Front crawl swimming technique. Swimming technique The main working movement that ensures the advancement of the swimmer
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 markedly.
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 due to 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 intermediate and long distances, must swim in a strictly defined and uniform 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.
SWIMMING IS AN IMPORTANT PART OF HUMAN MOTOR CULTURE. IN ANCIENT GREECE THEY SPOKEN ABOUT THE UNCULTURED PERSON: "HE CAN'T NEITHER SWIM NOR READ". A HEALTHY PERSON, ACCORDING TO THE LAWS OF PHYSICS, CANNOT DROWN IN WARM AND CALM WATER. THE HUMAN BODY IS MORE THAN 60% WATER, AND THE LUNGS HAVE A FEW LITERS OF AIR. STANDING ON YOUR CHEST IN WATER, DRIVE AS MUCH AIR AS YOU CAN INTO YOUR LUNGS AND LIE ON THE WATER. YOUR BODY IS NEAR THE WATER SURFACE. IF YOU START GRADUALLY EXHAUSTING THE AIR FROM THE LUNGS, THE BODY WILL ALSO GRADUALLY SUBMERGE INTO WATER. WITH GREAT WILLPOWER, YOU CAN CONTINUE EXHAUSTING UNTIL THE BODY Sinks TO THE BOTTOM OF THE WATER. THE SPECIFIC WEIGHT OF THE BODY IN INHALATION FOR MEN SWIMMERS IS ON AVERAGE EQUAL TO 0.98 G/CM, AND FOR WOMEN - 0.96 G/CM 3 (WHICH IS EXPLAINED BY THE LARGE VOLUME OF FAT TISSUE IN THE BODY OF WOMEN). ON EXHAUST THE AVERAGE SPECIFIC WEIGHT IS MORE: IN MEN 1.06 G/CM 3 AND IN WOMEN 1.04 G/CM 3. REMEMBER THAT THE SPECIFIC WEIGHT OF FRESH WATER IS 1.00 G/CM 3 AND THAT THE BODY IS SUMER IN WATER CAN DROWN ONLY IF ITS SPECIFIC GRAVITY IS GREATER THAN WATER SPECIFIC WEIGHT. A FLOATING HUMAN IS HIGHER BUOYANCY THAN A STANDING PERSON.
KINEMATICS OF SWIMMING: Crawl 1 - EXIT OF THE ELBOW OF THE LEFT HAND FROM THE WATER; 2 - EXIT OF THE LEFT HAND FROM THE WATER; 3 - PASSING THE ELBOW OF THE RIGHT HAND PAST THE SHOULDER; 4 - THE MOMENT OF COMPLETE IMMERSION OF THE LEFT HAND INTO WATER; THE SECOND HALF-CYCLE IS SIMILAR TO THE FIRST, IT BEGINS WITH THE ELBOW OF THE RIGHT HAND OUT OF THE WATER (ALONG THE R. KHALYANDU). EDUCATION OF CHILDREN START WITH A SIX-STROKE OPTION. OBJECTIVES: Phase I - to lose the forward speed as little as possible, Phase II - to start increasing the speed, Phase III - to increase the speed, Phase IV - to increase the speed as much as possible. Exhalation (when turning the head to the right) is carried out in the III and IV phases of the first half-cycle, and inhalation - in the I and II phases of the half-cycle.
KINEMATICS OF SWIMMING: BRASS 1 – THE BEGINNING OF EXTENSION IN THE KNEE JOINTS; 2 - THE TIME OF RIGHTENING THE LEGS IN THE KNEE JOINTS; 3 - THE END OF THE MOVEMENT OF THE BRUSHES BACK; 4 - THE BEGINNING OF EXTENSION OF THE ARMS IN THE ELBOW JOINTS (BY R. HALJAND et al.) TASKS: PHASE I - INCREASE SPEED, PHASE II - INCREASE THE SPEED AS HIGHER POSSIBLE, PHASE III - MINIMIZE THE SPEED DROP, PHASE IV - LOSE SPEED AS LESS AS POSSIBLE. EXHAUST IS CARRIED OUT IN PHASE II AND BEGINNING OF PHASE III, AND INHALE IS AT THE END OF PHASE III AND BEGINNING OF PHASE IV. FROM THE END OF PHASE IV TO THE BEGINNING OF PHASE II - BREATH HOLDING.
