Download CHAPTER 24 – FLEXIBILITY and BODY COMPOSITION

EXERCISE AND SPORT PHYSIOLOGY
CHAPTER 24 – FLEXIBILITY and BODY COMPOSITION
Text between pages 150 and 157 answers to questions on page 157 of the text book.
1) a) Stretching is a key element in any warm-up. Using an example, identify two other elements of a warm-up and explain how they help to prepare an athlete.4 marks
Answer
• Jogging gradually elevates heart rate and ventilation rates.
• Increases core temperature.
• Sport specific skill practice.
• This works the neuromuscular systems related to the chosen activity.
b) Describe three different methods of stretching and state a sport that would benefit most from each type. 6 marks
Answer
• Passive stretching:
• This happens when the stretch is assisted by a partner or object to stretch the muscle beyond its normal range.
• Suitable for activities where movement ranges is important, for example in gymnastics.
• Could be developed into PNF.
• Proprioceptive neuromuscular facilitation (PNF):
• PNF involves stretching.
• Followed by an isometric contraction.
• Followed by further stretching (PNF).
• Suitable for activities where range of movement is important.
• Example gymnastics.
• Static stretching:
• This is a form of stretching when the muscle is stretched to a point of tension.
• And then held for a time period.
• Very relevant to activities where static balance is important.
• Example gymnastics balance.
• Active stretching:
• Occurs when the stretch is done slowly to extend the joint.
• And stretch the muscle to an unassisted range of movement.
• Suitable for all sports.
• Ballistic stretching:
• Occurs when body movements are used in a swinging/bouncing fashion to extend joint range.
• Suitable for explosive events such as sprinting.
c) Identify two physiological adaptations to skeletal tissue following a three-month flexibility training programme.
2 marks
Answer
• Inhibition of stretch reflex as muscle spindles lengthen.
• Which means that muscle will stretch further before stretch reflex limits flexibility.
• To increase in resting length of skeletal muscle.
2) a) Give two advantages of using static stretching within a flexibility programme.2 marks
Answer
Advantage:
• Stretches are done slowly.
• But greater range of motion achieved.
• Stimulates the Golgi tendon organs.
• And takes advantage of the inverse stretch reflex.
• The inverse stretch reflex causes active skeletal muscle to contract and shorten.
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SECTION B –
OPTION B3 –
CHAPTER 24
ANSWERS TO QUESTIONS
2) continued
b) Identify two structural limitations to muscle flexibility.2 marks
Answer
• Elasticity of ligaments.
• Tendons.
• Surrounding muscles.
• Shape of articulating bones.
3) You have been asked to prepare a flexibility training programme for a group of A-level Physical Education students who wish
to improve their flexilibity for their chosen individual activity.
a) Identify key factors that would need to be considered during the planning of the programme.4 marks
Answer
• Assess your flexibility using the sit and reach test for example.
• Determine your flexibility goals, such as hip mobility for a gymnast.
• Consider your time constraints - time of day/days available/times per day.
• Look at your exercise preference - could be general or sport specific.
• Consider the type of training (static, passive, ballistic or acive) you need to do.
• Consider what facilities are available to you such as a gym, or availability of a carpet at home!
• Apply relevant training principles such as progression, overload, duration, frequency, intensity and variance.
• Place basic elements within a session such as warm-up, work-out and cool-down.
b) Outline the content of a basic programme that aims to achieve an increase in flexilibity for these students. 4 marks
Answer
• Day 1, during cool-down, static stretching (6 exercises), 6 repetitions at each exercise, hold end point for 6 seconds, 15 second
rest between repetitions.
• Day 3, during warm-up, ballistic stretching (6 exercises) 6 sets of 20 performed in a circuit.
• Day 5, separate session, active stretching or PNF (10 exercises), 6 repetitions at each exercise, hold end point for 6 seconds, 15
second rest between repetitions.
• For PNF, hold end point for 6 seconds, relax, then forcepast end point for a further 3 seconds.
4) What is meant by the term body composition? There are several field techniques for estimating body composition. Describe
and evaluate the use of skinfold fat thickness measurements, identifying one strength and one weakness of this technique. 6 marks
Answer
2 marks for definition:
• Body composition is a term used to describe the chemical composition of the body consisting of two components: fat mass and lean
body mass.
• Fat mass is known a body fat or accumulated adipose tissue.
• Lean body mass or the fat-free mass, including the mass of other tissues such as muscle, bone and skin.
2 marks for description of test:
• Skinfold fat thickness measurements
• Pinch the skin between thumb and index finger.
• The use skinfold calipers to record skinfold thickness at a minimum of 3 sites on the body.
• Repeat the measurements three times and record the mean score for the sum of the three skinfold measurements.
• Find your predicted percentage body fat by using the Jackson and Pollock nomogram.
1 mark from the following for strength of technique:
• Is a quick method that needs limited equipment ie skinfold calipers and nomogram chart.
