CBSE Textbook: Physiology and Injuries in Sports | Physical Education Class 12(XII) - Notes & Model Test Papers - Humanities/Arts PDF Download

 Page 1


227
Physical EDUCATION-XII
UNIT 
VII
PHYSIOLOGY AND INJURIES 
IN SPORTS
Overview
 W Physiological factors determining components of Physical Fitness
 W Effect of exercise on Muscular System 
 W Effect of exercise on Cardio- Respiratory System
 W Physiological changes due to ageing
 W Sports injuries: Classification (Soft Tissue Injuries – Abrasion, Contusion, 
Laceration, Incision, Sprain & Strain; Bone & Joint Injuries - Dislocation, 
Fractures - Green Stick, Comminuted, Transverse, Oblique & Impacted)
At the end of the chapter, you will be able to:
 W recognize the physiological factors determining the components 
of physical fitness
 W comprehend the effects of exercise on Muscular system
 W know the effects of exercise on cardiorespiratory system 
 W figure out the physiological changes due to ageing
 W identify and classify sports injuries
Discussion
 W The injuries you have suffered on the Games field.
 W The Sport/Game you were playing when the injury occurred.
 W The cause of the injury.
 W The treatment.
 W Could the injury have been prevented?
 W Share your information with the class.
Page 2


227
Physical EDUCATION-XII
UNIT 
VII
PHYSIOLOGY AND INJURIES 
IN SPORTS
Overview
 W Physiological factors determining components of Physical Fitness
 W Effect of exercise on Muscular System 
 W Effect of exercise on Cardio- Respiratory System
 W Physiological changes due to ageing
 W Sports injuries: Classification (Soft Tissue Injuries – Abrasion, Contusion, 
Laceration, Incision, Sprain & Strain; Bone & Joint Injuries - Dislocation, 
Fractures - Green Stick, Comminuted, Transverse, Oblique & Impacted)
At the end of the chapter, you will be able to:
 W recognize the physiological factors determining the components 
of physical fitness
 W comprehend the effects of exercise on Muscular system
 W know the effects of exercise on cardiorespiratory system 
 W figure out the physiological changes due to ageing
 W identify and classify sports injuries
Discussion
 W The injuries you have suffered on the Games field.
 W The Sport/Game you were playing when the injury occurred.
 W The cause of the injury.
 W The treatment.
 W Could the injury have been prevented?
 W Share your information with the class.
228
Physical EDUCATION-XII
7.1  Physiological Factors Determining the Component of Physical 
Fitness
Exercise physiology is a study of the body’s response to exercise. In the human body 
we majorly study skeletal, muscular, nervous, endocrine, cardiovascular, metabolic, 
respiratory, digestive, urinary and reproductive systems which are somehow affected 
by exercises. During exercise, all systems of our body work jointly but responses 
of these systems are independent. Metabolic system produces energy and takes 
care of intake and output of energy. Cardiovascular system controls circulation, 
transports oxygen and energy to muscles and waste products from muscles to 
kidney. Respiratory system takes in air, diffuses oxygen to lungs and muscle tissue 
and removes carbon dioxide from body. Neuromuscular and skeletal system allows 
body movements through muscle contraction. Neuroendocrine and Immune system 
help to maintain homeostasis of the body. To develop fitness, each component has a 
different exercise, which is performed with different intensity, and volume, so the 
responses of systems are different. Here we will study on three major physiological 
factors that determine the various components of fitness.
7.1.1 SKELETAL MUSCLES FACTOR
Skeletal muscles are made up of muscles fibres which are divided into two categories 
Slow twitch fibres or Type I fibres and Fast twitch fibres or Type II fibres. Mostly 
muscles contain a mix of both fast and slow twitch fibres and the proportion of theses 
fibres is dependent on genetics, hormones, and habits of exercises. Composition of 
fibres in muscles plays a dominant role in development of strength, endurance, and 
speed performance. Skeletal muscles have four properties contractility, excitability, 
extensibility, and elasticity. These characteristics present in muscles determine 
different components of fitness.