DYNAMICS OF NAVIGATION VERTICALLY DIRECTIONAL FORCES: FORCES OF GRAVITY; PUSHING FORCE; LIFTING FORCE. HORIZONTALLY DIRECTIONAL FORCES - PROMOTING FORCE; Drag force; FORCE OF RESISTANCE TO VORTEX FORMATION. (A PRESSURE DIFFERENCE IS CREATED, WHICH AS LIKE THE BODY IS SUCKED BACK). DURING SLIDING, DOWNING THE SWIMMER'S HEAD INCREASES RESISTANCE BY 8-12%, AND ITS DEVIATION FROM THE OPTIMUM POSITION UP - BY 10-20%; FORCE OF FRICTION ON WATER; FORCE OF RESISTANCE OF WAVE FORMATION; FORCES OF INERTIA.
FORCES ACTING WHEN SWIMMING G - FORCE OF GRAVITY; FT - DRIVING FORCE GENERATED BY THE SWIMMER'S MOVEMENTS; FA - PUSHING (ARCHIMEDOV) FORCE; FIN - INERTIA FORCE ARISING WHEN ACCELERATING AND BRAKING THE SWIMMER'S BODY. FTR - FRICTION FORCE; FB - FORCE OF WATER Drag. FTV - VORTEX-GENERATING RESTORATION FORCE (AND WAVE-GENERATION FORCE ACTING IN THE SAME DIRECTION)
THE VALUE OF THE MIDELEV (FRONT) SECTION OF THE BODY AND THE VORTICATION OF WATER JETS IN DIFFERENT POSITIONS OF A SWIMMER IN THE WATER (ACCORDING TO L.P. MAKARENKO; KONSILMAN)
TOPOGRAPHY OF WORKING MUSCLES EFFECTIVE USE OF ROCKING BY HANDS AND LEGS IS POSSIBLE IF THE SWIMMER'S BODY IS A SUFFICIENTLY RIGID STRUCTURE WHICH IS IN A Streamlined And Balanced Position. THIS IS PROVIDED DUE TO THE STRENGTH OF THE ABDOMINAL AND BACK MUSCLES. THE OTHER MUSCLES OF THE BODY MUST BE RELAXED. WHEN SWIMMING Crawl, THE MOST ACTIVE MUSCLES CARRYING OUT THE BENDING OF THE HAND. THE ACTIVITY OF THE LEGS MUSCLES IS HIGH IN THE BRASS.
THE ENERGY OF SWIMMING FORCES ON WHICH WATER RESISTANCE DEPENDS ARE THE MAIN OF THOSE WHAT A SWIMMER HAS TO OVERCOME. BECAUSE THE DENSITY OF WATER IS 800 TIMES GREATER THAN AIR, SWIMMING REQUIRES A LARGE ENERGY COST AND IS THE LOST ECONOMICAL TYPE OF HUMAN LOCOMATION. EFFICIENCY FOR SWIMERS 1 -5%; FOR GROUND HUMAN LOCOMATIONS - 20 -40%; IN THE GREEN TURTLE, TROUT AND GOLDFISH (10, 14 AND 40%), IN THE HUMAN WITH FINS ABOUT 17%. BRASS (AT A SPEED OF 0.3 - 0.5 M/S) IS 30% MORE ECONOMICAL THAN Crawl.
OPTIMIZATION OF SWIMMING THE MAIN REQUIREMENTS TO THE TECHNIQUE AND TACTICS OF A SWIMMER ARE THE REQUIREMENTS TO MAXIMIZE THE DRIVING FORCE AND MINIMIZE THE SUM OF BRAKING FORCES. IT IS IMPORTANT TO EXCLUDE UNPRODUCTIVE ENERGY COSTS: REMOVE EXCESSIVE MOVEMENTS; CHOOSE THE OPTIMUM PATE OF MOVEMENTS; REDUCE THE BRAKING FORCES; ELIMINATE UNPRODUCTIVE MUSCLE STRESSES. IN SWIMMING, AS IN ANY OTHER SPORT, THE ABILITY TO RELAX THE MUSCLES THAT ARE NOT PARTICIPATED IN THE PERFORMANCE OF PROMOTIONAL WORK IS IMPORTANT. HANDS IN THE AIR REDUCE THE HARMFUL WATER RESISTANCE, AND ALLOWS YOU TO OBTAIN THE START POSITION FOR THE NEXT STROKE MORE QUICKLY, I.E. INCREASES THE PATE OF SWIMMING MOVEMENTS. ON THE OTHER SIDE, BRINGING THE HANDS IN THE AIR DESTROYS THE BUOYABILITY OF THE BODY.
