Physiological features of the activities of football players
Physiological features of the activities of football players.
Effective participation in the game depends - in the most general sense - on the psycho-physiological status of the player, which determines his individual characteristics, as well as on high performance, which allows him to endure intense competitive and training loads. Experts of physiology, biochemistry, and also sports medicine, analyzing such dependencies, came to the conclusion that the number of main indicators characterizing the intensity of the load in football should be attributed primarily to the level of energy consumption by the player during the game itself. The intensity of metabolic transformations is expressed at the same time in calories or in the amount of oxygen consumed.
It is known that when consumed (consumed) 1 l of oxygen in the body, about 5 kcal is released. Energy costs and oxygen demand in the game of football are, respectively, 0.18 kcal / kg min and 37 ml / kg min. A high level of metabolic transformations and a large variety of movements that characterize football, on the one hand, have a comprehensive effect on the body, and on the other, they impose huge demands on athletes.
Studies of changes in the basic physiological functions of highly qualified football players showed that during the game 60-80% of the time they work in the mode of 80-100% of the maximum oxygen consumption (MPC), which places increased demands on the aerobic abilities of football players. The average oxygen consumption per game for highly qualified football players ranges from 3.3 to 4.5 liters per minute. The magnitude of energy consumption for 90 minutes of the game is 1490-1980 kcal. According to the existing classification (I.V.Zimkin and others), the game of football with its energy consumption can be attributed to a very significant work.
The volatile nature of the loads in football forces the player to put anaerobic (oxygen-free) energy potential into action. This often leads to an increase in the level of lactic acid in the blood, which can reach very high values - 120-150 mg%. At maximum loads, the amount of lactic acid in the blood and muscles increases by 30-50%, and such loads for 90 min of the game amount to about 10%.
Such high values of energy consumption of football players during the game are possible with an increase in the work of the cardiovascular system of the body by 8-12 times compared with its activity at rest.
The heart rate (HR) of the players during the game varies within fairly wide limits: from 200 beats per minute. The average heart rate (depending on the game role) in the game reaches values from 163 to 177 beats / min.
Forwards, most of the other players work in the activity area with a heart rate above 180 beats / min (up to 40% of the total playing time); For mid-line players, gaming activity in the 160-180 beats / min mode is more typical (74% of the total playing time). The game of defenders (especially “free”) is the least intense in this respect.
The pulse cost of the game of football players during the two halves of 45 minutes is 14,500 - 16,000 heartbeats. At the same time, the power zones in which the players have to work during the game are very wide (Table 1). In addition, the heavy loads carried by players during a football match enhance the respiratory system and circulatory system. The respiration rate increases to 30-50 breaths per minute, ventilation of the lungs to 60-110 l / min, and the minute volume of the heart to 15- 25 l with a pressure from 170/65 to 200/50 mm. Hg Art. At the most intense moments of the game, up to 4-5 liters of oxygen per minute is transported to tissues, and oxygen debt reaches a value of 10-20 liters.
During the game there is a large loss of fluid by the body, due to excessive sweating. Weight loss by players during the match is on average 2.5-3 kg. It is believed that a football match causes significant changes in the body of football players and the normalization of the functions of the players after particularly intense games is 48-72 hours.
It should be emphasized that during the game the activity of a football player is not limited to movements with and without the ball. Many situations manifest themselves and are not reflected directly in the motor activity, but in mental processes and often have a decisive influence on the effectiveness of the game of a football player and his team.