Slow twitch fibres or Type I fibres or slow oxidative fibres contain large numbers of 
oxidative enzymes, have more capillaries, higher concentration of myoglobin and 
mitochondrial enzyme than fast twitch fibres which promote aerobic activity and 
resistance against fatigue. Due to higher concentration of capillaries the colour of 
fibres becomes red and has greater supply of blood. Such types of fibres contract at 
low rate and keep contracting for longer duration without fatigue; thus, producing 
large amounts of energy slowly. Slow twitch fibres help in long distance running, 
swimming, cycling etc.
Page 3


227
Physical EDUCATION-XII
UNIT 
VII
PHYSIOLOGY AND INJURIES 
IN SPORTS
Overview
 W Physiological factors determining components of Physical Fitness
 W Effect of exercise on Muscular System 
 W Effect of exercise on Cardio- Respiratory System
 W Physiological changes due to ageing
 W Sports injuries: Classification (Soft Tissue Injuries – Abrasion, Contusion, 
Laceration, Incision, Sprain & Strain; Bone & Joint Injuries - Dislocation, 
Fractures - Green Stick, Comminuted, Transverse, Oblique & Impacted)
At the end of the chapter, you will be able to:
 W recognize the physiological factors determining the components 
of physical fitness
 W comprehend the effects of exercise on Muscular system
 W know the effects of exercise on cardiorespiratory system 
 W figure out the physiological changes due to ageing
 W identify and classify sports injuries
Discussion
 W The injuries you have suffered on the Games field.
 W The Sport/Game you were playing when the injury occurred.
 W The cause of the injury.
 W The treatment.
 W Could the injury have been prevented?
 W Share your information with the class.
228
Physical EDUCATION-XII
7.1  Physiological Factors Determining the Component of Physical 
Fitness
Exercise physiology is a study of the body’s response to exercise. In the human body 
we majorly study skeletal, muscular, nervous, endocrine, cardiovascular, metabolic, 
respiratory, digestive, urinary and reproductive systems which are somehow affected 
by exercises. During exercise, all systems of our body work jointly but responses 
of these systems are independent. Metabolic system produces energy and takes 
care of intake and output of energy. Cardiovascular system controls circulation, 
transports oxygen and energy to muscles and waste products from muscles to 
kidney. Respiratory system takes in air, diffuses oxygen to lungs and muscle tissue 
and removes carbon dioxide from body. Neuromuscular and skeletal system allows 
body movements through muscle contraction. Neuroendocrine and Immune system 
help to maintain homeostasis of the body. To develop fitness, each component has a 
different exercise, which is performed with different intensity, and volume, so the 
responses of systems are different. Here we will study on three major physiological 
factors that determine the various components of fitness.
7.1.1 SKELETAL MUSCLES FACTOR
Skeletal muscles are made up of muscles fibres which are divided into two categories 
Slow twitch fibres or Type I fibres and Fast twitch fibres or Type II fibres. Mostly 
muscles contain a mix of both fast and slow twitch fibres and the proportion of theses 
fibres is dependent on genetics, hormones, and habits of exercises. Composition of 
fibres in muscles plays a dominant role in development of strength, endurance, and 
speed performance. Skeletal muscles have four properties contractility, excitability, 
extensibility, and elasticity. These characteristics present in muscles determine 
different components of fitness.
Slow twitch fibres or Type I fibres or slow oxidative fibres contain large numbers of 
oxidative enzymes, have more capillaries, higher concentration of myoglobin and 
mitochondrial enzyme than fast twitch fibres which promote aerobic activity and 
resistance against fatigue. Due to higher concentration of capillaries the colour of 
fibres becomes red and has greater supply of blood. Such types of fibres contract at 
low rate and keep contracting for longer duration without fatigue; thus, producing 
large amounts of energy slowly. Slow twitch fibres help in long distance running, 
swimming, cycling etc.
229
Physical EDUCATION-XII
Fast twitch fibres or Type II fibres or Fast glycolytic fibres contain a good volume of 
glycolytic enzymes which promote anaerobic activity but due to a smaller number 
of mitochondria they have limited aerobic capacity and low fatigue resistance. Fast 
twitch fibres do not require blood supply to produce energy, so their colour is lighter 
as compared to slow twitch fibre. Such fibres have fast contraction rate, tire rapidly 
and Type consume lots of energy, and can produce small amount of energy quickly. 
Fast twitch muscle fibre helps in anaerobic activities like jumps, throws, sprint etc.