THE LESS THE ANGLE OF ATTACK, THE LESS: THE MIDEL OF THE BODY AND, CONSEQUENTLY, THE FORCE OF LEADAL RESISTANCE; JET SEPARATION SURFACE AND, CONSEQUENTLY, VORTEX FORMATION RESISTANCE FORCE. THE SWIMMER MUST CHOOSE A BODY POSITION AS POSSIBLE HORIZONTAL AND EXTENDED IN THE DIRECTION OF MOVEMENT. TO REDUCE NON-PRODUCTIVE ENERGY COSTS, INTRA-CYCLE SPEED VACURATIONS SHOULD BE DECREASED. THEY ARE SMALLER IN THE CROIL THAN IN THE BRASS. THIS IS ACHIEVED BY THE CONTINUOUS WORK OF THE KROLIST'S LEGS AND THE THAT ONE HAND STARTS THE GRIP STROKE AT THE MOMENT WHEN THE OTHER HAND HAS NOT FINISHED THE PUSH-OFF. ALL OF THE SAYING EXPLAINS WHY CRULS IS A FASTER STYLE THAN BRASS. THE KINEMATICS OF PROMOTIONAL ACTIONS ADOPTED WHEN SWIMMING Crawl PROVIDES LOWER VALUES OF THE FORCES OF THE FRONT RESISTANCE, RESISTANCE OF VORTEX FORMATION AND FORCES OF INERTIA OF THE ACCELERATED AND BRAKED UNITS OF THE BODY.
The “Swimming Techniques” section is divided into four parts: the first contains materials on the basics of swimming training. They will be useful for athletes from other sports preparing for summer polyathlon competitions. Methodological aids cannot completely replace the advice of an experienced coach, however, they will help to avoid many mistakes when preparing for competitions.
The second part highlights more complex methods for improving the technique in the translation of the film “What’s the limit? Alexander Popov.
The third part contains literature on the technique and methods of teaching swimming in various areas: in universities, for children, in triathlon.
Swimming Basics
The swimming technique is described in selected chapters from the book by I. L. Gonchar “Fundamentals and Features of the Technique of Sports and Applied Swimming”:
Front crawl (freestyle)
Body position: the body occupies a horizontal position, the head is lowered into the water, the eyes are open, the gaze is directed forward - down. When swimming, the body rotates along the longitudinal axis of the body up to 30 degrees or more, accompanying the working and preparatory part of the stroke with the hands.
Leg movements: alternating, counter up - preparatory movement and down - whip-like, with the foot from the hip - working. The movements of the legs provide a horizontal position of the body and create a certain traction force that promotes movement in the water.
Breathing: carried out in close contact with the work of the hands. As a rule, at the end of the stroke, the swimmer turns his head to the side with his hand and makes an energetic breath through his mouth while carrying his hand, then turns his head down, and when stroked with his hand, he exhales through his mouth and nose at the same time, which eliminates the possibility of water entering the respiratory tract. Inhalation is usually performed by the swimmer under
"convenient hand" for 2 strokes with hands, for 3 or more - depending on the solution of the tasks.
Movement coordination: when swimming crawl on the chest, coordination of 6 kicks with 2 strokes of hands is distinguished - six-stroke crawl, 4 kicks with 2 strokes of hands - four-stroke crawl, 2 kicks with 2 strokes of hands - two-stroke crawl. The use of these combinations is due to both the individual characteristics of the swimmers and the solution of the tasks at short, medium and long distances.
Front crawl swimming technique(according to D.E. Councilman, 1982)
1 - one arm straightened in elbow joint, starts the stroke. The other, bending at the elbow joint, leaves the water with the elbow up, the legs perform alternating “fluttering” movements up and down. 
