📌 Snapshot
- Growth versus development, warm up, cool down and exercise effects on the body explained with tables and MCQs.
- Why growth stops but development never does, and what heredity, nutrition, hormones and exercise add to each.
- How a sprinter's heart, lungs, muscles and gut change during and after training, with the formulas you need.
- Warm up, conditioning and cool down compared, with exam traps drawn from near identical numbers.
📖 Detailed Notes
Written and reviewed by Rohit Singh, Computer Science & Commerce faculty at UniDrill (MCA, Osmania University · 6 years teaching). Based on NCERT Health and Physical Education Class XI, Chapter 3.
Why does your heart pound before you even start running?
You line up for a 100 metre sprint and your heart is already thumping. Nobody has moved yet. That is your body preparing: hormones are in the blood, breathing is quickening, muscles are tensing. The chapter explains this preparation and what regular exercise does to your body over weeks and years. It has two halves. The first asks how a person grows and develops from the womb to adolescence. The second asks what warm up, conditioning, cool down and exercise do inside the muscles, heart, lungs and gut.
Growth and development: two words, two ideas
Growth is the process by which the body increases in size and shape. It is biological, it starts at conception in the mother's womb and goes on after birth until physical maturity. It is quantitative: height, weight, volume and size can be measured. Development is a progressive series of qualitative changes, the emerging and expanding of capabilities. Acquiring skills and knowledge is a sign of development.
How they are linked. Growth forms the basis for developing functional capacities. Without proper growth, the required development may not be reached at a given stage. But growth ends at some stage of life, while development continues till death.
| Point | Growth | Development |
|---|---|---|
| Nature | Quantitative | Quantitative as well as qualitative |
| What it covers | Height, weight, size and shape of the body and its organs | Physical changes along with cognitive, social and emotional changes |
| Cause | Cell division | Motor and mental processes and their interplay |
| Duration | Limited period | Life long process |
| Measurement | Can be measured objectively | Observed through behaviour; hard to measure (mental ability, academic achievement) |
| Scope | One aspect of personality; limited | All aspects of personality; vast |
| What sets the limit | Heredity | Mostly the environment available to the person |
Pause and predict: a sprinter's legs get longer and heavier between ages 12 and 15. In the same years she also learns to control her nerves before a race. Which change is growth and which is development?
Check your answer: Longer, heavier legs are growth, because they are a measurable change in size. Learning to control nerves is development, because it is a qualitative change in emotional ability.
Factors that decide how a child grows
Nine factors are named in the chapter. Learn them in two groups: those you are born with (heredity, gender) and those that act on you afterwards.
| Factor | How it works |
|---|---|
| Heredity | Biological transmission of traits from parents: height, weight, body structure, colour of hair and eyes, intelligence, aptitudes, instincts. Hereditary traits are innate, present at birth. Everyone inherits physical structure, reflexes, innate drives, intelligence and temperament |
| Environment | The sum total of surroundings and stimulation received from conception. Physical (weather, climate, surroundings), social (society, institutions, laws, customs, culture, education) and psychological (love, affection, emotion, friendship) |
| Gender | Boys are generally taller and heavier, but girls show early physical growth during adolescence; body composition and structure differ |
| Nutrition | Adequate calories are needed for normal growth and the need changes with phases of development; malnutrition harms structural and functional development |
| Exercise | Growth through use and atrophy (the reverse of growth) through disuse; repeated activity builds muscle strength through better circulation and supply of nutrients and oxygen |
| Hormones | Chemical substances from ductless endocrine glands that raise or lower the activity of the body or organs |
| Learning and reinforcement | Development consists of maturation and learning; activity must be repeated till results are obtained |
| Pollution | Air pollution harms the respiratory organs and growth; lead exposure, for example from old lead-based paint, obstructs normal development of the brain and organs in children |
| Socio-economic status | Better nutrition, facilities, regular meals, sleep and exercise in high income families; big families with limited income may not get enough nutrition |
Heredity and environment: seed and soil. Heredity is responsible for the inborn traits, instincts, emotions and physical traits. Environment is responsible for the growth and development of mental and social traits. The chapter calls them complementary, like seed and soil or ship and wave. A seed from a champion fruit tree still needs soil, water and sun, and the best soil cannot make a mango from a neem seed.
