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Physiology and Sports

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physiology and sports physical education class 12

Physiology and sports

Sports physiology is the study of the lengthy-and brief-time period effects of training and conditions on athletes. This specialised  field of study is going hand in hand with human anatomy. Anatomy is all about structurewhere physiology is about function.

Physiological factors determining strength

  1. The size of the muscle-The strength of the muscle depends on the size of the muscle.It is well-known fact that  bigger muscles produce more force. The force produced by the same size of muscle in men and women is approximately same  but men are found to be stronger because they have larger muscles and bigger muscles in comparison to females. The size of muscles can be changed with the help of strength training such as weight lifting. So, strength is determined by the size of the muscle.

  2. Body weight- There is a positive relationship between body weight and  strength. Heavier the weightlifter , heavier it will lift the weight.

  3. Muscle composition-Muscle composes of two types of muscles which are fast twitch fibres(white fibres) and slow twitch fibres (red fibres).Fast twitch fibres are capable of contracting  faster and therefore they can produce more force.Whereas slow twitch fibres are capable of contracting slowly but they can hold the contraction for a long time. SO strength also depends on the composition of muscle.The composition of muscles cannot be changed by training and are genetically determined.

  4. The intensity of nerve impulse- Our muscles comprises of many motor units (units responsible for contraction of muscles) .When the signal is released from the central nervous system , motor units start to work and muscle begin to contract. The contraction of muscles depends on the intensity of nerve impulse received from the central nervous system.So the intensity of nerve impulse also determines the amount strength.

Physiological factors determining speed

Speed is one of the important components of physical fitness which is determined by following factors:

  1. The mobility of nervous system- Mobility of nervous system means excitation and relaxation of motor units which causes contraction and relaxation in muscles.The mobility of nervous system takes place in events such as sprinting , running etc. (See this link know the difference between sprinting and running). After few seconds the excitation spreads to nearby centres causing the whole body to be stressed. This leads to the reduction of speed of the player. The mobility of nervous system can be increased up to a certain extent by training.
  2. Muscle composition-Muscles compose of  two types of fibres fast twitch fibres and slow twitch fibres (Learn more about fibres here). Fast twitch fibres are able to contract faster and slow twitch fibres contract slowly. fast twitch fibres are capable of contracting faster whereas slow twitch fibres are capable of contacting slowly . So the type of muscle composition also determines speed. Muscle composition cannot be changed , they are determined genetically.
  3. Explosive strength-  Explosive strength is vital for every quick and explosive movement. Such movements include a quick punch in boxing,weight lifting, sprinting etc.  Explosive strength depends on muscle composition,muscle size, metabolic process and muscle coordination. All factors that determine explosive strength can be improved by training except muscle composition (it is determined genetically and cannot be modified). 
  4. Flexiblity- It is the ability of  the body to bend without breaking any joint, ligament or tendons. There is a negative relationship between elasticity(flexibility) and inelasticity (non- flexible).Flexibility allows maximum range of movement without internal resistance.
  5. Bio-chemical reserves and metabolic power-  For muscles to work continuously with high speed , it requires more energy so that the demand of energy keeps on fulfilling until the player stops. For this purpose  adenosine triphosphate (ATP) and creatine phosphate (CP) stores in the muscles should be enough. In case energy gets depleted, then the speed of contraction of muscles decreases which also leads to the reduction of speed.The amount of ATP, CP can be increased by training. 

Physiological factors determining endurance

EnduranceEndurance is the ability of the person to do sports movement with the desired quality and speed under the condition o fatigue.It involves a large number of muscles.In all sports , directly or indirectly endurance is used.It is usually measured by a number of repetitions.

  1. Aerobic capacity - To maintain momentum , muscles need energy which can be supplied in the presence of oxygen.Therefore , the ability of the organisms to maintain the adequate supply of oxygen to the working muscles for energy liberation is important for endurance performance.The aerobic capacity depends on following factors: 
  2. Oxygen Intake- It refers to intake of oxygen from the oxygen from the atmosphere.  It further depends on lung size, active alveoli, the strength of respiratory muscles, the size of chest cavity etc.
  3. Oxygen transport- After intake of oxygen , another task is to transport the oxygen to various parts of the body . It depends on the amount of oxygen absorbed from lungs and ability of the circulatory system to carry it quickly to working muscles. It also depends on haemoglobin count in blood, the more the count, the more the oxygen will be carried and vice versa. The general concentration of haemoglobin in the body of the sportsperson is 14%-15%.The concentration of haemoglobin cannot be increased by training.The transportation of oxygenated blood depends on the capacity of the heart, which can be increased by  training.
  4. Oxygen uptake-The amount of oxygen which can be absorbed and consumed by working muscles from the blood is  called  is called oxygen uptake. It depends on the rate of diffusion which further depends on the speed of blood flow, temperature and pressure of oxygen in the blood. The speed and amount of oxygen consumption also depend on the number , size and capacity of mitochondria and these factors can be improved through training.
  5. Energy reserves- Aerobic capacity further depends on energy reserves for getting the energy to muscles.Therefore ,the aerobic capacity depends on upon the muscle glycogen and sugar level in the blood. If the glycogen falls below the certain level , then fatigue occurs. For long duration activities , the muscle glycogen and liver glycogen reserves are important. In extraordinary long duration activities, fats can also be used as energy fuel. It exists in such amount that it cannot be exhausted easily. Hence, it is not a limiting factor for endurance performance.