2 - the arm performing the stroke is bent at the elbow joint. The elbow is held in a high position. 
3 - the arm performing the stroke is bent at the elbow joint to its maximum angle and is under the swimmer's chest. At this moment, the hand that performs the preparatory movement above the water enters the water in front of the swimmer at the width of his shoulder. 
4 - at the time when the hand has almost completed the stroke, the head turns to the side to inhale. 
5 - while the hand is out of the water, a breath is taken (through the mouth). 
Mistakes in teaching the front crawl swimming method and how to eliminate them
| Mistakes | Causes | Consequences | How to fix |
|---|---|---|---|
| The main mistakes in the position of the body and head | |||
| The head is raised high above the water. The torso is bent. | A high position of the head above the water, due to the fear of lowering the head into the water or the inability to breathe properly | The midsection is enlarged. The drag increases. The necessary coordination is disturbed, as the muscles of the neck shoulder girdle and the backs are very tense | Swimming on one leg, with arms extended forward and head down. Look down or even back. When swimming crawl in full coordination, fix the gaze on the legs: look down - back. Learn to breathe |
| Trunk flexed at the hips | Excessive tension in the muscles of the body | Increased resistance due to incorrect position of the hips | Chest slide exercises with free crawl leg movements |
| The trunk deviates to the left and to the right (wriggles - “prowls”) | The phase of entering the hands into the water is incorrectly performed | The length of the path increases. Increases overall resistance | Strengthen motor skills on land and in water by correct execution exercises |
| The head is strongly lowered into the water | Poor head control. Eyes closed | High pelvic position, inefficient footwork. Difficulty breathing. Resistance rises | Swim with your head up in a series of training tasks. Swim while holding your breath while looking ahead |
| Strong vibrations of the body relative to the longitudinal axis of the body | Inability to balance: A) when turning the head to inhale, the torso performs a strong roll; B) after immersing the hands in the water, the hands go far beyond the midline of the body, and the elbows fall through |
Increases water resistance | Swim with your head held high. Swim with the help of leg movements and one arm extended forward. Swim with holding your breath while inhaling, monitor the start of the stroke. Start the stroke with your elbows raised. |
| Rapid movement of the head to inhale | Untimely turn of the head for inspiration | Breathing failures | Perform training exercises for general coordination of movements in the method with breathing |
| Huge angle of attack of the torso (swimming while standing) | Legs don't work | Significantly increases resistance, decreases swimming speed | Build footwork skills |
| Fluctuations of the swimmer's body in the vertical plane | Strong "vertical component" in arm movements; lack of proper rhythm of movements | Significant resistance increase | Training tasks for setting the stroke, especially the position of the elbow (one of the most important requirements) |
| Mistakes in hand movements | |||
| Mistakes when entering the water | Errors in the preparatory part of the movement. Weak mobility in the shoulder joints | Body vibrations at the level of the shoulder line. Errors in the capture phase | Training tasks on land. Swimming with the help of movements of the legs and one arm, the other arm is extended forward. |
| Too long grip | The desire of swimmers to perform a better catch | Increase in the "vertical component". Decrease in traction force in rowing motion | Take control when performing exercises aimed at improving the technique of hand movements |
| Elbow drop during the middle part of the stroke | The palm as the main working surface does not reach the optimal stroke position. The support is reduced. Increased body vibration | Low level of swimmer's strength training | Include in workout strength exercises on land and in water. Take control of this part of the movement while improving your swimming technique |
| Short stroke | Low level of power readiness of the swimmer. Very high pace of movement | Swimming speed reduction | Work on stroke quality |
| The stroke is performed by the side | Stroke efficiency decreases, hands get tired quickly | Practice rowing movements on the elements in full coordination. At the same time, make sure that the movements of the brush are rectilinear. | |
| Slow stroke | Insufficient development of the muscles of the shoulder girdle and back | Weak traction. Low speed | Special exercises to develop the muscles of the shoulder girdle. Swim short stretches at high speed |
| Wrist lag during stroke | The basic requirement of the stroke is not fulfilled: there is no high position of the elbow | Reduced stroke efficiency, reduced tractive effort | Perform special strength exercises. Focus on improving swimming technique |