Two views. For the exam: heredity sets the limits of growth, while development is more affected by the environment. Another reading: modern biology and psychology describe heredity and environment as continuously interacting, so the same genes can produce different outcomes in different surroundings and a good environment unlocks inherited potential. Why it matters: a question that says "limits of growth" expects heredity, and one that says "complementary" expects both together.
Hormones in sport. Three glands are named. The thyroid gland releases thyroxin, which influences skeletal and muscular growth, and shortage affects growth and development. The adrenal glands, close to the kidneys, secrete adrenaline, which causes a strong and rapid heartbeat, releases stored sugar from the liver and controls blood pressure. The gonads (reproductive glands) secrete hormones that affect growth and sexual behaviour. This is why your heart pounds before the sprint: adrenaline is already acting.
Changes at each stage of life
| Stage | What happens |
|---|---|
| Early childhood | Between birth and age 3 a child typically doubles in height and quadruples in weight; skills such as sitting, walking and using a spoon. Ages 3 to 5: rapid growth and fine motor skills (control of pencils, crayons, scissors); skipping and balancing on one foot. Ages 5 to 8: growth slows while body proportions and motor skills become more refined; language and cognition develop quickly |
| Middle childhood | Growth is slow and steady until puberty; puberty begins earlier than it used to and can start as early as 8 or 9 years; it begins earlier in females; children gain enthusiasm for learning and build competence and self-esteem |
| Adolescence | The second period of accelerated growth, taken here as 12 to 18 years; may gain 15 to 20 cm in height and 8 to 10 kg in weight; females begin to develop earlier than males; females mature at about age 13 and males at about 15; important for cognitive development |
Why does a growth spurt matter in sport? The spurt arrives at different ages in different people, so a 13 year old team mate may be a head taller than you without being "better". This is one reason school sport groups children by age and not by build.
Warm-up: preparing the body
A warm-up is a short activity carried out before any intense or skilled activity. It usually has 10 to 40 minutes of light activity such as slow jogging, calisthenics and stretching. It should not be done vigorously. Its pattern is a gradual rise in intensity (a "pulse raiser"), then joint mobility exercise, then stretching, then the main activity.
What a warm-up does. It raises body temperature and heart rate, increases blood flow, respiratory rate and perspiration, and lowers the viscosity of joint fluids, the way warming oil makes it flow better. Stretching increases blood flow and helps protect muscles, tendons and ligaments from injury. It also practises basic movements and prepares the player psychologically to compete.
| Point | Figure or fact given |
|---|---|
| Optimum duration suggested by researchers | 15 to 20 minutes |
| Intensity | Gradual rise until the player works at 70 per cent of maximal heart rate |
| Effect on body temperature | A rise of 2 to 3 degrees that can last for 45 minutes |
| Practical tips | Begin with a continuous slow run, keep it progressive, avoid fatigue, finish with short sprints; 10 to 15 minutes with heart rate rising to 120 to 140 beats per minute |
Beyond the textbook. For the exam: the warm-up should reach 70 per cent of maximal heart rate. In reality: maximal heart rate is commonly estimated as 220 minus age, so for a 16 year old the estimate is 204 beats per minute and the 70 per cent target is $0.70 \times 204 \approx 143$ beats per minute. Why it matters: it shows that the target depends on the person and not on a single number for everyone, which is why the chapter says intensity should follow the fitness level of the athlete.