Muscles fibres play a dominant role in sports performance. Regular training can 
change the proportion of slow and fast twitch fibres.
There are variations of types of fibres among athletes participating in the same 
sports also Sprinters generally have a higher percentage of Type II fibres and a lower 
percentage of Type I fibres, while endurance athletes have a higher percentage of 
Type I fibres and a lower percentage of Type II fibres. The amount of force generated 
through muscle contraction depends on the number and types of motor units, length 
of muscles, nature of neural stimulation of the motor units and contractile history 
of muscle.
Do you Know?
Sports Slow Twitch Fibre Fast Twitch Fibre
Long Distance Runners 70 to 80 % 20 to 30 %
Sprinters 25 to 30 % 70 to 75 %
Non-Athletes 48 to 52 % 48 to 52 %
7.1.2 ENERGY PRODUCTION FACTOR
Cellular respiration is a process in which ATP (Adenosine triphosphate) is formed 
through food. Main source of energy in food is in form of carbohydrates, proteins, 
and fats. Each has different complex chemical process to form ATP energy. During 
exercise, the load on the metabolic system increases manifold because of increase 
in the demand of energy by different systems. In this process, carbohydrates give 
instant energy as compared to fats and proteins, but fats give a larger amount of 
energy as compared to carbohydrates and proteins. Higher intensity aerobic activity 
requires carbohydrates in the form of glucose and glycogen as fuel.
Page 4


227
Physical EDUCATION-XII
UNIT 
VII
PHYSIOLOGY AND INJURIES 
IN SPORTS
Overview
 W Physiological factors determining components of Physical Fitness
 W Effect of exercise on Muscular System 
 W Effect of exercise on Cardio- Respiratory System
 W Physiological changes due to ageing
 W Sports injuries: Classification (Soft Tissue Injuries – Abrasion, Contusion, 
Laceration, Incision, Sprain & Strain; Bone & Joint Injuries - Dislocation, 
Fractures - Green Stick, Comminuted, Transverse, Oblique & Impacted)
At the end of the chapter, you will be able to:
 W recognize the physiological factors determining the components 
of physical fitness
 W comprehend the effects of exercise on Muscular system
 W know the effects of exercise on cardiorespiratory system 
 W figure out the physiological changes due to ageing
 W identify and classify sports injuries
Discussion
 W The injuries you have suffered on the Games field.
 W The Sport/Game you were playing when the injury occurred.
 W The cause of the injury.
 W The treatment.
 W Could the injury have been prevented?
 W Share your information with the class.
228
Physical EDUCATION-XII
7.1  Physiological Factors Determining the Component of Physical 
Fitness
Exercise physiology is a study of the body’s response to exercise. In the human body 
we majorly study skeletal, muscular, nervous, endocrine, cardiovascular, metabolic, 
respiratory, digestive, urinary and reproductive systems which are somehow affected 
by exercises. During exercise, all systems of our body work jointly but responses 
of these systems are independent. Metabolic system produces energy and takes 
care of intake and output of energy. Cardiovascular system controls circulation, 
transports oxygen and energy to muscles and waste products from muscles to 
kidney. Respiratory system takes in air, diffuses oxygen to lungs and muscle tissue 
and removes carbon dioxide from body. Neuromuscular and skeletal system allows 
body movements through muscle contraction. Neuroendocrine and Immune system 
help to maintain homeostasis of the body. To develop fitness, each component has a 
different exercise, which is performed with different intensity, and volume, so the 
responses of systems are different. Here we will study on three major physiological 
factors that determine the various components of fitness.
7.1.1 SKELETAL MUSCLES FACTOR
Skeletal muscles are made up of muscles fibres which are divided into two categories 
Slow twitch fibres or Type I fibres and Fast twitch fibres or Type II fibres. Mostly 
muscles contain a mix of both fast and slow twitch fibres and the proportion of theses 
fibres is dependent on genetics, hormones, and habits of exercises. Composition of 
fibres in muscles plays a dominant role in development of strength, endurance, and 
speed performance. Skeletal muscles have four properties contractility, excitability, 
extensibility, and elasticity. These characteristics present in muscles determine 
different components of fitness.