| The hand "flops" when entering the water | Errors in the preparatory part of the movement | "Lubricating" the start of the stroke | Fulfill special exercises to study and improve the preparatory part of the stroke on land and in water |
| Carrying over the water with a straight arm | The result of incorrect training or lack of any training | Errors in the stroke, especially in its initial part | Do special exercises |
| Feet hit the surface of the water | Excessive bending of the legs at the knee joints. There is no movement of the legs "from the hip" | Swim with straight leg movements. Practice swimming with a board in your hands. Swim crawl with your head held high | |
| Feet move too deep | Sluggish leg movements | The resistance grows. Decreased swimming speed | Perform specific leg exercises |
| The range of motion is too great | The result of incorrect training | Decreased efficiency of leg movements | Take control of the range of motion in the work on the technique |
| Feet are slightly mobile | Limited mobility in the ankle joints | Decreased efficiency of leg movements | Work on increasing mobility in the ankle joints |
| No movement from the hip | The trainee did not understand the task | Low speed. The appearance of feet on the surface and an abundance of splashes are possible | Work more with straight legs. Swim with a board. Swim with your head held high |
| Stops kicking while inhaling | Motor skill is not fixed | The transmission of momentum from one link to another is disrupted. Resistance rises | Swim more “on one foot”, reinforce the skill of continuous footwork |
| Late breath | Disturbed coordination of hand movements and breathing | The face is immersed in water - breathing is difficult. The entrance to the water and the capture are violated, i.e. stroke start | Practice coordinating hand movements and breathing. Make sure that the breath is performed at the moment when the body is tilted to the side as much as possible, this coincides with the exit of the hand from the water and the beginning of its passage through the air |
| Excessive muscle tension in the arms and legs | Insufficient special training | Rapid fatigue, decreased swimming speed | Performing numerous tasks, while varying the tension of the muscles of the arms and muscles of the legs |
| Long influx after immersing the hand in water | Excessive influx in training | Violation of uniformity in advancement, decrease in the pace of swimming | Perform a variety of hand-eye coordination exercises |
Improving swimming technique
Translation (subtitles) sections of the film "What's the limit? Aleksandre Popov" devoted to the technique of swimming:
- kayak paddle principle and necessary exercises
- The Three R's: Rhythm, Sweep, Relax
- 12 features of starts and turns of Alexander Popov
- interview with coach Gennady Turetsky
Literature
Sheila Taormina, a member of the US national team at four Olympics, talks about how to make the most effective stroke. Underwater photographs of champion swimmers confirm her theory, and descriptions of training exercises allow her to put her new knowledge into practice.
This book presents: material that characterizes the many-sided influence of swimming on the human body; Short story the development of this sport and the technique of sports methods of swimming; "ideal" of an elite swimmer (features of his physique, strength and functional readiness, level of development of flexibility, etc.); modern facilities training of the strongest swimmers (simulators, special pools - hydro treadbahn, special devices for developing strength in water, special swimmer gymnastics complexes), with the help of which record holders and world champions, Olympic champions - Galina Prozumenshchikova, Marina Koshevaya, Vladimir Salnikov, Alexander Popov , Denis Pankratov, Evgeny Sadovy and other famous Russian swimmers.
The manual summarizes the material of the organization of the process of learning to swim and the formation of swimming skills. The manual contains more than 700 exercises for teaching swimming technique.
The tutorial is written according to new program in the discipline "Swimming". Much attention is paid to the methodology of training and teaching swimming, the theory of teaching motor actions is presented in a modern way. The new competition rules approved by FINA, the program for the Youth Sports School were adopted as a basis. Addressed to faculty students physical education universities, will be useful to teachers, coaches, athletes.
The book is mainly focused on preparing for a triathlon. But it will also be interesting in polyathlon, because it outlines the principles of training, their periodization, proper nutrition, endurance building, stretching, recovery, injury prevention.
SWIMMING
1. What was called in Ancient Greece a man who couldn't read or swim?
Answer: such a person was called uneducated.
2. What is swimming?
Answer: the ability of a person to stay on the water (static swimming) and move in the right direction (dynamic swimming).
3. Which of the great Russian commanders paid special attention to swimming in preparing troops for hostilities?
Answer: Alexander Vasilievich Suvorov.