General and specific warm-up.
| Feature | General warm-up | Specific warm-up |
|---|---|---|
| Content | Rhythmic movements of large muscle groups: walking, jogging, stationary bike, skipping, easy aerobics | Exercises matched to the main activity and its movements |
| Aim | Better neuromuscular coordination, higher body temperature, less viscosity in muscle fibres | Preparing the body for the demands of the particular sport |
| Intensity | Light; governed by the athlete's fitness level | More vigorous |
| Example | Easy jog before any sport | Basketball: layups and free throws · cricket: bowling, catching, batting · lawn tennis: wall practice and service practice · shot put: standing throws and gliding · hockey: dribbling, stick rotation, hits · weightlifting: rowing, high pull, snatch squat |
Four methods of warming up. Exercise (walking, jogging, jumping, bending, stretching), massage (gives muscle tone, helps remove lactic acid, aids recovery and healing of minor injuries), hot water bath (raises body temperature and blood circulation; helpful for relaxation after competition) and hot beverage (a small amount of tea, soup or coffee stimulates body functions, but a large quantity causes discomfort).
Beyond the textbook. For the exam: stretching is part of the warm-up. In reality: many coaches now prefer active, sport like movements such as skips, leg swings and short runs before speed and power events, and keep long held stretches for the cool-down. Why it matters: the chapter itself says warm-up exercises should not be vigorous and should rise gradually, which fits this approach.
Sports conditioning
Conditioning complements sports training. It enhances strength, balance, coordination, flexibility, speed and power that carry over into all sports, and it is an important step in injury prevention. A good programme includes strength, power, speed, quickness, agility, movement skills, deceleration, balance, reactivity and anaerobic capacity. It should be specific to the sport and fit the individual needs of the athlete.
Cool-down (limber down)
A cool down is a session of light exercise, usually gentle exercise and stretching, after strenuous activity. Its aim is to promote recovery and return the body to the pre-exercise level. During a hard workout muscle fibres, tendons and ligaments get damaged and waste products build up, so the body needs to switch down gradually.
| What cooling down does | Why it helps |
|---|---|
| Heart rate and breathing return gradually toward resting levels | Avoids a sudden drop |
| Avoids fainting or dizziness | Stopping suddenly can leave blood pooled in the large leg muscles |
| Removes metabolites such as lactic acid from muscles | Reduces soreness and fatigue |
| Prepares muscles for the next session | Stretching builds elasticity and helps repair after aerobic and anaerobic exercise |
Pause and predict: a footballer finishes a match, sits down at once and stands up a minute later feeling dizzy. Which part of the routine did he skip, and what happened inside his legs?
Check your answer: He skipped the cool-down. When vigorous activity stops suddenly, blood can pool in the large muscles of the legs, so less blood reaches the brain on standing and he feels faint.
Effects of exercise on the cardiovascular system
The cardiovascular system is the heart, blood vessels and blood. Each measure below is a number the examiner can ask for.
| Measure | At rest | During exercise or after training |
|---|---|---|
| Heart rate | 60 to 80 beats per minute; 72 is normal | 140 to 180 beats per minute |
| Stroke volume (blood pumped by each ventricle per beat) | About 70 ml in males and 50 ml in females | Increases |
| Cardiac output | About 5 litres per minute | Rises about 4 to 5 fold; endurance training raises it by increasing stroke volume |
| Cardiac hypertrophy ("athlete's heart") | Normal size | Enlargement of the heart after 7 to 10 years of vigorous training |
| Blood volume | 5 to 6 litres in an adult | Endurance training raises resting blood volume by about 8 per cent and plasma volume by 12 per cent (hemodilution); more and larger blood vessels; capillarisation |
Cardiac output is the amount of blood pumped by each ventricle in one minute:
$$\text{Cardiac output} = \text{Heart rate} \times \text{Stroke volume}$$
Worked example: a footballer's heart. At rest a male player has a heart rate of 72 beats per minute and a stroke volume of 70 ml. During a sprint his heart rate reaches 180 beats per minute and his stroke volume reaches 120 ml.
| Step | What we do | Result |
|---|---|---|
| 1 | Resting output: $72 \times 70\ \text{ml}$ | $5040\ \text{ml min}^{-1} \approx 5\ \text{L min}^{-1}$ |
| 2 | Exercise output: $180 \times 120\ \text{ml}$ | $21600\ \text{ml min}^{-1} = 21.6\ \text{L min}^{-1}$ |
| 3 | Compare | $21.6 \div 5.04 \approx 4.3$ times, inside the 4 to 5 fold range |
A common wrong step is to add the two values (heart rate plus stroke volume). Cardiac output is a product, because each beat moves a volume, so more beats and bigger beats multiply the result.
