swimmer's mouth, a funnel (fossa) is formed on the surface of the water, and he can take a breath when part of the mouth is below the water level. Excessive head rotation and excessive head movement can cause unnecessary swaying of the torso around the longitudinal axis and disrupt the structure of movements of the arms and legs.
Combination of arms and legs
During one complete cycle of arm movements (stroke with the right and stroke with the left hand), you can make up to ten kicks. Usually the ratio of the tempo of the movements of the legs and the tempo of the movements of the arms is 6:1, that is, the swimmer makes six kicks in one cycle of the arms. A four-hit crawl (four kicks per cycle of arm movements) is rarely used, since with normal leg spreading, a small speed of movement gives a small supporting and promoting effect, and with a wide spreading of the legs up and down, the resistance exerted by water increases so much that the speed of advancement swimmer's forward decreases. Eight- and ten-beat versions of the crawl are also rarely used. Such a frequency of movements either leads to rapid fatigue of the swimmer, or causes a decrease in the amplitude of movements, which reduces the efficiency of kicking.
Effect of swimming speed on swimmer's technique
Copying or applying the technique of movements of any outstanding swimmer is rational only after analyzing it and identifying the innovations introduced by him into the technique of swimming, as well as establishing the degree of their suitability for a particular athlete and finding such a form of movements through which the individual abilities of a particular swimmer will be used in the best possible way. .
A swimmer's technique can vary somewhat depending on the speed at which he swims. An athlete swimming a short distance seeks to develop top speed, in connection with which he energetically performs even those movements whose efficiency is relatively small, but which, in his opinion, help him swim at least a little faster. In addition, at a high swimming speed, the water shaft that occurs in front of the swimmer's head increases, the water resistance increases significantly during the preparatory movements of the arms and legs, which also leaves a certain imprint on the swimming technique. Finally, an increase in the tempo of movements also somewhat changes their shape. All this causes differences in the technique of swimming for short and long distances the same swimmer.
Training exercises
1. I.p.: lying in the water on the chest and holding on to the side with two straight arms. - Perform crawl leg movements with exhalation into the water while lowering the head face down. Leg movements are mastered more successfully if the shoulder girdle is at the level of the water surface.
2. I.p.: the same, holding on to the side with one hand, the other is pressed to the body. - Perform leg movements with a turn of the head to inhale towards the pressed hand. The position of the hands and the direction of turning the head for inhalation must be alternated to the right and left sides. When turning the head for inhalation, it is required to exclude even the slightest lifting of the head up. Head rotation is possible due to the cervical spine and / or rotation of the shoulders.
3. Perform leg movements with head lowering into the water for exhalation, holding hands, straightened at the elbows, on the near side of the board. Head movements up and down.
4. Perform leg movements with a turn of the head and shoulders towards the pressed hand, holding with one hand the middle of the near side of the board, press the other hand to the body. Work out the position of the hands and the direction of inhalation in both directions.
5. I.p .: hands without a board are extended forward. - Perform leg movements. Exhale into the water, lowering your head face down. During the lifting of the head, the supporting movement of the palms on the water is allowed.
6. I.p.: one arm is extended, the other along the body. - Perform leg movements with a turn of the head and shoulders to inhale towards the pressed hand. While turning the head, increase the work with the legs. The position of the hands and the direction of inhalation must be worked out in both directions.
7. I.p.: lying on the chest and holding the side with both hands. - An imitation of a stroke and a preparatory movement is performed with the head lowered into the water while holding the breath. Practice alternately with both hands.
8. I.p.: the same, but the movement of one hand is consistent with the turn of the head to inhale and exhale into the water towards the other hand, which makes the stroke. It is very important that during inhalation the head does not rise, but only turns so that at the moment of inhalation the back of the head is in the water (or as close to the surface as possible).
9. On a delayed breath with the face lowered into the water, perform rowing and preparatory movements with the free hand, holding the board with one hand by the middle of the near edge. At the same time, follow the rhythmic work of the legs. Perform the exercise alternately with both hands.
10. The same exercise, but without the board. - From the middle of the stroke, turn your head towards the rowing hand and inhale. At the first stages of training, it is recommended to make a short pause for the working hand at the moment when it finishes the preparatory movement. The pause is necessary in order to have time to finish the exhalation by the beginning of the next stroke. Exercise to work out first with one, then with the other hand.
11. I.p.: both hands hold the board by the middle of the near edge. - An alternating movement of the arms is performed with a turn of the head to inhale towards the working arm.
12. Pushing off from the side of the pool and after sliding with arms extended forward, they begin to move their legs and, without turning their heads to inhale, while holding their breath, rowing movements are made first with one and then with the other hand. At the same time, attention is paid to the frequent and rhythmic work of the legs.
13. The same, but with the coordination of breath. - When learning the crawl on the chest, this exercise is the main one, and the success of mastering this style of swimming largely depends on how well it is learned.
14. The same, but with alternating work of the hands, with breathing under one and under the other hand. - When performing this exercise, it is not always possible to hold in front of the surface of the water the hand that does not work. Therefore, the task focuses on the fact that at the moment when the hands are in front, there is contact with the thumbs.
15. I.p.: standing at the bottom of the pool in a half-tilt position, one hand in front, the other behind. - Synchronous imitation of the preparatory movement with the hand located behind and the rowing movement with the hand extended forward. After a short pause and a change in the position of the hands, simultaneous movements are again imitated. After mastering this movement, the task is to inhale and exhale at the time of the pause of the hands. The purpose of this exercise is to form a stable skill of coordinated hand movement.
16. The same exercise is performed without a pause and with a breath at the end of the stroke of the arm under which it should be performed.
17. After the movements in exercises 15 and 16 are mastered, they proceed to their implementation in combination with movements of the legs and arms; on holding the breath; without turning the head face down.
18. Swimming crawl in combination with inhalation, movements of the legs and arms, achieving all the requirements for front crawl on the chest.
19. Swimming crawl: inhale every other time; after 3; after 5 strokes.
20. The same, but swimming on one hand, a board in the legs.
The main mistakes of students in the technique of crawl swimming on the chest
Beginning swimmers, when studying swimming techniques, often perform movements with significant errors, while serious violations of the basic structure of movements lead to a sharp decrease in swimming speed and excessive energy consumption.
1. High position of the head. - If the position of the body is incorrect, the face is raised above the water, and therefore breathing is difficult.
2. Belated breath. - Inhalation occurs in the middle and in the second half of the movement of the hand over the water. This increases the swing of the body relative to the longitudinal axis, which, in turn, is reflected in the work of the legs.
3. Incomplete exhalation. - It leads to a decrease in pulmonary ventilation, causes suffocation, prevents the swimmer from following the correct execution of swimming movements and causes the pace to increase, reducing the length of the strokes.
4. Exhalation retention. - Instead of starting to inhale, continue exhaling after turning the head.
5. The abrupt start of the stroke. - The swimmer starts the stroke from top to bottom as soon as the hand is on the water. This tires the swimmer and leads to a weakening of the main part (middle) of the stroke. There is no influx.
6. Short stroke. - The swimmer does not finish the second half of the stroke, he is in a hurry to make preparatory movements. A similar mistake is observed in swimmers who seek to accelerate the pace in order to increase the speed of progress. An increase in pace due to a reduction in the length of the stroke leads to an increase in energy consumption and a decrease in the speed of progress.
7. Zigzag movements of the brush during the stroke (from side to side).
8. Low position of the pelvis. - Causes the legs to sink too deep when moving down, increasing the resistance of the water.
9. Excessive deflection in the lower back. - It interferes with the correct execution of the second half of the stroke; water resistance increases.