4. When was butterfly swimming included in the program of the modern Olympic Games?
Answer: in 1956 at the Olympics in Melbourne (Australia).
5. When the athletes of our country won the gold medal for the first time Olympic medal in swimming?
Answer: in 1964, at the Olympic Games in Tokyo (Japan), a 16-year-old schoolgirl from the city won the first gold medal in the history of Russian swimming, overcoming the 200 m breaststroke fastest in 2 minutes 46.4 s (Olympic record).
6. At what Olympiad in the unofficial team event did the swimmers of our country manage to become winners for the first time?
Answer: at the Olympics in Mexico City (Mexico) in 1968, our team of swimmers took third place in the team event.
7. Was there a case when our swimmers occupied the entire podium at the Olympic Games?
Answer: in 1976 at the Games in Montreal (Canada), athletes Marina Koshevaya, Marina Yurchenya and Lyubov Rusanova won gold, silver and bronze in the 200 m breaststroke competition.
Answer: the most successful for our swimmers were Olympic Games in 1980 in Moscow. The main hero of the swimming competition was Vladimir Salnikov, who for the first time overcame the distance of 1500 m freestyle faster than 15 minutes (his result was 14 minutes 58.27 s).
9. Which of the Russian swimmers has performed most successfully in recent years?
Answer: quadruple Olympic champion from.
10. What is the fastest way to swim?
Answer: crawl on the chest.
11. What types of swimming include as a kind of motor activity?
Answer: sports, applied, synchronized, underwater, game swimming, diving.
12. What are the main forces acting on a swimmer while swimming?
Answer: gravity (it is directed downwards and drowns a person), water pressure force (directed upwards, this is a lifting force, which, according to the law of Archimedes, is equal to the weight of the displaced liquid and is applied at its center of gravity), water resistance force (prevents the swimmer from moving forward) , traction force (the swimmer develops this force with his active muscle efforts).
13. What movements does a full cycle in the front crawl technique consist of?
Answer: the cycle includes two strokes with the arms (right and left) and six percussion movements with the legs (three with each leg).
14. What is the name of the "folk" way of swimming, the prototype of the front crawl on the chest?
Answer: swimming with seedlings.
15. What is the name of the main movement in swimming that ensures the advancement of the swimmer?
Answer: rowing.
16. What are the ways of sports swimming?
Answer: front crawl, back crawl, breaststroke, butterfly (dolphin).
17. Which of the sports swimming methods is the quietest?
Answer: brass.
18. At what point should a swimmer's legs begin to move when swimming with a breaststroke?
Answer: immediately after the completion of the arm stroke.
19. What are the ways to start swimming?
Answer: start with a jump from the bedside table, start with a push from the wall of the pool.
20. Into what phases is the technique of performing a turn in swimming divided?
Answer: swimming, actually turning, starting position before repulsion, repulsion, sliding, first rowing movements.
21. How to perform a turn when swimming on the front crawl?
Answer: somersault forward.
22. What is studied in swimming first of all - the technique of swimming methods or the technique of performing turns?
Answer: first they master the ways of swimming, and then they learn how to perform turns.
23. From which side is it best to swim up to a drowning person in order to help him?
Answer: it is better to swim up to a drowning person from behind, this is the safest.
24. What grip of a drowning person is the most dangerous for the rescuer and how to get rid of it?
Answer: the most dangerous is the capture of a lifeguard by a drowning man from behind by the torso and hands down, it is best to release from such a capture by a sharp movement of the arms to the sides with simultaneous deep immersion in water.
Answer: at a water temperature below +15 C (with the exception of swimmers specially trained for swimming and hardening in cold water).
26. What should be done first of all if a person rescued from the water has no consciousness, breathing and pulse?
Answer: first of all, it is necessary to free the stomach and airways of the victim from water, for this you need to put him with his stomach on your knee and put pressure on his back.
27. How can the rescuer be freed from the rescuer who is drowning by the hands?
Answer: by turning the hands of the rescuer towards the thumbs of the drowning person.
28. What should a person who cannot swim immediately do when he gets into the water?
Answer: calm down, take a comfortable breathing position above the water, do not make quick chaotic movements, calmly get rid of shoes, clothes, call for help and try to move towards the shore.
29. In which direction is it best to perform exercises when learning to swim in open water?
Answer: towards the coast.