Slow twitch fibres or Type I fibres or slow oxidative fibres contain large numbers of 
oxidative enzymes, have more capillaries, higher concentration of myoglobin and 
mitochondrial enzyme than fast twitch fibres which promote aerobic activity and 
resistance against fatigue. Due to higher concentration of capillaries the colour of 
fibres becomes red and has greater supply of blood. Such types of fibres contract at 
low rate and keep contracting for longer duration without fatigue; thus, producing 
large amounts of energy slowly. Slow twitch fibres help in long distance running, 
swimming, cycling etc.
229
Physical EDUCATION-XII
Fast twitch fibres or Type II fibres or Fast glycolytic fibres contain a good volume of 
glycolytic enzymes which promote anaerobic activity but due to a smaller number 
of mitochondria they have limited aerobic capacity and low fatigue resistance. Fast 
twitch fibres do not require blood supply to produce energy, so their colour is lighter 
as compared to slow twitch fibre. Such fibres have fast contraction rate, tire rapidly 
and Type consume lots of energy, and can produce small amount of energy quickly. 
Fast twitch muscle fibre helps in anaerobic activities like jumps, throws, sprint etc.
Muscles fibres play a dominant role in sports performance. Regular training can 
change the proportion of slow and fast twitch fibres.
There are variations of types of fibres among athletes participating in the same 
sports also Sprinters generally have a higher percentage of Type II fibres and a lower 
percentage of Type I fibres, while endurance athletes have a higher percentage of 
Type I fibres and a lower percentage of Type II fibres. The amount of force generated 
through muscle contraction depends on the number and types of motor units, length 
of muscles, nature of neural stimulation of the motor units and contractile history 
of muscle.
Do you Know?
Sports Slow Twitch Fibre Fast Twitch Fibre
Long Distance Runners 70 to 80 % 20 to 30 %
Sprinters 25 to 30 % 70 to 75 %
Non-Athletes 48 to 52 % 48 to 52 %
7.1.2 ENERGY PRODUCTION FACTOR
Cellular respiration is a process in which ATP (Adenosine triphosphate) is formed 
through food. Main source of energy in food is in form of carbohydrates, proteins, 
and fats. Each has different complex chemical process to form ATP energy. During 
exercise, the load on the metabolic system increases manifold because of increase 
in the demand of energy by different systems. In this process, carbohydrates give 
instant energy as compared to fats and proteins, but fats give a larger amount of 
energy as compared to carbohydrates and proteins. Higher intensity aerobic activity 
requires carbohydrates in the form of glucose and glycogen as fuel.
230
Physical EDUCATION-XII
Do you know?
Metabolism: is the process of overall energy transformations occurring in the 
body.
Anabolism: is the process where the simple molecules combine to generate 
complex 
molecules: Catabolism: is the process of breakdown of food and stores to produce 
energy for work.
Carbohydrates work as a fuel for short duration exercise, fats are utilized for long 
duration exercises and proteins contribute a small but important proportion of 
nourishment. Basically, three energy system works in our body ATP-CP (Creatine 
phosphate) system, anaerobic system, and aerobic system. ATP- CP system provides 
energy if the activity is less than 10 second. Such activities are dynamic in nature 
and of very short duration and very intensive. They include jumps, throws, sprints, 
weightlifting, powerlifting etc. Anaerobic system provides energy for less than two 
minutes, in activities like 200m, 400m races. Aerobic system provides energy for 
long duration activities like marathon, football, hockey etc. Aerobic and anaerobic 
systems work simultaneously, but which system is predominant depends upon type, 
duration, intensity of exercise, long and short-term nutritional status, proportions 
of types of muscle fibres etc.
7.1.3 CARDIORESPIRATORY FACTOR
The Cardiorespiratory system is combination of respiratory and cardiovascular 
systems which jointly work to transport oxygen to the cells and support metabolism 
by delivering nutrients, which provide energy to neuromuscular system and 
neuroendocrine system. During exercise, the demand for energy increases and to 
meet the demand, oxygen is required in appropriate volume to achieve the same. 
Demand of energy depends on intensity, duration, and type of activity. To match 
the same, the respiratory system -- pulmonary ventilation, external respiration, 
and internal respiration work together. The cardiovascular response to exercise is 
directly proportional to the demands of the skeletal muscles for Oxygen. Maximal 
oxygen consumption (VO2 Max), Blood pressure, blood volume, oxygen diffusion 
and extraction, muscle and arterial blood flow etc. simultaneously increase as per 
activity.