10. Hands when carrying them over the water are too bent. - Leads to excessive swaying of the body.
11. Legs move, remaining straight and tense all the time. - There is a rapid fatigue of the muscles of the legs. There will be very little progress in doing so.
12. Leg movements not from the hip, but from the knee. - Such work almost does not contribute to the progress of the swimmer forward.
13. Oscillations of the body around the anteroposterior axis. - Causes a change in the swimmer's direction of movement. The swimmer, viewed from above, swims in a wave-like curve.
14. Legs work non-rhythmically: after two blows with a normal amplitude of movement, a wide spreading of the legs follows (as a rule, not in a vertical, but in an inclined plane). - It is a consequence of excessive turning of the torso to one side when moving the arm above the water (especially when inhaling). The end result is a distortion of the footwork.
15. Somewhat less common are such errors as excessive vibrations of the body about the longitudinal axis; stroke with a completely straight arm; hand stroke with spread fingers; elbow stroke; work with a hand with a lowered elbow in a preparatory movement, etc.
elimination common mistakes when swimming front crawl
1. Low elbow position
From the initial position of the arms forward at the surface of the water, the legs work in a crawl - alternate rowing movements with the forearm and hand.
Crawl strokes with a straight arm in a standing position on the bottom and in motion.
Various exercises with self-control behind the high position of the elbow.
2. Mismatch of hand movements
Swimming with separate-alternate coordination.
Swimming with a stroke with one hand with its fast carrying.
3. Transverse bends of the body
Swimming with separate and separate-alternate coordination in the work of the hands with six- and eight-stroke footwork.
Swimming with bilateral breathing through one, three, five strokes.
Swimming on a delayed breath.
Swimming with the head held high (with the forehead not down, but forward, while the head remains in the water) without turning it to inhale.
4. Offset of the brush to the side at the beginning of the stroke
Swimming with a stroke with one hand, breathing towards the wrong hand.
Rowing movements with excessive displacement of the hand at the beginning of the stroke in the opposite direction.
Swimming with a stroke with one hand, the other is pressed to the body or up to the head.
Crawl on the back
When swimming crawl on the back, the swimmer lies on the surface of the water almost horizontally, the back of the head is immersed in the water. He advances forward with the help of alternate strokes with his right and left hands and alternate movements of his legs from top to bottom and from bottom to top. When the stroke is completed, the hand leaves the water and sweeps forward through the air. To perform one cycle of movements, which is conditionally divided into two half-cycles, which, in turn, consist of three generalized phases, there are 2 strokes with the hands, 6 movements with the legs, inhalation or exhalation.
Body and head position. The swimmer lies in a supine position. The longitudinal axis of the body is at an angle of 4-6 degrees with respect to the water surface. The shoulder girdle and head are located above the level of the pelvis. The back of the head is submerged in water, the neck is straight, the face is above the water. The trunk should not oscillate around the anteroposterior and transverse axes. Turns around the longitudinal axis are made in the direction of the rowing hand. This makes it easier to perform preparatory movements with the other hand and helps to strengthen the stroke. Turns should not be excessive. The limit of body oscillations around the longitudinal axis is determined primarily by the work of the legs. The oscillations must not appreciably affect the shape of the leg movements or change the direction of the leg movements.
Hand movements. Hands alternately perform strokes, with the help of which the swimmer moves forward. The movement of the hand consists of the influx and the supporting part of the stroke, the main part of the stroke, exit from the water, carrying through the air and immersion in water.
In the initial position, the hand with the palm turned outward is extended under water forward behind the head parallel to the surface of the water. During the influx and the supporting part of the stroke, the straightened arm gradually bends at the elbow joint and the palm takes its original position to start the main, most effective part of the stroke. The relaxed hand of the other hand is just below the level of the pelvis.
The main part of the stroke is performed with successive flexion and extension of the arm at the elbow. This allows the swimmer to keep the hand and forearm almost perpendicular to the direction of movement.
The division of the stroke when describing the movement into the supporting and main parts is conditional, since the entire stroke with the hand is performed in a single sweeping movement that moves the swimmer forward. When the arm comes out of the water, the shoulder, forearm and hand are sequentially shown in the air. The exit from the water is greatly assisted by the rotation of the shoulders, in which the shoulder of the rowing arm rises out of the water. After leaving the water, a straight or slightly bent arm at the elbow quickly moves up through the air and in the direction of the swimmer. During the movement of the hand through the air, the muscles of the hand are as relaxed as possible. In this case, the brush is turned with the palm outward with the fingertips down so as to enter the water with the little finger down. The brush at the very end of the stroke is turned with the palm inward, that is, towards the thigh. This rotation of the brush simplifies the execution roundabout hands above the water and the start of the stroke. In this phase, the straight arm descends into the water behind the head approximately at the line of the shoulder and takes the initial position for the influx.
Breath. For one cycle of the swimmer's movement, there is one breath or exhalation. At the end of the stroke with one arm (usually the stronger arm), the swimmer inhales through the mouth. Then, after a short delay, a slow exhalation follows through the mouth (and partly through the nose), which continues until the next breath. The end of the exhalation is reinforced to avoid water entering the mouth on the next inhalation.
When swimming crawl on the back, exhalation during the start and turns is specific. The bottom line is that after sliding under water on the back, the swimmer has to exhale in a position where the face is turned up. To prevent water from entering the nose, make a long and continuous exhalation through the nose.
Leg movements. The swimmer's legs perform almost constant movements from the bottom up and from the top down, so that the relaxed feet diverge at an angle of 50-60 degrees. At the same time, the working movement for the formation of traction force is carried out by the lower leg and foot in the up-back direction. Small movements of the feet near the surface of the water are ineffective; the main working phase is the movement of the foot from the bottom up (“kick up”).
Coordination of movements. The basis is continuously alternating strokes with hands. Leg movements are rhythmic and uniform. Calm crawl swimming on the back is characterized by circular uniformity of hand movements, the presence of an influx, a subjective feeling of ease of movement and a visual impression of freedom of movement. Inhalation is performed, as already noted, at the end of the stroke with one hand, and exhalation continues for almost the rest of the movement.
Training exercises
Learning the movements of the legs in the water begins from the starting position lying on your back along the side, holding it with one hand, and pressing the other to the body. Rare movements are performed with straight legs, followed by an increase in the rate of their movements. It is necessary to ensure that the feet and knees do not show on the surface of the water. This error occurs when the knees are bent too much. It is also impossible to allow a large amplitude of movement of the legs.
1. I.p.: the same, but the free arm moves first bent at the elbow behind the head, and then straight behind the head. With the correct position of the torso and legs, the arm straightened behind the head should lie freely in the water, without disturbing the lying position.
2. Lying on your back and holding a swimming board located above your chest with both hands, work your legs first at a slow and then at an accelerated pace. As you master the movements of the legs, the board moves further from the shoulders, taking a position first above the pelvis, then above the knees.
3. I.p .: lying on your back, one hand rests on the board in its middle, the other, bent at the elbow, behind the head. As you master the movements of the legs, straighten your arm at the elbow in the forward direction, keeping the position of the body unchanged. The position of the hands must be changed. Depending on the degree of knowledge of the exercise, move the support on the swimming board to the edge of the board closest to the shoulders.
4. I.p .: lying on your back, arms along the body. - Perform leg movements.
5. I.p.: the same, but the arms are bent at the elbows and located behind the head with the board; then no board. - Perform leg movements.
6. The exercise is the same (5), but the arms are straightened at the elbows and lie forward on the water, palm to palm. If the mobility of the shoulder joints is not sufficiently developed among those involved, then there is an underextension of the shoulders and arms, with the correct position of the body, the shoulders hang above the water, sinking the head. To do this, it can be recommended to perform the exercise with only one arm extended anteriorly, the other at the hip, achieving such an arrangement of the torso in which the entire arm located anteriorly would be in the water. Leg movements are considered mastered when students can swim without much effort, working with their legs alone with their arms extended behind their heads and lying on the surface of the water.