30. How can I eliminate a sudden cramp calf muscle while swimming?
Answer: you need to grab your toes with your hands and pull them towards you several times in a row, and then massage the calf muscle.
31. What should be done before you start swimming in an unknown body of water?
Answer: inspect the bathing area (including the bottom of the pond) and make sure that swimming will be safe.
32. Which capture of a drowning person for his transportation by a rescuer is the most reliable and safe?
Answer: "sea hold", when the rescuer passes his hand under the hand of the drowning person and grabs his other hand by the forearm or elbow, turns the victim on his back and transports him on his side, performing swimming movements with his legs and free hand.
33. Can a competitor sports swimming move from one track to another?
Answer: No, he must only swim in his own lane, otherwise he will be disqualified.
34. In what case is the start in the swim considered to be performed correctly?
Answer: if before the command "March!" or the starting shot, all participants in the swim were motionless.
35. After what number of false starts can the starter referee remove an athlete from the competition?
swimming?
Answer: after the third false start.
36. How many rowing movements with arms and legs can a swimmer perform underwater immediately after starting or turning?
Answer: no more than one rowing movement with arms and legs.
37. Is it possible for a swimmer to pull up on any objects (for example, floating ropes, handrails, ladders, etc.) while passing the distance?
Answer: a swimmer is prohibited from pulling up for any objects while overcoming the distance.
38. Is it considered a violation of the rules of the competition if a swimmer accidentally touches any objects?
Answer: does not count.
39. How is the result of a competitor in swimming determined?
Answer: this result is determined by the time elapsed since the command "March!" (or starting shot) until the swimmer's hand touches the side of the pool at the finish line.
40. Are there any differences in the competition rules different ways sports swimming?
Answer: such differences exist.
41. Is it allowed for an athlete-swimmer to push off from the bottom of the pool during the passage of the distance?
Answer: it is not allowed to push off not only from the bottom of the pool, but also from any other objects.
42. Which swimming method has the fewest restrictions in the competition rules?
Answer: crawl.
FORCES PROVIDING THE PROMOTION OF A SWIMMER Take it to your wall, read it in the evening! The question of what law underlies the advancement of a person in water has not been resolved to this day and is rather controversial. Many believe that Bernoulli's theorem, according to which the lift-creating pressure difference between the back of the hand and the palm provides the movement. This difference, combined with the pressure acting on the arm, creates a net force that propels the swimmer, in other words, a pulling force. The approval of this point of view was largely facilitated by the studies of Brown and Councilman, who concluded that the stroke is performed not strictly backward, but also diagonally. However, there is no less reason to assert that Newton's third law is at the heart of the swimmer's advancement: an action always corresponds to an equal and oppositely directed reaction. In relation to the phenomenon under consideration, the law can be expressed by the following formula: the acceleration that a swimmer gives to his body is proportional to the force with which he repels water. Moreover, the fact that the traction force is mainly provided by the repulsion of water back, and not by its accelerated flow at the back of the arm, confirms the significant difference in this force with different bending of the arm in the elbow joint during the stroke. Otherwise, his degree would not be as significant as it really is. With a diagonal movement of the arms, the swimmer pushes the water back. The brush is at an angle thumb located above the rest, and it is this that mainly ensures the repulsion of water back. The backward force causes, according to Newton's third law, an opposing force equal to it, which propels the swimmer. Thus, both Bernoulli's theorem and Newton's law explain the swimmer's progress, but Newton's law seems to play a more significant role. Progress when swimming well illustrates the principle of operation of the propeller of a boat engine. Although the propeller blades rotate in a circular path, their curved shape ensures that when the water passes from the leading edges to the rear, it moves back, and the boats move forward. On fig. 1.9 clearly shows how similar the movements of the swimmer's arms and the rotation of the propeller blades are: in the initial part of the stroke, or, in other words, when pulling up, the arm moves inward, up and back, and in the final, or in the repulsion phase, outward, up and back . The curvilinearity of the trajectory of the movement of the hands is associated with the provision of greater traction force when repelling slowly moving water. Having accelerated the movement of some of its layers, the hand moves to layers that have not yet been disturbed, and so on. Such a trajectory of movements provides greater efficiency of the stroke and by increasing its length.