Why a trained heart beats slower at rest. Endurance training increases cardiac output by increasing stroke volume, so each beat delivers more blood and fewer beats are needed at rest.
Effects of exercise on the respiratory system
Breathing is controlled by the medulla oblongata of the brain and supplies oxygen and removes carbon dioxide.
| Term | Meaning | At rest | During exercise |
|---|---|---|---|
| Tidal volume | Volume of air inspired or expired per breath | About 500 ml | Increases; up to 5 to 6 times at maximal exercise |
| Respiratory rate | Number of breaths per minute | 12 to 20 | 2 to 3 times |
| Minute (pulmonary) ventilation | Air breathed in one minute | About 8 litres per minute | Increases |
| Pulmonary diffusing capacity | Rate of gas diffusion between lung air sacs (alveoli) and blood in lung capillaries | Baseline | Increases for oxygen |
| Hyperventilation | Increased breathing through greater tidal volume, greater rate, or both | None | Occurs |
| Total lung capacity | Volume of air in the lungs at the end of maximal inspiration | Baseline | Slightly decreases |
| Vital capacity | Maximal air forcefully expired after maximal inspiration | Measured at rest | Defined as a lung measure |
$$\text{Minute ventilation} = \text{Tidal volume} \times \text{Respiratory rate}$$
Worked example: breathing at rest and in a sprint. At rest, $500\ \text{ml} \times 16 = 8000\ \text{ml} = 8\ \text{L min}^{-1}$. In a hard 400 metre run, suppose the tidal volume rises to 2500 ml and the rate to 32 breaths per minute. Then $2500 \times 32 = 80000\ \text{ml} = 80\ \text{L min}^{-1}$, ten times the resting value, because both factors rise together. The exercise figures are an illustration within the ranges above.
The rise in ventilation comes in two phases. First there is an initial rise because muscle activity stimulates the inspiratory centres. Then there is a slower, gradual rise because of the increase in temperature and chemical changes in arterial blood produced by muscular activity.
Effects of exercise on the muscular system
Skeletal muscles are the main muscles for physical activity, and their changes depend on the type of training.
| Change | What happens | Why it matters |
|---|---|---|
| Muscular hypertrophy | Muscles enlarge; fibre diameter and length increase; protein, glycogen and enzymes increase | Greater strength |
| Aerobic changes | More myoglobin for oxygen supply; more oxidation of glycogen; trained muscle uses more fat for energy | Better endurance |
| Anaerobic changes | Energy supply without oxygen improves: higher lactic acid tolerance, altered muscle blood flow, change in red and white fibres | Better short, explosive efforts |
| Capillary supply | Endurance training increases the capillary ratio (capillaries per fibre) and capillary density | Better delivery of oxygen and nutrients |
| Performance | Muscles contract with less exertion; the exercise can continue longer without anaerobic metabolism, delaying lactic acid build up; strength, flexibility and endurance increase | Higher work output |
Beyond the textbook. For the exam: regular exercise causes muscular hypertrophy and the chapter links it to the opposite effect, atrophy, through disuse. In reality: a limb kept in a plaster cast for weeks comes out visibly thinner, which shows disuse atrophy directly. Why it matters: it explains why rehabilitation after an injury starts with gentle use of the muscle and not complete rest.