• Can be conducted as a field test.
1 mark from the following for weakness of technique:
• Could be errors created when pinching the skin.
• May not pinch skin at designated site.
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EXERCISE AND SPORT PHYSIOLOGY
5) a) What is meant by the expression ‘an ideal body weight’? List two ways in which it can be determined.
3 marks
Answer
• An ideal body weight maintains appropriate weight and body composition to maximise physical performance and a healthy
lifestyle.
Can be determined by:
• Body mass index (BMI).
• Skinfold fat thickness.
• Bioelectrical Impedance Analysis (BIA).
• Underwater weighing.
• Body scanners.
b) Define body mass index (BMI). How does this concept assist in the understanding of the changing patterns of body composition?
3 marks
Answer
1 mark for definition:
• Body mass index (BMI) is a measurement of body weight in kilograms is divided by the square of the body height in metres.
2 marks for application:
• Since BMI is highly correlated with body composition BMI values are divided into five categories: underweight, normal weight,
overweight, obese and morbidly obese.
• This classification system has a major contribution to our understanding of the true prevalence of the general patterns of body
composition throughout the whole range of a general population.
• Particularly in changing trends within the overweight and obesity categories.
6) a) What is a balanced diet and suggest the proportion of carbohydrates, fats and proteins a 17 year old person should eat in order to maintain a physically active lifestyle?
4 marks
Answer
1 mark for definition:
• A balanced diet is the combination and proportions of carbohydrates (CHO), fats, proteins, roughage, water and essential
minerals and vitamins which best provide for an individual’s nutritional requirements.
3 marks for proportions:
• CHO 50% to 60%.
• Fat 25% to 35%.
• Protein 10% to 15%.
b) Briefly describe an outline for a week’s exercise programme that would be maintain a physically active lifestyle for a 17 year old student. In your answer identify the major fitness components to be stressed. 8 marks
Answer
You will need to refer to chapter 22 for content on aerobic training methods to help you this answer.
activity
major fitness component
Day 1
45 min slow walk
cardiorespiratory endurance
Day 2
15 min stretching (active + passive) – working
major muscle groups
flexibility, balance
Day 3
weights circuit at local gym
30 min light weights, repetition 6-8, 2 sets at each
of eight different exercises
muscle strength, local muscle
endurance, coordination, agility
Day 4
rest day
Day 5
30 min fast walk
cardiorespiratory endurance
Day 6
30 min aerobic class
cardiorespiratory endurance
Day 7
rest day
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SECTION B –
OPTION B3 –
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ANSWERS TO QUESTIONS
7) What do you understand by ’healthy eating’ and how can this concept be applied to dieting?
4 marks
Answer
1 mark for definition:
• Healthy eating is a healthy diet that contains the proportions of carbohydrates, fats and proteins, minerals, vitamins, water and
roughage needed for good health.
3 marks for application:
• Control of energy intake.
• This can be achieved by eating a wide variety of foods.
• Eat less fat particularly saturated fat, responsible for high blood cholesterol (use unsaturated vegetable oils).
• Eat more starchy foods rich in fibre (wholemeal bread).
• Eat less salt (causes of hypertension).
• Eat less refined and processed sugars.
• Drink less alcohol.
8) Identify some of the health implications of being obese.
4 marks
Answer
• Obesity has been strongly associated with a number of modern-day cardiovascular diseases, such as atherosclerosis, hypertension
and coronary and cerebral thrombosis.
• An obese person has an increased risk of suffering from mature diabetes, hernia, and gall bladder diseases, cirrhosis of the liver.
• And mechanical injuries to the body, such as backache and damage to joint structures (leading to joint pain and arthritis).
• In addition, an obese person would be more at risk during surgery.
• And an obese woman would be more likely to experience complications during pregnancy.
9) How can exercise be used as a means of weight control?
4 marks
Answer
• Most evidence points to a relationship between excessive body mass and physical inactivity.
• The purpose of an exercise programme is to lose body fat, not fat-free mass.
• Therefore it must be an aerobic programme.
• Where the duration of the exercise programme is long enough.
• Intensity of the exercise is low enough.
• And frequency of the exercise is sufficient enough to burn fats over a period of time.
• For example, jogging for one hour can use about 4200 kJ or the equivalent of 142 g of body fat.
• In addition, after each exercise session, the metabolic rate will remain high for up to several hours.
• Therefore, regular bouts of exercise will assist in maintaining the general metabolic level above resting values, and therefore will
contribute significantly to weight reduction.
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EXERCISE AND SPORT PHYSIOLOGY
10) What are the causes and physical effects of obesity on health, based on energy considerations? How can an obese person
reduce body mass and best monitor their progress to achieve this aim?
20 marks
Answer
5 marks for causes of obesity:
• Heredity - you inherit your body type from your parents i.e. lean, muscular or fat.