7. I.p .: lying on your back along the side of the pool and holding on to it with one hand, the other is extended forward. - Perform rowing and preparatory movements with one and then with the other hand. Learning the movements of the hands at the side of the pool is continued, connecting the movements of the legs with a delay of the hand behind the head for 1-2 seconds. In this case, the trainee manages to complete the respiratory cycle and make six kicks.
8. I.p .: lying on your back, holding the swimming board by the middle of its near edge (board on the water, arms outstretched) and working with your feet. - Perform preparatory rowing movements first with one and then with the other hand. At the initial stages of training, it is advisable to learn the stroke on the back with a straight arm with the movement of the brush near the surface of the water. When stroked with bending at the elbow, the hand may lag behind the movement of the elbow, as a result of which the so-called smearing stroke occurs with a reduced force of repulsion from the water.
9. The previous exercise (8), but perform with an alternating movement of the arms. When intercepting the board from one hand to the other, the hands must linger on it for a time that corresponds to the time of an odd number of kicks. This creates conditions for the subsequent formation of a six-stroke coordination of movements with arms and legs.
10. I.p.: standing on the bottom, both hands up (hands connected). - Bending, touch the back and hands of the water; after a preliminary squat, they push off with their feet and perform a slide on their back. Then, having begun continuous work with the legs, they make several rowing and preparatory movements with one hand, then the same movements are made with the other hand. After entering the hand into the water, it is necessary to ensure that it lingers for a moment at the top (pause through touching the palm of the hand on the palm).
11. The same exercise, but the movement is performed first with one and then with the other hand. As in swimming with a board, with separate-alternate work with the hands, it is necessary to pay attention to the pause for the hands at the moment when the hands meet behind the head.
12. I.p.: right hand above, left along the body. - Lying on your back after pushing off the bottom, start moving with your legs, simultaneously performing a stroke with your right and a preparatory movement with your left hand. This is followed by a pause in the movements of the arms, and the legs continue to work. Gradually shortening the pause, they achieve a continuous six-stroke coordination of movements with arms and legs.
13. Having fixed the board between the legs, they work only with their hands on the back.
The main mistakes of students in the technique of crawl swimming on the back
1. Strong flexion in the hip joints. - The swimmer "sits" in the water.
2. There is no flow phase. - The stroke starts as soon as the hand touches the water, sometimes even before the brush is completely submerged in the water. In this case, the straightness of the swimmer's progress is violated, part of the energy is spent aimlessly, the main part of the stroke is weakened.
3. Head thrown back. - Water fills the face; breathing is difficult.
4. Legs are too tight. - Movements are made with straightened legs.
5. Legs do not work from the hip joints, but from the knees.
6. Leg movements are too small or too large amplitude.
7. Hands are placed on the water too wide or too narrow.
These mistakes can be corrected by practicing swimming with the help of movements with one legs, using calm swimming and sliding on the back, etc.
Eliminating Common Mistakes in Backstroke Swimming
1. Early extension of the elbow during the stroke
Swimming on the back with pulling the rowing hand over the track.
Simultaneous and alternate rowing movements of the arms with an emphasis on pushing back in the second part of the stroke.
Swimming on your back with self-control over the extension in the second part of the stroke.
2. Violation of verticality in leg movements
Swimming with self-control behind the stationary position of the pelvis during rowing movements with the hands.
Swimming with an additional weight fixed on the belt.
Swimming with horizontal stabilizing planar elements, fixed on the swimmer's belt alternately from both sides.
3. Irregular shape of the brush during stroke
Imitation of rowing movements at a fixed support with self-control over the shape of the hand.
Performing various exercises in motion with self-control over the correct shape of the hand.
Exercises for the development of the muscles of the body and arms involved in the performance of rowing movements.
BREASTSTROKE
When swimming with a breaststroke, the body of the swimmer is located near the surface of the water in a straightened position on the chest, the head is lowered face down into the water. Moving forward is carried out due to simultaneous symmetrical strokes with arms and legs. Inhalation is performed at the beginning of the stroke with the hands, exhalation into the water coincides with the push with the legs.
Breaststroke swimming techniques are varied. There is a classic breaststroke, high-speed breaststroke and its varieties.
body position. The swimmer lies on the surface of the water on his chest with arms outstretched and feet, palms facing down, face lowered into the water to the eyebrows. During swimming, the body of the breaststroke changes the angle of attack from 0 to 15 degrees, which is associated with a slight raising of the shoulders and head when inhaling. The smaller and smoother the change in the angle of attack, the less counter resistance water. The breaststroke player must avoid excessive arching of the lower back when inhaling and during the kick.
Hand movements allow the swimmer to move forward and maintain the head and shoulders at the surface of the water for inhalation. The cycle of arm movements consists of a stroke and bringing the arms forward - preparation for the stroke. The arm stroke starts from a sliding position with outstretched arms and legs, spreading the arms to the sides and down and resting the hands on the water. Then, bending the arms at the elbows, actively include the forearms in the stroke. During the stroke, the swimmer leans on the water with his palms and forearms. At the end of the stroke, the elbows are closer to the body, and the hands are closer to the chin. Removal of hands anteriorly begins immediately after the stroke. Finishing the stroke, the arms are bent at the elbows and at the same time brought forward, the hands are approaching each other, the palms are facing down.
Leg movements ensure the advancement of the swimmer forward, contribute to maintaining the balance of the body in a horizontal position. Leg movements consist (conditionally) of three phases: pulling the legs to the pelvis, spreading the feet, preparing for the push and the actual push.
When pulling up, the legs with a slight muscle tension are bent at the knee and hip joints. The knees go down a little and spread apart to the sides about the width of the shoulders. The feet, moving near the surface of the water, are passively located with their toes along the line of motion. In the starting position for the push, the feet turn with their toes to the sides and are taken over (dorsal flexion), and the shins take a position almost perpendicular to the surface of the water.
Performing a push, the swimmer spreads his feet to the sides, strongly pushing off the water with his hips, shins and inner surfaces of the feet. The legs gradually move towards each other and straighten at the knees. The push begins with the extension of the legs, first in the hip, then in the knee and ankle joints. This sequence of inclusion in the movement allows the swimmer to develop the greatest pulling force and perform the pull-up and push with the legs in a single continuous movement. After the push with the legs, the inertial sliding forward continues with simultaneous straightening, connection and raising of the legs to the surface of the water.
Breath. During the breaststroke cycle, the swimmer takes one breath and one breath. A quick breath and a slow exhalation are performed through the mouth, and the breath is taken at the beginning of the stroke with the hands. After inhalation, the face is lowered into the water so that the line of water reaches the level of hair growth.
Coordination of movements hands and feet with breathing occurs as follows. I.p.: sliding. The hands begin the stroke, at the end of which the legs bend at the knee and hip joints, preparing for the push. Having finished the stroke, the hands return to the SP, and the legs from the starting position for the push perform a powerful whip-like push. As a result, the swimmer slides forward with outstretched arms and legs. Inhalation is carried out at the beginning of the stroke with the hands; exhalation begins with a push with the legs and continues until the next breath.
Training exercises
1. Starting position for learning the movements of the legs in the water - stretched out on the chest on the surface of the water. - Holding hands on the side, they bend the legs at the knee and hip joints, spread the feet with toes outward, rowing movement by straightening the legs at the knee and hip joints and their subsequent reduction with acceleration to the end of the movement.
2. If it is impossible to avoid erroneous actions, the exercise is performed while standing on the bottom and holding on to any support with your hand. Learn the movement with one and then the other foot.