  • Lactic Acid tolerance- When oxygen cannot be used as a source of energy then body uses glucose to get energy through a process called glycolysis. When the body has plenty of oxygen, pyruvate is shuttled to the aerobic pathway to be further broken down for more energy. But when oxygen is limited, the body temporarily converts pyruvate into a substance called lactate, which allows glucose breakdown--and thus energy production--to continue.The ability to tolerate a higher concentration of lactic acid is a significant factor in determining anaerobic capacity. The lactic acid tolerance is important for activities that last for  about 40 seconds or more . The lactic acid tolerance capacity can be improved through  training. So, it can help in improving performance.
  • Movement economy- Position of the head, torso, shoulders, arms , hips, legs, ankles should be in a proper position to reduce the energy consumption. This is known as movement economy. It helps the player to do activity for a long time with limited energy. Proper position of the head, torso, shoulders. arms, hips, legs, ankles can be seen here.
  • Muscle composition- Muscles compose of  two types of fibres fast twitch fibres and slow twitch fibres . Fast twitch fibres are able to contract faster and slow twitch fibres contract slowly.Slow twitch fibres are best used for aerobic activities or endurance activities. They produce the small level of force for long periods of time and that is why they are better suited for endurance activities. In fact, it is found that elite marathoners have 90% slow twitch fibres in muscles of the leg. So the type of muscle composition also determines endurance. Muscle composition cannot be changed , they are determined genetically.

Physiological factors determining flexibility

The ability to bend easily without breaking is known as flexibility.Flexibility depends on various factors. Some of the factors can be modified by training but some of them are genetically decided.Factors which determine flexibility are :
  1. Type of joint- Human body has many types of joints. Some of them favour for the small range of movement whereas some favour high range of movements.For example , ball and socket joint has more range of movement than the knee joint.
  2. Age and Gender-With the increase in age, flexibility decreases. The reason for the decrease in flexibility is, many body parts start to contract which does not allow flexibility. However, the body can be made flexible again with the help of  training. Gender also determine flexibility. Women are found to be more flexible than men.
  3. The stretchability of muscles- The length and stretchability of muscle also determine the flexibility of player. For joints to do some movement,  muscles require doing some contraction. If muscles are not doing some stretching for a long period of time, their size decreases which eventually affect stretchability. The stretchability of muscles can be modified by training .
  4. Body temperature- Body temperature also determines the flexibility of player. A hot bath improves flexibility whereas a cold bath decreases flexibility.
  5. Past injury- After an injury , injured part grows thick .The tissues which cause thickening are known as fibrous tissues. Fibrous tissues are less elastic and can lead to limb shortening and decrease flexibility.