Page 5


227
Physical EDUCATION-XII
UNIT 
VII
PHYSIOLOGY AND INJURIES 
IN SPORTS
Overview
 W Physiological factors determining components of Physical Fitness
 W Effect of exercise on Muscular System 
 W Effect of exercise on Cardio- Respiratory System
 W Physiological changes due to ageing
 W Sports injuries: Classification (Soft Tissue Injuries – Abrasion, Contusion, 
Laceration, Incision, Sprain & Strain; Bone & Joint Injuries - Dislocation, 
Fractures - Green Stick, Comminuted, Transverse, Oblique & Impacted)
At the end of the chapter, you will be able to:
 W recognize the physiological factors determining the components 
of physical fitness
 W comprehend the effects of exercise on Muscular system
 W know the effects of exercise on cardiorespiratory system 
 W figure out the physiological changes due to ageing
 W identify and classify sports injuries
Discussion
 W The injuries you have suffered on the Games field.
 W The Sport/Game you were playing when the injury occurred.
 W The cause of the injury.
 W The treatment.
 W Could the injury have been prevented?
 W Share your information with the class.
228
Physical EDUCATION-XII
7.1  Physiological Factors Determining the Component of Physical 
Fitness
Exercise physiology is a study of the body’s response to exercise. In the human body 
we majorly study skeletal, muscular, nervous, endocrine, cardiovascular, metabolic, 
respiratory, digestive, urinary and reproductive systems which are somehow affected 
by exercises. During exercise, all systems of our body work jointly but responses 
of these systems are independent. Metabolic system produces energy and takes 
care of intake and output of energy. Cardiovascular system controls circulation, 
transports oxygen and energy to muscles and waste products from muscles to 
kidney. Respiratory system takes in air, diffuses oxygen to lungs and muscle tissue 
and removes carbon dioxide from body. Neuromuscular and skeletal system allows 
body movements through muscle contraction. Neuroendocrine and Immune system 
help to maintain homeostasis of the body. To develop fitness, each component has a 
different exercise, which is performed with different intensity, and volume, so the 
responses of systems are different. Here we will study on three major physiological 
factors that determine the various components of fitness.
7.1.1 SKELETAL MUSCLES FACTOR
Skeletal muscles are made up of muscles fibres which are divided into two categories 
Slow twitch fibres or Type I fibres and Fast twitch fibres or Type II fibres. Mostly 
muscles contain a mix of both fast and slow twitch fibres and the proportion of theses 
fibres is dependent on genetics, hormones, and habits of exercises. Composition of 
fibres in muscles plays a dominant role in development of strength, endurance, and 
speed performance. Skeletal muscles have four properties contractility, excitability, 
extensibility, and elasticity. These characteristics present in muscles determine 
different components of fitness.
Slow twitch fibres or Type I fibres or slow oxidative fibres contain large numbers of 
oxidative enzymes, have more capillaries, higher concentration of myoglobin and 
mitochondrial enzyme than fast twitch fibres which promote aerobic activity and 
resistance against fatigue. Due to higher concentration of capillaries the colour of 
fibres becomes red and has greater supply of blood. Such types of fibres contract at 
low rate and keep contracting for longer duration without fatigue; thus, producing 
large amounts of energy slowly. Slow twitch fibres help in long distance running, 
swimming, cycling etc.
229
Physical EDUCATION-XII
Fast twitch fibres or Type II fibres or Fast glycolytic fibres contain a good volume of 
glycolytic enzymes which promote anaerobic activity but due to a smaller number 
of mitochondria they have limited aerobic capacity and low fatigue resistance. Fast 
twitch fibres do not require blood supply to produce energy, so their colour is lighter 
as compared to slow twitch fibre. Such fibres have fast contraction rate, tire rapidly 
and Type consume lots of energy, and can produce small amount of energy quickly. 
Fast twitch muscle fibre helps in anaerobic activities like jumps, throws, sprint etc.
Muscles fibres play a dominant role in sports performance. Regular training can 
change the proportion of slow and fast twitch fibres.