3. I.p .: holding the board with straight hands on the edge farthest from you. - Perform rowing and preparatory movements with legs with a pause after the stroke. At the moment of pause, the body slides, and by its forward movement one can judge the effectiveness of the stroke. Stops after the preparatory movement should not be allowed, since when the legs are held in a bent position, they sink, followed by a suspension of forward movement.
4. The same, but perform in coordination with breathing - During the preparatory movement, you need to raise your head above the water and take a breath, at the time of the stroke with your feet, lower your head into the water and exhale.
5. I.p.: lying on the chest, arms forward without a board. - Make movements with the legs, first on a delayed breath with the head lowered into the water, then in combination with breathing. When raising the head to inhale, support movements of the brushes on the water are acceptable.
6. I.p.: lying on the water, hands pressed to the body. - Perform leg movements on a delayed breath with the head lowered into the water and in coordination with the inhalation and exhalation into the water.
7. I.p .: standing at the bottom in a half-tilt, head raised above the surface of the water, hands forward at the surface of the water. - On the count of "one", stroke with your hands, on the count of "two" - a preparatory movement, on the count of "three" - a pause.
8. The same, but with the head lowered into the water while holding the breath. - As you master this exercise, perform the movement in coordination with the breath.
9. I.p.: lying on the chest in the water. - Make alternate movements with arms and legs through a pause. Sequential movements of the arms and legs are first carried out on a delayed breath, and then the stroke of the arms should be coordinated with breathing.
10. After the movements of the arms in combination with the successive work of the legs are learned, they perform the task of preparatory movement of the legs at the moment when the arms have finished the stroke, that is, in the combination that is characteristic of the breaststroke.
11. The same, but do the movements with the legs twice in a row, then stroke with the arms with inhalation: that is, coordinate two pushes with the legs with one stroke with the arms.
12. The same, but for two strokes with the hands (inhale for each stroke) one push with the legs follows.
13. Fasten the board between the legs; only breaststroke arms work in coordination with breathing.
The main mistakes of students in breaststroke swimming technique
1. In leg movements:
Asymmetry;
During the preparatory movement, the legs in the hip joints bend too much;
The legs in the ankle joints are bent at the beginning of the preparatory movements;
When pulling up the legs, the knees are spread too wide or too narrow;
The feet are not spread apart before the start of the working movement with the legs;
The push with the legs is directed to the sides, the stroke with the legs is divided into two parts: the push to the sides and pulling the legs without bringing them together;
The leg stroke begins with extension at the knee joints;
The kick stroke does not end with bringing the legs together;
After pulling up the legs, a pause is maintained before the push.
2. In hand movements:
Asymmetry;
The sharp start of the stroke;
During the stroke, the palms are turned downwards;
The stroke is made with straight arms;
The hands sink too deep during the stroke;
There is no raking and supporting movement with the elbows at the moment of transition from working movements to preparatory ones;
The stroke is too long, the hands go beyond the line passing through the shoulder joints;
After the movements immediately following the stroke, and before the movement of the arms under the water anteriorly, there is a short pause: the arms freeze in a static position, then move forward.
3. In a combination of movements, breathing and the position of the torso and head:
The head rises with a delay, i.e. after the start of stroke with hands;
The legs are pulled up too early - in the middle of the stroke with the hands;
The legs are pulled up too late - after the end of the stroke with the hands;
Exhalation is delayed and partially produced after raising the head;
Incomplete exhalation;
Excessively low lowering of the head when exhaling; sudden movements of the head when it is raised and lowered; large range of head movements or head diving;
The pelvis is too low: the swimmer's body has an excessively large "angle of attack";
When raising the head, the swimmer bends in the lower back;
The swimmer's body oscillates strongly around the transverse axis.
The five most common mistakes in breaststroke
1. Excessive shoulder stroke- one of the worst mistakes during breaststroke swimming. An increased arm stroke creates a situation where the arms are too far behind the back, passing through the face.
shoulders.
2. Correction. While in the pool, lie down on the dividing strip so that it runs at the level of the armpits. Stretch your legs horizontally, as with a breaststroke, and make a stroke with your hands. In this position, it is impossible to push your hands beyond the line. These movements should be fixed in muscle memory by training.
3. Breath too late. - One of the basic principles in swimming is that when a part of the body (head, arm) is above the water, the other part of the body serves as support in the water. The same principle applies to the breaststroke breathing technique. When the swimmer's body rises for inspiration, his head passes over the water. At this point, you need to use your hands as support in the water. Common mistake in this case- this is a breath when the hands are already in the shoulder area, or even worse, are already approaching the chest. When this happens, the head is still above the water, but the support is gone as the arms cover the stroke. At such moments, the swimmer feels that he is drowning at the moment of inhalation. Inhalation should begin at the moment the stroke is started with the hands.
4. Pauses in the middle of a cycle. - The main body position in the breaststroke technique is directly below the surface of the water. The hips should move very close to the surface. This position is difficult to maintain at the end of the stroke, when the swimmer is ready to stretch his arms forward (arm return). When the palms are near the chest, the center of gravity shifts and the hips begin to sink. It is a mistake to pause at that time. With the correct breaststroke technique, there can be no pause (pausing in the strokes with the hands, the swimmers get very tired), the arms should be thrown forward with acceleration along with the entire upper body.
5. Correction. Use freestyle kicks and breaststroke strokes. The strokes must be very fast. This exercise will keep the hips from sinking as the kicks will support them.
6. Head movement instead of body movement- a very common mistake that occurs in 90% of swimmers. Contrary to the generally accepted opinion in breaststroke technique, there are no (or minimal) movements of the neck, otherwise the full potential of the body will not be used when moving forward. Head nodding causes excessive up and down movement of the body, which reduces the speed of movement, increases the distance between the hips and the surface of the water and, accordingly, increases the resistance. One way to immobilize your head while swimming is to place a tennis ball or something larger under your chin. If during inhalation the face is in a vertical position (eyes look forward) - this is bad. In the breaststroke technique, the head is an extension of the straight spine, so you should look at an angle, keeping your hips near the surface of the water.
7. Ineffective kick. A good kick is the main thing in breaststroke swimming technique. The main mistakes in kicking are: kicking over the legs, kicking too wide and, at worst, a mixed butterfly-breaststroy kick. Understanding kicking (pushing) with your feet is understanding which part of the leg is pushing the water and where.
Eliminate Common Mistakes When Swimming Breaststroke
1. Increasing the length of the stroke with your hands
An elongated rowing movement of the hands with the hands clenched into a fist.
Extended arm stroke with visual control.
Swimming on one hand, board in the legs.
2. Delay in moving the arms forward after the end of the stroke
Swimming on one hand, with a board in the legs.
Exercise for 2 strokes with hands, 1 push with legs.
Breaststroke on a long pause in sliding.
3. Wide leg position at the end of the kick stroke
Leg movements at a fixed support with a slight dilution.
Swimming with the help of legs with an emphasis on inward effort.
Swimming with the help of legs with incomplete extension of them in the knee joints.
4. Excessive leg flexion at the hip joints
Swimming with one leg, arms along the body, inhalation is performed at the moment of the preparatory movement of the legs.
Swimming with legs breaststroke on the back with a board located above the knees. Perform narrow movements with the knees.
5. Early leg curl
Swimming in coordination of movements with arms and legs through a pause.
BUTTERFLY (DOLPHIN)
When swimming as a dolphin, the swimmer moves forward due to powerful simultaneous strokes of the arms and wave-like movements of the body. Inhalation is done at the end of the stroke with the hands, and exhalation lasts the rest of the movement.
Body position and leg movements. The body of the swimmer is located on the surface of the water in an extended position. The head is lowered face down into the water. Unlike other swimming methods, where the position of the body is relatively stable, when swimming as a dolphin, the active movement of the body up and down is combined with continuous synchronous and symmetrical movements of the arms and legs.