Effects of exercise on the digestive system
| Effect | How it works |
|---|---|
| More blood flow | Better circulation to the organs of the digestive tract improves their working |
| Faster metabolism | Slightly raises the resting metabolic rate, the calories burned at rest |
| Prevents constipation | Reduces the time food takes to pass through the large intestine, so less water is absorbed from the stool; faster breathing and heart rate stimulate contractions of the intestinal muscles |
| Prevents digestive diseases | Strengthens internal organs such as the liver, stomach, intestine and glands |
Exam traps
| The trap | Why it's tempting | The truth |
|---|---|---|
| "Growth continues throughout life." | Growth and development sound alike | Growth stops at some stage; development is lifelong |
| "Growth is qualitative." | It is also called improvement | Growth is quantitative; development is both |
| "Development is limited by heredity." | Genes feel decisive | Heredity sets limits of growth; development is more affected by the environment |
| "Girls grow later than boys in adolescence." | Boys end up taller | Girls show earlier growth and begin to develop earlier |
| "Cardiac output is heart rate plus stroke volume." | Both are in the formula | It is the product: heart rate times stroke volume |
| "Warm-up should be vigorous." | More effort feels more useful | It should be gradual, with the vigorous work saved for the specific warm-up |
| "Cool-down is optional rest." | You are already finished | It returns heart rate and breathing to resting levels and removes lactic acid |
| "Tidal volume is 5 litres." | Mixing it with blood volume | Tidal volume at rest is about 500 ml; blood volume is 5 to 6 litres |
60-second revision
| Topic | Lock this in |
|---|---|
| Growth | Increase in size and shape; quantitative; limited period; set by heredity |
| Development | Qualitative as well as quantitative; lifelong; shaped by environment |
| Nine factors | Heredity, environment, gender, nutrition, exercise, hormones, learning, pollution, socio-economic status |
| Three glands | Thyroid (thyroxin) · adrenal (adrenaline) · gonads |
| Stages | Early childhood · middle childhood · adolescence (12 to 18 years here) |
| Warm-up | Gradual; 70 per cent of maximal heart rate; 2 to 3 degree rise lasting 45 minutes; general then specific |
| Conditioning | Strength, balance, coordination, flexibility, speed, power; prevents injury |
| Cool-down | Light exercise and stretching; removes lactic acid; avoids dizziness |
| Heart | Resting 72 beats per minute · exercise 140 to 180 · cardiac output = HR × SV · about 5 litres per minute at rest |
| Lungs | Tidal volume 500 ml · rate 12 to 20 · minute ventilation about 8 litres per minute |
| Muscles | Hypertrophy · more myoglobin · more capillaries · more fat used |
| Gut | More blood flow · metabolism · prevents constipation |
Where this chapter connects
- Previous: Understanding Health gave the physical dimension of health that this chapter explains from the inside.
- Next: Individual Games shows the warm-up and conditioning ideas in specific sports.
- Same theme: Health Related Physical Fitness builds on strength, endurance and flexibility, and Measurement and Evaluation shows how these changes are tested.
🎯 Practice MCQs
First 3 questions free · create a free account to unlock the rest — answers & explanations included, no payment needed
Q1. Which of the following correctly distinguishes growth from development?
▸ Show answer & explanation
Answer: B
Growth is a quantitative increase in size and shape for a limited period, while development includes qualitative change and continues till death. Option A reverses the two, option C reverses the time scales and option D swaps the causes.
Q2. Match List I with List II. List I: (i) Thyroid gland (ii) Adrenal gland (iii) Gonads (iv) Endocrine glands. List II: (p) Reproductive glands affecting growth and sexual behaviour (q) Secretes thyroxin influencing skeletal and muscular growth (r) Ductless glands that release hormones (s) Secretes adrenaline for strong and rapid heartbeat
▸ Show answer & explanation
Answer: A
Thyroxin comes from the thyroid, adrenaline from the adrenal glands, the gonads are the reproductive glands and endocrine glands are ductless. The other options swap at least two pairs.