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Glandular malfunction - a small percentage of obese people suffer from a glandular malfunction, which results in a hormonal
imbalance in the body.
This tends to create adipose tissue abnormally.
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Overeating is the major cause for most people is a positive energy balance i.e. energy intake is greater than energy output.
A positive energy balance is often associated with poor eating habits and unbalanced diets containing a high proportion of fat.
This results in an individual becoming exhausted through work (exercise) more quickly than someone with a higher proportion of
carbohydrate in his/her diet.
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Overindulgence in food is also associated with psychological, social and cultural factors.
For example, the overeater may eat in an attempt to relieve anxieties.
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Childhood obesity, it has been shown that childhood obesity is strongly linked to adult obesity, i.e. the fat child grows into a fat
adult!
The development of fat cells begins during the first 2 years of life.
Numbers of fat cells in young overfed children may proliferate to five times the normal number of cells.
So, as the child grows, she/he has thousands of extra fat cells just waiting to fill with fat.
In the adult the number of fat cells remains constant but the cells increase in size as weight is gained.
Once this weight is gained it will be maintained unless a negative energy balance is achieved.
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Lack of aerobic exercise: there is strong evidence to suggest that overweight children and adults are far less active than their
thinner counterparts.
Obesity has the long-term effect of limiting the mobility of joints, thus restricting the person’s ability to co-ordinate movements.
It also places an additional strain on the cardiovascular and respiratory systems, as described earlier.
Bodily strength, endurance and speed are impaired as a result of weight gain.
So a combination of physical and psychological factors (such as poor self-esteem, learned helplessness caused by repeated failure
at sporting activities and unwillingness to expose the body to the scrutiny of others) often inhibit the person from participating in
sport and leisure activities.
5 marks for physical effects on health are:
• A major problem for the obese person is that he or she has a low metabolic rate (partly due to lack of activity) and therefore tends
to remain fat.
• In addition, an increase in adipose tissue (fat under the skin) and a decrease in sweat gland density make it much harder for the
vascular system to remove waste heat energy.
• This waste heat is produced as part of the process of conversion of food fuel into useful work or energy in the body’s muscles and
organs and has to leave the body from the skin surface.
• Therefore, a thick insulating layer under the skin will tend to restrict flow of heat outwards.
• The heart has to work harder to pump blood faster round the circulatory system.
• Since more energy is used in just moving the body mass.
• So that heat energy, carried by the blood, can be released more rapidly near the skin surface.
• All these factors result in heart overload and increased respiratory functioning, to keep pace with the increases in total metabolic
functioning.
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Because of increased weight bearing loads, there is a greater risk of mechanical injury to the body particularly on joints, which are
more likely to become arthritic.
Obese people are more likely to suffer from cardiovascular and other diseases.
And has greater surgical risks.
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SECTION B –
OPTION B3 –
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ANSWERS TO QUESTIONS
10) continued
7 marks for how to reduce body mass:
• Diet alone: regular controlled reduced balanced diet to achieve a negative energy balance.
• One of the problems associated with dieting alone is that a person also loses water, glycogen and lean muscle tissue.
• Since muscle tissue is a major determinant of basal metabolic rate (BMR), then it would follow that a reduction in lean muscle
tissue will also reduce BMR.
• Thus making it increasingly difficult to lose further weight.
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Aerobic exercise and/or dieting.
This problem can be counteracted if regular aerobic exercise is taken, since active muscle is less likely to be used as a source of
energy itself.
As a result, metabolic rate is less likely to fall and therefore more weight loss (from adipose tissue) will occur resulting from a
negative energy balance.
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This can be achieved by continuing to eat a balanced but reduced diet, along with a corresponding increase of energy expenditure.
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As a result, metabolic rate is less likely to fall and therefore more weight loss (from adipose tissue) will occur.
Where the duration of the exercise programme is long enough,
Intensity of the exercise is low enough.
And frequency of the exercise is sufficient enough to burn fats over a period of time with a target heart rate working within the fat
burning zone.
For example: jogging for one hour can use about 5000 kJ or the equivalent of 169 g of body fat.
And an increase of energy output of approximately 5000 kJ per day through exercise will burn off around 1kg of body fat in 1 week.
The result of such an excess of energy output through exercise, against input via food, is a steady progressive long-term weight loss.
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In addition, after each exercise session, the metabolic rate will remain high for up to several hours.
And so continue to burn off energy until the body returns to its resting state.
Also he or she would begin to utilise fat as a fuel food sooner in the exercise period (called glycogen sparing) thereby conserving
muscle and liver glycogen stores.
3 marks for best monitor to achieve this aim:
• Body mass index (BMI) is a measurement of body weight in kilograms is divided by the square of the body height in metres.
• It requires a simple calculation and the resulting BMI value places the subject within one of the five categories ranging from
underweight, normal weight, overweight, obesity and extreme obesity.
• Subject will be able to chart progress as body mass reduces.
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