The swimmer makes a wave-like movement of the body up and down in a vertical plane so that when the shoulders and feet fall, the pelvis rises, and vice versa. Due to the wave-like movements of the body and significant fluctuations in the vertical plane of the shoulder girdle, the angle of attack changes during one cycle within ± 20 degrees. The amplitude of movement in the vertical plane increases sequentially from the shoulders to the shins. The movements of the feet up are accompanied by bending the legs at the knee joints, and down - by straightening. As a result, the swimmer makes a sweeping kick with his legs.
Energetic sweeping blow with feet down - the main working movement of the legs (from top to bottom). When the feet make a sweeping blow down, the pelvis rises up; during the movements of the legs and feet up, the pelvis vigorously goes down, the shoulder girdle moves forward and slightly up. The maximum angle of flexion of the legs in the knee joints is about 100-120°, in the hip - about 150-160°. The range of motion of the hips is approximately 5-7, the stop is approximately 25% of the swimmer's body length.
The working movement is considered complete at the moment of full extension of the legs in the knee joints.
Leg movements play a coordinating role and make a significant contribution to the creation of driving forces. When swimming as a dolphin, about 70% of the swimming speed in full coordination depends on the movements of the legs.
Flexion of the legs in the knee joints is carried out within 45-55 degrees. When moving up, they connect, increasing the efficiency of the sweeping stroke. In one cycle of leg movements, two blows are usually made, unequal in amplitude and effort. Usually the swimmer accentuates the second stroke, which falls at the end of the stroke with his hands and is performed during inhalation. Leg movements keep the body near the surface of the water and help the swimmer actively move forward.
Hand movements. Conventionally, they are divided into immersion of the hands in the water, the influx and the supporting part of the stroke, the main part of the stroke, the exit of the hands from the water and their movement above the water. After passing over the water, the hands enter the water approximately shoulder-width apart, palms down (first the hand enters, then the forearm and shoulder). To avoid diving, swimmers, straightening their arms under water, bend in the shoulder joints, damping the movement of the shoulders down or pushing the arms straightened under water somewhat to the sides. Lightweight swimmers experience the effect of drowning force to a lesser extent.
influx begins after the entry of hands into the water. At this time, the arms and torso stretched forward make a slight movement up and down. The influx can be observed when swimming at a slow pace, when swimming at a fast pace, it is almost imperceptible.
Supporting part of the stroke begins from the moment when the speed of the forearm and hand exceeds the speed of the flow around. By this time, it is necessary that the swimmer completes the movement of the arms to the side and inward and the hands return to the position that they occupied immediately after entering the water (shoulder-width apart). If this does not happen, then the forearms and hands will move at an angle to the flow around the stream and the traction force from the stroke in the main part will significantly weaken. In the supporting part of the stroke, the arms, moving down and towards the midline of the body, gradually bend at the elbow joints, bringing the swimmer's shoulders up and forward.
From this position, the swimmer starts basic , the most efficient part of the stroke. First, he directs his palms to the midline of the body, then he finishes the stroke with the movement of the palms to the sides of the hips; elbows at the end of the stroke approach the surface of the water. At the beginning of the main part of the stroke, the swimmer, as it were, "captures" the water, bending his arms at the elbow joints and turning his elbows outward. Then the swimmer vigorously pushes off the water, sending his shoulders forward and turning his elbows to the sides. The end of the stroke coincides with the removal of the hands from the water. As the shoulders approach the horizontal position, the elbows move up and out of the water as they come out of the water. The main part of the stroke is completed by turning the palms and forearms into a plane perpendicular to the direction of the swimmer's movement, to further ensure maximum thrust.
Carrying above water is usually performed with straight arms; while both hands move forward through the sides. First, the hands are turned back down, and then they are turned so that they enter the water with their palms down. Swimmers with good shoulder mobility carry their arms through the air with their elbows slightly bent. In this case, the hands enter the water at an angle to its surface, giving the swimmer the opportunity to quickly start the stroke with his hands and increase the pace of swimming.
capture . This part of the stroke is characterized by a slight bending of the arms in the wrist and elbow joints. The beginning of the capture is carried out by moving the hands forward-downward-to the sides. The rowing surfaces of the hands perform movements at a small angle of attack. In the second half of the grip, the hands move down-back-to-side also with a small angle of attack. During the grip, the elbows remain high, the arms move quickly, and the upper body drops down with a small amplitude. The grip ends at the moment when the angle between the surface of the water and the forearm is approximately 30°, and the hands are at the maximum distance from each other. In the capture phase, the head is lowered into the water, the face is turned forward and down.
Breath. For a full cycle of hand movements, as a rule, one breath and one exhalation are used. A quick breath through the mouth begins at the end of the stroke, that is, when the hands are taken out of the water. After a short pause, exhale. To prevent water from entering the mouth, the end of the exhalation is done with amplification.
Breathing is coordinated with the movements of the hands. To inhale, the swimmer's head is slightly raised facing forward at the moment of the highest position of the shoulder girdle at the end of the main phase of the arm stroke. Gradual extension of the neck begins in the first half of the stroke. Towards the end of the hand repulsion, the swimmer's mouth appears above the surface of the water, the gaze is directed parallel to the surface. The main part of the inhalation coincides with the release of the hands from the water. The breath ends at the very beginning of the movement of the hands over the water; when the arms pass the line of the shoulders, the face plunges into the water.
Well-trained swimmers take one breath in and out for two complete cycles of movement.
Coordination of movements hands and feet with breathing occurs as follows: one of the kicks down is performed when the hands enter the water, the second - at the end of the stroke with the hands. Inhalation is done at the end of the stroke with the hands, exhalation after a short pause.
With an increase in swimming speed, the combination of movements changes. So, for swimming at a slow pace, the phases are lengthened during separate work with arms and legs and a long pause in the initial position, which is also accompanied by sliding with the shoulders, head and arms immersed under water (diving). When swimming at a fast pace, the cycle of movements is compacted, and the swimmer assumes a relatively high and stable body position.
General coordination of movements. The most rational coordination of movements when swimming with a dolphin is observed with two-stroke coordination. It to a greater extent ensures the uniformity of the swimmer's movements forward throughout each cycle. For one cycle of hand movements, there are two kicks of the legs from the bottom up and from the top down.
If the swimmer increases the number of strokes to three, then he will have to lengthen the cycle of movement of the arms (usually this can be done by inflating), which will lead to a decrease in the pace of speed. Three-stroke coordination of movements is used to improve the technique of swimming.
In the practice of sports swimming with a butterfly (dolphin), one-stroke coordination of movements is used. With such coordination, the first blow is performed from top to bottom, then the legs go up. The second stroke is not performed, and the arm stroke is performed when the legs and torso are in an extended, streamlined position. Studies and calculations have shown that a decrease in leg kicks during a cycle from two to one leads to a decrease in the swimmer's average speed. However, if the swimmer is able to improve streamlining at the same time, then the loss of speed will be small.
Much more often, when swimming with a butterfly (dolphin), coordination is used, in which the second blow is slightly weakened, and the first is still fully performed. With this coordination, if the swimmer manages to simultaneously improve the streamlining, the speed of the athlete is close to the speed of swimming in two-stroke coordination, and the movements will be 10-12% more economical.
Training exercises
Leg movements
1. Swimming with a board in your hands while holding your breath (head lowered into the water), with moderate bending of the legs at the knee joints, without significant pelvic oscillations (movements "from the knee").
2. The same, but the movements of the legs are accompanied by the swaying of the pelvis.
3. Swimming with only legs without a board, arms extended forward, head between arms:
a) on holding the breath (5-8 movements);
b) with one breath for every 2-4 kicks.