Effects of exercise on Cardio-Vascular System

Organs (heart,lungs,kidneys and brain) ,arteries, veins and capillaries which transport nutrients and oxygen to the various body of parts forms cardiovascular system. The cardiovascular system is responsible for transporting oxygenated blood to parts and transporting deoxygenated blood to lungs back.
Effects of exercise on cardiovascular system are:
  1. The increase in the size of heart- After performing an exercise for a long time the strength and size of heart increases. In fact left ventricle adapts the most. Heart walls grow thick and strong.
  2. The decrease in resting rate- regular exercise for a long period of time decrease the resting rate of the heart. It is observed that after a period of 10-week training , resting rate reduces from 72 beats per minute to 60 beats per minute. After exercise efficiency of the heart increases.While at rest it can pump more blood in fewer beats.
  3. The amount of blood pumped increases-  Stroke volume  (amount of blood pumped with the single heartbeat) increases. Normal stroke volume of males is found to be less than that of athletes or players.
  4. The increase in cardiac output at rest- The amount of blood pumped in one minute.Regular exercise is helpful in increasing cardiac output of the heart. The players who regularly exercise are found to have the cardiac output of 25-35 litres per minute whereas the cardiac output of untrained individuals is 14-20 litres per minute. 
  5. Better supply of blood- To meet energy requirement of muscles, capillaries  increases, widens so that blood can provide energy to muscles properly.Because of this , blood supply becomes more efficient and effective,
  6. Decreased blood pressure- After doing regular exercise for a period of time, blood pressure decreases. Hence reducing the chances of heart attack.
  7. The increase in blood volume- After exercising for a period of time , blood volume increases. Blood composes of plasma,platelets, white blood cells and red blood cells. After doing exercise plasma(contains urea, water, minerals, glucose,patients,fats etc) and red blood cells (contains haemoglobin which help in transporting oxygen) increase to meet the increasing demand of energy and nutrients of muscles.
  8. Reduced heart diseases- Regular exercise develops capillaries, the heart becomes strong, blood flow in arteries,veins increases. High blood flow in arteries and veins prevent stress hormones to accumulate. This also prevents plaque ( a substance that  builds up and harden arteries walls) to accumulate that can lead to coronary heart diseases.Hence reducing the risk of heart disease.

Effects of exercise on respiratory system

  1. Increase in tidal air capacity- Tidal air capacity is the amount of oxygen flows in and out of the lungs in each respiratory movement. It has been observed that tidal air capacity can be increased after doing regular exercise.
  2. Decrease in rate or frequency of respiration- When a normal person starts exercising then his rate of respiration but as he continues to do exercise for a long period of time, his rate of respiration decreases.
  3. Strengthens muscles- Regular exercises helps to the over functioning of lung's muscles of the diaphragm which makes them flexible and strengthens them.
  4. Second wind is rarely felt- Second wind is a condition in running or jogging when a person is too out of breath. Initially it is a crucial stage but afterwards, the respiratory system adapts automatically and an athlete does not feel it .
  5. Activates alveoli- Due to bad lifestyle, our alveoli become inactive because of the lesser requirement of oxygen but when a person starts doing exercise , his lungs work hard to meet the oxygen requirements of the body and ultimately activates alveoli.
  6. Increases residual air volume- Residual air volume is the amount of air left in the lungs after the exhalation. When a person starts to do exercise , his residual air volume increases.
  7. The increase in the size of lungs and chest- When someone does some exercises , his body requires more amount of oxygen than at normal (rest) state. Due to which lungs inhale more oxygen and heart pumps more blood to meet the demand. 
  8. Prevent diseases- When we don't do  any exercise , our lungs reduce the efforts to prevent energy loss. This causes the waste products to stick inside the lungs.To get it clean regularly , we should do exercise regularly.
  9. Increase in vital air capacity- It is the amount of oxygen inhaled and exhaled with maximum effort. In a normal human being it varies from 350cc to 4500cc but in athletes it increases to 5500cc.
Effects of exercise on the circulatory system

Components of the circulatory system include Heart, Lungs and Arteries, Viens. The role of heart is to pump blood so that oxygenated blood and deoxygenate blood can be delivered to their respective organs on time ( oxygenated blood will be pumped to organs from lungs and deoxygenated blood will be pumped back to lungs ). The tubes or vessels which transfer blood are called as arteries and veins. The role of lungs is to provide oxygen to the deoxygenated blood so that it can be sent back to muscles.Thus effects of exercise in lungs, heart and arteries,veins will be counter under the topic of effects of exercise on the circulatory system.

  1. Activates alveoli- Due to bad lifestyle, our alveoli become inactive because of the lesser requirement of oxygen but when a person starts doing exercise , his lungs work hard to meet the oxygen requirements of the body and ultimately activates alveoli.
  2. Increase in tidal air capacity- Tidal air capacity is the amount of oxygen flows in and out of the lungs in each respiratory movement. It has been observed that tidal air capacity can be increased after doing regular exercise.
  3. Decrease in rate or frequency of respiration- When a normal person starts exercising then his rate of respiration but as he continues to do exercise for a long period of time, his rate of respiration decreases.
  4. Strengthens muscles- Regular exercises helps to the over functioning of lung's muscles of the diaphragm which makes them flexible and strengthens them.
  5. The increase in the size of heart- After performing an exercise for a long time the strength and size of heart increases. In fact left ventricle adapts the most. Heart walls grow thick and strong.
  6. The decrease in resting rate- regular exercise for a long period of time decrease the resting rate of the heart. It is observed that after a period of 10-week training , resting rate reduces from 72 beats per minute to 60 beats per minute. After exercise efficiency of the heart increases.While at rest it can pump more blood in fewer beats.
  7. The amount of blood pumped increases-  Stroke volume  (amount of blood pumped with the single heartbeat) increases. Normal stroke volume of males is found to be less than that of athletes or players.
  8. The increase in a number of capillaries- Number of capillaries increase and become more and more active to provide oxygenated blood to all muscles. 

