Physiology and Injury in Sports class 12 Notes

Physiology and Injury in Sports class 12 Notes

•PHYSIOLOGICAL FACTORS DETERMINING PHYSICAL FITNESS

(A) PHYSIOLOGICAL FACTORS DETERMINING ENDURANCE

Endurance is an ability to withstand fatigue. It is of two types :
Aerobic and Anaerobic endurance. Endurance is an important component of physical fitness. The physiological factors which determine endurance are :

(i) Maximal Oxygen Uptake : Maximum / Maximal Oxygen Uptake /intake (VO₂ max) refers to the highest rate at which Oxygen can be taken up and consumed by body during intense exercise. Thus, this enhanced oxygen utilization during exercises will improve mitochondrial respiration and subsequently endurance improves.

(ii) Pulmonary Diffusion : Pulmonary diffusion is the exchange of oxygen and carbon dioxide between lungs and the blood. More and faster pulmonary diffusion improves the

endurance.

(iii) Cardiac Output : Cardiac output is the ability of heart to pump out blood in one minute. Cardiac output helps to circulate blood to working tissues, thus endurance is enhanced.

(iv) Lactate Threshold : Lactate threshold is the ability to tolerate the lactic acid in blood produced during anaerobic activity. Better lactate threshold delays fatigue and tiredness, thus endurance improves.

(v) Aerobic Capacity : It is the capacity of an individual to work for long duration with slow speed. This ability improves with regular exercise.

(vi) Blood Volume and Flow : Endurance activities need sufficient amount of oxygen and nutrients which are transported by blood. The regular training increases the haemoglobin in red blood cells and increases blood plasma by which endurance is boosted.

vii) Hydration : Endurance activities cause sweating and loss of important minerals. Thus, sufficient amount of water is required which helps to improve endurance.

(viii) Red Muscle Fibers : The red muscle fibers (slow-twitch muscle fibers) can carry more oxygen, thus helpful for aerobic endurance. Thus, the higher percentage of red muscle fiber increases endurance.

(B) PHYSIOLOGICAL FACTORS DETERMINING STRENGTH

Strength is the ability to resist or overcome resistance. It is of three types : Maximal Strength, Explosive Strength and Strength endurance. Factors which affect the strength are :

(i) Muscles covering Sarcolemma : The muscle fibers covering ‘Sarcolemma’ bind the muscles to work together. The Sarcolemma covering increases the muscle cross-sectional area and helps in strength component.

(ii) White Muscle Fibers : White muscle fibers (fast twitch muscle fibers) have more connective tissues and they bring fast and strong contractions. Greater percentage of white muscle fibers help in explosive strength.

(iii) Muscular Contraction : Muscular contraction is of two types : Concentric and Eccentric. It regulates our muscular action in controlled manner. It helps in accuracy and efficiency of movement, thus helpful in strength development.

(iv) Muscle Length : Every muscle is of different size. Long muscles have more potential of strength as compared to small muscles.

(v) Myoglobin : Myoglobin is a type of protein present in muscle fibers to store oxygen which produces energy during emergencies. Thus, higher myoglobin increases the strength of individual.

(vi) Nerve Impulses : Nerve impulses are the brain messages to skeletal muscles to respond. The strong nerve impulse brings powerful contraction of muscles thus the strength is higher.  The intensity of neuromuscular responses (impulses) determine strength.

(vii) Adequate Energy : The muscular movements need sufficient energy. Greater number of mitochondria in muscle fibers produces more energy and stronger and longer muscular contraction.

(viii) Age : Strength of muscles is maximum between 20 to 40 years of age and then gradually weakens.

(ix) Gender : Men have more strength as compared to women due to bigger and longer muscle length.

(x) Body Weight : Body weight is also related with strength of an individual.

(C) PHYSIOLOGICAL FACTORS DETERMINING SPEED

Speed is an ability to do work at faster rate. It has three parts : Reaction time, Acceleration, and Speed of Movement and Locomotors Ability. Speed basically depends upon heredity (80%) and good training (20%). It also depends upon strength, endurance, flexibility and coordinative ability. The physiological factors which determine speed are :

(i) Fast Twitch Muscle Fiber : The greater the percentage of fast twitch muscle fibers (white muscle fibers), faster is the speed.