4. Dolphin leg swimming, arms extended along the hips.
5. Swimming with the help of legs only, but on the side. The lower arm is extended forward (next to the head), upper arm- along the thigh. Swim without stopping; inhale as in a crawl (turn the head, but up). Practice on the right and left side.
6. Dolphin swimming on one leg, but on the back. The arms are extended forward and lie on the water.
7. Swimming on one leg, but with the addition of breaststroke arm movements for inhalation.
When swimming using movements only with the legs, attention should be paid to the fact that the toes of the legs are pulled back, and the feet are turned inwards, and the bending of the legs at the knee joints is moderate and the movements start “from the hip”. When learning the leg movements of a dolphin with a board, you need to ensure that the shoulders are kept at the water level. To do this, it is necessary to press your palms on the board during the kick with your feet down, otherwise most of the effort will be spent not on moving forward, but on swinging the shoulder girdle up and down.
Hand movements
1. I.p.: standing at the bottom in a half-tilt, hands forward on the surface of the water, head raised facing forward. - The rowing and preparatory movements are imitated.
2. Exercise number 1 on a delayed breath with the head lowered into the water.
3. Exercise number 1 in coordination with breathing. At the end of the preparatory movement, it is necessary to pause to complete the breathing cycle.
4. In the position lying on the chest and clinging to the drain trough or path with your feet, perform hand movements like a dolphin while holding your breath.
5. After sliding, perform 4-6 movements with the hands of a dolphin while holding the breath.
6. Swimming on one hand with a board at your feet.
7. Swimming with dolphin arms and crawl legs.
Coordination of movements
1. Swimming with dolphin leg movements and strokes with one hand, the other is extended forward. - First, hold the breath, then with the breath, as when swimming crawl on the chest with the head turned towards the rowing hand. It is necessary to monitor the correct coordination of kicks and hand movements. The first blow takes place during the entry of the hand into the water, the second coincides with the end of the stroke. The "working" hand can be changed every 5-10 strokes and / or after 25-50 m. This is the best exercise for mastering and improving the ratio of movements in a two-strike dolphin, since it requires much less strength than swimming with full coordination of dolphin movements.
2. Swimming with a multi-strike dolphin with diving. - After the hands enter the water, they linger in the influx in front, the swimmer performs 2-4 movements with the legs and torso, after which the hands make a stroke. At the end of the stroke - inhale.
3. Swimming with a "separate" two-stroke dolphin. - When the arms are stretched forward after carrying - a pause is given for the hands. At this time, a double kick is performed - and again a pause. That is, in the pause of the hands - the legs work, and in the pause of the legs - the hands work and a breath is taken.
4. Swimming with a two-stroke coordinated dolphin.
The main mistakes of students in the technique of swimming butterfly (dolphin)
1. Hands placed on the water too narrow (narrower than shoulder width) or too wide. - The narrow entry into the water does not allow for a quick start of the catch, and while the arms are brought to the initial position for the catch, the swimmer's shoulders sink too deep. A wide insertion of hands causes additional counter resistance, and to an even greater extent than with a narrow entry of hands into the water, the effectiveness of the capture phase is reduced. The elimination of this error is facilitated by special exercises aimed at improving joint mobility.
2. Delay of the arms extended forward in the influx. - The error generates a violation of the rhythm of movements, leads to a drop in speed. Suitable for swimmers with low functional readiness and disappears as training progresses.
3. Elbows sinking during pull-ups and push-offs. - One of the most serious mistakes, sharply reducing the effectiveness of the support on the water and the amount of tractive effort. The reason for it may be an insufficient level of development of power capabilities or inattention when performing this technical element, as well as the swimmer's desire to make strokes faster than necessary.
4. Short stroke. - Performing a shortened stroke, due to the fact that the swimmer starts to take his hands out of the water too early to carry, reduces the efficiency of the stroke and, in addition, leads to excessive bending of the body in the lower back and a high rise of the shoulder girdle, which, in turn, sharply increases the angle attack and drag. As a rule, this error, like the previous one, is caused by limited hand strength.
5. The end of the stroke with the hands is not performed energetically enough.
6. When removing hands from the water, the swimmer bends strongly in the lower back.
7. High position of the head and shoulder girdle during the carrying. - The error leads to an increase in the angle of attack of the body and an increase in drag. As a result - failure of the shoulder girdle when putting hands into the water. The greater the height of the shoulder girdle during the carry, the deeper it will fall when the hands enter the water. Often this error is caused by holding the head in a high position after inhalation. To avoid this, the swimmer is instructed to immediately lower the head face down after inhalation and try to carry the elbows as high as possible in relation to the head. It is recommended to “cover” the head with the elbows during the carrying. This almost imperceptible movement of the head down is accompanied by a decrease in the angle of attack of the body, the swimmer does not push the wave with his chest, but rolls over it from above.
8. Raise the head and inhale too early (at the beginning of the stroke) or too late (during the removal of the hands from the water).
9. Excessive bending of the knees when swinging the legs before impact. - The indicated defect increases the counter resistance acting on the body of the swimmer. In addition, the working movement is performed "from the knee", and not from the hips; as a result, the resulting force is directed more upwards, rather than backwards.
10. The exit from the water of the feet and shins during the swing. - This error reduces the effectiveness of the strike, due to the fact that a significant part of the working movement is performed in vain, since the swimmer kicks through the air, while only the heels should be shown from the water, and the entire working movement should be performed under water.
11. Stroke with legs is not performed energetically enough.
12. Violation of coordination of movements. - In terms of coordination, the dolphin is perhaps the most difficult way to swim. A slight mismatch in the time of performing movements with arms and legs can lead to a sharp violation of the rhythm of movements and a decrease in swimming speed - the swimmer's technique "falls apart".
Elimination of typical mistakes when swimming with the "butterfly" ("dolphin") style
1. Excessive range of motion of the shoulders
Swimming with only your feet with a board in your hands, first at a slow pace, and then with a gradual acceleration.
The same, but without the board, the arms are extended forward and are at the surface of the water.
When swimming as a dolphin, make sure not to make a sharp start of the stroke with your hands and perform the first part of the stroke in a horizontal plane.
2. Low foot position at the end of the second kick
Swimming as a dolphin on its side exclusively with the help of legs.
Swimming like a dolphin on your back, using only your legs.
Swimming like a dolphin using only the legs.
3. Shortened end of stroke with hands
When swimming exclusively with the help of hands, make sure that at the end of the stroke, the hands touch the hips; Perform the exercise on a delayed breath and in coordination with the breath.
When swimming, the legs work like a dolphin, and the arms use a crawl; change the hand after a given segment of the distance or after 2 strokes.
4. Incorrect coordination of the second kick and the end of the stroke with the arms
Swimming with a multi-stroke dolphin (3-, 4-, 5-stroke) with a stroke with one hand, alternate strokes with your hands; follow the correct end of the stroke with the hand and the second kick with the feet.
We bring to your attention the journals published by the publishing house "Academy of Natural History"
2.1 Resistance. The swimmer's speed is the result of two forces. One of them slows down. This is the resistance caused by the water that the swimmer pushes along the body. There are three types of water resistance:
1) frontal or frontal resistance;
2) friction of the skin;
3) “tail retraction” or additional (“vortex” drag).
Frontal resistance is created by water directly in front or in any part of the body.
Friction of the skin is caused by the resistance of water located directly at the body.
Additional drag, or “tail” drag, is created by water that cannot fill the space behind poorly streamlined parts of the body, and the swimmer has to drag some water along with him.