Ageing

Ageing is a process which is characterised by degeneration of organs  and various systems respectively. Ageing depends on genetics, diet, environmental conditions, pollution, radiation. This process continues to grow and cannot be stopped.

Changes in body due to Ageing
  1. Change in muscle and strength- Size of muscle decreases and overall body fat increases. Due to above two changes , muscle strength also decreases.
  2. Metabolism and body composition- Due to increasing age, body requires less energy and metabolism slows down. Consequently, there is an increase in body fat and lean body weight (tendons,ligaments,tissue,tendons,muscle and water) decrease.
  3. Bone Density- It results in the decrease in bone density. This happens due to the shortage of minerals in the body. The bones become denser or more prone to injuries. The decrease in bone density begins in the early forties.
  4. Changes in respiratory system- The elasticity of lung muscles decreases and it leads to decrease in efficiency of lungs as well. Oxygen uptake  and oxygen exchange decrease.Ability to breath deeply decreases due to a reduction in elasticity of muscles. Pulmonary oxygen is reduced which leads to reduced endurance with shortness of breath and fatigue. it can be said that tidal volume, vital capacity, lung capacity are decreased, whereas residual volume is increased.
  5. Changes in cardiovascular system -Cardiovascular system composes of lungs, heart and blood vessels. With the advancing age, there is a progressive reduction in the elasticity of cardiac muscle strength. Stroke volume, cardiac output and blood flow are decreased with age. Blood vessels( arteries and veins) also lose their elasticity.There is less nourishment of cells in the body. Heart valves become rigid.
  6. Changes in the nervous system- Researchers and observations show that there is a decrease in reaction time and movement time with the increase in age.The weight of brain, growth of nerve endings and network of the nervous system decreases . It also makes it difficult for a person to recall memories.
  7. Changes in Digestive system or Gastrointestinal system- There is a decrease in the production rate of HCl (Hydrochloric Acid), digestive  enzymes and saliva. This results in the decrease in digestion and decrease in appetite. The efficiency of lungs decreases along with repairing damaged liver cells.
  8. Changes in urinary system or excretory system- Excretory system consist of kidneys, bladder, ureter, urethra. Due to ageing , the mass of kidneys decreases , the capacity of bladder decrease. The process of filtration of blood decrease. There is an increase in residual urine.
  9. Change in flexibility- Due to ageing , spinal cord decrease in length which also leads to the reduction in flexibility. There is also increase in reduction in flexiblity of tendons and ligaments.

Role of regular exercises on Ageing

  1. Reduce the loss of muscle mass- Muscle mass decreases with advancing age.Ageing has a negative impact on metabolism.Regular exercise decreases the loss of lean body mass and loss in metabolism rate. Regular exercise also reduces the accumulation of fats.
  2. Maintaining bone density- Due to advancing age, digestive device and kidneys lessen their tactics which cause them to incomplete extraction of nutrients and minerals (vitamin d helps our body to soak up calcium)  from meals which cause the reduction in bone density. doing physical activities often continues the digestive machine and excretory system wholesome which in turn hold bones sturdy.
  3. Diseases- Sporting activities helps us to shield towards numerous illnesses including diabetes,weight problems, hypertension and so forth.
  4. Improves muscle strength- Exercises increase the size of muscle which ultimately increases muscle strength.
  5. Enhances the capacity of lungs- Regular exercise enhances the capacity of lungs. It reduces the loss of elasticity of the lungs and chest wall. It plays a key role in keeping the chest strong. Regular exercise increases oxygen uptake and oxygen exchange.
  6. Improves flexiblity-Regular exercises improves the elasticity of tendons,ligaments, and joint capsules.Exercise decrease the stiffness of joints. In this way there is increase in  flexiblity.
  7. Reduces stress and tension- Regular exercise has a unique capacity to exhilarate and relax to depression and reduce stress and tension. In fact, regular exercise reduces levels of body's stress hormones such as adrenaline and cortisol Regular exercise also stimulates the production of endorphins, the body's natural painkillers and mood elevators. Such benefits of exercise help in delaying the ageing process. 
 It can be concluded that regular exercise can play a very effective role on ageing process because it has an ample benefits which usually help in delaying the ageing process. It is a well established fact that no one can stop the clock of ageing as it is inevitable but physical exercise can slow its tick.


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