(ii) Neuromuscular Responses : Higher and faster the neuromuscular responses (motor impulses), faster and stronger is the muscle contraction, thus gains speed.

(iii) ATP Energy Store : Greater the ATP storage (Phosphates stores), faster is the energy release for speedy and anaerobic activities.

(iv) Flexibility : Higher the flexibility, more is the range of movement, thus helpful in speed.

(v) Anaerobic Capacity : An anaerobic capacity increases the short term endurance of an individual, it also improves the speed ability of an individual.

(vi) Coordinative Ability : Speed is also dependent on coordinative ability.

(D) PHYSIOLOGICAL FACTORS DETERMINING FLEXIBILITY

Flexibility is an ability of joints to move in maximum range. Flexibility is of two types : Passive flexibility and Active flexibility. Following physiological factors determine flexibility :

(i) Joint Articulation : The joint structure or articulation is the main factor of flexibility. It is attached to various muscles, ligaments, cartilages and tendons. It makes the joint strong and
flexible.

(ii) Ligament Elasticity : Ligament connects two or more bones around the joint. More the elasticity of ligaments, greater is the flexibility of the joints.

(iii) Muscle Stretch ability : Higher the muscle stretch ability, more is the range of joint movements, thus helpful in flexibility.

(iv) Disease or Injury : Many types of diseases affect flexibility like Parkinson’s, a Rheumatoid Arthritis etc. Injury also affects the flexibility of individual.

(v) Age : Children have more flexibility than adults. Age is directly related with flexibility.

(vi) Gender : Females have more flexible body than males due to anatomical structure.

•Effects of Exercise on Cardio-respiratory system

Cardio-respiratory system is the combination of Circulatory and Respiratory systems. It helps to provide oxygenated blood to working muscles (during exercise). This oxygenated blood reaches to working muscles through blood vessels like arteries, arterioles, veins etc. Thus, it is the system which provides energy to bodyduring exercise.

(A) SHORT TERM EFFECTS ON CARDIO RESPIRATORY SYSTEM

(i) Increased in Cardiac Output : Cardiac output is the amount of blood pumped out in one minute, i.e. it is the product of stroke volume by heart rate per minute. Regular training increases the cardiac output. Thus, more blood is pumped out from heart for the working tissues.

(ii) Return of Normal Pulse Quickly : The pulse or heart rate returns to normal quickly after exercise. Thus, body feels relaxed after some time.

(iii) Faster Adaptation to Working Load : In a trained person, the heart can adapt to working load quickly, i.e. quick adjustment of heart according to body needs.

(iv) Maximal Oxygen Uptake Ability Increases : It is the maximum amount of oxygen utilized by body during exercise. The alveoli efficiency improves, i.e. maximal oxygen uptake ability increases. Thus, more oxygen reaches the working tissues for energy production during stressful activity.

(v) Increase in Vital and Tidal Volume : With regular exercise the Tidal Volume (volume of air inhaled / exhaled during normal breathing) and Vital Capacity (maximum amount of air
exhaled after deep inspiration) of lungs increase, by which more oxygen reaches to working tissues.

(vi) Faster Removal of Waste : There is faster removal of waste products from the body; moreover, there is better defence against diseases, germs, etc.

(vii) Hydro-Balance in Body : The water/hydro balance in body is maintained through exercise. Thus, dehydration can be delayed.

(viii) Decrease in Blood Viscosity (Density) : The blood viscosity decreases, i.e. plasma content increases. Therefore, there is an easy and fast flow of blood through capillaries, moreover,  faster circulation of blood.

• EFFECTS OF EXERCISE ON MUSCULAR SYSTEM

(A) SHORT TERM EFFECTS ON MUSCULAR SYSTEM

(i) Efficiency Improvement : As a result of regular exercise, there is an increase in the number of capillaries in muscles. By this, there is increased and faster circulation of blood, thus it improves the efficiency of muscles.