The amount of resistance that a liquid exerts to the movement of a body immersed in it depends on the properties of this liquid (on its viscosity and density), the size of the frontal section of the body, the speed of the body, on the shape of the body and the smoothness of its surface. This dependence is expressed by the formula:
v 2
where F is the value of water resistance;
k is the coefficient of density and viscosity of the liquid;
S - frontal section of the body;
v - the speed of the body
C is the streamlining coefficient, which depends on the shape of the body and the smoothness of its surface.
When analyzing the technique of sports swimming, the coefficient of density and viscosity can be ignored. The swimmer is in the same environment - water.
The dependence of water resistance on the shape of the body, the smoothness of its surface: the shape of the body has a great influence on the amount of water resistance. A body with a streamlined shape experiences water resistance 25-30 times less than a body with the same frontal section, but without a streamlined shape.
The shape of the back of the body affects the amount of resistance more than the shape of the front. This is explained by the fact that during swimming, an area of low pressure is created behind the swimmer. When the body moves forward, then in the place where it was, a void should form, which is immediately filled with water. An area of low pressure is created behind the body, which, as it were, “does not allow” it to move forward.
The body of the swimmer needs to be given the most streamlined shape, slight changes in shape cause significant changes in the amount of resistance (Fig. 3).
The amount of water resistance is affected not only by the general shape of the body, but also by how its surface is wetted by water. When flowing around a body with a well-wetting surface, a layer of water adjacent to the body, as it were, sticks to it and is carried along with it. The next layer of water carries away the third, and so on.
The sebaceous glands secrete a certain amount of fat on the surface of the skin, which makes it elastic and helps to reduce friction of the skin.
Currently, high-class athletes use high-tech suits to reduce drag.
2.2. Frontal section of the body and its influence on the resistance value.
The frontal, or midsection, section of the body is the projection of the body onto a plane perpendicular to the direction of its movement.
The resistance changes in direct proportion to the change in the magnitude of the frontal section of the body. If the frontal section increases three times, then the resistance will increase three times, if it decreases five times, then the resistance will decrease by the same amount.
In order to reduce harmful resistance during swimming, the body must be positioned so that the frontal section of those parts that are under water is as small as possible and so that during the preparatory movements of the limbs the frontal section is minimal. Working movements of the arms and legs should be performed, increasing the frontal section of the limbs to the maximum.
Increasing the resistance during working movements is useful - the reliance on the water and the traction force increase.
The human body will have a minimum frontal surface if it moves in the direction of its longitudinal axis.
When swimming near the surface of the water, it is better to position the body with a slight angle of attack so that the shoulder girdle is slightly higher than the pelvis. In this case, the oncoming currents of water will create additional lift, improving the conditions for moving the legs and facilitating breathing.
The magnitude of the angle of attack depends on which method the swimmer uses, on the speed of swimming and on the individual characteristics of the swimmer.
Creating an angle of attack leads to a slight increase in the frontal section and an increase in water resistance. However, at a positive angle of attack, a lift force is generated that helps keep the body closer to the surface of the water, in a “higher” position. As a result, if the angle of attack is not too large, the frontal section practically does not increase. When the angle of attack is large, the floating of the body to the surface of the water can no longer compensate for the increase in the frontal section of the body, and the resistance of the water increases noticeably.
Therefore, an attempt to artificially take a high position in the water does not bring success. Some swimmers lie higher in the water than others because they have better buoyancy and greater speed. Many raise their heads, trying to artificially take a high position in the water. However, only the upper part of the body is raised, while the lower part is immersed. The movements of the arms and legs become less effective: the swimmer has to expend a relatively large part of the effort to overcome the increasing resistance and keep his head above the water.
As the speed of advance increases, the resistance of the water increases only under the swimmer, and not above him. Therefore, when improving the swimmer's style, one should strive to find the angle of attack that corresponds to the individual characteristics of the given athlete (within the limits indicated when describing the swimming technique in one way or another).
To swim faster, an athlete needs to: 1) reduce resistance; 2) increase the driving force; 3) use a combination of these two factors. This problem can be solved only by finding a rational technique. The biggest improvement in swimming technique for last years there was a decrease in resistance.
General physical training classes contribute to the development of the strength necessary for fast movement at a distance with the least water resistance. As the swimmer becomes fatigued, less propulsion is applied and the streamlining of their body deteriorates.
When performing working movements with rowing surfaces, it is necessary to give a non-streamlined shape, and during preparatory movements over water - the most streamlined.
2.3. Forces that move the swimmer forward: The forces that propel the swimmer forward are generated by the arms and sometimes the legs, but mainly by grabbing the water with the hands and pushing it back with the feet.
Traction force: An athlete in the water moves due to the movements of the limbs, the work of which is provided by muscle forces. The swimmer carries out the main advancement from the work of the hands. When the hands move in the water, hydrodynamic reactive support forces F appear on their rowing surfaces, acting in the direction opposite to the movement of the hands. The horizontal component of the reactive support force that propels the swimmer forward is called the thrust force (Fx), and the vertical component is called the lifting force (Fy). The force F, as well as the force of the counter hydrodynamic resistance of the medium, depends on the speed of the rowing surface of the limb, its midship section, the density of water and the streamlining coefficient. For creating greatest strength thrust, the swimmer performs a stroke with acceleration and seeks to increase the force of water pressure on the rowing surface. The greatest pressure will occur on the hand, as it has a large midsection, high speed and less streamlining (Fig. 4).
Hand movements. There are three variations of the armstroke, with variations used in freestyle or butterfly strokes. The speed of the swimmer's progress depends on the efficiency of the stroke. Distinguish: 1) stroke with a lowered elbow; 2) straight arm stroke; 3) correct stroke.
The worst stroke is considered to be with a lowered elbow. It does not move the swimmer forward enough, as it pushes too little water back. This is how beginners usually swim.
The stroke with a straight arm is more effective than with a lowered elbow. The best stroke will be the one that minimizes the up and down components of the straight arm stroke. The movement begins as in a stroke with a straight arm, but the elbow is higher. During the stroke, it bends, and towards the end it almost straightens.
The arm is mobile in its joints at the shoulder, elbow, wrist joints, in the joints of the hand and fingers. This allows you to place the working planes in the most favorable positions for generating thrust. Example: By flexing the wrist in the first half of the stroke and extending it in the second, the swimmer keeps the palm in a position relatively perpendicular to the surface of the water, which makes best use of the resistance of the water for effective support. In addition, the optimal position of the hand at the exit from the water reduces the influence of the drowning force. The water pressure on the hand is about 70% of the total pressure over the entire hand. The brush is the main element of the mover, its main working plane.
To give the body a greater amount of movement, a sufficiently high impulse of force is needed. This means that it is necessary to choose such a trajectory of movement of the mover, which would ensure continuous contact of the working surface with water. It has the shape of a curve.
The movements of the arms and legs during swimming most often have a rotational and reciprocating-rotational character. In this case, the direction of movement of the brush changes smoothly. The path traveled by the hand in water is 3 times longer than the path traveled by the elbow. The speed of movement of the brush at some moments of the stroke exceeds 4 m per second.
The angle of attack of the hand during the stroke largely determines the effectiveness of the movement. Relative to the trajectory of its own movement, the hand is oriented during the stroke, as a rule, at an acute angle.
If the hand is involved in creating a continuous support on the water, then the function of the shoulder is to transfer the results of this contact with water to the swimmer's body through a system of rigid links in order to move it in a given direction. A rigid system is necessary for the rational transfer of power from one link to another. The system of support links can be shortened and lengthened, change the relative position.
The first half of the stroke in all strokes should be done with the elbows high. A high position of the elbow and optimal rigidity of the hand is facilitated by a slight turn of the hand with the palm outward in the phase of entering the water and capturing water.