There are variations of types of fibres among athletes participating in the same 
sports also Sprinters generally have a higher percentage of Type II fibres and a lower 
percentage of Type I fibres, while endurance athletes have a higher percentage of 
Type I fibres and a lower percentage of Type II fibres. The amount of force generated 
through muscle contraction depends on the number and types of motor units, length 
of muscles, nature of neural stimulation of the motor units and contractile history 
of muscle.
Do you Know?
Sports Slow Twitch Fibre Fast Twitch Fibre
Long Distance Runners 70 to 80 % 20 to 30 %
Sprinters 25 to 30 % 70 to 75 %
Non-Athletes 48 to 52 % 48 to 52 %
7.1.2 ENERGY PRODUCTION FACTOR
Cellular respiration is a process in which ATP (Adenosine triphosphate) is formed 
through food. Main source of energy in food is in form of carbohydrates, proteins, 
and fats. Each has different complex chemical process to form ATP energy. During 
exercise, the load on the metabolic system increases manifold because of increase 
in the demand of energy by different systems. In this process, carbohydrates give 
instant energy as compared to fats and proteins, but fats give a larger amount of 
energy as compared to carbohydrates and proteins. Higher intensity aerobic activity 
requires carbohydrates in the form of glucose and glycogen as fuel.
230
Physical EDUCATION-XII
Do you know?
Metabolism: is the process of overall energy transformations occurring in the 
body.
Anabolism: is the process where the simple molecules combine to generate 
complex 
molecules: Catabolism: is the process of breakdown of food and stores to produce 
energy for work.
Carbohydrates work as a fuel for short duration exercise, fats are utilized for long 
duration exercises and proteins contribute a small but important proportion of 
nourishment. Basically, three energy system works in our body ATP-CP (Creatine 
phosphate) system, anaerobic system, and aerobic system. ATP- CP system provides 
energy if the activity is less than 10 second. Such activities are dynamic in nature 
and of very short duration and very intensive. They include jumps, throws, sprints, 
weightlifting, powerlifting etc. Anaerobic system provides energy for less than two 
minutes, in activities like 200m, 400m races. Aerobic system provides energy for 
long duration activities like marathon, football, hockey etc. Aerobic and anaerobic 
systems work simultaneously, but which system is predominant depends upon type, 
duration, intensity of exercise, long and short-term nutritional status, proportions 
of types of muscle fibres etc.
7.1.3 CARDIORESPIRATORY FACTOR
The Cardiorespiratory system is combination of respiratory and cardiovascular 
systems which jointly work to transport oxygen to the cells and support metabolism 
by delivering nutrients, which provide energy to neuromuscular system and 
neuroendocrine system. During exercise, the demand for energy increases and to 
meet the demand, oxygen is required in appropriate volume to achieve the same. 
Demand of energy depends on intensity, duration, and type of activity. To match 
the same, the respiratory system -- pulmonary ventilation, external respiration, 
and internal respiration work together. The cardiovascular response to exercise is 
directly proportional to the demands of the skeletal muscles for Oxygen. Maximal 
oxygen consumption (VO2 Max), Blood pressure, blood volume, oxygen diffusion 
and extraction, muscle and arterial blood flow etc. simultaneously increase as per 
activity.
231
Physical EDUCATION-XII
Do you know?
In games where ATP-CP system or anaerobic system works to produce energy for 
strength training. Stroke volume (the volume of blood pumped out of the left 
ventricle of the heart during each systolic cardiac contraction) is a vital parameter 
as far as cardiovascular system is concerned
7.1.4  PHYSICAL FITNESS COMPONENTS DETERMINED BY THE 
PHYSIOLOGICAL FACTORS
Now we will understand how the above-mentioned physiological factors determine 
fitness. We have taken four components of physical fitness namely strength, 
endurance, speed and flexibility.
Strength – Strength is the ability of the body to work against resistance and has varied 
sub-types such as Maximum Strength, Explosive Strength, Strength, Endurance etc. 
Each has different types of exercise, intensity and duration so physiological factors 
vary. Different sports require different amount of strength and according to that, 
mixture of the slow twitch fibre and fast twitch fibre is needed. Generally in all the 
strength related sports where sudden burst of energy is required, high percentage 
of fast twitch fibre is required.  In games like weightlifting, jumps, sprint or power, 
agility and strength dominating sports where force production is high, fatigue is 
quick, and fast twitch fibre percentage must be high in muscles.