(ii) Increased Muscle Temperature : During exercise muscles demand energy, which comes from contracting muscles.

(iii) Accumulation of Lactic Acid : Muscles require oxygen. If blood supply does not provide appropriate volume of oxygen to muscles, it leads to accumulation of lactic acid in muscles which result in pain, and soreness in muscles.

(iv) Increased Muscle Flexibility : Due to increase in blood flow and rise in temperature, elasticity of muscles increases. Stretching and mobility exercises also play a dominant role in increasing muscular flexibility.

(B) LONG TERM EFFECTS ON MUSCULAR SYSTEM

(i) Hypertrophy of Muscles : Regular exercise brings hypertrophy of muscles, thus increases the muscle mass, i.e. increase in myoglobin content of muscles and control weight of a person.

(ii) Gain in Strength : With regular exercise there is gain in muscular strength and power. This gain of strength is the result of thickening of sarcolemma and strengthening of muscles, ligaments and tendons.

(iii) Lactate Threshold Increases : Regular exercise increases the ability of muscles to tolerate more lactic acid for longer duration, i.e. lactate threshold increases, thus muscles delay tiredness and fatigue. It improves anaerobic endurance.

(iv) Increase in Glycogen Storage : Glycogen is generally stored in muscles and liver. Regular exercise helps the body to increase the storage of glycogen which may give continuous energy.

(v) Increase in Aerobic and Anaerobic Endurance : A trained muscle has more aerobic endurance, therefore, its capacity to work for longer duration without fatigue, is improved.

(vi) Increase in Size and Number of Mitochondria : Aerobic exercise leads to increase in size and numbers of mitochondria which take in more oxygen and produce more ATP and energy.

(vii) Proper Shape of Body : Regular exercise provides proper shape to the body, thus improves physical personality; moreover, removes excessive fats from muscles.

MEANING OF SPORTS INJURIES

Every person is prone to injuries or accidents, irrespective to preventive steps physical fitness level or safety measures. Sports Injuries are referred as all those injuries which occur to individual during participation in sports or on playfield or during competition or in day today life during movement. It may be over the skin, muscle, bone or in combination. It causes pain, restriction to movement or physical demage to organ or impairment to performance etc. It may be due to incorrect movement, jumping, throwing, hitting, colliding, equipment failure, lack of warming-up, faulty skill action, over training etc. Sports injuries require specific first-aid; treatment steps or remedies.

According to Morris : “An athletic injury is defined as some physical damage to the body that occurs during athletic practice or competition causing a resultant loss of capacity or impairing performance.”

Sports medicine is also known as exercise medicine. It is the branch of medicine that deals with the diagnosis, treatment and prevention of injuries related to sports. It includes the assessment and management of patients with musculo-skeletal injuries and medical problems arising from sporting activity.

5. (B) CLASSIFICATION OF SPORTS INJURIES

Sports Injury are those types of injuries that occur during participation in sports or games, training or competitions. In sports, injuries are common and it can occur to anyone at anytime. Injury causes damage to any part – external or internal, which affects the health of an individual. Injuries can be classified as :

(I) SOFT TISSUE INJURIES : It is further of two types :
(a) Skin Injuries : It is an injury over skin like Contusion, Abrasion, Laceration, Incision, etc.
(b) Muscle Injuries : In this injury the muscles, tendons and ligaments are affected like Sprain, Strain etc.

(II) HARD TISSUE INJURIES : These injuries involve damage to bones of skeletal system like Fracture and Dislocation.
Injuries are further categorized as Minor injuries and Serious (Major) injuries.

MINOR INJURIES

These injuries do not affect much to the fitness of a player. They are less painful. The pain vanishes after sometime. In minor injuries, there is localized inflammation caused due to some damage over skin or muscles tissues. These injuries are caused by overuse of affected part. The patient gets relief by taking sufficient rest. In some cases, specific treatment is also required.

SERIOUS INJURIES

These injuries causes lot of pain and localized inflammation around the affected part. In these injuries, the health is affected and it declines the performance of a player. In serious injuries skin, muscle, tendons, ligaments and bones are damaged along with rupture of blood vessels or nerves etc.