Brush position. Five positions of the hand were studied: A - the hand is flat, the fingers are closed; B - the brush is flat, all fingers are closed, except for the big one; G - the brush is flat, the fingers are open; D - the brush is folded in a cup, all fingers are closed; E - the brush is flat, slightly bent, fingers are closed.
The greatest resistance was observed at the position of the hand A. In the other four positions, the resistance decreased according to the order in which they were listed. At hand positions D and E, both frontal (frontal) and additional (vortex) resistance were significantly less.
Why shouldn't you keep your fingers open? With this position of the brush, more effort is expended. Fatigue sets in and the speed of progress drops, especially when swimming long distances.
However, we must not forget that even the best swimmers in the world have flaws in stroke technique. The fact that an athlete, despite these shortcomings, achieves high results is explained by two reasons: 1) due to his exceptional features, developed strength and general physical fitness; 2) the flaws are so minor that they do not affect the result.
2.4. Uniform movement of the driving force. This principle can be called the principle of “continuous movement”. As the body moves forward, it will be more effective to apply force evenly, rather than in waves. Therefore, the crawl on the chest is the fastest of the sports swimming methods.
The stroke technique should, as far as possible, ensure uniform movement of the body in the water. In other words, when swimming, it is necessary to avoid various pauses. With a wave-like change in speed, most of the force that a swimmer could use to overcome the resistance of the water will be spent on overcoming the inertia of the body.
When swimming front crawl and backstroke, the start of the stroke with one hand coincides with the completion of the stroke with the other. In this case, a more even and constant application of forces is ensured. When swimming with a butterfly, the stroke begins immediately after the hands enter the water and any slip at this moment slows down the progress.
When breaststroke after moving the arms forward, it is useful to do a little sliding, which will allow you to better use the speed generated from the movements of the legs. Inertia will help the body to take a more even position, resulting in less resistance. If the slide is too long, then the speed drops, the feet sink into the water and the swimmer again has to expend a lot of effort to acquire acceleration.
2.5. Newton's 3rd law and hand movements over water: some coaches are indifferent to how the arm moves above the surface of the water, since the main phase of the stroke takes place under water. However, in three of the four swimming methods, the preparatory movements of the arms (carrying) are performed above the surface and their mechanics affect the efficiency of movements in general. An incorrect carry causes a disturbance in the rhythm of the arm movements, as a result of which the swimmer performs a stroke that is too fast or slow, forcing it or interrupting it with a pause.
One of the most serious disadvantages of arm movements above water is those that lead to an increase in frontal and additional resistance. If the movements of the arms above the water are performed in a wide swing counterclockwise, then the hips or feet move in the opposite direction.
The muscles involved in carrying the arm are attached to the shoulder. Contracting, they shorten and do their job, causing the body to deviate from the longitudinal axis. This is especially noticeable when swimming with the help of the hands (with a board or rubber circles between the legs). Performing a wide sweep in both backstroke and freestyle strokes causes the feet to move in the opposite direction.
When swimming on your back, it is best to carry it directly over your head - in this case, lateral body oscillations are almost not observed. In front crawl, this is achieved by reducing the radius of rotation of the arm by raising the elbow and bringing the hand as close to the body as possible.
When swimming with a butterfly, the movements of one hand are balanced by the same movements of the other hand.
When analyzing the technique of all swimming methods, it is necessary to refer to Newton's 3rd law, formulated more than 250 years ago. According to it, every action has an equal and opposite reaction. In other words, the reaction is directed in exactly the opposite direction and at an angle of 180 degrees. If the swimmer pushes the water straight down, then the counter forces push him straight up.
If the athlete pushes back with a force of 25 pounds (1 pound equals 453 g) with the hands and 5 pounds with the feet, then the total force propelling the swimmer is 30 pounds.
A number of authors believe that the force created during leg movements is inefficient, it requires large energy expenditures. The question is, what is the role of leg movements when swimming front crawl and backstroke? Recent studies have shown that when swimming at high speed, advancement is created not only due to arm movements, but also due to leg movements (in sprint).
Leg movements provide a horizontal position of the swimmer's body, carry out the function of balance, create traction forces, participate in the general coordination of the swimmer's movements, maintain the rhythmic pattern of movements of all links.
2.6. Momentum transfer principle: the amount of movement is quite easy to transfer from one part of the body to another. This effect is used in many movements that are performed in water and on land. The amount of movement that occurs during the hand “mill” at the start transfers completely to the body and helps the swimmer cover a greater distance after repulsion.
The same can be observed during the movements of the arms above the water when swimming in front crawl, backstroke and butterfly. So, when swimming on your back, a certain amount of movement occurs during circular movements above the water. Immediately before the brush enters the water, the velocity vector is directed downward (point A). If at this moment the hand is braked sharply (point B), then part of the momentum will be transferred to the body. As a result, the shoulders and head will sink into the water. When you watch backstroke swimmers, you may notice that some of them have their head bob up and down as a result of ineffective arm movement technique. To avoid this, the hand must be immersed in water at a speed equal to the speed of its movement above the water.
2.7. Square rule: the resistance a body experiences in water is approximately proportional to the square of the increase in its speed. For example, if an airplane traveling at 100 miles (1 mile equals 1609 meters) per hour develops 1,000 pounds of drag, then doubling its airspeed (200 miles per hour) will experience 4 times more drag. those. about 4000 pounds. The same law applies to the movement of a swimmer in the water.
So, if a swimmer lowers his arm into the water 2 times faster than before, then the resistance increases by 4 times. Therefore, accelerated movements of the hands above the water not only break the rhythm, but also, by increasing the resistance, slow down the swimmer's progress.
What should determine the speed of carrying? A swimmer cannot dip his hand into the water slowly in order to reduce resistance. The speed of the movement of the hand above the water must correspond to the speed of the stroke. Usually the transfer is a little faster, but it's not noticeable. It is difficult to perform a fast movement with one hand over the water while the other is making a slower stroke. Correspondence between the speed of the stroke and the speed of the carry is an important factor that determines the rhythm of hand movements.
When a swimmer increases the speed of movement of his hands in the water, then with the same stroke technique, his propulsive force increases by 4 times. At the same time, from the point of view of physiology, any increase in the speed of muscle contractions is accompanied by an increase in energy consumption by a factor of three. In other words, when the stroke rate doubles, the energy cost increases eightfold. Thus, while the fast-stroking arm increases propulsion, energy expenditure and, accordingly, oxygen consumption increase much faster. That is why swimmers, who are characterized by frequent arm movements, get tired quickly. This also explains why athletes who specialize in swimming in the middle and long distances must swim in a strictly defined and even rhythm.
There is a physical justification for speeds, according to which a person cannot swim in a second more than the length of his own body. But it is not always the case. It is possible and faster, but for this the athlete must not follow the wave that he creates, but planing on its crest. Vladimir Bure is one of the first who managed to “ride” the wave. In other words, he overtook not only time, but also himself. (Turkish, 2002).
When swimming a distance with a certain result, the swimmer will spend less energy if he swims at a uniform speed.
Example:
A swimmer swims a distance of 100 meters in 100 seconds. To overcome each meter of distance, he spends a certain amount of energy, which we will denote by the letter E. Thus, he will spend E 100 \u003d 100 E - one hundred conventional units of energy. Suppose now that the same swimmer swims 100 meters in 100 seconds, advancing unevenly: the first 60 meters in 75 seconds, and the next 40 meters in 25 seconds. The overall result will be the same - 100 seconds, but the energy consumption will be different. For the first 60 m, the swimmer will spend 0.8 2 x 60 = 38.4 conventional units of energy, i.e. less than when he swam in 60 s. For the last 40 m, the swimmer will spend 1.6 2 x 40 \u003d 102.4 E (conventional units). The total energy consumption is 38.4 + 102.4 = 140.8 conventional units.