Q3. A child inherits her father's height and her mother's eye colour, but her fluency in two languages comes from the schools and community she grows up in. This case best illustrates that:
▸ Show answer & explanation
Answer: C
Height and eye colour are inherited, while language is learned from the social environment. The chapter calls heredity and environment complementary, like seed and soil. Options A and B each ignore half the case, and option D ignores both.
🔒 9 more practice MCQs
Create a free account to unlock every MCQ in this chapter — answers and explanations included. No payment needed.
Already registered? Just log in and they'll all appear here.
Q4. According to the chapter, a child typically doubles in height and quadruples in weight between:
▸ Show answer & explanation
Answer: A
The doubling of height and quadrupling of weight occurs between birth and age three. After three years rapid growth continues with fine motor skills, and growth slows down between five and eight years.
Q5. A hockey coach tells her squad to jog slowly, do skipping and easy aerobics, and then dribbling, stick rotation and short passes before the match. Which statement describes this routine correctly?
▸ Show answer & explanation
Answer: C
Jogging, skipping and easy aerobics form the general warm-up, and dribbling, stick rotation and short passes are specific to hockey. Option A and option B each describe only half the routine, and a cool-down comes after the activity, not before.
Q6. Which of the following is an effect of warm-up as described in the chapter?
▸ Show answer & explanation
Answer: C
Warm-up raises heart rate, blood flow, internal muscle temperature, respiratory rate and perspiration and decreases the viscosity of joint fluids. Options A, B and D each state the opposite of at least one effect.
Q7. Assertion (A): A cool-down should follow strenuous exercise. Reason (R): Stopping vigorous activity suddenly can lead to blood pooling in the large muscles of the legs, causing dizziness.
▸ Show answer & explanation
Answer: A
The cool-down is recommended because sudden stopping can cause blood pooling in the leg muscles and dizziness, and it also helps remove lactic acid. The reason is one of the main explanations for the assertion.
Q8. At rest a male athlete has a stroke volume of 70 ml and a heart rate of 70 beats per minute. His cardiac output is approximately:
▸ Show answer & explanation
Answer: B
Cardiac output is heart rate times stroke volume: $70 \times 70\ \text{ml} = 4900\ \text{ml} = 4.9\ \text{L}$ per minute. Option A adds the two numbers, and options C and D are wrong by powers of ten.
Q9. Which of the following changes occurs in the respiratory system during heavy exercise?
▸ Show answer & explanation
Answer: B
The respiratory rate rises to two or three times its resting value. Tidal volume increases (up to five or six times at maximal exercise), the resting range of 12 to 20 is the value at rest, and the diffusing capacity for oxygen increases.
Q10. Read the statements. Statement I: Cardiac hypertrophy, or "athlete's heart", may appear after 7 to 10 years of vigorous physical training. Statement II: Endurance training lowers the blood volume by about 8 per cent. Which option is correct?
▸ Show answer & explanation
Answer: B
Statement I matches the chapter. Statement II is wrong because endurance training raises resting blood volume by about 8 per cent, and plasma volume by about 12 per cent.
Q11. Which of the following is NOT an aerobic change in muscles due to training?
▸ Show answer & explanation
Answer: D
Myoglobin, glycogen oxidation and use of fat are aerobic changes. Increased lactic acid tolerance is listed among the anaerobic changes, which help supply energy without oxygen.
Q12. A student says: "My digestion improves with regular exercise." Which of the following is NOT a reason given in the chapter?
▸ Show answer & explanation
Answer: D
The chapter lists increased blood flow, faster metabolism, prevention of constipation by speeding movement through the large intestine and prevention of digestive diseases. The stomach does not make blood plasma, so option D does not belong.
📊 Previous-Year Questions
Practise with real CUET Physical Education previous-year papers — every question solved, with the correct answer and a step-by-step explanation.
View solved CUET PYQ papers →Ready to drill Physical Education?
Unlock all MCQs, chapter tests, mocks & PYQs for ₹199/year.
Get UniDrill Pro